Contralateral prophylactic mastectomy: mind the genetics

Contralateral prophylactic mastectomy in the American College of Radiology Imaging Network 6667 trial: effect of breast MR imaging assessments and patient characteristics

PURPOSE

To assess which patient and magnetic resonance (MR) imaging factors are associated with the likelihood of contralateral prophylactic mastectomy (CPM) in patients with newly diagnosed breast cancer.

MATERIALS AND METHODS

The American College of Radiology Imaging Network 6667 trial was compliant with HIPAA; institutional review board approval was obtained at each site. All patients provided written informed consent. This study was a retrospective review of data from 934 women enrolled in the trial who did not have a known contralateral breast cancer at the time of surgical planning. The authors assessed age, menopausal status, index breast cancer histologic results, contralateral breast histologic results, breast density, family history, race and/or ethnicity, MR imaging Breast Imaging Reporting and Data System (BI-RADS) assessment, and number of MR imaging lesions for association with CPM by using the Fisher exact test, exact χ(2) test, and multivariate logistic regression analyses.

RESULTS

Eighty-six of the 934 (9.2%) women underwent CPM and were more likely to be younger (mean age, 48 years [range, 27-78 years] vs mean age, 54 years [range, 25-86 years]; P < .0001), be premenopausal (55 of 86 [64%] vs 349 of 845 [41%], P < .0001), have ductal carcinoma in situ (DCIS) in the index breast (31% [27 of 86] vs 19% [164 of 848], P = .02), have greater breast density (71 of 86 [83%] vs 572 of 848 [68%], P = .004), and have a family history of breast cancer (44 of 86 [30%] vs 150 of 488 [18%], P = .01) than those who did not undergo CPM. Distributions of race and/or ethnicity, contralateral lesion pathologic results, and number of MR imaging lesions were similar in both groups. With multivariate modeling, younger age, greater breast density, DCIS index cancer, and family history remained significant, whereas menopausal status did not. Positive MR imaging assessments were not significantly more frequent in the CPM group than in the group of women who did not undergo CPM (14 of 86 [16.3%] vs 113 of 848 [13.3%], P = .43).

CONCLUSION

In patients with newly diagnosed breast cancer who underwent breast MR imaging at which a contralateral breast cancer was not identified, patient factors and not breast MR imaging BI-RADS scores were chief determinants in decisions regarding CPM. Online supplemental material is available for this article.

Prophylactic Mastectomy: An Appraisal

The main indication of prophylactic mastectomy pertains to BRCA1 or BRCA2 mutation carriers. Prophylactic mastectomy includes the simple method and the subcutaneous method. Both methods can be followed by breast plastic reconstruction either at the same time or later. This review examines key issues regarding prophylactic mastectomy: the selection of patients, its effectiveness, its limitations, convergence/divergence in existing guidelines, and future perspectives.

Gene expression in histologically normal epithelium from breast cancer patients and from cancer-free prophylactic mastectomy patients shares a similar profile

INTRODUCTION

We hypothesised that gene expression in histologically normal (HN) epithelium (NlEpi) would differ between breast cancer patients and usual-risk controls undergoing reduction mammoplasty (RM), and that gene expression in NlEpi from cancer-free prophylactic mastectomy (PM) samples from high-risk women would resemble HN gene expression.

METHODS

We analysed gene expression in 73 NlEpi samples microdissected from frozen tissue. In 42 samples, we used microarrays to compare gene expression between 18 RM patients and 18 age-matched HN (9 oestrogen receptor (ER)+, 9 ER-) and 6 PM patients. Data were analysed using a Bayesian approach (BADGE), and validated with quantitative real-time PCR (qPCR) in 31 independent NlEpi samples from 8 RM, 17 HN, and 6 PM patients.

RESULTS

A total of 98 probe sets (86 genes) were differentially expressed between RM and HN samples. Performing hierarchical analysis with these 98 probe sets, PM and HN samples clustered together, away from RM samples. qPCR validation of independent samples was high (84%) and uniform in RM compared with HN patients, and lower (58%), but more heterogeneous, in RM compared with PM patients. The 86 genes were implicated in many processes including transcription and the MAPK pathway.

CONCLUSION

Gene expression differs between the NlEpi of breast cancer cases and controls. The profile of cancer cases can be discerned in high-risk NlEpi from cancer-free breasts. This suggests that the profile is not an effect of the tumour, but may mark increased risk and reveal the earliest genomic changes of breast cancer.

Recall of and reactions to a surgeon referral letter for BRCA genetic counseling among high-risk breast cancer patients

BACKGROUND

The oncology care setting represents an important opportunity to identify and refer women at increased risk for hereditary breast and ovarian cancer. However, little is known about the effectiveness of provider approaches to inform patients of hereditary cancer risk or patient uptake of genetic counseling (GC). This qualitative study examined the impact of a surgeon referral letter on recently diagnosed breast cancer patients' uptake of BRCA GC.

METHODS

Qualitative open-ended, in-depth interviews were conducted with 26 high-risk breast cancer patients sent a referral letter for BRCA GC by their surgeon. Data were analyzed by a grounded theory approach.

RESULTS

Most women (approximately 80%) recalled receiving the letter, and 62% of all (n = 16) women pursued GC. Recall of the letter did not seem to be associated with uptake of GC (P = .49, Fisher's exact test). The results highlight key areas for improvement that may help increase the impact of the letter. Half of the women in this sample believed that the letter was sent to all breast cancer patients, rather than those with specific risk factors. Few women mentioned any implications for the information obtained during GC or testing regarding their current breast cancer diagnosis or treatment. Of the women who did not attend, many perceived that dealing with the GC and testing process in the midst of a cancer diagnosis and treatment was overwhelming. Among the women who had chosen not to attend GC, most stated they would reconsider after completing their treatment.

CONCLUSIONS

Patient recall of a surgeon referral letter does not seem to increase the number of high-risk women who attend GC after a breast cancer diagnosis. The letter approach in its current format does not seem to be a wholly effective means of communicating with some patients who may be overwhelmed by their cancer diagnosis or unaware that GC and testing may have implications for their current treatment decisions, possibly resulting in a missed opportunity to engage in informed decision making.