Incidence and significant predicting factors for chemotherapy-induced severe thrombocytopenia in lymphoma patients

Abstract

20519 Background: Severe thrombocytopenia (TCP) is a complication of chemotherapy (CT), resulting in frequent transfusions and treatment delays. The incidence and risk factors for TCP in lymphoma patients (pts) with current CT regimens are not well defined. Methods: Medical records of 1046 newly referred lymphoma pts to MD Anderson Cancer Center in 2003 were retrospectively reviewed over two years follow-up period. The incidence of severe TCP was determined, and logistic regression models were employed to identify the significant baseline clinical and laboratory features correlated with severe TCP. Results: 404 pts, who received ≥ 1 cycle of treatment and had adequate laboratory records, were included in the analysis (total CT cycles 2061). Grade (GR) 4 TCP (PLT nadir < 25×103/μL) was observed in 42% (170/404) of pts, in the median cycle 2 (range 1-11) and median PLT nadir of 12×103/μL (1- 24×103/μL). Bleeding occurred in 48% (81/170) of pts with GR 4 TCP compared to 8% (19/234) of pts with higher PLT counts (p=0.0001), although most bleedings (95%) were minor. Seventy-nine percent (134/170) of pts with GR 4 TCP received PLT transfusions, compared to only 2% (4/234) of pts with higher PLTs (p<0.0001). 137 out of 170 (81%) GR 4 TCP pts and 245 out of 398 (62%) GR 4 TCP episodes occurred in the 1st regimen. Therefore the logistic regression models analyzed the data set of 1st regimen. In the multivariate model, following variables were most important predictive factors for GR 4 TCP. Conclusions: The incidence of severe TCP in lymphoma pts is high. Predictive risk factors can be very useful to develop prophylactic strategy with PLT growth factors in high risk pts to prevent TCP related complications. Variable Odds Ratio (95% CI) P value Myelosuppressive Risk of Regimen ( high vs low) 38.60 (18.70–79.66) <0.0001 Extra Nodal Involvement (yes vs no) 2.57 (1.29–5.09) 0.007 Type of Previous Therapy* (CT+RT vs no Rx) 3.53 (1.33–9.33) 0.011 PLT Count 0.995 (0.993–0.998) 0.001 Serum Beta2MicroG 1.153 (1.03–1.29) 0.014 * RT: radiotherapy; no statistical significance between RT or CT±surgery vs no Rx. No significant financial relationships to disclose.