ALBANY, NY – While survival rates for breast cancer generally have improved over the last decades, that is not true for one cohort of patients: men.
A study at the 2021 American Society of Clinical Oncology (ASCO) annual meeting pointed to the significant gender disparity in breast cancer results, with male patients having worse overall survival.
Researchers from the Albany, NY, VAMC and the Albany Medical Center cited recent studies finding increased mortality in male breast cancer (MBC), even after adjusting for age and other clinical factors. They suggested that the variation should be evaluated in terms of screening and treatment patterns in male breast cancer and set out to do that. Specifically, the authors said, data on MBC survival trends across the VA population has been limited.
To remedy that, the study team focused on 1,511 cases of male and 8,081 cases of female breast cancer between 2000-2018, pulling information from the National VA Cancer Cube Registry.
Results indicated that, while the number of new MBC cases per year remained steady over the study period, female breast cancer cases jumped up by about 13.6% a year on average, with little difference between white and African American (AA) patients.
Interestingly, for FBC, peak incidence was between ages 50-60, but men tended to be much older when they were diagnosed with breast cancer, with a peak age of greater than 70. Males were more likely to present at a later disease stage — stage III and IV)– compared to females — 26.94% vs 13.8%, respectively.
Worse performance status — ECOG 3 or higher — at presentation also was more likely in men, 3.72%, compared to women, 1.32%, according to the report.
“Our findings show that males have a worse 5-year survival both in early and late-stage disease and across both Caucasian and AA races,” the authors wrote. “This poor survival difference remains when comparing MBC patients older than 50 years but not when comparing the younger subset in both groups. These findings suggest that the overall poor survival of MBC may be related to late detection, advanced age at presentation and subsequent increased comorbidities and poor performance status.”
That male breast cancer patients present at a later disease stage and have a worse overall survival when compared to women raised the question of whether enough screening was occurring, according to the researchers. “These results imply the possible underutilization of screening in males as well as differences in the clinical and pathological behavior of male and female breast cancer,” they added.
Another recent study on the issue, conducted by the Washington DC VAMC, came up with similar results. With results reported in Clinical Breast Cancer researchers gathered data from 152 VA medical centers to analyze the database of veteran patients with breast cancer diagnosed between 1998 and 2016 using biostatistical software. The primary objective was to compare patients’ demographics, breast cancer characteristics and outcomes for male and female veterans.2
Researchers compared 1,528 MBC cases with 7,336 FBC with a mean follow-up time of 5.5 years (SD 4.17). Among patients, the mean age at diagnosis was 68.6 years and 57.3 years for MBC and FBC, respectively (P <0.0001).
The study also determined that higher numbers of MBC patients (95%) were 50 or older, compared to FBC patients (72%). More MBC patients (16.8 vs. 9.1% and 9.0 vs. 4.0%) also presented with higher disease stage (III and IV, respectively).
The study also found that estrogen receptor-positive tumors were more common in men with breast cancer, 59%, vs. women, 52%.
Treatment differences also were observed:
- Hormonal treatment was received by 27% of MBC vs. 19% FBC;
- Chemotherapy 21.3% vs. 41.5%; and
- Radiation 23.5% vs. 60.9%.
As in the Albany study, mortality rates were found to be considerably higher among men: 42% of MBC and 20% of FBC veterans died during the study. The authors pointed out that higher death rates, 1.285 (95% CI: 1.150, 1.434, P < 0.0001) for males persisted after adjusting data for age, race, stage and grade, compared to females.
“To the best of our knowledge, this is the largest comparison series of MBC and FBC to date in the veteran population,” DC VAMC authors wrote. “The higher mortality rate in MBC patients may be due to late presentation, higher stage at the time of diagnosis and/or tumor biology. Veterans’ exposures to hazardous materials during their military deployments as an additional factor for worse prognosis need further investigation.”
- Ajmal Z, Khan AM, Zahra FT, Gemoets D, Mehdi SA. (June 4-8, 2021) Gender disparity in breast cancer: A population-based study in the U.S. Department of Veterans Affairs. ASCO 2021 annual meeting. Virtual. https://meetinglibrary.asco.org/record/200839/abstract
- Aggarwal A, Adepoju B, Yacur M, Maron D, Sharma MC. Gender Disparity in Breast Cancer: A Veteran Population-Based Comparison. Clin Breast Cancer. 2021 Jan 26:S1526-8209(21)00026-4. doi: 10.1016/j.clbc.2021.01.013. Epub ahead of print. PMID: 33619003.