CNS Most Common Site of Testicular Lymphoma Relapse

BOSTON—A Rare Cancer Network study of testicular lymphoma found that relapses are most likely to occur in the central nervous system (CNS), Mahmut Ozsahin, MD, PhD, said at the 42^nd Annual Meeting of the American Society for Therapeutic Radiology and Oncology.

Dr. Ozsahin, of Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland, said that seven European cancer centers provided records of 36 adult patients treated between 1980 and 1999 for the retrospective study of this rare but aggressive form of extranodal lymphoma. Median follow-up was 42 months. Most patients had stage I or II disease; all had high-grade lymphoma.

Half the patients had a complete work-up, Dr. Ozsahin said. The others had partial staging only. All but one had the testicle removed, but otherwise treatments varied substantially. Half the patients had radiotherapy plus chemotherapy, and 31% had chemotherapy alone. Radiotherapy was used alone for four patients, and one patient only had surgery.

"The combined treatment modality was superior to radiation therapy or chemotherapy alone," Dr. Ozsahin said, noting that most patients benefited from chemotherapy, usually the CHOP regimen (cyclophosphamide, doxorubicin, vincristine, prednisone).

In patients receiving radiotherapy, no relapses occurred in the irradiated volumes. Neither radiotherapy technique nor dose affected outcomes.

After a mean follow-up of 11 months, 14 patients had relapsed. The sites of progression were the CNS (8 patients), para-aortic nodes (4 patients), and contralateral testis (2 patients). Delivering chemotherapy as intrathecal prophylaxis to the cerebrospinal fluid did not prevent CNS relapse, Dr. Ozsahin said.

At 5 years, the overall survival rate was 47%, the lymphoma-specific survival rate was 66%, and the disease-free survival rate was 43%.

"We should find more effective CNS prophylaxis modalities, maybe whole brain radiotherapy," Dr. Ozsahin concluded.