Determinants of and outcomes associated with chemoimmunotherapy dose density in elderly subjects with diffuse large B-cell lymphoma (DLBCL).

8061 Background: RCHOP is the standard first line therapy for DLBCL but elderly patients often receive suboptimal doses. Relative dose intensity (RDI) less than 70-90% has previously been associated with inferior survival in CHOP treated patients. We now investigate the clinical determinants of immunochemotherapy dose delivery and comparative effectiveness of dose intensity on lymphoma-specific outcomes in persons over the age of 60. Methods: SPORE MER (Molecular Epidemiology Resource) is a prospectively accrued observational study in which University of Iowa and Mayo Clinic patients with a diagnosis of Non Hodgkins lymphoma have been enrolled since 2003. We reviewed data from the Iowa patients along with medical records from DLBCL patients over the age of 60 treated with anthracycline based chemo immunotherapy consecutively enrolled up through to December 2009. Statistical tests of associations between RDI and clinicopathologic factors, as well as survival outcomes, were performed. Results: We identified 92 patients over the age of 60. The median age was 70. 47 subjects experienced at least 1 dose reduction, 26 subjects had dose delays, and 20 subjects were unable to complete therapy. RDI ranged from 0.30-1.70 (median 0.92) for doxorubicin and from 0.29-1.70 (median 0.97) for cyclophosphamide. 24 and 19% of subjects received < 80% of RDI for dox and cy respectively. Age (p< 0.001 for both dox and cy) and performance status (p=0.04 for dox) but not number of medications, ACE27 co-morbidity score, body surface area, nor need for acute care visits were associated with decreased RDI. Adjusted for IPI, RDI did NOT have a significant effect on event-free or lymphoma-specific survival. Conclusions: Among clinical variables, age is the dominant variable associated with delivery dose intensity for chemotherapy in elderly patients treated for DLBCL; and among elderly patients receiving chemo immunotherapy, we did not find an association between dose intensity and lymphoma-specific outcomes. [Table: see text]