SAN FRANCISCO -- Persons treated for Hodgkin's disease in childhood are at high risk for developing a second malignancy and should be monitored closely by their physicians throughout their lifetime, researchers at the University at Buffalo and Roswell Park Cancer Institute (RPCI) have shown.
Results of two studies on this issue were presented on May 2, 1999 at the annual meeting of the Society for Pediatric Research.
The findings showed that persons treated for Hodgkin's Disease as children were at nine times the risk of developing a second cancer, with risks of developing certain types of cancer much higher than that, compared to patients without Hodgkin's disease.
The risk of developing thyroid cancer in males was especially high -- 164 times that of controls.
"These are big relative risks," said Daniel M. Green, M.D., UB professor of pediatrics, a specialist in pediatric oncology at RPCI and senior researcher on the studies. "These studies should alert physicians to the need for careful and continuing screening at a much earlier age than the American Cancer Society recommends for the population at large."
The studies involved 182 patients treated at RPCI for Hodgkin's disease between 1960 and 1989. All were less than 20 years old when their disease was diagnosed. By the time they were 30, 27 percent of the patients had developed at least one second cancer, excluding skin cancer. A second study reported on incidence of skin cancer only.
The relative risks for developing one of the more prevalent second cancers were found to be nine times greater than for persons without Hodgkin's disease in both males and females. The relative risk for thyroid cancer was 164 times greater for males and 39 times greater for females; for breast cancer, eight times greater for females; for non-Hodgkin's lymphoma, 15 times greater for males and 23 times greater for females; and leukemia, 19 times greater for males and 25 times greater for females.
"With higher survival rates for Hodgkin's disease, we are going to see more second cancers down the road," said Julie A. Reynolds, M.D., pediatric resident at The Children's Hospital of Buffalo and first author on the study. "We need to look at the data to see the influence of various treatments, and to educate the patient about the need for screening." No one treatment was found to have a significant effect on second-cancer risk.
In the study on basal cell carcinoma alone, headed by Green, findings showed that the most important variable was combined treatment with radiation and chemotherapy.
Of patients who received radiation therapy alone, 3 percent developed skin cancer by the age of 14, and 5.6 percent of patients who received combined therapy developed skin cancer by the time they were 20.
"Children and adolescents who have been treated successfully for Hodgkin's disease should be told about their risk of developing non-melanoma skin cancer, and should receive thorough examinations of the skin and be well-schooled regarding safe sun exposure," Green said.
Additional researchers on the studies were Maurice P. Barcos, M.D., Ph.D., and Michael Zevon, Ph.D., both of UB and RPCI; and R. Jeffrey Lee, M.D., and Brenda C. Hall, pediatric nurse practitioner in oncology, both of RPCI.