A three-year study on the effects of irradiation in a lung cancer-susceptible mouse model was led by Dr. Jerry Shay, Vice Chairman and Professor of Cell Biology at University of Texas Southwestern. Shay and colleagues observed gene expression changes in the mice, then applied that information to humans with early stage cancer. The results revealed a breakdown of which patients have a high or low chance of survival. The findings provide for insight into helping patients assess therapy risk.
Radiation and chemotherapy not only destroy tumors but can damage healthy tissues as well. According to Shay, with appropriate screening, patients can avoid additional radiation or chemotherapy treatment they don’t need. “We’re trying to find better prognostic indicators of outcomes so that only patients who will benefit from additional therapy receive it.”
The study monitored lung cancer development in mice after irradiation. The researchers found some types of irradiation resulted in an increase in invasive, more malignant tumors. They looked at gene expression changes in mice well before some of them developed advanced cancers. Genes in the mice that correlated with poor outcomes where then matched with human genes. The researchers compared the predictive signatures from the mice with over 700 human cancer patient signatures. The overall survivability of the patients correlated with the predictive signature in mice meaning that the classifier that predicted invasive cancer in mice also predicted poor outcomes in humans.
This study looked at adenocarcinoma which is a type of lung cancer in the air sacks that can affect both non-smokers and smokers. The findings also predicted overall survival in patients with early-stage breast cancer. However, the genes were not predictive of squamous cell carcinoma. Other types of cancers have not been tested yet.
According to the American Cancer Society, more than a quarter of a million new cases of lung cancer and close to 160,000 deaths from lung cancer will occur in 2014. They also report that the risk of developing cancer to be 1 in 13 for men and 1 in 16 for women. Lung cancer is the second most common cancer in both men and women.
The current research was funded in part by a five-year grant from NASA. NASA funds cancer research due to cancer risks encountered by astronauts during space missions. Shay believes that the findings could lead to more personalized care and pave the way to better, more science-based care and decision making. Shay notes, “Personalized medicine is coming. Think this is the future – patients looking at their risks of cancer recurrence and deciding what to do next. We can better tailor the treatment to fit the individual. That’s the goal.”