Isolated testicular relapse in acute lymphoblastic leukemia - Effective treatment with the modified CCG-112 protocol

BACKGROUND: The testes have been considered a sanctuary site for leukemic cells and testicular relapses used to account for a major proportion of the poor outcome of boys with acute lymphoblastic leukemia. With use of aggressive chemotherapy which includes intermediate or high dose methotrexate, the incidence of testicular relapses has declined. However once these patients have received cranial irradiation as a part of the front line protocol, high dose methotrexate needs to be avoided because of risk of developing leucoencephalopathy. AIM: To study the use of non cross resistant chemotherapeutic agents along with a regimen containing lower doses of methotrexate in patients of isolated testicular relapse (ITR). MATERIALS AND METHODS: This is a retrospective analysis of 12 consecutive patients with ITR treated with modified version of the CCG-112 protocol which consists of intensive systemic chemotherapy, cranial chemoprophylaxis along with testicular irradiation. RESULTS: One patient died of regimen related toxicity. Two patients relapsed in the bone marrow during maintenance. Of the nine patients who completed treatment, eight are alive and in remission. One patient had a bone marrow relapse two months after completing treatment. The Kaplan Meier estimates give us an Event Free Survival (EFS) of 66.7% at 10 yrs. CONCLUSIONS: Thus, though the incidence is very low, patients with ITR should be treated aggressively since they have an excellent chance of achieving a long term EFS.