J Clin Oncol 31, 2013 (suppl; abstr 8541)
Shivlal Pandey, S. Vincent Rajkumar, Angela Dispenzieri, Martha Lacy, Morie Gertz, Francis Buadi, David Dingli, Suzanne R. Hayman, Stephen J. Russell, John Anthony Lust, Steven R. Zeldenrust, Prashant Kapoor, Arleigh Robertson McCurdy, Robert A. Kyle, Shaji Kumar; Mayo Clinic, Rochester, MN
Background: Achievement of a complete response (CR) to treatment is an important predictor of outcome for patients (pts) with myeloma (MM). The goal of the current study was to assess whether the treatment that resulted in CR has any impact on the outcomes.
Methods: We identified 462 pts with MM, who fulfilled the IMWG criteria for CR, seen at Mayo Clinic between 1991 and 2011. The treatment was classified into groups by the regimen that led to CR (Table), and also based on whether an autologous stem cell transplant (ASCT) was part of the regimen. The remaining 21 pts had a variety of regimens and are not included in the Table.
Results: The median age at diagnosis was 58.5 yrs (27.1–82.3 yrs) with 56% males. The overall survival (OS) from diagnosis for the entire cohort was 10.7 yrs (95% CI; 9.3, NR). The median interval from diagnosis to the recorded CR was 10.3 mos (range 1- 170), with 272 (58.4%) and 385 (82.7%) obtaining a CR in <12 mos and <24 months from diagnosis. We first compared the outcomes based on whether ASCT was part of the regimen; 328 had an ASCT while 117 pts received only chemotherapy. Median time to progression (TTP) following a CR was 5.1 yrs for the ASCT group compared with 5.5 yrs for the rest (P=0.3). Median OS from CR was 9.1 yrs for the ASCT group and 7.5 yrs for the rest (P=0.5) and OS from diagnosis was 10.1 yrs for the ASCT group and 12.6 for the rest (P=0.5). Examining the outcomes based on the regimen utilized showed that the TTP and OS from CR as well as OS from diagnosis were similar for all the groups (Table). Among pts who had a CR within a year of diagnosis, there were no differences in terms of the TTP or OS from the onset of CR or from diagnosis between the ASCT vs. chemotherapy groups or between the different regimens (P=NS for all comparisons).
Conclusions: The current study highlights an important message regarding CR in MM. The results suggest that the prognostic value of CR is independent of the nature of therapy, and likely reflects the contribution of disease biology to obtaining a CR.