Effect of complete response on outcome following autologous stem cell transplantation for myeloma

We studied the effect of complete response (CR) among 126 consecutive patie nts who underwent stem cell transplantation (SCT) for myeloma, The CR rate with SCT was 33%. Median overall survival (OS) from diagnosis of myeloma wa s 56 months. OS following SCT was 22 months. Progression-free survival (PFS ) was 12 months. OS was not different between patients who achieved CR and those who did not, median survival 25 vs 24 months, P = 0.5. Corresponding median times for PFS were 15 and 11 months, P = 0.2. The plasma cell labeli ng index (PCLI) was high (greater than or equal to1%) in 36% thigh risk gro up) and was associated with poor OS and PPS (P<0.001), Achieving CR did not influence OS or PFS in either the high or the low risk group. In contrast, OS and PFS were significantly influenced by high PCLI both in patients who achieved CR and those who did not. OS was poor (<30 months) in high risk p atients regardless of CR status and in low risk patients who did not achiev e CR, compared to low risk patients achieving CR (57 months), making them c andidates for novel posttransplant treatment options, Outcome following SCT is dependent more on biological variables such as the PCLI than on CR stat us.