Kathryn J. Ruddy
Although treatment for male breast cancer in the United States has evolved in recent years, significant gaps in care remain, according to study results published in Cancer.
Researchers noted that certain patient-, tumor-, and treatment-related factors appeared associated with survival outcomes.
“Our study highlights unique practice patterns and factors associated with prognosis in [male breast cancer],” Kathryn J. Ruddy, MD, MPH, director of cancer survivorship in the department of oncology at Mayo Clinic Cancer Center in Rochester, Minnesota, said in a press release. “The racial, economic and age-related health disparities we found could inform future efforts to target interventions to optimize outcomes in men with breast cancer.”
Only 1% of all breast cancer cases occur among men, yet studies have suggested incidence of male breast cancer is rising.
Investigators used the National Cancer Database to assess treatment patterns and identify prognostic factors among 10,873 men diagnosed with stage I to stage III breast cancer (median age at diagnosis, 64 years; 84.1% white) between 2004 and 2014.
Results showed 24% of men underwent breast-conserving surgery, and 70% of those men also received radiation. Moreover, 44% of men underwent treatment with chemotherapy, whereas 62% with ER-positive breast cancer received anti-estrogen therapy.
Researchers observed a significant increase during the 10-year study period in the rates of total mastectomy, contralateral prophylactic mastectomy and post-breast conservation radiation (P < .05 for all). The rates of genomic testing on tumors and anti-estrogen therapy use also increased significantly, according to the researchers.
Results of a survival analysis showed a 5-year OS rate of 79.1% and median OS of 12.1 years among the cohort.
Factors found to be associated with worse OS included older age (HR for age at diagnosis = 1.04; 95% CI, 1.03-1.04); black race (HR = 1.22; 95% CI, 1.07-1.38); higher Charlson Comorbidity Index (HR for score of 2-3 = 2.22; 95% CI, 1.93-2.55); higher tumor grade (HR for poorly differentiated = 1.68; 95% CI, 1.44-1.95); higher stage of disease (HR for stage II = 1.85; 95% CI, 1.66-2.06; HR for stage III = 3.92; 95% CI, 3.44-4.46); and having undergone total mastectomy (HR = 1.16; 95% CI, 1.02-1.31).
Conversely, factors associated with better OS included residing in an area with a higher median household income (HR for $63,000 = 0.78; 95% CI, 0.67-0.91); having PR-positive tumors (HR = 0.82; 95% CI, 0.72-0.93); and undergoing treatment with chemotherapy (HR = 0.67; 95% CI, 0.6-0.74), radiotherapy (HR = 0.82; 95% CI, 0.74-0.9) and endocrine therapy (HR = 0.74; 95% CI, 0.68-0.81).
The study’s reliance on a retrospective database served as its primary limitation.
“We hope to launch a clinical trial that will inform our systemic therapies for male breast cancer in the near future,” Ruddy told HemOnc Today. “Obtaining funding for such a study has been challenging to date, unfortunately.” – by Jennifer Southall
For more information:
Kathryn J. Ruddy, MD, MPH, can be reached at Division of Medical Oncology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905; email: email@example.com.
Disclosures: Ruddy reports receiving and selling stock from Merck and Pfizer in February 2018. Please see the study for all other authors’ relevant financial disclosures.