Prognostic impact for different sites of extranodal involvement in patients with diffuse large B-cell lymphoma in the rituximab era.

Abstract

e18505 Background: Extranodal involvement is considered poor prognostic factor for patients with diffuse large B-cell lymphoma (DLBCL); however, the prognostic impact of each involvement site has not yet been fully elucidated. Methods: We retrospectively analyzed data for 1,221 patients with DLBCL uniformly treated by R-CHOP therapy between 2003 and 2006. Patients with distinct forms of DLBCL, such as intravascular lymphoma, primary effusion lymphoma, and pyothorax-associated lymphoma, were excluded from the study. Primary CNS lymphoma and intraocular lymphoma were also excluded. We evaluated 26 extranodal involvement sites (orbita, nasal cavity, paranasal sinus, Waldeyer ring, salivary gland, thyroid gland, breast, thymus, lungs, pleura, stomach, small intestine, colon, peritoneum, liver, pancreas, kidney, spleen, adrenal gland, testes, ovary/uterus, bones, bone marrow, peripheral blood, skin, and subcutaneous tissue) with respect to prognostic impact. Results: The median age was 64 years (range, 15–91 years). Nine hundred and ten patients (74.6%) were treated with 6-8 cycles of therapy. Local irradiation was added in 297 patients (24.4%). Univariate analysis revealed that the patients with certain extranodal involvement had significantly worse overall survival (OS) than did the patients without the extranodal involvement; these sites included nasal cavity, paranasal sinus, lungs, pleura, small intestine, peritoneum, liver, pancreas, stomach, spleen, adrenal gland, testes, bones, bone marrow, peripheral blood, skin, and subcutaneous tissue. Patients with Waldeyer ring involvement had significantly better OS. Multivariate analysis revealed that patients with involvement of pleura (P < 0.001), small intestine (P = 0.015), peritoneum (P = 0.002), adrenal gland (P < 0.001), testes (P = 0.005), bone marrow (P < 0.001), and peripheral blood (P = 0.002) had significantly worse, but Waldeyer ring had significantly better OS (P = 0.038). Conclusions: Extranodal involvement affects the prognosis of patients undergoing R-CHOP therapy for DLBCL. Waldeyer ring involvement may be a better prognosis factor.