Unfortunately, cancer survivors have to be mindful that their cancer has a possibility of returning. Childhood survivors of Hodgkin lymphoma are no exception; they have an increased risk of developing subsequent malignant neoplasms (SMNs).
In order to better understand this risk, researchers from the University of Alabama at Birmingham revisited a study that had enrolled 1,136 patients diagnosed with Hodgkin lymphoma prior to age 17 between 1955 and 1986, following them for a median of 26.6 years.
The researchers identified 196 solid SMNs that had occurred in 162 patients during the follow-up period. They found that childhood Hodgkin lymphoma survivors had a 14-fold increased risk of developing a SMN compared with the general population. Forty years after a diagnosis of Hodgkin lymphoma, the incidence of developing solid SMNs was 26.4%. In this group, radiotherapy significantly increased the risk of developing certain types of cancers, with cancer type varying according to the site of therapy. For example, female patients who received chest radiotherapy for a Hodgkin lymphoma diagnosis between the ages of 10 and 16 had an increased risk of developing breast cancer, whereas male patients diagnosed with Hodgkin lymphoma under the age of 10 who received chest radiotherapy had an increased risk of lung cancer. In addition, female patients with Hodgkin lymphoma diagnosed under age 10 who received neck radiotherapy had the highest risk of thyroid cancer. All survivors of childhood Hodgkin lymphoma who received high-dose alkylating agents and radiotherapy in the abdominal/pelvic area were at increased risk for colon cancer. Overall, the incidence of breast, lung, colon, and thyroid cancer in childhood Hodgkin lymphoma survivors was 45.3%, 4.2%, 9.5%, and 17.3%, respectively.
"This large, multi-institutional, international cohort of childhood Hodgkin lymphoma allowed us to determine the risk of new solid cancers such as breast cancer, colorectal cancer, and thyroid cancer," remarked the study's senior author, Smita Bhatia, MD, MPH, Director of the School of Medicine Institute for Cancer Outcomes and Survivorship of the University of Alabama at Birmingham. "More importantly, we were able to use host and clinical characteristics to identify subgroups of Hodgkin lymphoma survivors who were particularly vulnerable to developing these new cancers."
Commented Allison Thompson-Graves, MD, one of the authors of the study, "As a physician and a childhood Hodgkin lymphoma survivor who developed radiation-related breast cancer 34 years after treatment, I cannot emphasize enough the importance of these data for the long-term care of survivors, as they not only underscore the necessity of lifelong cancer screening in that population, but also provide a stratification of risk for specific malignancies within subgroups, allowing for a more targeted approach to screening."
Hopefully, these results will provide physicians with motivation to continue screening cancer survivors for various malignancies long after remission is achieved.
For More Information
Holmqvist AS, Chen Y, Teh JB, et al (2018). Risk of solid subsequent malignant neoplasms after childhood Hodgkin lymphoma—identification of high-risk populations to guide surveillance: a report from the Late Effects Study Group. Cancer. [Epub ahead of print] DOI:10.1002/cncr.31807
Image courtesy of Joel Mills