In patients with type 2, or adult-onset, diabetes, treatment with a class of drugs called thiazolidinediones (TZDs) may significantly reduce the risk of overall death and death from lung cancer, according to a study presented at a cancer prevention research conference in Baltimore this week.

This research “makes the case that in addition to being a cancer chemopreventive agent, TZDs are also useful perhaps in improving the outcome or lifespan of lung cancer patients,” said Dr. Luke Ratnasinghe of the National Center for Toxicological Research at the US Food and Drug Administration and lead author of the study. Drugs in the TZD class include Avandia (rosiglitazone) and Actos (pioglitazone).

The study population consisted of some 128,000 men who were 40 years of age or older with a diagnosis of diabetes. A total of 3600 subjects also had lung cancer.

“We first asked the question - if you stratify the groups by use of TZDs, do you get differences in the incidence of lung cancer?” Ratnasinghe explained. “And the first part of the story is that folks who have diabetes and take TZDs have about a 30-percent reduced risk of getting lung cancer.”

“Then, when we took the patients with Diabetes and lung cancer and followed them over time, the lung cancer patients who were also taking TZDs had again about a 30-percent better outcome - that is a 30-percent reduced rate of death,” compared with patients with Diabetes and lung cancer who were not taking these agents, Ratnasinghe reported.

The study also showed that, compared with diabetics using no medication to control their Diabetes, TZD users had a 23-percent lower risk of death and insulin users had a 70-percent higher risk of death from lung cancer.

The TZDs help cells throughout the body to use insulin - the body’s key blood sugar-regulating hormone. The drugs work by binding with receptors, known as PPAR gamma, which are present mainly in fat cells. Since PPAR gamma receptors induce cell death, scientists have theorized that they also may suppress growth of lung cancer tumors.

Based on the current findings, Ratnasinghe and colleagues believe more studies are warranted to see whether TZDs may help reduce rates of death among lung cancer patients.