Gene may predict if further cancer treatments are needed

UT Southwestern Medical Center researchers are developing a new predictive tool that could help patients with breast cancer and certain lung cancers decide whether follow-up treatments are likely to help.
Dr. Jerry Shay, Vice Chairman and Professor of Cell Biology at UT Southwestern, led a three-year study on the effects of irradiation in a lung cancer-susceptible mouse model. When his team looked at gene expression changes in the mice, then applied them to humans with early stage cancer, the results revealed a breakdown of which patients have a high or low chance of survival.

The findings offer insight into helping patients assess treatment risk. Radiation therapy and chemotherapy that can destroy tumours also can damage surrounding healthy tissue. So with an appropriate test, patients could avoid getting additional radiation or chemotherapy treatment they may not need, Dr. Shay said.

‘This finding could be relevant to the many thousands of individuals affected by these cancers and could prevent unnecessary therapy,’ said Dr. Shay, Associate Director for Education and Training for the Harold C. Simmons Comprehensive Cancer Center at UT Southwestern. ‘We’re trying to find better prognostic indicators of outcomes so that only patients who will benefit from additional therapy receive it.’

Dr. Shay’s study closely monitored lung cancer development in mice after irradiation. His group found some types of irradiation resulted in an increase in invasive, more malignant tumours. He examined the gene expression changes in mice well before some of them developed advanced cancers. The genes in the mouse that correlated with poor outcomes were then matched with human genes. When Dr. Shay’s team compared the predictive signatures from the mice with more than 700 human cancer patient signatures, the overall survivability of the patients correlated with his predictive signature in the mice. Thus, the classifier that predicted invasive cancer in mice also predicted poor outcomes in humans.

His study looked at adenocarcinoma, a type of lung cancer in the air sacks that afflicts both smokers and non-smokers. The findings also predicted overall survival in patients with early-stage breast cancer and thus offer the same helpful information to breast cancer patients; however the genes were not predictive of another type of lung cancer, called squamous cell carcinoma. Other types of cancers have yet to be tested.

UT Southwestern Medical Center