Gene May Help Predict Lung Cancer Patient Survival
FRANKFURT (Reuters Health) - Patients with lung cancer are more likely to survive longer if they have high levels of a protein produced by a so-called "repair gene," scientists told a cancer drug meeting on Wednesday.
In a study of patients who had undergone surgery for the most common type of lung cancer, known as non-small-cell lung cancer, the investigators found that those with high levels of the protein had the longest survival time.
"Currently, every patient with lung cancer gets the same treatment, chemotherapy, and surgery when possible," said Dr. Gerold Bepler, a professor of medicine and oncology at the University of South Florida in Tampa.
"However, we can't predict who will respond to chemotherapy and what factors are associated with survival of lung cancer," he told Reuters Health.
"If this gene turns out to be a reliable predictor, we could tell which patients could do without chemotherapy, and which ones should get it," he added. Most patients with lung cancer have, at best, a limited response to chemotherapy, Bepler noted.
The repair gene is known as ERCC1. It works by correcting mistakes made during cell division by removing the defective DNA portion and replacing it with a corrected version. Bepler and colleagues were surprised that high levels of ERCC1 expression were associated with longer survival because the gene has been known to repair damage inflicted on cancer cells that have undergone chemotherapy, so that they become resistant to treatment.
He and colleagues studied 51 patients with non-small-cell lung cancer in early to advanced stages. All of the patients' tumors had been surgically removed, and five had also undergone radiation treatment. One patient had received both radiation and chemotherapy.
The investigators assessed whether patients had low, intermediate or high levels of ERCC1 expression. Those with low levels had a median survival of approximately 35 months, slightly less than 3 years. The intermediate group had a median survival of approximately 62 months or slightly more than 5 years, and the group with high levels had a median survival of approximately 94 months, or nearly 8 years.
Bepler and his investigative team theorized that, following surgical removal of the tumor, patients with high levels of ERCC1 expression benefit because the gene begins to act against the remaining malignant cells. In patients with low levels, the likelihood of this cellular repair is reduced.
"This finding could help physicians refine which patients receive chemotherapy," Bepler said. He noted that people with low levels of ERCC1 expression were less likely to develop resistance to chemotherapy drugs, and would therefore benefit from this type of treatment. But patients with high ERCC1 expression levels did not respond well to chemotherapy.
The meeting was jointly sponsored by the American Association for Cancer Research, the National Cancer Institute (news - web sites) and the European Organization for the Research and Treatment of Cancer.