SAN FRANCISCO—Seven years seems to be the cutoff point for multiple myeloma patients receiving tandem autotransplants to avoid relapse and achieve long-term survival. "Most relapses were seen in the first 3 years," Guido Tricot, MD, said at the American Society of Hematology (ASH) 42nd Annual Meeting. "Relapses start to decrease between 3 and 7 years. After 7 years, it is exceptional to relapse."
Dr. Tricot and his colleagues at the Myeloma and Transplantation Research Center, University of Arkansas for Medical Sciences, Little Rock, reviewed a database of 1,000 consecutive transplant patients. The analysis concentrated on more than 500 patients who received their first transplant at least 5 years prior to the data analysis.
"We all know that autotransplants are superior to conventional chemotherapy in terms of complete response rate," Dr. Tricot said. He cited a complete response rate 10 times higher with autotransplants, compared with conventional chemotherapy, with long-term survival twice as high.
The questions that need to be answered, he said, are: "Can we cure any patients with tandem autotransplants, and, if that is possible, what are the variables associated with long-term event-free survival?"
Of the patients in this series who were 5 years post-transplant, most were 50 years of age or older, Dr. Tricot said, and about one third had cytogenetic abnormalities, including 17% with chromosome 11 and 13% with chromosome 13 abnormalities. Within 5 years, 72% had a second transplant.
Median survival was 30 months; event-free survival was 17 months. Seven years after the first transplant, 35% of the patients were alive, and 24% had event-free survival. Seven years seemed to be the defining point for avoiding relapse.
To appreciate the independent contribution of complete response to long-term event-free survival, the researchers did a separate analysis of the 309 patients alive 1 year after their first transplant. Of those, 111 were in complete remission.
Although there was a trend for complete response patients to have better long-term event-free survival, no significant differences in complete response and non-complete response patients were observed in any risk group, Dr. Tricot said.
The authors concluded that although attaining a complete response was a favorable variable in univariate analysis, it is not absolutely required for long-term event-free survival and that no further relapses are seen 7 years after the first transplant.
