Effectiveness of prophylactic mastectomy in the prevention of breast tumors in C3H mice

ASCO/SSO review of current role of risk-reducing surgery in common hereditary cancer syndromes

BACKGROUND

A significant portion of cancers are accounted for by a heritable component, which has increasingly been linked to mutations in specific genes. Clinical interventions have been formulated for mutation carriers within affected families. The primary interventions for mutation carriers of highly penetrant syndromes are surgical.

METHODS

The American Society of Clinical Oncology and the Society of Surgical Oncology formed a task force charged with presenting an educational symposium on surgical management of hereditary cancer syndromes at annual society meetings, and this resulted in a position paper on this topic. The content of both the symposium and the position paper was developed as a consensus statement.

RESULTS

This article addresses hereditary breast, colorectal, ovarian/endometrial, and multiple endocrine neoplasias. A brief introduction on the genetics and natural history of each disease is provided, followed by detailed descriptions of modern surgical approaches, clinical and genetic indications, timing of prophylactic surgery, and the efficacy of surgery (when known). Although several recent reviews have addressed the role of genetic testing for cancer susceptibility, this article focuses on the issues surrounding surgical technique, timing, and indications for surgical prophylaxis.

CONCLUSIONS

Risk-reducing surgical treatment of hereditary cancer is a complex undertaking. It requires a clear understanding of the natural history of the disease, realistic appreciation of the potential benefits and risks of these procedures in potentially otherwise healthy individuals, and the long-term sequelae of such interventions, as well as the individual patient's and family's perceptions of surgical risk and anticipated benefit.

ASCO/SSO review of current role of risk-reducing surgery in common hereditary cancer syndromes

Although the etiology of solid cancers is multifactorial, with environmental and genetic factors playing a variable role, a significant portion of the burden of cancer is accounted for by a heritable component. Increasingly, the heritable component of cancer predispositions has been linked to mutations in specific genes, and clinical interventions have been formulated for mutation carriers within affected families. The primary interventions for mutations carriers for highly penetrant syndromes such as multiple endocrine neoplasias, familial adenomatous polyposis, hereditary nonpolyposis colon cancer, and hereditary breast and ovarian cancer syndromes are primarily surgical. For that reason, the American Society of Clinical Oncology (ASCO) and the Society of Surgical Oncology (SSO) have undertaken an educational effort within the oncology community. A joint ASCO/SSO Task Force was charged with presenting an educational symposium on the surgical management of hereditary cancer syndromes at the annual ASCO and SSO meetings, resulting in an educational position article on this topic. Both the content of the symposium and the article were developed as a consensus statement by the Task Force, with the intent of summarizing the current standard of care. This article is divided into four sections addressing breast, colorectal, ovarian and endometrial cancers, and multiple endocrine neoplasia. For each, a brief introduction on the genetics and natural history of the disease is provided, followed by a detailed description of modern surgical approaches, including a description of the clinical and genetic indications and timing of prophylactic surgery, and the efficacy of prophylactic surgery when known. Although a number of recent reviews have addressed the role of genetic testing for cancer susceptibility, including the richly illustrated Cancer Genetics and Cancer Predisposition Testing curriculum by the ASCO Cancer Genetics Working Group (available through http://www.asco.org), this article focuses on the issues surrounding the why, how, and when of surgical prophylaxis for inherited forms of cancer. This is a complex process, which requires a clear understanding of the natural history of the disease and variance of penetrance, a realistic appreciation of the potential benefit and risk of a risk-reducing procedure in a potentially otherwise healthy individual, the long-term sequelae of such surgical intervention, as well as the individual patient and family's perception of surgical risk and anticipated benefit.

Prophylactic mastectomy for the prevention of breast cancer

BACKGROUND

Breast cancer is the most common cancer and the second most common cause of cancer-related death among North American and Western European women. Recent progress in understanding the genetic basis of breast cancer, along with rising incidence rates, have resulted in increased interest in prophylactic mastectomy as a method of preventing breast cancer, particularly in those with familial susceptibility.

OBJECTIVES

The primary objective was to determine whether prophylactic mastectomy reduces death from any cause in women who have never had breast cancer and in women who have a history of breast cancer in one breast. The secondary objective was to examine the effect of prophylactic mastectomy on other endpoints including breast cancer incidence, breast cancer mortality, disease-free survival, physical morbidity, and psychosocial outcomes.

SEARCH STRATEGY

Electronic searches were performed in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Cancerlit, and the Science Citation Index.

SELECTION CRITERIA

Inclusion criteria were studies in English of any design type including randomized or nonrandomized controlled trials, cohort studies, case-control studies, and case series with at least ten participants. Participants included women at risk for breast cancer in at least one breast. Interventions included all types of mastectomy performed for the purpose of preventing breast cancer, including subcutaneous mastectomy, total or simple mastectomy, modified radical mastectomy, and radical mastectomy.

DATA COLLECTION AND ANALYSIS

Information on patients, interventions, methods, and results were extracted by at least two independent reviewers. Methodological quality was assessed based on how well each study minimized potential selection bias, performance bias, detection bias, and attrition bias. Data for each study were summarized descriptively; quantitative meta-analysis was not feasible due to heterogeneity of study designs and insufficient reporting. Data were analyzed separately for bilateral prophylactic mastectomy (BPM) and contralateral prophylactic mastectomy (CPM).

MAIN RESULTS

Twenty-three studies, including more than 4,000 patients, met inclusion criteria. No randomized or nonrandomized controlled trials were found. Most studies were either case series or cohort studies. All studies had methodological limitations, with the most common source of potential bias being systematic differences between the intervention and comparison groups that could potentially be associated with a particular outcome. Thirteen studies assessed the effectiveness of BPM. No study assessed all-cause mortality after BPM. All studies reporting on incidence of breast cancer and disease-specific mortality reported reductions after BPM. Nine studies assessed psychosocial measures; most reported high levels of satisfaction with the decision to have prophylactic mastectomy (PM) but more variable satisfaction with cosmetic results. Only one study assessed satisfaction with the psychological support provided by healthcare personnel during risk counseling and showed that more women were dissatisfied than satisfied with the support they received in the healthcare setting. Worry over breast cancer was significantly reduced after BPM when compared both to baseline worry levels and to the groups who opted for surveillance rather than BPM. Three studies reported body image/feelings of femininity outcomes, and all reported that a substantial minority (about 20%) reported BPM had adverse effects on those domains. Six studies assessed contralateral prophylactic mastectomy. Studies consistently reported reductions in contralateral incidence of breast cancer but were inconsistent about improvements in disease-specific survival. Only one study attempted to control for multiple differences between intervention groups, and this study showed no overall survival advantage for CPM at 15 years. Two case series were exclusively focused on adverse events from prophylactic mastectomy with reconstruction, and both reported rates of unanticipated re-operations from 30% to 49%.

REVIEWERS' CONCLUSIONS

While published observational studies demonstrated that BPM was effective in reducing both the incidence of, and death from, breast cancer, more rigorous prospective studies (ideally randomized trials) are needed. The studies need to be of sufficient duration and make better attempts to control for selection biases to arrive at better estimates of risk reduction. The state of the science is far from exact in predicting who will get or who will die from breast cancer. By one estimate, most of the women deemed high risk by family history (but not necessarily BRCA 1 or 2 mutation carriers) who underwent these procedures would not have died from breast cancer, even without prophylactic surgery. Therefore, women need to understand that this procedure should be considered only among those at very high risk of the disease. For women who had already been diagnosed with a primary tumor, the data were particularly lacking for indications for contralateral prophylactic mastectomy. While it appeared that contralateral mastectomy may reduce the incidence of cancer in the contralateral breast, there was insufficient evidence about whether, and for whom, CPM actually improved survival. Physical morbidity is not uncommon following PM, and many women underwent unanticipated re-operations (usually due to problems with reconstruction); however, these data need to be updated to reflect changes in surgical procedures and reconstruction. Regarding psychosocial outcomes, women generally reported satisfaction with their decisions to have PM but reported satisfaction less consistently for cosmetic outcomes, with diminished satisfaction often due to surgical complications. Therefore, physical morbidity and post-operative surgical complications were areas that should be considered when deciding about PM. With regard to emotional well-being, most women recovered well postoperatively, reporting reduced cancer worry and showing reduced psychological morbidity from their baseline measures; exceptions also have been noted. Of the psychosocial outcomes measured, body image and feelings of femininity were the most adversely affected.

Educational Review: Role of the Surgeon in Hereditary Breast Cancer

Up to 10% of the breast cancers detected in the United States are related to an inherited germline mutation, usually in the BRCA1 or BRCA2 genes, and the majority of these patients will at some point require surgical evaluation and/or treatment. Women who harbor a genetic predisposition for breast cancer face an increased risk for early onset disease, bilateral tumors, and other non-breast malignancies, such as ovarian cancer. These issues raise questions regarding the appropriate surveillance regimen, and the potential efficacy of risk reduction strategies that should be considered. Once a breast cancer diagnosis has been established, the prognosis appears to be similar to stage-controlled sporadic breast cancer, despite an increased prevalence of adverse primary tumor features. However, the role of breast conservation therapy for these patients and the optimal means of addressing the substantially increased risk for contralateral tumors is not yet defined. The reported literature in this area, including a discussion of the value of genetic counseling and genetic testing, is reviewed.

Prophylactic mastectomy

The Society of Surgical Oncology has developed a position statement54 that lists conditions warranting consideration of prophylactic mastectomy (Table 4). It must be stressed that there are no absolute indications for prophylactic mastectomy. The data are limited about the efficacy of prophylactic mastectomy in humans, but recent studies suggest that it results in up to 90% reduction in the risk for breast cancer. Total mastectomy is technically a more definitive procedure, although reported series have had a predominance of patients undergoing subcutaneous, nipple-sparing procedures. Prophylactic mastectomy may improve longevity in BRCA mutation carriers, but this must be balanced against the impact on quality of life. The benefits of prophylactic mastectomy relative to chemoprevention are unclear because there are no prospective randomized studies comparing these two strategies. Contralateral prophylactic mastectomy in patients with a unilateral cancer is unlikely to improve survival, but this approach may be considered for high-risk or difficult-to-observe patients, to facilitate breast reconstruction, and for the psychologic benefits. Patients considering prophylactic mastectomy should be well informed of risk-reduction alternatives and the limitations in the efficacy and cosmetic results of the procedure.

Prophylactic surgery in women with a hereditary predisposition to breast and ovarian cancer

PURPOSE

To review the published literature on the efficacy and adverse effects of prophylactic mastectomy (PM) and prophylactic oophorectomy (PO) in women with a hereditary predisposition to breast and ovarian cancer and to provide management recommendations for these women.

METHODS

Using the terms "prophylactic," "preventive," "bilateral," "mastectomy," "oophorectomy," and "ovariectomy," a MEDLINE search of the English-language literature for articles related to PM and PO was performed. The bibliographies of these articles were reviewed to identify additional relevant references.

RESULTS

There have been no prospective trials of PM or PO for the reduction of breast cancer or ovarian cancer incidence or mortality. Most of the available retrospective studies are composed of women who had surgery for a variety of indications and in whom genetic risk was not well characterized. However, some reports in women at increased risk of breast or ovarian cancer have shown that PM and PO can reduce cancer incidence.

CONCLUSION

Interest in and use of PM and PO are high among physicians and high-risk women. PM and PO seem to be associated with considerable reduction in the risk of breast and ovarian cancer, albeit incomplete. The surgical morbidity of PM and PO is low, but the complications of premature menopause may be significant, and few studies address quality-of-life issues in women who have opted for PM and PO. Management recommendations for high-risk individuals are presented on the basis of the available evidence.

Prophylactic mastectomy; evolving perspectives

It is not at all uncommon for surgeons dealing with breast disease to be confronted with the issue of prophylactic mastectomy. Recent advances in understanding the genetic basis of susceptibility to breast cancer and a better identification of the histological factors affecting a woman's lifetime risk of developing breast cancer have contributed to placing prophylactic mastectomy in a proper clinical perspective. Existing data suggest that prophylactic total mastectomy significantly reduces, but does not totally eliminate, the risk of subsequent development of cancer. However, the benefit of prophylactic mastectomy over alternative strategies (surveillance and chemoprevention) remains to be proven. Currently, prophylactic mastectomy may be considered in a few, carefully selected patients. The decision to perform a prophylactic mastectomy should be a multidisciplinary one. Detailed patient' counselling is very important; the patient should understand the limitations of prophylactic mastectomy and the need for postoperative follow-up. Furthermore, she should be well informed about the alternative strategies.

Synchronous elective contralateral mastectomy and immediate bilateral breast reconstruction in women with early-stage breast cancer

BACKGROUND

The role of elective contralateral mastectomy (ECM) in women with early-stage breast cancer who elect or require an ipsilateral mastectomy and desire immediate bilateral breast reconstruction (IBR) is an intellectual and emotional dilemma for both patient and physician. In an attempt to clarify the rationale for this approach, we reviewed our experience with ECM and IBR and evaluated operative morbidity, the incidence of occult contralateral breast cancer, and patterns of recurrence.

PATIENTS AND METHODS

We retrospectively reviewed the records of 155 patients with primary unilateral breast cancer (stage 0, I, or II) and negative findings on physical and mammographic examinations of the contralateral breast who underwent ipsilateral mastectomy and simultaneous ECM with IBR between 1987 and 1995.

RESULTS

The median age of the patients was 46 years (range, 25 to 69 years). Clinical stage at diagnosis was stage 0, I, and II in 19.4%, 54.2%, and 26.4% of patients, respectively. Factors likely to influence the use of ECM were family history of breast cancer in first-degree relatives (30%), any family history of breast cancer (56%), difficulty anticipated in contralateral breast surveillance (48%), associated lobular carcinoma in situ (23%), multicentric primary tumor (28%), significant reconstructive issues (14%), and failure of mammographic identification of the primary tumor (16%). Skin-sparing mastectomies were performed in 81% of patients. Overall, 70% of patients underwent reconstruction using autogenous tissue transfer. Reoperations for suspected anastomotic thrombosis were performed in seven patients. Two patients experienced significant partial or complete flap loss. Histopathologic findings in the ECM specimen were as follows: benign, 80% of patients; atypical ductal hyperplasia, 12% of patients; lobular carcinoma in situ, 6.5% of patients; ductal carcinoma in situ, 2.7% of patients; and invasive carcinoma, 1.3% of patients. Eighteen patients (12%) had evidence of locoregional or distant recurrences, with a median follow-up of 3 years. In one patient (0.6%), invasive ductal carcinoma developed on the side of the elective mastectomy.

CONCLUSIONS

The use of ECM and IBR cannot be justified if the only oncologic criterion considered is the incidence of occult synchronous contralateral disease. However, in a highly selected population of young patients with a difficult clinical or mammographic examination and an increased lifetime risk of developing a second primary tumor, ECM and IBR is a safe approach.

A review of hereditary breast cancer: from screening to risk factor modification

The identification of genetic mutations thought to be directly responsible for the development of breast cancer represents a major advance in our understanding of this disease. Mutations in BRCA1 and BRCA2 are thought to be responsible for the majority of inherited breast cancer. Although these mutations account for approximately 5% of breast cancer cases, the identification of these genes will have a profound impact on the way patients and their physicians view breast cancer risk. Genetic testing for BRCA1 and BRCA2 mutations is already available. Interpreting results of genetic tests for these mutations is problematic and the clinical management of women carrying these gene mutations is far from straightforward. The purpose of this paper is to review recent developments in the genetic aspects of breast cancer, including genetic testing, to critically review risk factor modification, and to discuss screening and potential prophylactic measures.

Inherited breast cancer

Five to ten percent of breast cancer is attributable to the autosomal dominant inheritance of a high-risk susceptibility gene. There are a number of known inherited cancer syndromes that confer a higher risk of breast cancer. Recently, the BRCA1 gene, which is responsible for 45% of hereditary early-onset breast cancer and for the majority of co-inheritance of breast and ovarian cancer, has been cloned. Another gene that confers an increased risk of breast cancer is the BRCA2 gene, which maps to the long arm of chromosome 13 by linkage analysis. Mutations in BRCA2 account for approximately 40% of hereditary early-onset breast cancer. In addition, at least 7% of breast cancer may occur in women who are heterozygous for mutations in a gene for ataxia-telangiectasia, an autosomal recessive chromosome instability syndrome. Predictive testing for some predisposing conditions is possible through indirect or direct mutation testing. In this article, the genetics of breast cancer are reviewed, and practical concerns for the surgeon in counseling high-risk patients are addressed.

The practice of prophylactic mastectomy: a survey of Maryland surgeons

OBJECTIVES

Bilateral prophylactic mastectomy is a drastic breast cancer preventive option for which indications are not standardized and efficacy has not been proven. To estimate the magnitude of this controversial practice, surgeons were surveyed on their recommendations about and performance of prophylactic mastectomy.

METHODS

A cross-sectional survey was sent to general surgeons (n = 522), plastic surgeons (n = 80), and gynecologists (n = 801) licensed to practice in Maryland in 1992. Proportions responding were 41.9%, 66.3%, and 54.9%, respectively. In addition, there were 30 respondents who identified "other" as their specialty. The respondents were asked about the role of bilateral prophylactic mastectomy and the number of times they had recommended and performed it in a year.

RESULTS

Seven hundred forty-two surgeons responded (51.8%). More plastic surgeons (84.6%) than general surgeons (47.0%) and gynecologists (38.3%) agreed that bilateral prophylactic mastectomy has a role in the care of high-risk women. Eighty-one percent of plastic surgeons had recommended the procedure, compared with 38.8% of general surgeons and 17.7% of gynecologists.

CONCLUSIONS

Indications and practice patterns reveal heterogeneity of medical opinion and practice of prophylactic mastectomy. This study raises the need for better evaluation of the efficacy and appropriateness of prophylactic mastectomy.