Men who develop breast cancer are often not treated until the disease has spread to the point that treatment becomes difficult, new results show.
Although most breast cancer patients are women, men make up roughly 1% of cases, Dr. Marina Garassino from the Orion Collaborative Group reports at the ESMO Conference Lugano (ECLU), organized by the European Society for Medical Oncology.
Her group conducted a retrospective analysis of 146 men with invasive breast cancer who were diagnosed between 1990 and 2007 across the 12 institutions in the ORION collaborative group.
What they found was that the disease often had already reached an advanced stage when the men were diagnosed. In 50% of cases the cancer had already reached the lymph nodes, a development that increases the likelihood of metastatic spread to other parts of the body.
All the men underwent surgery to remove their cancer. After surgery, 48 received radiotherapy and 100 received adjuvant chemotherapy or hormone therapy. After a median follow-up of 5.2 years, the estimated 10-year disease-free survival rates were 80% for men with the earliest stages of disease, and 44% for those with the largest tumors.
When the researchers looked at the characteristics of the tumors, they found that 73% were positive for estrogen receptors and/or progesteron receptors. Among a sub-group of 41 patients, 48.7% had tumors that overexpressed the protein HER-2/neu, which is an indication of an aggressive tumor.
"Male breast cancer is a rare disease and not well known," Dr. Garassino said. "It is treated the same way as female breast cancer, although our large retrospective series suggests that it has somewhat different histological characteristics."
If treated early enough, the disease is highly responsive to hormone therapy, Dr. Garassino said. In those cases, the prognosis may even be better than in women, she added. An ongoing case-control trial is examining this suggestion.
"What is important for people to know is that most of the patients in our study had a delay in their diagnosis due to the fact that a mass in their breast was misunderstood," Dr. Garassino said. "Therefore it is important that every mass in a man's breast must immediately be considered suspicious."
"Better understanding of male breast cancer will also provide better insights for treating these patients with modern targeted therapies", the researcher added. "We are currently conducting a molecular study on tissues to define help characteristics that might be important for this purpose."