Gene could guide better treatment of most common breast cancer

Scientists have identified a gene which if present in certain breast cancer patients indicates how they will respond to specific therapies.

The Nottingham Trent University-led team involved a collaboration with the Queensland University of Technology Senior Research Fellow, Dr Pascal Duijf. Who is based at TRI. Their work could help to ensure that patients are spared ineffective drugs and unnecessary side effects.

In team looked at patients with oestrogen receptor positive breast cancer, which accounts for about two-thirds of all cases globally. Currently, there is no proven test to predict response to endocrine therapy or chemotherapy for these breast cancer patients.

Their study involved analysing the tissue and treatment history of almost 13,000 patients with oestrogen receptor positive breast cancer, and the presence and role of the protein ‘sperm associated antigen 5’, or SPAG5.

Writing in the Journal of the American Medical Association (JAMA) Network Open the team found that there were worse outcomes for patients who showed an increased expression of SPAG5, who underwent endocrine therapy alone.

A subgroup of patients with the more aggressive ‘luminal B’ tumours responded well and survived longer, however, if they received endocrine therapy along with anthracycline-based combination chemotherapy.

Scientific lead for the study, Nottingham University Hospital Clinical Senior Scientist, Dr Tarek Abdel-Fatah, said SPAG5 is found in 30% of oestrogen receptor positive luminal B subclass of breast cancers, which constitutes 40% of all breast cancer patients.

“We found that 80% of those patients will benefit from adding chemotherapy to endocrine therapy. Our work will help to guide clinicians to the optimal treatment for these patients.”

Nottingham Trent University Professor of Informatics, Graham Ball, said: “There is an urgent need for an improved method of determining how these patients will respond to therapy.

“Although endocrine therapy has extended survival for patients with oestrogen receptor positive breast cancer, resistance to it is common and reported in up to half of patients. We need to prevent the time and distress of patients receiving needless chemotherapy and suffering unnecessary side-effects.

“We have been studying this particular molecule and its important role in breast cancer for some time. We believe it will be a significant biomarker in helping to get the most effective treatment to patients as quickly as possible.”

Source: Nottingham Trent University

Photo: Dr Pascal Duijf, courtesy Queensland University of Technology