Young people with favorable-risk Hodgkin lymphoma and a complete early response to chemotherapy experienced a high rate of 2-year event-free survival with the use of limited radiotherapy in a recent study.
More than 90% of children with favorable-risk Hodgkin lymphoma can achieve long-term survival, but many will suffer toxic effects from radiotherapy, explained Monika L. Metzger, MD, MSc, and coinvestigators in JAMA (2012;307:2609-2616). Pediatric oncologists strive to minimize toxic effects while maintaining excellent cure rates, stated Metzger, of the Department of Oncology at St. Jude Children’s Research Hospital and the Health Sciences Center at the University of Tennessee, both in Memphis, Tennessee, and colleagues.
The researchers evaluated the efficacy of four cycles of VAMP—vinblastine, Adriamycin (doxorubicin), methotrexate, and prednisone—in 47 persons younger than age 21 years (median age 13.2 years, range 4.7-20.6 years) with favorable-risk Hodgkin lymphoma who achieved a complete response after two cycles and did not receive radiotherapy. The 41 patients who achieved less than a complete response (median age 14.0 years, range 4.4-19.1 years) were given 25.5 Gy-involved-field radiotherapy.
All patients had stage I or II disease, with fewer than three nodal sites and no B symptoms, mediastinal bulk, or extranodal extension.
Metzger’s team desired a 2-year event-free survival rate of greater than 90%, and considered 80% to be unacceptably low. The 2-year event-free survival rate for the entire group proved to be 90.8%, and 89.4% for those who did not require radiotherapy compared with 92.5% for those who did.
Although one patient withdrew consent before the 5-year mark, the 5-year event-free survival rate for the remaining 87 patients was 88.5% and the 5-year overall survival rate was 100%, with one patient dying approximately 7.5 years after enrollment. Five-year event-free survival was similar for those who did and did not undergo irradiation: 87.5% and 89.4%, respectively.
Therapy was well-tolerated without major complications, and delay or dose modifications due to adverse toxic effects were rare.
“To our knowledge, this is the first trial in which a select group of children with favorable-risk Hodgkin lymphoma experienced a high rate of 2- and 5-year event-free survival without exposure to radiotherapy, alkylating agent, epipodophyllotoxin, or bleomycin chemotherapy and a relatively low cumulative dose of anthracyclines,” noted the authors.