The outcomes for men with breast cancer worsen if treatment is delayed for a long time, a new study has revealed.
According to Dr. Marina Garassino from the Orion Collaborative Group, men are often diagnosed with breast cancer when the disease reaches its advanced stage.
In 50pct 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.
The study was conducted over 146 men with invasive breast cancer who were diagnosed between 1990 and 2007 across the 12 institutions in the ORION collaborative group.
All 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 80pct for men with the earliest stages of disease, and 44pct for those with the largest tumours.
The researchers looked at the characteristics of the tumours and found that 73pct were positive for estrogen receptors and/or progesteron receptors.
Among a sub-group of 41 patients, 48.7pct had tumours that over-expressed the protein, an indication of an aggressive tumour.
"Male breast cancer is a rare disease and not well known," said 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," she added.
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.
"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.
"We are currently conducting a molecular study on tissues to define help characteristics that might be important for this purpose," she added.
The study was presented at ESMO Conference Lugano (ECLU), organized by the European Society for Medical Oncology.