This Article Abstract Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Save to my personal folders Download to citation manager Rights & Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Malmström, P. Articles by Fernö, M. Search for Related Content PubMed PubMed Citation Articles by Malmström, P. Articles by Fernö, M. Social Bookmarking                            What's this?

S-Phase Fraction and Urokinase Plasminogen Activator Are Better Markers for Distant Recurrences Than Nottingham Prognostic Index and Histologic Grade in a Prospective Study of Premenopausal Lymph Node–Negative Breast Cancer

From the Jubileum Institute, Department of Oncology, and Department of Pathology and Cytology, Lund University Hospital, Lund; Department of Pathology, Helsingborg Hospital, Helsingborg, Sweden; and Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.

Address reprint requests to Per Malmström, MD, Department of Oncology, Lund University Hospital, SE-221 85 Lund, Sweden; email: Per.Malmstrom{at}onk.lu.se

	ABSTRACT

TOP ABSTRACT INTRODUCTION PATIENTS AND METHODS RESULTS DISCUSSION REFERENCES

 
PURPOSE: Histologic grade, Nottingham Prognostic Index (NPI), estrogen receptor (ER) and progesterone receptor (PgR) status, and tumor size have previously been shown to be important prognostic indicators for distant recurrence of breast cancer. The purpose of this study was to compare the prognostic value of these factors with flow cytometric S-phase fraction (SPF), urokinase plasminogen activator (uPA), and plasminogen activator inhibitor type 1 (PAI-1) in premenopausal patients with lymph node–negative breast cancer.

PATIENTS AND METHODS: In 237 consecutive premenopausal patients with lymph node–negative breast cancer and freshly frozen tumor material available, SPF, ER and PgR status, uPA and its inhibitor PAI-1, histologic grade, and NPI were evaluated.

RESULTS: SPF was univariately the most powerful prognostic factor for distant recurrence, followed by uPA, histologic grade, PgR, age, ER, NPI, and PAI-1, the latter being nonsignificant. Multivariate analysis revealed that neither NPI nor histologic grade was significant after adjustment for SPF, a fact that may be explained by the strong association between these factors. uPA was, however, an independent prognostic factor in addition to SPF, NPI, or histologic grade.

CONCLUSION: In this prospective study, SPF and uPA were found to be independent prognostic factors in premenopausal women with lymph node–negative breast cancer. We suggest that SPF, if performed under standardized conditions, can replace histologic grade as a selection instrument for adjuvant medical treatment. The value of the combination of SPF and uPA needs to be confirmed in an independent prospective trial.

	INTRODUCTION

TOP ABSTRACT INTRODUCTION PATIENTS AND METHODS RESULTS DISCUSSION REFERENCES

 
THE NOTTINGHAM Prognostic Index (NPI), developed on the basis of histologic grade, tumor size, and lymph node status, is one of the most frequently used classification systems for prognostic considerations in breast cancer.^1-5 Because of its simplicity and availability, NPI is suitable for routine clinical use.

In a previous study on lymph node–negative breast cancer patients from southern Sweden, flow cytometric S-phase fraction (SPF), tumor size, and progesterone receptor status (PgR) were found to be useful prognostic indicators for selection of patients with high frequency of early relapse.⁶ The former study was performed retrospectively, and as a consequence there was a need for a prospective investigation in order to confirm the prognostic importance of these factors. Another reason for a new study was the introduction, since the previous study, of public mammographic screening, influencing median patient age and breast tumor size at diagnosis. New cell biologic prognostic factors have also been identified, among which factors of the urokinase plasminogen activator (uPA) system seem to be some of the most significant. uPA is involved in the degradation of extracellular matrix during tumor cell invasion.^7-9 It converts plasminogen to plasmin, which degrades components of the stroma.⁷ Furthermore, the effect of uPA is modulated by two inhibitors, plasminogen activator inhibitor type 1 (PAI-1) and type 2 (PAI-2).¹⁰ Since the first results reported by Duffy et al in 1988, showing uPA to be a prognostic factor in breast cancer,¹¹ several other groups have confirmed these results.^12-16 Also, the inhibitors PAI-1 and PAI-2 have been demonstrated to be of prognostic significance in breast cancer, with high PAI-1 and low PAI-2 being associated with shorter survival.^15,17-21

A prospective study including 237 premenopausal patients with lymph node–negative breast cancer has been carried out in the southern health care region in Sweden. The purpose of this study was to compare the prognostic value of established prognostic factors, ie, histologic grade, NPI, estrogen receptor (ER) and PgR, and tumor size with SPF, uPA, and its inhibitor PAI-1 in premenopausal patients with lymph node–negative breast cancer.

	PATIENTS AND METHODS

TOP ABSTRACT INTRODUCTION PATIENTS AND METHODS RESULTS DISCUSSION REFERENCES

 
Patients
In the South Swedish Breast Cancer Registry during the period September 1, 1991, to December 7, 1994, 237 premenopausal patients with breast cancer without lymph node metastases and with frozen tumor tissue sent to the research department in Lund were identified. ER, PgR, and SPF analyses were performed routinely every week in accordance with the regional treatment program of the South Sweden Breast Cancer Group. The study was approved by the ethics committee of Lund University Hospital. The study material constitutes 75% of the total premenopausal lymph node–negative breast cancer patient population in South Sweden with tumors sufficiently large to permit a perioperative sample for laboratory analysis, and 60% of all premenopausal patients with lymph node–negative breast cancer during this period.

All patients underwent radical operation for early breast cancer with either a standardized sector resection or a modified radical mastectomy. Dissection of levels 1 and 2 of the axilla was performed in all patients. A median number of nine nodes were identified in the resected axillary specimen. Patients treated with breast-conserving surgery were randomized to either postoperative radiotherapy 50 Gy in 25 fractions to the remaining breast parenchyma or to no further treatment in a Swedish multicenter trial evaluating postoperative radiotherapy. Radiotherapy, 50 Gy in 25 fractions, was given to seven patients after mastectomy because of narrow margins at surgery. Adjuvant medical treatment was given to 29 patients ( Table 1). Patients were examined once yearly at the departments of surgery and/or oncology. Hospital records of all patients were reviewed from March to June 1998. Median follow-up for the 200 patients alive without signs of distant recurrence was 48 months (range, 4 to 72).

The histologic grade used in this index was evaluated according to Elston and Ellis.¹ The grading procedure consisted of judgment of tubule formation, nuclear pleomorphism, and mitotic count. The number of mitoses was counted in 10 high-power fields, and the results were adjusted to the area of the microscopic field. Each of the three morphologic features, tubules, nuclear pleomorphism, and number of mitoses, was given a score of 1 to 3 points. The overall histologic grade was obtained by adding the score of each characteristic, giving a possible total score of 3 to 9 points. The histologic grade allocation was as follows: grade 1, 3 to 5 points; grade 2, 6 to 7 points; and grade 3, 8 to 9 points.

Before the present investigation, a reproducibility study of histologic grading, according to Elston and Ellis,¹ of 93 invasive breast carcinomas was performed by seven pathologists in South Sweden Health Care Region, all with long experience in breast cancer morphology. Histologic grading was performed without any knowledge of patient history. The reproducibility was found to be moderate, with a kappa of 0.54.²² After termination of the reproducibility study, the same seven pathologists reevaluated and graded the 237 tumor specimens of this study. Each pathologist evaluated one seventh of the samples. Ten preparations were excluded because of poor staining. The same principles for processing of specimens and grading were adhered to in the reproducibility study and in the present study. Thus, all breast cancer specimens were routinely processed, fixed in formalin, embedded in paraffin, cut in 5-µm-thick sections, and stained with hematoxylin and eosin.

Analytic Methods
Fresh tumor material from all patients was obtained perioperatively, sent on dry ice, and stored at the research laboratory, Department of Oncology, Lund. ER and PgR content were measured routinely every week with enzyme immunoassay (EIA) according to kit instructions (Abbott Laboratories, Diagnostic Division, Chicago, IL). The buffer used for cytosol extraction contained Tris-HCl 10 mmol/L, EDTA 1.5 mmol/L, Na₂Mo0₄ 5.0 mmol/L, and monothioglycerol 1.0 mmol/L, giving a pH of 7.4 (final concentration). Cytosol samples with receptor content 25 fmol/mg protein were classified as ER or PgR positive and samples with values below this level as ER or PgR negative.²³

Flow cytometry (FCM) DNA analysis was also performed routinely every week in an Ortho-Cytotron Absolute (Ortho Diagnostic Systems, Raritan, NJ) after staining with propidium iodide.²⁴ In accordance with the Convention of Nomenclature for DNA Cytometry,²⁵ ploidy status was defined as follows: one DNA cell population equals diploid, and two or more cell populations equal nondiploid. In 90% (213 of 237) of the FCM DNA histograms it was possible to reliably estimate the percentage of nuclei corresponding to the SPF. A planimetric method was used.²⁶ Samples with an SPF 12% were classified as high SPF, and values below this level as low SPF.⁶

Residual cytosol samples from steroid receptor analysis were stored at -70°C. In the present study, these cytosols were used for uPA and PAI-1 analyses. uPA was analyzed with luminometric immunoassay (AB Sangtec Medical, Bromma, Sweden) and PAI-1 with an enzyme-linked immunosorbent assay (Monozyme, Copenhagen, Denmark) according to kit instructions. Since the aim was to identify a high-risk group roughly corresponding to the long-run recurrence rate in this patient group, the upper tertile was chosen as the cutoff for both uPA (0.23 ng/mg protein) and PAI-1 (0.91 ng/mg protein).

Statistics
In this study, we have focused on the prognostic value of uPA and PAI-1 in relation to that of more established prognostic factors such as tumor size, NPI, histologic grade, SPF, and receptor content. Distant disease-free survival (DDFS) was chosen as the primary end point, since only 17 patients had died during the study period. Median follow-up was defined as median follow-up for those patients still alive and free from distant recurrence at the latest hospital visit. The Kaplan-Meier method was used to estimate distant recurrence-free survival, and the log-rank test was used to compare survival in different strata. The survival curves were continued as long as at least five patients remained at risk.²⁷ The Cox proportional hazards model was also used for estimation of univariate hazard ratios (HRs). Proportional hazards assumptions were checked both graphically and using Schoenfeld’s test.²⁸ Deviations from the assumption motivated the complementary analysis using separate models for two disjoint time intervals. All factors were used as dichotomous covariates in the statistical analysis. The only exception was age, which was also analyzed as a continuous variable. Cutoff values were chosen before statistical analysis. Standard cutoffs were used for established prognostic factors and were the same as for previously published patient series.⁶ For uPA and PAI-1, the upper tertile was chosen. Associations between the factors were analyzed using Fisher’s exact test and, unless otherwise stated, P < .05 was considered as significant. All P values correspond to two-sided tests. Stata 6.0 (Sata Corp, College Station, TX) was used for all the statistical analyses.

	RESULTS

TOP ABSTRACT INTRODUCTION PATIENTS AND METHODS RESULTS DISCUSSION REFERENCES

 
Patient and Tumor Characteristics
Characteristics of the 237 patients studied are listed in Table 1. During the follow-up period, locoregional recurrences were diagnosed in 29 patients. Of these, 18 patients had breast recurrences, eight had chest wall recurrences, and three had recurrences both locoregionally and in the breast parenchyma. Prognostic indicators for local recurrences will be reported elsewhere. Distant metastases were recorded in 36 patients. DDFS was 90% (95% confidence interval [CI], 85% to 93%) at 3 years. The comparatively favorable prognosis, as indicated by the 3-year DDFS of this patient group with small tumors and without lymph node metastases, was also reflected by evaluated tumor characteristics ( Table 2).

View larger version (20K): [in this window] [in a new window]   Fig 1. Distant disease-free survival of 237 premenopausal patients with lymph node–negative breast cancer in relation to (A) histologic grade, (B) NPI, (C) SPF, (D) uPA, and (E) PAI-1.

As 208 of the 237 patients were given no adjuvant treatment, the multivariate analyses were also repeated for the untreated patients. The HRs for distant recurrence were somewhat lower for all factors but for uPA, whose prognostic value was even more pronounced in this subgroup. Since uPA was found to be an independent prognostic factor, it can be used in addition to SPF and histologic grade for prognostic considerations.

Kaplan-Meier estimates of distant recurrence-free survival stratified by SPF and uPA and by histologic grade and uPA are presented in Fig 2, A and B, respectively. Each of the three factors was dichotomized into a high- and a low-risk group (Table 4). In order to simplify comparisons between Fig 2, A and B, cases with missing data on SPF, uPA, or histologic grade (n = 43) were excluded. The distribution of the remaining 32 distant recurrences and the size of the risk sets are given below the graphs.

View larger version (22K): [in this window] [in a new window]   Fig 2. Distant disease-free survival stratified by (A) SPF and uPA, and (B) histologic grade and uPA, in 194 cases with complete information on these three factors. The number of patients at risk and the number of distant recurrences in each subgroup are given below each graph. Abbreviations: S, SPF; U, uPA; G, histologic grade; -, low risk; +, high risk.

Disease-Free Survival Univariate analyses with disease-free survival (locoregional and distant recurrences) as an end point were also performed, yielding lower HRs for all factors analyzed except PAI-1 compared with DDFS. The following three factors had the highest HRs: SPF HR 3.1 (95% CI, 1.8 to 5.3), uPA HR 2.6 (95% CI, 1.5 to 4.5), and histologic grade HR 2.4 (95% CI, 1.4 to 4.0). The relative risk of PAI-1 increased and was statistically significant (HR 1.9 [95% CI, 1.1 to 3.3], P = .02).

Overall Survival Of 17 patients who died, all but one died from breast cancer. Overall survival (OS) at 3 years was 96% (95% CI, 92% to 98%). In univariate analyses, SPF, histologic grade, NPI, and uPA were all highly significant predictors for OS. Also, ER and PgR were highly significant, whereas the prognostic value of PAI-1, age, ploidy, and tumor size was less pronounced. Bivariate analyses showed that the HRs for uPA (high v low) was significantly higher than one after adjustment for histologic grade (HR = 3.7, P = .03), but not after adjustment for SPF (HR = 2.6, P = .15). SPF remained the strongest prognostic factor (HR = 5.7, P = .005).

	DISCUSSION

TOP ABSTRACT INTRODUCTION PATIENTS AND METHODS RESULTS DISCUSSION REFERENCES

 
In this consecutive premenopausal patient group with lymph node–negative breast cancer, SPF was a more powerful prognostic factor than histologic grade and NPI for DDFS, DFS, and OS. SPF was also found to be more informative than other more or less established prognostic factors (tumor size, ER, and PgR). The only factor that was significant in multivariate analyses including SPF was uPA, confirming that uPA is an important prognostic factor in breast cancer.^7,11-16,18 In addition, high uPA was also a marker for distant recurrence in patients with low SPF and identified 39% of the distant recurrences in the low-risk group (seven of 18). Thus, by using a combination of either high SPF and/or high uPA, 66% of all distant recurrences were identified in a patient group consisting of 40% of the entire population.

We have previously shown that SPF is an important prognostic factor in lymph node–negative breast cancer.⁶ The present study, where SPF has been prospectively measured, is thus a confirmation of SPF as a significant prognostic factor.^6,29 It is worth emphasizing that the flow cytometric DNA analyses have been performed routinely every week and that the same cutoff as in the previous investigation was used for SPF.

Tumor size is usually regarded as an important prognostic factor in lymph node–negative breast cancer.³⁰ This could not be confirmed in the present study. One reason may be that the median tumor size has decreased since the introduction of mammography screening programs.

Several reports have demonstrated that uPA and PAI-1 are valuable prognostic factors for disease-free survival in breast cancer.^15,18-20 These factors are presently being used as selection instruments for adjuvant medical treatment in a German multicenter trial.³¹ We were able to confirm the prognostic importance of uPA, but in contrast to several earlier studies^15,17,18-21 PAI-1 was not a prognostic factor for DDFS in the present one. However, it was predictive for disease-free survival in univariate analyses. There are several possible explanations for this discrepancy. The majority of patients evaluated in previous studies were postmenopausal women with lymph node metastases and tumors larger than 2 cm.^15,18,19,32 The number of locoregional recurrences was high in this study, as patients treated with breast-conserving surgery without postoperative irradiation were also included. This suggests that PAI-1 is also a marker for local recurrence. Two studies, both with a smaller number of premenopausal patients than the present study, have evaluated lymph node–negative patients exclusively. Subgroup analysis of premenopausal patients demonstrated prognostic value of PAI-1 for DFS but not for OS in the study of Grøndahl-Hansen et al,¹⁷ whereas in the trial of Kim et al PAI-1 was without prognostic value.³³ The majority of publications have reported DFS and OS but not DDFS. In only three reports was PAI-1 found to be an independent prognostic factor for DDFS.^19,20,32 A recent univariate analysis of a Dutch database also demonstrated the prognostic importance of PAI-1 for DFS, DDFS, and OS in 593 premenopausal node-negative breast cancer (J.A. Foekens, personal communication, October 1999). A meta-analysis of studies of uPA and PAI-1 including our study is in progress within the European Organization for Research and Treatment of Cancer Receptor and Biomarker Study Group.

On the basis of histologic grade³⁰ or NPI,^1-3 patients with lymph node–negative breast cancer are frequently selected for adjuvant treatment. In the present study, both factors were highly significant in univariate analyses of DDFS, but in multivariate analyses, including SPF, they gave no additional prognostic information. This could be explained by their strong association with SPF. In our study, SPF is thus a better choice than histologic grade for identification of patients at high risk of recurrence. We have also shown that the prognostic value of tumor size is questionable in this group of patients with relatively small tumors. This and the fact that NPI only categorizes node-negative patients into two groups, with the exception of patients with tumors 7 cm or larger, is the likely explanation why NPI was a weaker prognostic factor than histologic grade in the present study.

When choosing among prognostic factors suitable for clinical use, it is also important to consider other aspects, such as availability, reproducibility, and cost. The advantage of histologic grading is that it can easily be performed at the time of primary microscopic examination, in principle on all cases without being much more time consuming for the pathologist. One major disadvantage of the evaluation of histologic grade is that it is difficult to obtain good reproducibility if many pathologists are involved.³⁴ However, with a limited number of breast cancer–dedicated pathologists, histologic grading has been shown to give reproducible results.^1,3 The seven pathologists involved in the present study participated in a quality control study preceding this investigation.²²

One advantage of flow cytometric SPF is that if the analysis is performed under strict conditions by experienced technicians, a good inter- and intralaboratory reproducibility can be achieved³⁵ (Bendahl et al, manuscript in preparation). The disadvantages of this technique are that the equipment is not always available, that tissue from small tumors usually cannot be obtained, and that SPF cannot be reliably calculated in all DNA histograms. For those cases where information of SPF is not available, histologic grade is a suitable alternative.

Further subdivision of patient groups with widely varying recurrence rates can be obtained by using combinations of prognostic markers as demonstrated in Fig 2. By using SPF, a small high-risk group is identified with a recurrence rate of 35%. Irrespective of prognostic factor selected for identification of high-risk groups, a number of recurrences appeared in low-risk groups (Fig 1). A large proportion of these in the low-SPF group, 39% (seven of 18), were identified by high uPA values. Thus, a combination of high SPF and/or high uPA could be used as a selection instrument for patients requiring adjuvant therapy.

The dilemma for the clinician treating breast cancer patients is at what recurrence rate is adjuvant medical treatment indicated. Ideally, the selected cutoff point for a prognostic marker should identify a population with such a low risk of recurrence that adjuvant treatment is questionable.³⁶ One advantage of variables with a continuous increase in risk such as SPF is that cutoff points can be adjusted to identify patient groups with recurrence rates above the level that is considered high enough to justify adjuvant medical treatment.

Another important issue, not as frequently discussed, is whether the prognostic value of a factor varies with time after primary operation.^5,37,38 The prognostic value of the factors included in the present study was apparent only for the first 3 years after operation. Thereafter, no factor was useful. Interestingly, for three of four recurring patients with histologic grade 3 but low SPF, the recurrences were detected after more than 4 years. Prognostic factors identifying early recurrences are more useful as selection instruments, since prevention or delay of early relapses will have a greater impact on the number of person-years saved by adjuvant treatment. In the present study, 33% (12 of 36) of all distant recurrences occurred more than 3 years after primary surgery. These late recurrences, according to a recent hypothesis, may be explained by the fact that the majority of breast cancer metastases initially are in a dormant state with no or limited angiogenic capacity.³⁹ It is also not known what reduction of late recurrences can be obtained by administering 4 to 8 months of chemotherapy in conjunction with primary operation.

The usefulness of a prognostic factor increases if it also has predictive value for treatment. Data from several studies indicate that high percentage of DNA-synthesizing cells also is a predictive marker for response to chemotherapy in disseminated disease,⁴⁰ induction chemotherapy,⁴¹ and adjuvant treatment.⁴² This argues in favor of SPF, or another proliferation marker such as thymidine labeling index,⁴³ as a selection instrument compared with histologic grade.

We conclude that SPF, prospectively measured in clinical routine, was the most important prognostic factor for distant recurrence and survival of premenopausal women with lymph node–negative breast cancer. Histologic grade and NPI were strongly associated with SPF and therefore without additional prognostic value. In this study on node-negative patients with small tumors, standard use of NPI was inferior to histologic grade. In cases lacking SPF, histologic grade could be used as an alternative. Furthermore, uPA, but not its inhibitor PAI-1, was shown to be an independent prognostic factor in addition to each of the three factors, SPF, histologic grade, and NPI. Therefore, uPA might further improve prognostication in premenopausal lymph node–negative breast cancer patients.

	ACKNOWLEDGMENTS

 
Supported by grants from the Swedish Cancer Society, Gunnar, Arvid and Elisabeth Nilsson Foundation, Mrs Berta Kamprad Foundation, John and Augusta Persson Foundation for Medical Science, and University Hospital of Lund Research Foundation.

We thank participating pathologists Lola Anagnostaki, Erik Holm, Sven Johansson, Otto Ljungberg, and Görel Östberg for histologic grading of tumor biopsies. Bo Baldetorp’s expertise on flow cytometric S-phase analysis has been of utmost importance for this study. The continuous efforts of Torgil Möller and Britt-Marie Lundh at the Regional Tumor Registry in Lund was the basis for this study. The excellent technical assistance of Ghita Fallenius, Ulla Johansson, Eva Långström, and Gunilla Sellberg is gratefully acknowledged. We thank Eva Henriksson for preparation of illustrations. We are also indebted to participating departments of surgery and oncology of the South Sweden Breast Cancer Group for primary care and follow-up of the patients.

	REFERENCES

TOP ABSTRACT INTRODUCTION PATIENTS AND METHODS RESULTS DISCUSSION REFERENCES

 
1. Elston CW, Ellis IO: Pathological prognostic factors in breast cancer: I. The value of histological grade in breast cancer—Experience from a large study with long-term follow-up. Histopathology 19: 403-410, 1991[Medline]

2. Galea MH, Blamey RW, Elston CW, et al: The Nottingham Prognostic Index in primary breast cancer. Breast Cancer Res Treat 22: 207-219, 1992[Medline]

3. Ellis IO, Galea M, Broughton N, et al: Pathological prognostic factors in breast cancer: II. Histological type—Relationship with survival in a large study with long-term follow-up. Histopathology 20: 479-489, 1992[Medline]

4. Balslev I, Axelsson CK, Zedeler K, et al: The Nottingham Prognostic Index applied to 9,419 patients from the studies of the Danish Breast Cancer Cooperative Group (DBCG). Breast Cancer Res Treat 32: 281-290, 1994[Medline]

5. Sauerbrei W, Hubner K, Schmoor C, et al: Validation of existing and development of new prognostic classification schemes in node negative breast cancer. Breast Cancer Res Treat 42: 149-163, 1997[Medline]

6. Sigurdsson H, Baldetorp B, Borg Å, et al: Indicators of prognosis in node-negative breast cancer. N Engl J Med 322: 1045-1053, 1990[Abstract]

7. Danø K, Andreasen PA, Grøndahl-Hansen J, et al: Plasminogen activators, tissue degradation, and cancer. Adv Cancer Res 44: 139-226, 1985[Medline]

8. Liotta LA, Steeg PS, Stetler-Stevenson WG: Cancer metastasis and angiogenesis: An imbalance of positive and negative regulation. Cell 64: 327-336, 1991[Medline]

9. Stephens RW, Brünner N, Jänicke F, et al: The urokinase plasminogen activator system as a target for prognostic studies in breast cancer. Breast Cancer Res Treat 52: 99-111, 1998[Medline]

10. Andreasen PA, Georg B, Lund LR, et al: Plasminogen activator inhibitors: Hormonally regulated serpins. Mol Cell Endocrinol 68: 1-19, 1990[Medline]

11. Duffy MJ, O’Grady P, Devaney D, et al: Urokinase-plasminogen activator, a marker for aggressive breast carcinomas: Preliminary report. Cancer 62: 531-533, 1988[Medline]

12. Jänicke F, Schmitt M, Hafter R, et al: Urokinase-type plasminogen activator (u-PA) antigen is a predictor of early relapse in breast cancer. Fibrinolysis 4: 69-78, 1990

13. Foekens JA, Schmitt M, van Putten WLJ, et al: Prognostic value of urokinase-type plasminogen activator in 671 primary breast cancer patients. Cancer Res 52: 6101-6105, 1992[Abstract/Free Full Text]

14. Spyratos F, Martin PM, Hacène K, et al: Multiparametric prognostic evaluation of biological factors in primary breast cancer. J Natl Cancer Inst 84: 1266-1272, 1992[Abstract/Free Full Text]

15. Grøndahl-Hansen J, Christensen IJ, Rosenquist C, et al: High levels of urokinase-type activator and its inhibitor PAI-1 in cytosolic extracts of breast carcinomas are associated with poor prognosis. Cancer Res 53: 2513-2521, 1993[Abstract/Free Full Text]

16. Fernö M, Bendahl P-O, Borg Å, et al: Urokinase plasminogen activator, a strong independent prognostic factor in breast cancer, analysed in steroid cytosols with a luminometric immunoassay. Eur J Cancer 32A: 793-801, 1996

17. Grøndahl-Hansen J, Christensen IJ, Briand P, et al: Plasminogen activator inhibitor type 1 in cytosolic tumour extracts predicts prognosis in low risk breast cancer patients. Clin Cancer Res 3: 233-239, 1997[Abstract]

18. Jänicke F, Schmitt M, Pache L, et al: Urokinase (uPA) and its inhibitor PAI-1 are strong independent prognostic factors in node negative breast cancer. Breast Cancer Res Treat 24: 195-208, 1993[Medline]

19. Bouchet C, Spyratos F, Martin PM, et al: Prognostic value of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor PAI-1 and PAI-2 in breast carcinoma. Br J Cancer 69: 398-405, 1994[Medline]

20. Foekens JA, Schmitt M, van Putten WLJ, et al: Plasminogen activator inhibitor-1 and prognosis in primary breast cancer. J Clin Oncol 12: 1648-1658, 1994[Abstract/Free Full Text]

21. Foekens JA, Buessecker F, Peters HA, et al: Plasminogen activator inhibitor–2: Prognostic relevance in 1012 patients with primary breast cancer. Cancer Res 55: 1423-1427, 1995[Abstract/Free Full Text]

22. Boiesen P, Bendahl P-O, Anagnostaki L, et al: Histologic grading in breast cancer. Reproducibility between seven pathologic departments. Acta Oncol 39: 41-45, 2000[Medline]

23. Fernö M, Stål O, Baldetorp B, et al: Results of two or five years of adjuvant tamoxifen correlated to steroid receptors and S-phase levels. Breast Cancer Res Treat 59: 69-76, 2000[Medline]

24. Baldetorp B, Dalberg M, Holst U, et al: Statistical evaluation of cell kinetic data from DNA flow cytometry (FCM) by the em algorithm. Cytometry 10: 695-705, 1989[Medline]

25. Hiddemann W, Schuman J, Andreeff M, et al: Convention on nomenclature for DNA cytometry. Cytometry 5: 445-446, 1984

26. Baisch H, Göhde W, Linden WA: Analysis of PCP-data to determine the fraction of cells in the various phases of cell cycle. Radiat Environ Biophys 12: 31-39, 1975[Medline]

27. Altman DG : Practical Statistics for Medical Research. London, United Kingdom, Chapman & Hall, 1991, pp 386-387

28. Schoenfeld D: Partial residuals for the proportional hazards regression model. Biometrika 69: 239-241, 1982[Abstract/Free Full Text]

29. Clark CM, Mathieu M-C, Owens MA, et al: Prognostic significance of S-phase fraction in good-risk, node-negative breast cancer patients. J Clin Oncol 10: 428-432, 1992[Abstract/Free Full Text]

30. Zujewski J, Liu ET: The St. Gallen’s Consensus Conference: An assessment. J Natl Cancer Inst 90: 1587-1589, 1998[Free Full Text]

31. Thomssen C, Prechtl A, Pölcher M, et al: Interim-analysis of a randomized trial on risk-adapted adjuvant chemotherapy in node-negative breast cancer patients guided by the prognostic factors uPA and PAI-1. Breast Cancer Res Treat 57: 4, 1999 (abstr)

32. Knoop A, Andreasen PA, Andersen JA, et al: Prognostic significance of urokinase-type plasminogen activator and plasminogen activator inhibitor-1 in primary breast cancer. Br J Cancer 77: 932-940, 1998[Medline]

33. Kim SJ, Shiba E, Kobayashi T, et al: Prognostic impact of urokinase-type plasminogen activator (PA), PA inhibitor type-1, and tissue type PA antigen levels in node negative breast cancer: A prospective study on multicenter basis. Clin Cancer Res 4: 177-182, 1998[Abstract]

34. Gilchrist KW, Kalish L, Gould VE, et al. Interobserver reproducibility of histopathological features in stage II breast cancer: An ECOG study. Breast Cancer Res Treat 5:3-10, 1985

35. Baldetorp B, Bendahl P-O, FernöM, et al: Reproducibility in DNA flow cytometric analysis of breast cancer: Comparison of 12 laboratories’ results for 67 sample homogenates. Cytometry 22: 115-127, 1995[Medline]

36. Hayes DF, Trock B, Harris AL: Assessing the clinical impact of prognostic factors: When is "statistically significant" clinically useful? Breast Cancer Res Treat 52: 305-319, 1998[Medline]

37. Collett K, Skjærven R, Mæhle BO: The prognostic contribution of estrogen and progesterone receptor status to a modified version of the Nottingham Prognostic Index. Breast Cancer Res Treat 48: 1-9, 1998[Medline]

38. Hilsenbeck SG, Ravdin PM, de Moor CA, et al: Time-dependence of hazard ratios for prognostic factors in primary breast cancer. Breast Cancer Res Treat 52: 227-237, 1998[Medline]

39. Demicheli R, Retsky MW, Schwarzendruber DE, et al: Proposal for a new model of breast cancer metastatic development. Ann Oncol 8: 1075-1080, 1997[Abstract/Free Full Text]

40. Hietanen P, Blomqvist C, Wasenius V-M, et al: Do DNA ploidy and S-phase fraction in primary tumour predict the response to chemotherapy in metastatic breast cancer? Br J Cancer 71: 1029-1032, 1995[Medline]

41. Spyratos F, Briffod M, Tubiana-Hulin M, et al: Sequential cytopunctures during preoperative chemotherapy for primary breast carcinoma. Cancer 69: 470-475, 1992[Medline]

42. Stål O, Skoog L, Rutqvist LE, et al: S-phase fraction and survival benefit from adjuvant chemotherapy or radiotherapy of breast cancer. Br J Cancer 70: 1258-1262, 1994[Medline]

43. Amadori D, Nanni O, Marangolo M, et al: Disease-free survival advantage of adjuvant cyclophosphamide, methotrexate and fluorouracil in patients with node-negative rapidly proliferating breast cancers: A randomized multicenter study. J Clin Oncol 18: 3125-3134, 2000[Abstract/Free Full Text]

Submitted February 23, 2000; accepted November 2, 2000.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				L. Harris, H. Fritsche, R. Mennel, L. Norton, P. Ravdin, S. Taube, M. R. Somerfield, D. F. Hayes, and R. C. Bast Jr American Society of Clinical Oncology 2007 Update of Recommendations for the Use of Tumor Markers in Breast Cancer J. Clin. Oncol., November 20, 2007; 25(33): 5287 - 5312. [Abstract] [Full Text] [PDF]

				G. M. Callagy, P. D. Pharoah, S. E. Pinder, F. D. Hsu, T. O. Nielsen, J. Ragaz, I. O. Ellis, D. Huntsman, and C. Caldas Bcl-2 Is a Prognostic Marker in Breast Cancer Independently of the Nottingham Prognostic Index Clin. Cancer Res., April 15, 2006; 12(8): 2468 - 2475. [Abstract] [Full Text] [PDF]

				M. Colozza, E. Azambuja, F. Cardoso, C. Sotiriou, D. Larsimont, and M. J. Piccart Proliferative markers as prognostic and predictive tools in early breast cancer: where are we now? Ann. Onc., November 1, 2005; 16(11): 1723 - 1739. [Abstract] [Full Text] [PDF]

				K. Rennstam, M. Ahlstedt-Soini, B. Baldetorp, P.-O. Bendahl, A. Borg, R. Karhu, M. Tanner, M. Tirkkonen, and J. Isola Patterns of Chromosomal Imbalances Defines Subgroups of Breast Cancer with Distinct Clinical Features and Prognosis. A Study of 305 Tumors by Comparative Genomic Hybridization Cancer Res., December 15, 2003; 63(24): 8861 - 8868. [Abstract] [Full Text] [PDF]

				H. E. Cunliffe, M. Ringner, S. Bilke, R. L. Walker, J. M. Cheung, Y. Chen, and P. S. Meltzer The Gene Expression Response of Breast Cancer to Growth Regulators: Patterns and Correlation with Tumor Expression Profiles Cancer Res., November 1, 2003; 63(21): 7158 - 7166. [Abstract] [Full Text] [PDF]

				M. P. Look, W. L. J. van Putten, M. J. Duffy, N. Harbeck, I. J. Christensen, C. Thomssen, R. Kates, F. Spyratos, M. Ferno, S. Eppenberger-Castori, et al. Pooled Analysis of Prognostic Impact of Urokinase-Type Plasminogen Activator and Its Inhibitor PAI-1 in 8377 Breast Cancer Patients J Natl Cancer Inst, January 16, 2002; 94(2): 116 - 128. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Save to my personal folders Download to citation manager Rights & Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Malmström, P. Articles by Fernö, M. Search for Related Content PubMed PubMed Citation Articles by Malmström, P. Articles by Fernö, M. Social Bookmarking                            What's this?