Breast cancer gene important in lung cancer treatment

26 Sep 2007
A gene which indicates a greater susceptibility to breast cancer has been found to play a significant role in non-small cell lung cancer (NSCLC). It may therefore possibly be used, not only to predict outcome for patients with NSCLC, but also in individualising therapy.

Speaking at the 14th European Cancer Conference in Barcelona, Dr Rafael Rosell said that those NSCLC patients who had high levels of BRCA1 had nearly double the risk of dying early from the disease than those patients with low expression.

Furthermore it was found that both breast cancer and NSCLC patients with low BRCA1 expression had high sensitivity to cisplatin-based chemotherapies, while high BRCA1 expression meant high sensitivity to antimicrotubule agents; drugs that tackle cancer by preventing cell division. This is a clear step in the personalisation of anti cancer therapy, as Dr Rosell made clear: "We believe that BRCA1 could be a landmark predictor of sensitivity to chemotherapy in NSCLC and assessment of its expression could be useful for customising adjuvant chemotherapy. We believe that patients with the highest expression levels should receive antimicrotubule (or taxane), non-platinum based chemotherapy."

126 patients from Poland were sampled, with analysis carried out of the expression of 5 different genes. Only the BRCA1 gene and the stage of the disease bore any relation to the survival: Patients with high expression had a 1.98 times higher risk of dying within three years than patients with low expression. Respectively, patients with advanced disease had a 7.91 times higher risk than those at the early stages.

A further 58 patients from Italy were tested in an Italian group, with those that had high levels of BRCA1 found to be 2.4 times more likely to die, under the same time limits as the first group.

This validation of the original findings by an independent data set further strengthened their conclusion that over-expression of BRCA1 was strongly associated with poor survival in NSCLC patients.

The researchers are currently running a trial of 450 patients to test different chemotherapy regimens based on the patient's BRCA1 levels, with a further 700 patients in 2008.

Dr Rosell concluded by describing his findings as having "crucial therapeutic implications", saying that "they contradict the currently held belief that cisplatin based chemotherapy is the gold standard in high risk [lung cancer] patients."