Isolated late testicular relapse of B-cell acute lymphoblastic leukemia treated with intensive systemic chemotherapy and response-based testicular radiation: A Children's Oncology Group study

The incidence of isolated testicular relapse (ITR) of acute lymphoblastic leukemia (ALL) has decreased with contemporary treatment strategies, but outcomes are suboptimal with a 58% 5-year overall survival (OS). This study aimed to improve outcome in patients with ITR of B-cell ALL (B-ALL) occurring after 18 months of first clinical remission using intensive systemic chemotherapy and to decrease long-term sequelae by limiting use of testicular radiation.

Forty patients in first ITR of B-ALL were enrolled. Induction (dexamethasone, vincristine, daunorubicin, and intrathecal triple therapy) was preceded by one dose of high-dose methotrexate (MTX, 5 g/m2 ). Following induction, 25 of 26 patients who had persistent testicular enlargement underwent testicular biopsy. Eleven had biopsy-proven disease and received bilateral testicular radiation (24 Gy), whereas twenty-nine did not.

Overall 5-year event-free survival (EFS)/OS was 65.0 ± 8.8%/73.1 ± 8.3%, with 5-year EFS 62.1 ± 11.0% vs. 72.7 ± 14.4% for patients who did not receive radiation therapy (XRT) (n = 29) compared with those who did (n = 11), respectively (P = 0.64). There were six second bone marrow relapses and six second ITRs. The proportion of second relapses was similar in the patients that received testicular radiation and those who did not. However, the 5-year OS was similar for patients who did not receive XRT (72.6 ± 10.2%) compared with those who did (72.7 ± 14.4%) (P = 0.85).

A 5-year OS rate of 73.1 ± 8.3% was obtained in children with first ITR of B-ALL occurring after 18 months of CR1 (length of first clinical remission) using intensive chemotherapy and limiting testicular radiation.

Pediatric blood & cancer. 2017 Dec 29 [Epub ahead of print]

Julio C Barredo, Caroline Hastings, Xiamin Lu, Meenakshi Devidas, Yichen Chen, Daniel Armstrong, Naomi Winick, Brent Lee Wood, Rochelle Yanofsky, Mignon Loh, Julie M Gastier-Foster, Dean Thomas Jorstad, Robert Marcus, Kim Ritchey, William L Carrol, Stephen P Hunger

Division of Hematology and Oncology, Department of Pediatrics, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida., Department of Hematology/Oncology, Children's Hospital & Research Center Oakland, Oakland, California., University of Florida, Gainesville, Florida., Biostatistics & Children's Oncology Group, University of Florida, Gainesville, Florida., Children's Oncology Group, Gainesville, USA., Department of Pediatrics, UT Southwestern, Dallas, Texas., University of Washin, Seattle, Washington., Cancer Care Manitoba, Winnipeg, Manitoba, Canada., Helen Diller Family Comprehensive Cancer Center, UCSSF Medical Center-Parnassus, San Francisco, California., Department of Pathology, Nationwide Children's Hospital, Columbus, Ohio., Children's Hospital of Wisconsin, Milwaukee, Wisconsin., Nemours Children's Clinic, Pensacola, Florida., Department of Pediatric Hematology/Oncology, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania., Department of Pediatrics, New York University School of Medicine, New York, New York., Department of Pediatric Oncology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.