Complete remission and survival in multiple myeloma

Abstract

8523 Background: While longer survival has been the ultimate index of better treatment in multiple myeloma, earlier endpoints have included the frequencies and durations of partial (PR) and complete remission (CR). This report describes a retrospective review with multivariate analysis of outcomes among newly diagnosed patients who received the sequence of primary chemotherapy followed by intensive therapy within the first year. Methods: Clinical outcomes were assessed in 759 consecutive patients with multiple myeloma, treated between 1987–2007, of whom 406 patients also received intensive therapy supported by autologous stem cells within the first year. Response to treatment was rated according to EBMT criteria. CR required disappearance of serum myeloma protein by immunofixation on two consecutive studies. Multiple prognostic variables were assessed in order to identify features associated with long survival. All survival times were compared by landmark analyses for those alive after 1 year, in order to avoid potential bias from the guaranteed survival of patients with responsive disease. Results: The response rate among all patients was 66% (including CR in 8%) after primary chemotherapy and then 75% after including results after high-dose therapy (including CR in 20%). The median survival for all patients was 56 months. Survival comparisons dating from 12 months after start of treatment were significantly longer for 144 patients whose disease was in CR (median 9.6 years), than for those with PR or NR (median 4.0 and 2.2 years, respectively). For those patients evaluated at 12 months, Cox regression analysis indicated that the occurrence of CR, the presence of ISS Stage I disease, and provision of intensive therapy were associated independently with long survival, in that order. Median survival times from onset of CR were similar (10–15 years) for groups of patients who achieved CR after only chemotherapy or after intensive therapy for NR, PR or as consolidation of CR. Conclusions: Survival times were similar at approximately 10–12 years for different groups of patients with CR by whatever pathway that may have been achieved. Prospective clinical trials are needed for definitive evaluation of CR as a surrogate marker for long term survival. No significant financial relationships to disclose.