Prophylactic surgery to reduce breast cancer risk: a brief literature review

Risk-reducing mastectomy for the prevention of primary breast cancer

BACKGROUND

Recent progress in understanding the genetic basis of breast cancer and widely publicized reports of celebrities undergoing risk-reducing mastectomy (RRM) have increased interest in RRM as a method of preventing breast cancer. This is an update of a Cochrane Review first published in 2004 and previously updated in 2006 and 2010.

OBJECTIVES

(i) To determine whether risk-reducing mastectomy reduces death rates from any cause in women who have never had breast cancer and in women who have a history of breast cancer in one breast, and (ii) to examine the effect of risk-reducing mastectomy on other endpoints, including breast cancer incidence, breast cancer mortality, disease-free survival, physical morbidity, and psychosocial outcomes.

SEARCH METHODS

For this Review update, we searched Cochrane Breast Cancer's Specialized Register, MEDLINE, Embase and the WHO International Clinical Trials Registry Platform (ICTRP) on 9 July 2016. We included studies in English.

SELECTION CRITERIA

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.

DATA COLLECTION AND ANALYSIS

At least two review authors independently abstracted data from each report. We summarized data descriptively; quantitative meta-analysis was not feasible due to heterogeneity of study designs and insufficient reporting. We analyzed data separately for bilateral risk-reducing mastectomy (BRRM) and contralateral risk-reducing mastectomy (CRRM). Four review authors assessed the methodological quality to determine whether or not the methods used sufficiently minimized selection bias, performance bias, detection bias, and attrition bias.

MAIN RESULTS

All 61 included studies were observational studies with some methodological limitations; randomized trials were absent. The studies presented data on 15,077 women with a wide range of risk factors for breast cancer, who underwent RRM.Twenty-one BRRM studies looking at the incidence of breast cancer or disease-specific mortality, or both, reported reductions after BRRM, particularly for those women with BRCA1/2 mutations. Twenty-six CRRM studies consistently reported reductions in incidence of contralateral breast cancer but were inconsistent about improvements in disease-specific survival. Seven studies attempted to control for multiple differences between intervention groups and showed no overall survival advantage for CRRM. Another study showed significantly improved survival following CRRM, but after adjusting for bilateral risk-reducing salpingo-oophorectomy (BRRSO), the CRRM effect on all-cause mortality was no longer significant.Twenty studies assessed psychosocial measures; most reported high levels of satisfaction with the decision to have RRM but greater variation in satisfaction with cosmetic results. Worry over breast cancer was significantly reduced after BRRM when compared both to baseline worry levels and to the groups who opted for surveillance rather than BRRM, but there was diminished satisfaction with body image and sexual feelings.Seventeen case series reporting on adverse events from RRM with or without reconstruction reported rates of unanticipated reoperations from 4% in those without reconstruction to 64% in participants with reconstruction.In women who have had cancer in one breast, removing the other breast may reduce the incidence of cancer in that other breast, but there is insufficient evidence that this improves survival because of the continuing risk of recurrence or metastases from the original cancer. Additionally, thought should be given to other options to reduce breast cancer risk, such as BRRSO and chemoprevention, when considering RRM.

AUTHORS' CONCLUSIONS

While published observational studies demonstrated that BRRM was effective in reducing both the incidence of, and death from, breast cancer, more rigorous prospective studies are suggested. BRRM should be considered only among those at high risk of disease, for example, BRCA1/2 carriers. CRRM was shown to reduce the incidence of contralateral breast cancer, but there is insufficient evidence that CRRM improves survival, and studies that control for multiple confounding variables are recommended. It is possible that selection bias in terms of healthier, younger women being recommended for or choosing CRRM produces better overall survival numbers for CRRM. Given the number of women who may be over-treated with BRRM/CRRM, it is critical that women and clinicians understand the true risk for each individual woman before considering surgery. Additionally, thought should be given to other options to reduce breast cancer risk, such as BRRSO and chemoprevention when considering RRM.

Breast cancer diagnosis and factors influencing treatment decisions in Ghana

Researchers in this study explored the reactions of women with breast cancer and identified factors influencing treatment decisions. A qualitative exploratory approach was employed. Participants were recruited from a tertiary hospital and a breast cancer support group. Purposive sampling recruited 12 women. It was found that women identified breast lesions accidentally or intentionally and that diagnosis was delayed. Emotional reactions to diagnosis included shock and sadness. Factors that influenced treatment were the influence of other people, alternative sources of treatment, faith and support, knowledge, "tuning the mind," and effects on intimacy. Health professionals should develop effective communication and counseling skills for clients.

Baseline mammographic breast density and the risk of invasive breast cancer in postmenopausal women participating in the NSABP study of tamoxifen and raloxifene (STAR)

Mammographic breast density is an established risk factor for breast cancer. However, results are inconclusive regarding its use in risk prediction models. The current study evaluated 13,409 postmenopausal participants in the NSABP Study of Tamoxifen and Raloxifene. A measure of breast density as reported on the entry mammogram report was extracted and categorized according to The American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) classifications. An increased risk of invasive breast cancer was associated with higher mammographic breast density (P < 0.001). The association remained significant after adjusting for age, treatment, and smoking history [HR 1.35, 95% confidence interval (CI): 1.16-1.58], as well as when added to a model including the Gail score (HR 1.33, 95% CI: 1.14-1.55). At five years after random assignment, time-dependent area under the curve (AUC) improved from 0.63 for a model with Gail score alone to 0.64 when considering breast density and Gail score. Breast density was also significant when added to an abbreviated model tailored for estrogen receptor-positive breast cancers (P = 0.02). In this study, high BI-RADS breast density was significantly associated with increased breast cancer risk when considered in conjunction with Gail score but provided only slight improvement to the Gail score for predicting the incidence of invasive breast cancer. The BI-RADS breast composition classification system is a quick and readily available method for assessing breast density for risk prediction evaluations; however, its addition to the Gail model does not seem to provide substantial predictability improvements in this population of postmenopausal healthy women at increased risk for breast cancer.

Occult malignancy in patients undergoing contralateral prophylactic mastectomy

OBJECTIVE

To identify factors that predict for occult malignancy or high-risk lesions (HRL) in the contralateral breast among women undergoing contralateral prophylactic mastectomy (CPM).

BACKGROUND

A growing number of women are choosing to undergo CPM, yet the benefit of this procedure for the average woman with breast cancer remains uncertain. The identification of reliable predictors of occult malignancy or HRL in the contralateral breast may aid in selecting patients most likely to benefit from CPM.

METHODS

Patients undergoing mastectomy with CPM for their first diagnosis of unilateral stage 0 to III breast cancer were retrospectively identified (1997-2005). Univariate and multivariate logistic regression was used to identify factors predictive of HRL and/or occult contralateral breast cancer (CBC).

RESULTS

Among 2965 patients, 407 (13%) underwent CPM. Occult CBC was identified in 24 (6%) patients, and 114 (28%) had an HRL. On univariate analysis, multifocality/multicentricity of the index cancer was the only factor associated with occult malignancy in the CPM (OR 2.88, P = 0.04). On multivariate analysis, patient age and progesterone receptor positivity of the index cancer were associated with finding either malignancy or a HRL in the CPM.

CONCLUSIONS

The diagnosis of multifocality/multicentricity invasive index cancer was associated with occult malignancy in the CPM; however, lack of standardized definitions and differences in pathologic evaluation limit the application of this finding in the preoperative setting. Until reliable predictors for occult disease are identified, the low rates of occult CBC do not support the use of CPM in average-risk women with newly diagnosed breast cancer.

Prophylactic mastectomy for the prevention of breast cancer

BACKGROUND

Recent progress in understanding the genetic basis of breast cancer has increased interest in prophylactic mastectomy (PM) as a method of preventing breast cancer.

OBJECTIVES

(i) To determine whether prophylactic mastectomy reduces death rates from any cause in women who have never had breast cancer and in women who have a history of breast cancer in one breast, and (ii) 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

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, 2002), MEDLINE and Cancerlit (1966 to June 2006), EMBASE (1974 to June 2006), and the WHO International Clinical Trials Registry Platform (WHO ICTRP) search portal (until June 2006). Studies in English were included.

SELECTION CRITERIA

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.

DATA COLLECTION AND ANALYSIS

At least two authors independently abstracted data. Data 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

All 39 included studies were observational studies with some methodological limitations; randomized trials were absent. The studies presented data on 7,384 women with a wide range of risk factors for breast cancer who underwent PM.BPM studies on the incidence of breast cancer and/or disease-specific mortality reported reductions after BPM particularly for those with BRCA1/2 mutations. For CPM, studies consistently reported reductions in incidence of contralateral 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. Another study showed significantly improved survival following CPM but after adjusting for bilateral prophylactic oophorectomy, the CPM effect on all-cause mortality was no longer significant.Sixteen studies assessed psychosocial measures; most reported high levels of satisfaction with the decision to have PM but more variable satisfaction with cosmetic results. 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.Case series reporting on adverse events from PM with or without reconstruction reported rates of unanticipated re-operations from 4% in those without reconstruction to 49% in patients with reconstruction.

AUTHORS' CONCLUSIONS

Sixteen studies have been published since the last version of the review, without altering our 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. BPM should be considered only among those at very high risk of disease. There is insufficient evidence that CPM improves survival and studies that control for multiple confounding variables are needed.

Women's perceptions of the personal and family impact of genetic cancer risk assessment: focus group findings

Women with a personal or family history of breast or ovarian cancer are increasingly presenting for genetic cancer risk assessment (GCRA). To explore the personal and family impact of GCRA, four focus groups were conducted of women seen for risk assessment. Participants were 22 primarily non-Latina White women with a personal or family history of breast or ovarian cancer. Analysis of the data identified new themes related to balancing time to assimilate risk information with the need to make timely healthcare decisions, physicians' lack of sufficient genetic knowledge, and concern for daughters regardless of the daughters' age. Other themes related to protecting others, knowledge as empowerment, reassessing personal attribution of cancer risk, managing uncertainty, reappraising body image, and experiencing divergent family responses to communication of cancer risk and healthcare decisions. Understanding the personal and family impact of GCRA may enable genetics professionals to tailor their counseling efforts to better meet the needs of these women. Additional research is needed to extend these findings and identify interventions to support positive outcomes of GCRA.

Time to decide about risk-reducing mastectomy: a case series of BRCA1/2 gene mutation carriers

BACKGROUND

The purpose of this research was to explore women's decision-making experiences related to the option of risk-reducing mastectomy (RM), using a case series of three women who are carriers of a BRCA1/2 gene mutation.

METHODS

Data was collected in a pilot study that assessed the response of women to an information booklet about RM and decision-making support strategies. A detailed analysis of three women's descriptions of their decision-making processes and outcomes was conducted.

RESULTS

All three women were carriers of a BRCA1/2 gene mutation and, although undecided, were leaning towards RM when initially assessed. Each woman reported a different RM decision outcome at last follow-up. Case #1 decided not to have RM, stating that RM was "too radical" and early detection methods were an effective strategy for dealing with breast cancer risk. Case #2 remained undecided about RM and, over time, she became less prepared to make a decision because she felt she did not have sufficient information about surgical effects. Case #3 had undergone RM by the time of her second follow-up interview and reported that she felt "a load off (her) mind now".

CONCLUSION

RM decision making may shift over time and require decision support over an extended period.

Contralateral prophylactic mastectomy

BACKGROUND

Women with unilateral breast carcinoma are at increased risk for developing contralateral breast carcinoma (CBC). The authors sought to identify predictors of malignant or moderate to high-risk histologic findings in contralateral prophylactic mastectomy (CPM) specimens, and to determine the efficacy of CPM.

METHODS

The authors performed a retrospective review of 239 patients with unilateral early-stage breast carcinoma who underwent CPM. The number of CBCs expected if the contralateral breast had been left intact was calculated based on CBC rates observed in the Surveillance, Epidemiology, and End Results (SEER) database and on life-table analysis by family history.

RESULTS

In the current study, 11 patients (4.6%) had occult contralateral malignancies (4 invasive carcinomas and 7 ductal carcinomas in situ) and 44 (18.4%) patients had moderate to high-risk pathology (8 lobular carcinoma in situ, 11 atypical lobular hyperplasia, 25 atypical ductal hyperplasia). At 1846 patient-years of follow-up, only 1 patient (0.4%) developed a new CBC compared with 11 expected cancers based on SEER data. One CBC was observed among 140 patients with a family history of breast carcinoma, compared with 16 expected cancers based on life-table analysis adjusted for adjuvant therapy. The determinants of significant findings at CPM were invasive lobular histology, estrogen and progesterone receptor positivity, additional ipsilateral moderate to high-risk pathology, and age > 40 years at cancer diagnosis.

CONCLUSIONS

CPM was associated with a low risk of subsequent development of breast carcinoma. Evaluation of histologic findings in the ipsilateral breast may help to predict the likelihood of significant disease in the contralateral breast and assist in risk stratification.

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.

Biased cognitive processing of cancer-related information among women with family histories of breast cancer: evidence from a cancer stroop task

Stimuli associated with sources of stress have been shown to interfere with cognition. The authors hypothesized that women with the stress of having a family history of breast cancer (FH+) would exhibit greater interference on a task with cancer-related stimuli than women without cancer in the family (FH-). The authors developed a modified Stroop color-naming task to test this hypothesis in a sample of FH+ (n = 72) and FH- (n = 96) women. Consistent with the hypotheses, FH+ women had longer color-naming times and more errors (ps < .01) on a cancer word list relative to noncancer lists. This biased processing was not mediated by the significantly higher perceived risk, general distress, or cancer-specific distress in FH+ women. Maladaptive alterations in processing cancer stimuli may have important clinical implications, as these women must process complex cancer-related information critical to their health (e.g., options for chemoprevention, screening).