The use of adjuvant radiation therapy in male breast cancer and its impact on outcomes

Treatments of Interest in Male Breast Cancer: An Umbrella Review

Background: Male breast cancer (MaBC) is a rare disease and due to its rarity and the lack of specific protocols for its management, treatment algorithms are extrapolated from female breast cancer (FBC). To optimize MaBC treatment, we conceived an umbrella review with the aim of supplying an evidence-based summary of systematic reviews published about this topic in the last twenty years. Methods: This umbrella review was performed according to a predefined protocol (PROSPERO number CRD42024574299). We performed a literature search of the PubMed and Cochrane Libraries databases and we considered systematic reviews on MaBC treatment published from 2004 to 2024. We evaluated relevant treatments in the management of MaBC, including surgery, radiotherapy, and systemic treatments. We conducted the quality assessment according to A MeaSurement Tool to Assess systematic Reviews version 2 (AMSTAR-2), and the description of the main findings of eligible articles. Results: Seven systematic reviews were selected and the main findings were compiled. Breast-conserving surgery is a reasonable treatment approach and, in selected cases, equivalent in terms of safety and survival outcomes compared to mastectomy. Sentinel lymph node biopsy represents a successful surgical practice with similar accuracy compared to female cases. Adjuvant radiotherapy improves overall survival in MaBC patients following partial mastectomy and after radical mastectomy, in case of involved nodes. Finally, Tamoxifen is associated with an improvement of survival outcomes; aromatase inhibitor and gonadotrophin-releasing hormone should be used only in case of contraindications to tamoxifen. Conclusions: Further research and improved guidelines for MaBC treatment should consider these evidence-based data.

Omission of adjuvant radiotherapy in low-risk elderly males with breast cancer

PURPOSE

Randomized clinical trials demonstrate that lumpectomy + hormone therapy (HT) without radiation therapy (RT) yields equivalent survival and acceptable local-regional outcomes in elderly women with early-stage, node-negative, hormone-receptor positive (HR +) breast cancer. Whether these data apply to men with the same inclusion criteria remains unknown.

METHODS

The National Cancer Database was queried for male patients ≥ 65 years with pathologic T1-2N0 (≤ 3 cm) HR + breast cancer treated with breast-conserving surgery with negative margins from 2004 to 2019. Adjuvant treatment was classified as HT alone, RT alone, or HT + RT. Male patients were matched with female patients for OS comparison. Survival analysis was performed using Cox regression and Kaplan - Meier method. Inverse probability of treatment weighting (IPTW) was applied to adjust for confounding.

RESULTS

A total of 523 patients met the inclusion criteria, with 24.4% receiving HT, 16.3% receiving RT, and 59.2% receiving HT + RT. The median follow-up was 6.9 years (IQR: 5.0-9.4 years). IPTW-adjusted 5-yr OS rates in the HT, RT, and HT + RT cohorts were 84.0% (95% CI 77.1-91.5%), 81.1% (95% CI 71.1-92.5%), and 93.0% (95% CI 90.0-96.2%), respectively. On IPTW-adjusted MVA, relative to HT, receipt of HT + RT was associated with improvements in OS (HR: 0.641; p = 0.042). RT alone was not associated with improved OS (HR: 1.264; p = 0.420).

CONCLUSION

Among men ≥ 65 years old with T1-2N0 HR + breast cancer, RT alone did not confer an OS benefit over HT alone. Combination of RT + HT demonstrated significant improvements in OS. De-escalation of treatment through omission of either RT or HT at this point should be done with caution.

An Update on the General Features of Breast Cancer in Male Patients-A Literature Review

Male breast cancers are uncommon, as men account for less than 1 percent of all breast carcinomas. Among the predisposing risk factors for male breast cancer, the following appear to be significant: (a) breast/chest radiation exposure, (b) estrogen use, diseases associated with hyper-estrogenism, such as cirrhosis or Klinefelter syndrome, and (c) family health history. Furthermore, there are clear familial tendencies, with a higher incidence among men who have a large number of female relatives with breast cancer and (d) major inheritance susceptibility. Moreover, in families with BRCA mutations, there is an increased risk of male breast cancer, although the risk appears to be greater with inherited BRCA2 mutations than with inherited BRCA1 mutations. Due to diagnostic delays, male breast cancer is more likely to present at an advanced stage. A core biopsy or a fine needle aspiration must be performed to confirm suspicious findings. Infiltrating ductal cancer is the most prevalent form of male breast cancer, while invasive lobular carcinoma is extremely uncommon. Male breast cancer is almost always positive for hormone receptors. A worse prognosis is associated with a more advanced stage at diagnosis for men with breast cancer. Randomized controlled trials which recruit both female and male patients should be developed in order to gain more consistent data on the optimal clinical approach.