Children with favorable-risk Hodgkin’s lymphoma who achieve a complete early response to chemotherapy may not require radiation therapy or may undergo limited radiation therapy, according to the results of a study published in the Journal of the American Medical Association. This limited use of radiotherapy still resulted in a high rate of 2-year event-free survival.
Hodgkin’s lymphoma is a cancer of the lymph system. Children and adolescents diagnosed with Hodgkin’s lymphoma have 5-year overall survival rates greater than 90 percent. The current standard treatment for all stages of disease in children with Hodgkin’s lymphoma is multi-agent chemotherapy combined with low-dose radiation therapy; however, the treatment can carry late toxic effects, including the development of secondary cancers, heart disease, lung problems, and thyroid dysfunction.
Risk-adapted therapy refers to therapy based on predetermined risk stratification and is designed to maximize outcome and minimize therapy. Multi-agent chemotherapy plus radiation is risk-adapted therapy for favorable-risk Hodgkin’s lymphoma. A newer trend is response-adapted therapy, which refers to treatment that is tailored according to the initial response.
The current study was a multi-institutional, phase 2 clinical trial that was conducted to evaluate response-adapted therapy by tailoring the treatment to the disease response—specifically, patients who achieved a complete response after 2 cycles of chemotherapy (instead of 4) would not receive radiation therapy. The study included 88 patients with stages I and II Hodgkin’s lymphoma. These patients had favorable-risk Hodgkin’s lymphoma and were assigned to receive 4 cycles of VAMP chemotherapy (vinblasatine, Adriamycin, methotrexate, and prednisone).
After 2 cycles of chemotherapy, 47 patients achieved a complete response and received no radiation therapy. The remaining 41 patients were given 25.5 Gy-involved-field radiotherapy. The primary outcome measure for the study was 2-year, event-free survival.
Overall, the 2-year, event-free survival was 90.8 percent. The 2-year, event-free survival for patients who achieved early complete response was 89.4 percent, compared to 92.5 percent for those who did not achieve early complete response and underwent radiotherapy. The estimated 5-year, event-free survival for patients who did not undergo radiation was 89.4 percent, compared to 87.5 percent for those who did.
The researchers concluded that among patients with favorable?risk Hodgkin lymphoma and a complete early response to chemotherapy, the use of limited radiotherapy resulted in a high rate of 2-year, event-free survival.
While it will be important to confirm these results in larger studies, this response-adapted treatment regimen could mean a safer cure for favorable-risk Hodgkin’s lymphoma in kids and might result in fewer secondary cancers later in life.
Metzger ML, Weinstein HJ, Hudson MM, et al. Association between radiotherapy vs no radiotherapy based on early response to VAMP chemotherapy and survival among children with favorable-risk hodgkin lymphoma. Journal of the American Medical Association. 2012; 307(24): 2609-2616.