Gene signature predicts cancer outcomes

Predictive biomarkers are important in cancer--they help physicians select the best course of treatment for patients whose cancers are likely to respond, and save those patients who are not expected to benefit from rounds of unpleasant and invasive treatment. Existing predictive methods aren't too effective in esophagogastric junction cancer, and a new signature of 86 genes might help make doctors' decisions clearer.

Esophagogastric junction cancer occurs at the point where the esophagus and stomach meet, and CT and PET imaging is used to predict the tumor's response to treatment, but their predictive capabilities are not always very high, and combining imaging with biomarkers could improve this.

To find new biomarkers, researchers from the University of Aberdeen (Scotland) looked at patients with advanced esophagogastric junction cancer. They scanned the patients using PET and CT imaging, produced gene expression profiles of the tumors, and analyzed the tumor tissue. They found a profile of 86 genes that could support the imaging results and help separate the patients into those who would respond to treatment and those who would not. Increased expression of the gene for leptin was the strongest biomarker in the signature, and is also linked with a better chance of survival.

"Leptin in particular may be a molecular biomarker that is useful to combine with PET," Dr. Russell Petty told the Oncology Report. "Leptin expression is associated with chemoresistance, but at the same time is also a favorable therapy-independent biomarker, so this combination of predictive and therapy-independent prognostic impacts mean that leptin has the potential to be a clinically useful biomarker."

The researchers concluded the combination of both molecular markers and imaging markers could support the treatment of this type of cancer. More research is needed, and validation of the 86-gene signature is ongoing. The data were presented at the ASCO 2012 Gastrointestinal Cancers Symposium.

- see the abstract
- check out the article in the Oncology Report