|
Advertisement |
|
|
||
 |
|
|||||
|
|||||
|
 |
||||||
|
||||||
|
||||||
|
Journal of Clinical Oncology, Vol 26, No 3 (January 20), 2008: pp. 507-508 © 2008 American Society of Clinical Oncology. DOI: 10.1200/JCO.2007.15.0805
Adjuvant Chemotherapy Following Neoadjuvant Therapy of Rectal Cancer: The Type of Neoadjuvant Therapy (chemoradiotherapy or radiotherapy) May Be Important for Selection of PatientsDepartment of Radiation Therapy, University of Rostock, Germany To the Editor: We read with great interest the valuable report of Collette et al1 concerning the effect of postoperative chemotherapy following neoadjuvant radio- or chemoradiotherapy (CRT) in rectal cancer. Nevertheless, we want to stress some important points. In the analysis, there was no differentiation between patients treated preoperatively with radiotherapy or CRT, because there were no overall differences in disease-free survival (DFS) and overall survival (OS) in the univariate analysis. Nevertheless, it is of great theoretical and practical importance that in the first presentation of the results in the European Cancer Conference 2005, Collette et al2 reported that in patients with ypT1/2 tumors there was a significant effect of postoperative chemotherapy on DFS following neoadjuvant radiotherapy alone (hazard ratio, 0.43; 95% CI, 0.24 to 0.78; P = .005), but not following neoadjuvant CRT (hazard ratio, 0.80; 95% CI, 0.51 to 1.25; P = .328). In the analysis published in JCO, this point was omitted. The authors themselves concluded in the abstract "The data further suggest that the patients in whom downstaging was obtained by preoperative radiotherapy alone significantly benefit from postoperative chemotherapy whereas the benefit is not obvious if it was obtained by radio-chemotherapy. " As nowadays most patients are treated with neoadjuvant CRT, we think that it is of important scientific interest to see the updated curves of DFS and OS for ypT0/1/2 tumors with and without postoperative chemotherapy separately for patients with neoadjuvant radiotherapy alone and CRT. Dividing the patients according to their lymph node status (ypN0 and ypN+ categories), Collette et al1 found in the univariate analysis no difference in DFS and OS comparing the patients who received postoperative chemotherapy or not. In our analysis,3 we also found no effect of postoperative chemotherapy following neoadjuvant CRT in ypN0 tumors. Colette et al1 saw their data in contrast to our results. However, we think the two study populations are not comparable because in our analysis,3 all patients received neoadjuvant CRT whereas in the publication of Colette et al,1 half of the patients received radiotherapy alone. Moreover, the population with ypN0 category contains patients with ypT0/1/2 and ypT3/4 tumors. Vice versa, the population with ypT0/1/2 contains lymph node-positive and lymph node-negative patients. To compare both the publications, it is of great scientific interest to analyze the patients of the EORTC study following neoadjuvant CRT with a ypN0 category according the value of adjuvant chemotherapy in DFS and OS. Our updated results again showed no advantage for postoperative chemotherapy following neoadjuvant CRT in patients with ypN0 tumors (Fig 1).
Up to now it is not defined what parameter may be the best for the selection of the patients to postoperative chemotherapy following neoadjuvant CRT. Tumor regression grading is correlated with the ypT and ypN category,4 but no data concerning the effect of postoperative chemotherapy are available. ypT may be a possible alternative as shown by Colette et al1 if there is an effect of adjuvant chemotherapy following neoadjuvant CRT. We think that also the ypN category is a possible candidate, and, as in most tumors and most analysis, this is the most important prognostic parameter.3-5 Patients with ypN0 category following neoadjuvant CRT may have an excellent prognosis (Fig 1) with or without chemotherapy.3-5Perhaps a combination of these three parameters may be the best and most thorough way to have this analysis done. We agree with Collette et al1 that it is important to include predictive prognostic factors in further phase III studies investigating preoperative treatment and postoperative therapy. Therefore it must be exactly differentiated what kind of therapy preoperatively is applied (radiotherapy alone or CRT) because this may have an effect on the further efficacy of postoperative chemotherapy. AUTHORS’ DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST The author(s) indicated no potential conflicts of interest.
REFERENCES
1. Collette L, Bosset JF, den Dulk M, et al: European Organisation for Research and Treatment of Cancer Radiation Oncology Group. Patients with curative resection of cT3-4 rectal cancer after preoperative radiotherapy or radiochemotherapy: Does anybody benefit from adjuvant fluorouracil-based chemotherapy? A trial of the European Organisation for Research and Treatment of Cancer Radiation Oncology Group. J Clin Oncol 25:4379-4386, 2007 2. Collette L, Calais G, Mineur L, et al: Eur J Cancer 3:170, 2005 (suppl) 3. Fietkau R, Barten M, Klautke G, et al: Postoperative chemotherapy may not be necessary for patients with ypN0-category after neoadjuvant chemoradiotherapy of rectal cancer. Dis Colon Rectum. 49:1284-1292, 2006[CrossRef][Medline] 4. Rodel C, Martus P, Papadoupolos T, et al: Prognostic significance of tumor regression after preoperative chemoradiotherapy for rectal cancer. J Clin Oncol 23:8688-8696, 2005 5. Liersch T, Langer C, Ghadimi BM, et al: Lymph node status and TS gene expression are prognostic markers in stage II/III rectal cancer after neoadjuvant fluorouracil-based chemoradiotherapy. J Clin Oncol 24:4062-4068, 2006
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
|||||||||||
|
|||||||||||
|
|
Copyright © 2008 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
|
