Researchers using our biobank samples uncover key differences in male breast cancer

By analysing patterns in tumour genes, Professor Valerie Speirs and her team at the University of Aberdeen discovered key differences in breast cancer in men. They also found male breast cancer doesn’t fit in the same categories used to classify breast cancer in women.

The researchers hope that a better understanding of the biology of male breast cancer will help drive more research. And in the future, this could change how we treat the disease.

Breast cancer is much less common in men than in women. Each year, around 400 men are diagnosed in the UK.

This makes it harder for researchers to gather enough samples to understand the disease. So, much of what guides treatment comes from studies involving women.

But, there’s growing evidence that there are biological differences between breast cancer in men and in women. Val and her team are studying these differences, ultimately to find the best ways to treat male breast cancer.

The researchers brought together data from 4 studies involving 195 men with breast cancer. They examined the activity of genes to look for groups of cancers with similar biological characteristics.

They found 2 groups. The first groups had higher activity in genes associated with oestrogen receptor signalling.

The second group had higher activity in genes linked to cancer cell growth, invasion into surrounding tissue and spread. This group also had higher activity in genes involved in organising the material that surrounds and supports cells.

This showed that male breast cancers can differ significantly from one another, even though most would be classed as oestrogen receptor (ER) positive.

The team also explored whether an approach developed to classify breast cancers in women was able to capture the patterns seen in men.

The team used a computer-based version of PAM50, a test which examines the activity of 50 genes, to predict which breast cancer subtype each tumour belonged to.

In women, breast cancer subtypes are closely linked to whether certain receptors are present. But using this same tool, the researchers didn’t find the same clear link in men, raising questions about how well this classification approach reflects male breast cancer.

To explore oestrogen receptor biology further, the researchers examined tissue from a collection of 506 male breast cancers.

They looked at chemical changes to the receptor, known as phosphorylation. These changes can affect how the receptor works, and some have previously been linked to improved survival in women with breast cancer.

But no association between phosphorylation and overall survival was found in any of the male breast cancer tissue samples in this study. This adds to evidence of key differences between breast cancer in men and women.

Following on from this research, Valerie and her team have just launched a new 2-year investigation to uncover more. The team will examine cancer‑associated fibroblasts (CAFs) generated from male and female breast cancer biopsies, including samples from the Breast Cancer Now Biobank.

CAFs are support cells that surround tumours and influence how the cancer grows, spreads and responds to treatment.

The research will explore how these cells respond to hormones such as oestrogen, whether they act differently between male and female tumours, what triggers their activity in men and how this may fuel tumour growth.

Research like this show the power of the Breast Cancer Now Biobank. By making samples available for studies like this, we’re helping researchers tackle some of the most difficult challenges in breast cancer research.

The Breast Cancer Now Biobank is generously supported by funding from Asda Tickled Pink.

This research was published earlier this year in The Journal of Pathology: Clinical Research.