Breast cancers do not manifest in the same way for men and women, according to a new study that is recommending more research on male breast cancer patients.
A team of researchers in the U.K. decided to focus on breast cancer in men, an area that has not been researched thoroughly due to the fact that breast cancer is rarely diagnosed in men. The researchers analyzed tumor samples taken from 1,203 male patients. They looked at other aspects of breast cancer on top of the typical tumor characteristics and found differences in the breast cancer tissue of male and female patients.
"Besides conventional tumor tissue characteristics, such as subtype and grade, we also examined additional features, such as the development of fibrotic connective tissue, and the density of tumor infiltrating lymphocytes, a type of white blood cell often found in tumors and implicated in killing tumor cells," said Dr. Carolien van Deurzen, a pathologist at the Erasmus Medical Center in the Netherlands. "Interestingly, we found that these two last factors were strongly associated with outcomes in Male BC [breast cancer], whereas tumor grade, a commonly used prognostic measure in female breast cancer was not."
A tumor grading system is typically used to categorize the cancer based on the disease's severity and prognosis by comparing the tumor cells to normal breast tissue. The researchers reasoned that this grading system might not have been as effective for men due to varying breast cancer subtypes.
The researchers found that the oestrogen-receptor positive breast cancer subtype was more common in men than women. Women, on the other hand, were more likely to have lobular tumors, HER2 (human epidermal growth factor receptor 2) positive and triple negative subtypes.
The researchers noted that even though less than one percent of all breast cancer cases occur in men, their findings suggest that since there are differences between men and women, clinical trials and studies should not rule out male patients. This lack of research could greatly affect how men are diagnosed and treated.
"It is also important that Male BC patients should take part in general breast cancer trials, since trials for them alone are difficult to run due to the rarity of the disease," van Deurzen said. "In the past, male patients have been persistently excluded, with no scientific rationale for doing so."
"It has always been assumed, based on limited information, that men with breast cancer should be treated in the same way as women; for the first time, by studying over 1000 cases, it is becoming clear that that this is not so," added David Cameron, a professor of oncology at the University of Edinburgh in the U.K. who was not involved with the research.
The study was presented at the 10th European Breast Cancer Conference.
