SABCS 2014: Breast Cancer in Men and Women Has Different Biologic Characteristics and Outcomes
Results from the largest series of male breast cancer cases ever studied showed that there was significant improvement in overall survival for male breast cancer patients over the duration of the study, but the improvement was not as good as has been seen for female breast cancer patients, according to research presented the 2014 San Antonio Breast Cancer Symposium (Abstract S6-05).
“Although we saw a significant improvement in overall survival for male breast cancer patients over time, the prognosis for men with breast cancer has not been improving as much as for women with the disease,” said Fatima Cardoso, MD, Director of the Breast Unit at the Champalimaud Cancer Center in Lisbon. “This is largely because male breast cancer is a rare disease—it accounts for just 1% of breast cancers—and we know very little about its biology and how best to treat patients.
Study Findings
“Our results provide new insight into the clinical and biologic characteristics of breast cancer in men, and show that they are not the same as those previously reported for breast cancer in women,” continued Dr. Cardoso. “Our results tend to show that men diagnosed with breast cancer are not well managed in the clinic. For example, even though most male breast cancers are estrogen receptor–positive, we found that only 77% of patients received endocrine therapy like tamoxifen. We also found that even though 56% of male breast cancers are diagnosed when the tumors are very small, only 4% of patients had breast-conserving surgery; most had a mastectomy, which significantly impacted their quality of life.”
Tumor analyses to determine the biologic characteristics of male breast cancer showed that 92% were positive for the estrogen receptor, 5% were positive for HER2, and 1% percent were triple-negative. In women, approximately 70% of breast cancers are estrogen receptor–positive, 20% are HER2-positive, and 10% to 15% are triple-negative.
Male Breast Cancer International Program
Dr. Cardoso is part of a global network of researchers that includes investigators from all the major breast cancer consortia in Europe and North America. The first goal of the Male Breast Cancer International Program was to analyze the largest series of male breast cancer cases ever studied.
Dr. Cardoso and her colleagues enrolled in the study 1,822 men with breast cancer treated between 1990 and 2010 at 23 centers in nine countries. Clinical data for the patients were all analyzed at the European Organisation for Research and Treatment of Cancer headquarters, and tumor samples were analyzed at three locations—two in Europe and one in the United States.
“We are continuing to analyze the tumor samples that we collected during this first part of the project,” said Dr. Cardoso. “But we have also begun part two, which is the prospective register of all men diagnosed with breast cancer in many European, Latin American, and North American countries during a 2-year period. This will allow the collection of a current series of these patients and assert the ability of the network to run clinical trials in this rare disease. We also hope to soon begin part three of the project, which will be a clinical trial to test a potential new treatment option for men with breast cancer.”
Funding for the study was provided by the Breast Cancer Research Foundation, European Breast Cancer Conference Council, Pink Ribbon NL, and Bröstcancerföreningarnas Riksorganisation. Dr. Cardoso acts as a consultant or advisory board member for Astellas; AstraZeneca; Celgene; Daiichi-Sankyo; Eisai; GE Oncology; Genentech; GlaxoSmithKline PLC; Merck, Sharp, and Dohme; Merus B.V.; Novartis; Pfizer; Roche; and Sanofi, and has been on the speakers bureau for Prime Oncology.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
