Deletion of the 17p Chromosomal Region Is Associated with a Very Poor Outcome in Multiple Myeloma Independently of the Type of Treatment.

Abstract 1817

Poster Board I-843

Deletion of the short arm of chromosome 17 [del(17p)] is known to confer a poor prognosis in multiple myeloma (MM). However, no large study has been specifically dedicated to this purpose, especially in the novel drug era. We analyzed a series of 1324 patients with MM at diagnosis, treated within or according to IFM trials, and analyzed for del(17p). Most of the patients were under 65 years of age (1122 of the 1324 patients), and were treates either with a VAD-based induction or a Velcade®/Dexamethasone-based induction, followed by one or two courses of high-dose melphalan. Del(17p) was correlated to the major other prognostic parameters, both for event free survival and overall survival. Del(13) was observed in 71% of the patients with del(17p). A significant association was observed with anemia < 10g/dl (p=.05), with thrombocytopenia < 130 G/l (p<.0001), with hypercalcemia (p=.001), and b2-microglobulin>3.5 mg/l (p=.006). No specific association was observed with t(4;14) (17% of the del(17p)-positive patients displayed t(4;14)). Del(17p) was observed in 10% of the patients. Del(17p) was associated with a very poor outcome, both in young and elderly patients. Actually, the prognostic value was observed only in patients displaying del(17p) in at least 70% of their plasma cells. The median EFS and OS were 18 and 28 months respectively, versus 30 and 69 months for patients lacking the del(17p). A particularly poor outcome was observed in patients presenting both del17p and t(4;14), with a median EFS of 4.5 months and a median OS of 12 months. Of particular importance, none of the treatment modality (high-dose melphalan, thalidomide, bortezomib) overcame the poor prognosis associated with del(17p), although patients lacking del(17p) displayed a better outcome when treated with Vel/Dex or MP-Thalidomide. In conclusion, del(17p) is associated with an especially poor outcome, independently of the type of treatment, including novel drugs.