Efficacy of prophylactic irradiation to the contralateral testis for patients with advanced-stage primary testicular lymphoma: an analysis of outcomes at a single institution.

BACKGROUND: Primary testicular lymphoma (PTL) is a rare, extranodal lymphoma that often relapses in the contralateral testis. We evaluated outcomes in patients with any stage of PTL who had received CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) with rituximab chemotherapy and prophylactic radiotherapy to the contralateral testis.

METHODS: We retrospectively identified 15 patients (median age 66 years; range 39-81) diagnosed with diffuse large B-cell PTL in the period 2000-2014. Characteristics and outcomes of these cases were evaluated.

RESULTS: All patients received initial orchiectomy followed by CHOP with or without rituximab. Thirteen patients received prophylactic irradiation to the contralateral testis. During follow-up (median 67 months; range 8-190), one patient died of PTL, three died of other disease, and nine were free from relapse. For stage I-II disease, 5-year progression-free and overall survival rates were 80 and 100%, respectively. For stage III-IV PTL, 5-year progression-free and overall survival rates were 50 and 72%, respectively. Notably, no patient developed contralateral testicular involvement after prophylactic irradiation.

CONCLUSIONS: The observed outcomes suggest that the combination of (i) CHOP plus rituximab and (ii) radiotherapy for local recurrence prophylaxis is promising for both stage I-II and stage III-IV PTL.