Surgery for Men with Breast Cancer: Do the Same Data Still Apply?

Utility of Axillary Staging in Older Patients with HER2-Positive Breast Cancer

BACKGROUND

The utility of sentinel lymph node biopsy (SLNB) in older patients remains controversial. Advancements in human epidermal growth factor receptor 2 (HER2)-directed therapy have revolutionized disease response rates and prognosis, supporting efforts to re-evaluate the utility of SLNB. We aimed to assess the differences in treatment and overall survival (OS) in older patients with HER2-positive breast cancer based on SLNB.

METHODS

Using the National Cancer Database (2010-2020), patients ≥ 70 years of age diagnosed with cT1-2/cN0/M0, HER2-positive breast cancer were identified. Logistic regression assessed associations with SLNB, systemic therapy, and radiation. Cox proportional hazard models were used to identify factors associated with OS. Analyses were stratified by treatment sequence, i.e. upfront surgery or neoadjuvant therapy (NAT) followed by surgery.

RESULTS

Of the 17,609 patients included, 94% underwent upfront surgery (n = 16,492) and the remaining underwent NAT (n = 1117). Those who underwent SLNB were more likely to receive adjuvant therapy, irrespective of nodal status {upfront surgery/systemic therapy (odds ratio [OR] 2.82, 95% confidence interval [CI] 2.17-3.67); upfront surgery/radiation (OR 3.97, 95% CI 3.03-5.21); NAT/radiation (OR 5.69, 95% CI 1.83-17.69)}. The breast pathologic complete response (pCR) rate was highest among the hormone receptor (HR)-negative/HER2-positive subtype (50.0%), of which none were found to be ypN+. Comorbidity burden was associated with significantly lower rates of adjuvant systemic therapy and worse OS.

CONCLUSIONS

Patients who underwent SLNB, regardless of pN status, were more likely to receive adjuvant therapy. Nodal positivity is exceedingly rare for patients with a breast pCR following NAT, especially among the HR-negative/HER2-positive subtype. It is reasonable to consider omission of SLNB in select subgroups of older patients with HER2-positive breast cancer.

Axillary Lymph Node Dissection is Associated with Improved Survival Among Men with Invasive Breast Cancer and Sentinel Node Metastasis

BACKGROUND

Male breast cancer (MBC) is rare, and management is extrapolated from trials that enroll only women. It is unclear whether contemporary axillary management based on data from landmark trials in women may also apply to men with breast cancer. This study aimed to compare survival in men with positive sentinel lymph nodes after sentinel lymph node biopsy (SLNB) alone versus complete axillary dissection (ALND).

PATIENTS AND METHODS

Using the National Cancer Database, men with clinically node-negative, T1 and T2 breast cancer and 1-2 positive sentinel nodes who underwent SLNB or ALND were identified from 2010 to 2020. Both 1:1 propensity score matching and multivariate regression were used to identify patient and disease variables associated with ALND versus SLNB. Survival between ALND and SLNB were compared using Kaplan-Meier methods.

RESULTS

A total of 1203 patients were identified: 61.1% underwent SLNB alone and 38.9% underwent ALND. Treatment in academic centers (36.1 vs. 27.7%; p < 0.0001), 2 positive lymph nodes on SLNB (32.9 vs. 17.3%, p < 0.0001) and receipt or recommendation of chemotherapy (66.5 vs. 52.2%, p < 0.0001) were associated with higher likelihood of ALND. After propensity score matching, ALND was associated with superior survival compared with SLNB (5-year overall survival of 83.8 vs. 76.0%; log-rank p = 0.0104).

DISCUSSION

The results of this study suggest that among patients with early-stage MBC with limited sentinel lymph node metastasis, ALND is associated with superior survival compared with SLNB alone. These findings indicate that it may be inappropriate to extrapolate the results of the ACOSOG Z0011 and EORTC AMAROS trials to MBC.

Penetrance of male breast cancer susceptibility genes: a systematic review

PURPOSE

Several male breast cancer (MBC) susceptibility genes have been identified, but the MBC risk for individuals with a pathogenic variant in each of these genes (i.e., penetrance) remains unclear. We conducted a systematic review of studies reporting the penetrance of MBC susceptibility genes to better summarize current estimates of penetrance.

METHODS

A search query was developed to identify MBC-related papers indexed in PubMed/MEDLINE. A validated natural language processing method was applied to identify papers reporting penetrance estimates. These penetrance studies' bibliographies were reviewed to ensure comprehensiveness. We accessed the potential ascertainment bias for each enrolled study.

RESULTS

Fifteen penetrance studies were identified from 12,182 abstracts, covering five purported MBC susceptibility genes: ATM, BRCA1, BRCA2, CHEK2, and PALB2. Cohort (n = 6, 40%) and case-control (n = 5, 33%) studies were the two most common study designs, followed by family-based (n = 3, 20%), and a kin-cohort study (n = 1, 7%). Seven of the 15 studies (47%) adjusted for ascertainment adequately and therefore the MBC risks reported by these seven studies can be considered applicable to the general population. Based on these seven studies, we found pathogenic variants in ATM, BRCA2, CHEK2 c.1100delC, and PALB2 show an increased risk for MBC. The association between BRCA1 and MBC was not statistically significant.

CONCLUSION

This work supports the conclusion that pathogenic variants in ATM, BRCA2, CHEK2 c.1100delC, and PALB2 increase the risk of MBC, whereas pathogenic variants in BRCA1 may not be associated with increased MBC risk.