PB1818 CLINICAL FEATURES AND PROGNOSTIC FACTORS OF PRIMARY TESTICULAR DIFFUSE LARGE B‐CELL LYMPHOMA (PT‐DLBCL): EXPERIENCE OF 35 PATIENTS FROM FUSCC

Abstract

Background:Primary testicular lymphoma (PTL) is a rare extranodal lymphoma, with diffuse large B cell lymphoma (DLBCL) as the predominant histological subtype. Factors that contribute to precise stratification and guide the treatment of this disease are still not well understood.Aims:This study aims to identify clinical features and prognostic factors of PT‐DLBCL patients.Methods:A total of 35 patients were included in this retrospective study who were diagnosed as PT‐DLBCL and treated in Shanghai Cancer Center, China from March 2007 to May 2018. The demographic details, clinico‐pathologic characteristics of the patients were summarized. Kaplan‐Meier survival curves were constructed for survival analyses.Results:The median age of the patients was 59 (range 36‐76) years old. All patients presented with testicular swelling, two had the presence of B symptoms. 33(94%) patients underwent orchiectomy. All patients received combination chemotherapy for 4‐6 cycles and central nervous system prophylaxis consisting of MTX for 4‐6 doses. 87% (28/32) patients achieved complete response, and ORR was 96.9% (31/32). 21 patients continued contralateral testis irradiation in our hospital. The median follow‐up time was 980 days (range 156‐2976 days). Median overall survival (OS) was not reached at the time of reporting. The estimated 5‐year PFS and OS rate were 67% and 84%. None of the 21 patients who received radiotherapy to the contralateral testis experienced relapse in that location in our study. All three patients who suffered from central nervous system relapse had the germinal center B‐cell subtype of DLBCL. Kaplan‐Meier analysis showed that PT‐DLBCL patients characterized by late stage (Stage III/IV) (P = 0.003), higher IPI score (IPI≥ 2) (P = 0.001) had a shorter progression free survival (PFS). More importantly, we found that patients with the ratio of the LDH level in CSF to the serum LDH level more than 6.5 suffered from a worse PFS (P = 0.032).Summary/Conclusion:Our work revealed that staging III/IV, IPI score ≥ 2 were adverse factors of PT‐DLBCL patients’ PFS. Significantly, the PT‐DLBCL patients with ratio of LDH level in CSF to the serum LDH level > 6.5 were indicated to have a worse PFS.