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Originally published as JCO Early Release 10.1200/JCO.2009.23.9996 on August 31 2009 © 2009 American Society of Clinical Oncology.
Nipple-Sparing Mastectomy: How Often Is the Nipple Involved?Department of Surgical Oncology, Roswell Park Cancer Institute, Buffalo, NY For most women with breast cancer, breast-conserving treatment (BCT) provides the same level of local control and survival as mastectomy. However, mastectomy is still necessary for some larger or multicentric invasive cancers, as well as for extensive ductal carcinoma in situ (DCIS). Some individuals may also choose mastectomy despite the likely success of BCT, most often because of real or perceived high risk of local recurrence or a second primary breast cancer associated with inherited susceptibility. The ability to provide a reconstructed breast or excellent appearance, coupled with a resurgence in use of mastectomy for cancer prevention and among some women—even those with small, node-negative cancers—has led to interest in preserving the nipple areolar complex. This may improve the final appearance of the reconstructed breast, and in some cases, a degree of nipple sensation is retained. Arguing against nipple preservation is the concern that it may defeat the primary purpose of mastectomy by leaving microscopic tumor in the nipple related to direct or ductal extension of cancer, or because after prophylactic mastectomy the residual breast tissue may develop cancer. The literature on so-called nipple-sparing mastectomy (NSM) is sparse. Reported rates of nipple involvement in the setting of cancer range from 0% to 50%. There are a number of small case series of women with cancer treated with NSM among whom recurrence in the nipple is rare. The risk of cancer after prophylactic NSM is also very low. These findings have led some to conclude that in "properly selected" patients, NSM is "oncologically safe."1 Against this backdrop, Brachtel et al2 used a prospective cohort of consecutive cases to define the true rate of cancer presence in the nipple in women treated by mastectomy and to identify factors associated with nipple involvement, to help define appropriate candidates for NSM. Their work, presented in this issue of Journal of Clinical Oncology, is the most thorough and complete study of this issue to date. Using an elegant technique for detection of disease in a large number of women undergoing mastectomy, they identified invasive cancer or DCIS in the nipple in 21% of women treated with mastectomy for cancer. The cancer in the nipple was DCIS in 62% of cases, with the remainder being identified as either invasive cancer or lymphovascular invasion. An additional 8% had lobular neoplasia in the nipple. There was no nipple involvement in the 84 mastectomy specimens performed for prophylaxis. Nipple involvement was most common among women with invasive cancer with associated DCIS (28%). There was nipple involvement in 36% of those with tumors larger than 2 cm, in 30% of women with one to three positive nodes, and 41% of those with four or more positive nodes. Only women with grade 1 invasive cancer or DCIS had rates less than 10%. Factors independently associated with nipple involvement were the size of the primary cancer, the distance between the tumor and the nipple, and amplification of HER2. Brachtel et al2 also examined the sensitivity of detecting nipple involvement by histological testing of a single en face frozen section of the subareolar tissue, which they termed the "retroareolar margin." This tissue showed cancer in 80% of women with nipple involvement. So where do we stand? Local or regional recurrence after mastectomy is a serious event that may lead to death. The best evidence is that one life is saved for every four local recurrences prevented.3 The risk of local or regional recurrence with mastectomy is a function of the size, character, and degree of node involvement of a cancer, but is approximately 5% even with small tumors and negative nodes. It is higher with larger tumors, involved nodes, or positive resection margins, leading to the use of radiation after mastectomy. Though perhaps not all DCIS in the nipple after NSM as described by Brachtel et al2 will manifest as a clinical cancer, in the absence of proof of safety, it does not appear reasonable to accept rates of residual cancer as high as 30% to 40% as defined in their study. We would not accept positive margin rates this high, or even the rate associated with a negative retroareolar margin as defined by Brachtel et al. Therefore, barring clinical trials demonstrating safety, the use of NSM in most women who receive mastectomy—those with medical indications based on tumor size and extent—should be strongly discouraged, a recommendation made even by proponents of NSM.1 This limits discussion of NSM primarily to the situation of small tumors otherwise amenable to breast conservation and to prophylactic mastectomy. In the current series, only those women with low-grade cancers had a risk of nipple involvement below 10%, and nipple involvement was a function of distance from the nipple. Others have also used the criteria of size, distance from nipple, and grade as selection criteria for offering NSM. Assuming 80% sensitivity of the retroareolar frozen section, it seems likely that with small peripheral cancer, the risk of cancer in the nipple is very low and that NSM may be safe. However, only the affected woman can be the real judge of how low is low enough, and the woman must be counseled that there are limited follow-up data on NSM. For prophylactic mastectomy, the discussion is different. Brachtel et al's2 data provide no real information on this issue; only long-term follow-up may tell this story. Given the extent of treatment these women have to undergo to prevent cancer, they may or may not be willing to accept this largely unquantifiable risk. Counseling women regarding local therapy in breast cancer is already complex. BCT is often what providers think is the logical choice. However, they need to be careful in assessing and listening to the concerns and desires of the woman. BCT may not be so logical to affected women, especially those at higher risks of second cancers. Recent studies suggest biases towards BCT among high-volume breast physicians that run counter to the feelings of the informed patient.4 This led Collins et al5 to develop decision support tools to assist in counseling and to define personal preferences, with the result that some women chose mastectomy in settings where BCT was possible. The stress of these decisions is compounded by the myriad of choices, apparent conflicting information from different physicians, and the relatively rapid time frame in which decisions are made. Conversely, offering skin-sparing mastectomy or NSM as an equivalent option to BCT is equally unfair. Despite the wonderful photographs of results of NSM proffered in medical journals, these surgical results are not breasts and often lack normal texture, shape, and sensation. The purported advantage of avoiding of the inconvenience of radiation that comes with BCT may be offset by the need for multiple operations to complete reconstruction. Modern breast conservation provides a high-quality cosmetic result, and in early breast cancers that would be considered eligible for NSM, provides equivalent low rates of local failure. Old data showing higher rates of local failure with BCT are simply that: old data. Modern radiation is extremely safe, and may become safer and better if and when accelerated partial breast irradiation is proven effective. Offering NSM as an alternative may be reasonable, but it is not equivalent to BCT. Brachtel et al2 do not provide us answers about the safety of NSM; we need long-term data on carefully defined cohorts for this. However, their detailed and elegant study provides us with superb data with which to frame these studies, supports the valid concerns about NSM in most situations treated by mastectomy, and should assist women who may choose mastectomy over BCT for selected early peripheral cancers or for breast cancer prevention. AUTHOR'S DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST The author(s) indicated no potential conflicts of interest.
NOTES See accompanying article on page 4948 REFERENCES 1. Spea SL, Hannan CM, Willey SC, et al: Nipple-sparing mastectomy. Plast Reconst Surg 123:1665–1673, 2009.[CrossRef][Medline] 2. Brachtel EF, Rusby JE, Michaelson JS, et al: Occult nipple involvement in breast cancer: Clinicopathologic findings in 316 consecutive mastectomy specimens. J Clin Oncol 27:4949–4955, 2009. 3. Early Breast Cancer Trialists' Collaborative Group. Effect 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 randomized trials. Lancet 266:2087–2106, 2005. 4. Opatt D, Morrow M, Hawley S, et al: Conflicts in decision-making for breast cancer surgery. Ann Surg Oncol 14:2463–2469, 2007.[CrossRef][Medline] 5. Collins ED, Moore CP, Clay KF, et al: Can women with early-stage breast cancer make an informed decision for mastectomy? J Clin Oncol 27:519–525, 2009.
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Copyright © 2009 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
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