Deletion of p53 as Detected by Fluorescence In Situ Hybridization Is Associated with Significant Shorter Event-Free Survival in Patients with Multiple Myeloma Who Are Receiving Allogeneic Blood Stem Cell Transplantation.

Deletion of chromosome band 17p13 (P53) is known to be an adverse prognostic factor for time to progression (TTP) and overall survival (OS) in myeloma patients receiving conventional or high-dose chemotherapy. In this retrospective multicenter study, we investigated the impact of P53 deletion as detected by fluorescence in situ hybridization combined with immunofluorescent cytoplasm immunoglobulin staining (cIg-FISH) on outcome after allogeneic blood stem cell transplantation (SCT) in 50 patients (pts) with advanced or relapsed multiple myeloma (MM). Median age was 51 years (34 – 67 ys.), 32 patients were male, 18 female. Thirty pts received a stem cell graft from an unrelated donor, and 20 pts from a HLA-identical sibling. P53 gene deletion was found in 5 out of 49 pts (10,2 %). Deletion 13 detected by cIg-FISH was found in 20 out of 47 pts (42%). There was a strong correlation between P53 deletion and deletion 13: four out of the five patients with P53 deletion also showed deletion in chromosome band 13q14. The estimated event-free (EFS) and overall survival (OS) at three years for the entire study population was 43% and 65%, respectively. For patients with del 13 only a trend for a worse 3 year EFS was seen (38% vs 42%, p=0.2), while pts with P53 deletion had a significant reduced EFS (0% vs 46%, p=0.0001). Three out of five pts with P53 deletion relapsed very early after allogeneic SCT (day 81, 108 and 287 respectively). These data suggest that P53 is a risk factor for patients with MM treated with allogeneic SCT which can not be overcome by this treatment strategy.