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Journal of Clinical Oncology, Vol 24, No 23 (August 10), 2006: pp. 3811-3812 © 2006 American Society of Clinical Oncology. DOI: 10.1200/JCO.2006.07.0623
In Reply:Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
Departments of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA We read with interest the thoughtful comments of Lagios et al regarding our recent article.1 We would like to respond to their concerns, as we all work to develop the best treatment for women with ductal carcinoma in situ (DCIS). DCIS is a heterogeneous disease both clinically and pathologically, which has presented many challenges. Tumor size, grade, and margins have been the main variables considered in pathologic evaluation and in determining the best local therapy. Silverstein and Lagios et al have published extensively on their experience and maintain a "prospective database" of DCIS patients. However, their patients were not treated on a protocol, and the selection criteria for treatment with radiation therapy compared with excision alone or mastectomy are not clearly defined. The pathologic evaluation of specimens may have been standardized, and the information prospectively gathered, but this would still ordinarily be considered a retrospective study. The oncoplastic surgical technique, which employs a skin-to-fascia resection2,3 used in many if not all of their cases, is not commonly used by breast cancer surgeons in the community. Lagios et al state that the Van Nuys approach has been validated independently, but we believe this issue is unresolved, as others have been unable to validate their prognostic index.4,5 There is no study that we know of that has shown that complete sequential embedding results in lower recurrence rates compared with standard histologic sampling. Whether the recurrence rate would be reduced using sequential processing of specimens is an important hypothesis. We agree that clinicopathologic correlation is important to help determine the full extent of the DCIS in the excision specimen. Mammographic imaging with use of magnification views has improved our ability to assess the extent of calcifications associated with DCIS lesions. The meticulous efforts of Lagios et al to perform sequential and complete embedding of specimens are laudable, but labor-intensive. Most centers do not have the resources to perform this technique, therefore limiting the value of attempts to promulgate its use. We are not convinced that there is "a growing consensus that such a resection should be processed sequentially in its entirety." The "Practice Guidelines for the Management of Ductal Carcinoma-in-Situ of the Breast"6 allow for complete sequential embedding, but do not recommend it in all cases. These guidelines were endorsed by the Board of Regents of the American College of Surgeons, the Society of Surgical Oncology, and the College of American Pathologists. It is also worth noting that while some cases of DCIS are diagnosed by core biopsy, and this is most often the case at our institution, it is possible that some are diagnosed by excision of calcifications, in which case sequential and complete embedding is not practical, given that most biopsied calcifications are benign. The requirement of sequential and complete embedding techniques (while commendable in their thoroughness) promoted by Lagios et al and their oncoplastic surgical technique are likely to limit the generalizability of their results. In our study, patients were initially diagnosed at a large number of both community and academic institutions. Restricting enrollment to only those patients with specimens processed in a specific manner would have limited the accessibility of patients to the study and the applicability of the results to the community at large. The size determination for DCIS is inherently difficult, as many DCIS lesions are not contiguous; hence our efforts to try to quantify DCIS in a number of different ways (single greatest dimension, number of low-powered fields involved, number of blocks involved). Although these methods may not provide an exact size of the lesion in millimeters, they are all reasonable means of helping clinicians understand the extent of a DCIS lesion. None is foolproof. Margin evaluation in our study was thorough and, as Lagios et al note, 84% of the patients had a re-excision following their initial excision; in 93% of those cases, the re-excision showed no evidence of residual DCIS. Necrosis was evaluated along with grade, and necrosis was not significantly associated with more local failures overall or in each grade. The point that a true recurrence differs from a new primary cancer arising in the ipsilateral breast, and that radiation therapy will not prevent the occurrence of a new primary, is well taken. However, whether a carcinoma is in the same quadrant is only a crude determinant of whether it represents a recurrence versus a new primary. Perhaps continued development and use of molecular techniques, such as those performed at William Beaumont Hospital in Michigan,7 will help us distinguish between the two processes and help clinicians guide treatment recommendations. Regarding the projection of a 12% local recurrence rate at 5 years, we acknowledge that this is hypothetical. The projected 5-year local failure rate was included in our article because we thought it might be more understandable to readers than the estimated average annual recurrence rate of 2.4%. The 5-year rate does not assume constancy but does assume that the average rate based on follow-up thus far is approximately the same as the average rate would be if all patients had a potential follow-up of 5 years. It is possible (due to competing risks and other factors) that the 12% 5-year estimate is either too high or too low. Regarding the location of the invasive and DCIS recurrences, three of the four invasive local failures and seven of the nine DCIS local failures were in the same quadrant as the original DCIS. As indicated in our article, we recognize that the use of radiation therapy for DCIS is an unresolved issue, and like Lagios et al, we believe that there is likely a subset of patients with DCIS for whom excision alone will be adequate treatment. The problem remains however, in selecting the patients for whom radiation therapy can be safely omitted. As Lagios et al point out, sparing patients unnecessary treatment and morbidity is a valid and important goal. However, we also would mention that little or no difference in cardiac morbidity was seen in a recent retrospective comparison of left- versus right-sided breast cancers treated with modern radiation technique.8 In addition, a recent meta-analysis showed very little nonbreast cancer mortality in recent trials of patients treated with breast-conserving surgery and radiation therapy.9 The psychological impact of a local recurrence also is worth mentioning. Although possibly not life-threatening, local recurrence can be very distressing for some patients, who may elect mastectomy for psychological reasons alone. We agree that the best local therapy for various subgroups of DCIS patients remains unclear. We believe that the best studies to clarify this are prospective trials. Authors' Disclosures of Potential Conflicts of Interest The authors indicated no potential conflicts of interest. REFERENCES
1. Wong JS, Kaelin CM, Troyan SL, et al: Prospective study of wide excision alone for ductal carcinoma in situ of the breast. J Clin Oncol 24:1031-1036, 2006 2. Anderson BO, Masetti R, Silverstein MJ: Oncoplastic approaches to partial mastectomy: An overview of volume-displacement techniques. Lancet Oncol 6:145-157, 2005[CrossRef][Medline] 3. Silverstein MJ, Recht A, Lagios MD (eds): Ductal Carcinoma in Situ of the Breast (ed 2). Philadelphia, PA, Lippincott Williams and Wilkins, 2002, pp 185-204 4. Boland GP, Chan KC, Knox WF, et al: Value of the Van Nuys Prognostic Index in prediction of recurrence of ductal carcinoma in situ after breast-conserving surgery. Br J Surg 90:426-432, 2003[CrossRef][Medline] 5. de Mascarel I, Bonichon F, MacGrogan G, et al: Application of the Van Nuys Prognostic Index in a retrospective series of 367 ductal carcinomas in situ of the breast examined by serial macroscopic sectioning: Practical considerations. Breast Cancer Res Treat 61:151-159, 2000[CrossRef][Medline] 6. Morrow M, Strom EA, Bassett LW, et al: Standard for the management of ductal carcinoma in situ of the breast (DCIS). CA Cancer J Clin 52:256-276, 2002 7. Goldstein NS, Vicini FA, Hunter S, et al: Molecular clonality determination of ipsilateral recurrence of invasive breast carcinomas after breast-conserving therapy: Comparison with clinical and biologic factors. Am J Clin Pathol 123:679-689, 2005[CrossRef][Medline] 8. Patt DA, Goodwin JS, Kuo YF, et al: Cardiac morbidity of adjuvant radiotherapy for breast cancer. J Clin Oncol 23:7475-7482, 2005 9. Clarke M, Collins R, Darby S, et al: Effects of radiotherapy and of differences in the extent of surgery for early breast cancer on local recurrence and 15-year survival: An overview of the randomised trials. Lancet 366:2087-2106, 2005[Medline]
Related Correspondence
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Copyright © 2006 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
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