Data included Medicare Part A and Part B costs from all providers--inpatient, outpatient, skilled nursing facility, home health care, hospice and physicians. The RTOG researchers calculated expected costs for the 47-month period for each arm of the trial, based on average estimates of survival probabilities and mean monthly costs for each month.

Incremental cost-effectiveness ratios were calculated as savings per life year in terms of overall survival and in terms of disease-free life years. Calculations were in 1996 dollars with the standard annual discount rate of 3 percent.

"Although radiation alone costs less in and of itself, the expected mean 47-month cost of that treatment was $57,357--compared to the two treatment arms that included chemotherapy," Konski said. "Concurrent chemo-radiation cost a little more $57,870, and represented an incremental increase of $697 per life year of overall survival and $2,048 per disease-free life year."

"Induction chemotherapy plus radiation therapy was the most cost-effective," Konski concluded. "At a 47-month cost of $49,018, this treatment saved $7,031 per disease free and $9336 per life year of total survival."