The clinical significance of chromosome 17p deletion in chronic lymphocytic leukemia: A study of 180 consecutive patients

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7035 Background: Preliminary data indicate that the presence of chromosome 17p deletion (17p-) by fluorescent in-situ hybridization (FISH) in chronic lymphocytic leukemia (CLL) may be uniquely associated with resistance to standard therapy and dismal survival. Methods: In order to determine the significance of 17p- in CLL in a large cohort, we analyzed the clinical course and treatment outcome of 180 consecutive 17p- CLL pts managed at our center. Results: *PT CHARACTERISTICS. 56 (31%) pts were untreated (UNT), and 124 (69%) had relapsed / refractory (RR) disease. RR pts were more likely to have impaired performance status (PS) (p=0.01), Rai stage 3/4 disease (p<0.01), and elevated β2m (p=0.07). *PROGRESSION TO FIRST THERAPY. For UNT patients with asymptomatic CLL, the 18 month progression to therapy risk was 46%, with 18 pts remaining treatment-free at 7 - 47 months. The 17p- clone was lost spontaneously in 2 pts on follow-up. *RESPONSE TO INITIAL THERAPY. Six UNT pts received rituximab, with 4 (67%) objective responses (OR) and 2 (33%) complete clinical responses (CCR). Twenty-nine UNT pts received fludarabine & rituximab therapy, with 22 (76%) OR and 14 (48%) CCR. All CCR pts tested by FISH showed elimination of their 17p- clone. *RESPONSE TO SALVAGE THERAPY. Results by treatment categories were: rituximab, OR 27% & CCR 0%; alemtuzumab containing regimens, OR 50% & CCR 19%; fludarabine & rituximab therapy, OR 44% & CCR 0%; intensive chemotherapy, OR 20% & CCR 4%; investigational agents, OR 10% & CCR 0%. SURVIVAL. UNT pts had a favorable survival substantially better than that reported in previous studies (median not reached, 2 yr survival 81%), whereas RR pts had a median survival of only 14 months (p<0.0001). Among RR pts, those with a normal performance status (n=35) had a favorable 2 year survival of 78%, with no deaths between 12 and 46 months. Conclusions: The outcome of 17p- CLL is not necessarily dismal. Half of early stage pts will not require therapy at a follow-up of up to 4 years. The 17p- clone may be lost spontaneously or be eliminated by effective therapy. Rituximab containing regimens are highly effective particularly in the frontline setting. No significant financial relationships to disclose.