Scientists have identified two key proteins in male breast cancer that may indicate a patient is less likely to survive the disease, in new research published in journal Clinical Cancer Research.
The study – funded by Harrogate-based charity Yorkshire Cancer Research – is one of the largest conducted into male breast cancer, analysing more than 700 cases and using male breast cancer samples from the Breast Cancer Now Tissue Bank.
On average, 350 men will be diagnosed with male breast cancer every year in the UK and 80 men will die from the disease.
The research – led by Professor Valerie Speirs and Dr Matt Humphries at the University of Leeds – adds to a small but growing body of evidence that male breast cancer may have differences in biology to female breast cancer.
What did the study find?
The researchers initially compared the expression of genes (which provide the instructions for cells to make particular proteins) in 10 female and 12 male breast cancer cases and found three distinct clusters where gene expression differed between the female and male cases.
Focusing on one of these clusters, the team found that the eIF family of genes were overexpressed in male breast cancer compared to female breast cancer. They then measured the corresponding protein levels in two sets of 477 and 220 male breast cancer samples (697 total) using simple staining techniques.
Looking at the survival data for the male breast cancer samples they then linked higher levels of two proteins in this family, called eIF4E and eIF5, to worse overall survival. This finding was only significant in one set of samples and in the combined set, but not in the set of 220 samples.
The discovery, means that a test for the two proteins could now be developed, and then assessed, to determine whether adjusting treatment in men with high levels of eIF4E and eIF5 could improve their outcomes.
Dr Matt Humphries, the paper’s first author, said:
“Currently, men with breast cancer are treated in exactly the same way as women. While some studies have been carried out into the disease in men, the numbers of samples examined have often been quite small.
“We screened breast tumours from hundreds of men to find out if their tumours expressed these proteins, and we found that a significant proportion of the men we tested had higher levels of these proteins. These men were almost two and a half times more likely to die from their disease than those who had low levels of the proteins.”
Baroness Delyth Morgan, Chief Executive at Breast Cancer Now, said:
“These important findings could now enable researchers to identify whether certain male breast cancer patients might benefit from more extensive treatment.
“It’s so important that we continue to investigate how male and female breast cancers differ biologically, to ensure all patients receive the most appropriate treatment and are given the best chance of survival.
“Finding out whether existing drugs could target the proteins identified in this study could open up the possibility of improving treatment for some aggressive male breast cancers.”
Dr Kathryn Scott, Interim Chief Executive at Yorkshire Cancer Research, said:
“We’re proud to have funded such an important discovery in the biology of male breast cancer. Breast cancer is often thought of as a disease that only affects women. It’s crucial that men are aware of the signs and symptoms of breast cancer so they are diagnosed at the earliest possible stage, but also that they are able to receive treatment that is tailored to their specific disease.”
Breast Cancer Now helped fund the creation of the male breast cancer sample “arrays” in addition to providing male breast cancer samples from the Breast Cancer Now Tissue Bank.
The Breast Cancer Now Tissue Bank is generously supported by funding from Asda’s Tickled Pink and Walk the Walk. Both are founding partners of the Bank and continue to support its work.