New Study Supports Personalised Medicine Approach to Basal-Like Breast Cancer

A new study by NBCF-funded researcher A/Prof Liz Caldon (Garvan Institute of Medical Research) has identified a protein that can provide information on the prognosis of both breast and ovarian cancer.

The study, accepted for publication in the Journal of Pathology: Clinical Research, will allow clinicians to determine which patients will respond best to drugs like CDK2 inhibitors, and help direct future research directions.

Basal-like breast cancer (BLBC) is a subtype that has a number of similarities with ovarian cancer, including similar gene mutations (BRCA1, CCNE1 and TP53). Indeed, women with these gene mutations often are at risk of developing both cancer types.

It is now common for women with breast and ovarian cancer to be grouped together in clinical trials, to provide larger numbers of patients for the studies. However, there remain unanswered questions about how comparable the two cancer types are. In this study, the team aimed to compare the behaviour of a protein called cyclin E1 between the two.

“Our key finding is that detection of cyclin E1 protein by staining tumour samples identifies BLBC patients whose disease is aggressive and may respond better to certain therapies.  However the measurement of cyclin E1 from DNA cannot be used to reliably identify these patients, despite the detection of cyclin E1 in DNA being valuable in ovarian cancer. We need the right tests to match patients to therapies,” said A/Prof Liz Caldon.

The researchers looked at samples from 76 women with BLBC, and then validated their results against other datasets of both breast and ovarian cancer. They found that an overexpression of the cyclin E1 protein can predict outcomes in both BLBC and high grade serous ovarian cancer (HGSOC). Changes in the gene associated with the cyclin E1 protein were also useful in determining the prognosis for women with HGSOC, but not in BLBC.

The outcomes show that it is not enough to look at the genetic profile of women with cancers – the expression of proteins is also important. This information will help direct future diagnostic tests and treatments.