Pancreatic cancer patients treated with a combination of chemotherapy and radiation after surgery survive approximately six months longer than those receiving surgery alone, Johns Hopkins Kimmel Cancer Center scientists report.
Previous clinical trials conducted in the 1980s and 90s in the United States established the benefit of postoperative chemotherapy and radiation. However, experts still disagree on whether to administer the treatments because results from European studies suggest the opposite effect - a decrease in survival.
"Some physicians might avoid chemotherapy and radiation if a benefit in survival is uncertain. However, without proof, I believe it is a disservice to these patients if we eliminate chemotherapy and radiation," says radiation oncologist Joseph Herman, M.D., who led the study.
Herman and his team sought to put the issue to rest by reviewing records of 616 Johns Hopkins patients whose pancreatic cancers were surgically removed between Aug. 30, 1993, and Feb. 28, 2005. The researchers compared the survival of 345 of the patients who had only surgery with 271 who were then treated with 5-fluorouracil (FU)-based chemotherapy agents and modern types of radiation.
Patients receiving the combined chemotherapy and radiation experienced an improved median survival when compared with patients who did not (21.2 vs. 14.4 months). Two-year survival also improved (43.9 percent vs. 31.9 percent), as did five-year survival (20.1 percent vs. 15.4 percent). Results will be published in the July 20 issue of the Journal of Clinical Oncology.
"The take-home message of this study is that patients who received combined chemotherapy and radiation appeared to have better survival than patients who have surgery alone, suggesting that it is safe and beneficial if it's done carefully and properly," says Herman, assistant professor in the Department of Radiation Oncology and Molecular Radiation Sciences.
He cautions that this is a retrospective study and that selection bias was possible as they may have selected out those patients who are healthy enough to receive the chemotherapy and radiation. "Regardless, it is still encouraging to say that many of these patients had very aggressive cancer and a lot of them are still alive several years after they received this combination therapy," says Herman.
Because data to assess treatment toxicity were unavailable, Herman and his study team focused on survival instead. He says the majority of patients were able to complete the therapy, suggesting that they tolerated it well.
The study also identified risk factors to determine those patients most likely to benefit from combined chemotherapy and radiation. Patients who clearly benefited included those with lymph-node-positive disease and those with tumors larger than 3 centimeters (about 1.2 inches). Patients with aggressive tumors also benefited, as did those with margin-positive disease, where the surgeon was unable to remove most of the tumor.
Groups were similar with respect to tumor size, nodal status and margin status, but those receiving combined chemotherapy and radiation were younger (median 64 vs. 70 years) and less likely to present with another serious disease.
"The survival benefit is still seen regardless of high-risk tumor characteristics and after controlling for age, other concurrent diseases and surgical complications," Herman says.