Abstract
R-CHOP chemotherapy composed of rituximab, cyclophosphamide, adriamycin, vincristine, and prednisolone which might increase the risk of Pneumocystis pneumonia in patients with non-Hodgkin lymphoma. We estimated the point prevalence of Pneumocystis pneumonia in non-Hodgkin lymphoma patients according to the number of R-CHOP cycles and investigated whether cytoreduction by chemotherapy is associated with Pneumocystis pneumonia development. We retrospectively established a cohort of patients who received R-CHOP for non-Hodgkin lymphoma in our institution. Using this cohort, we estimated the incidence rate and point prevalence of definite and probable Pneumocystis pneumonia. To assess factors associated with Pneumocystis pneumonia development several clinical variables, including absolute neutrophil and lymphocyte count at the time of non-Hodgkin lymphoma diagnosis and when the last R-CHOP cycle was administered, were compared between patients with and without Pneumocystis pneumonia. Of 713 patients in the cohort, 14 and 18 patients were diagnosed with definite and probable Pneumocystis pneumonia, respectively. The overall incidence of definite and definite plus probable PCP in NHL patients receiving R-CHOP were 2.0 % (14/713; 95 % CI, 1.1-3.3 %) and 4.5 % (32/713; 95 % CI, 3.2-6.4 %), respectively. This corresponded to 3.8 (95 % CI, 2.2-6.4) and 8.4 (95 % CI, 5.9-11.9) per 1000 persons. Many cases of Pneumocystis pneumonia (22/32, 68.7 %) developed after administration of the fourth R-CHOP cycle. However, there was no statistical difference in Pneumocystis pneumonia prevalence between patients receiving four or more cycles of R-CHOP and fewer than. Higher absolute neutrophil count (4,742/mm(3) vs. 2,627/mm(3); p < 0.01) was associated with Pneumocystis pneumonia development at the last R-CHOP cycle, while absolute lymphocyte count at the time of NHL diagnosis was not. Contrary to expectations, Pneumocystis pneumonia is not a frequent complication of R-CHOP treatment for non-Hodgkin lymphoma. Cytoreduction of R-CHOP might not be a risk factor of Pneumocystis pneumonia development. Universal prophylaxis against Pneumocystis pneumonia during R-CHOP treatment could not be strongly recommended.