Survivors of childhood Hodgkin lymphoma face ongoing risk for solid cancers
Adults who survived childhood Hodgkin lymphoma have a continued risk for subsequent malignant neoplasms, according to findings published in Cancer.
Researchers observed particularly elevated risks by age 50 years for breast, lung, colorectal and thyroid cancers among high-risk subgroups.
“These findings support the need for continued surveillance of patients with Hodgkin lymphoma, regardless of the era in which they were treated,” Smita Bhatia, MD, MPH, professor and vice chair of outcomes for pediatrics and director of the school of medicine institute for cancer outcomes at University of Alabama at Birmingham, and a HemOnc Today Editorial Board Member, and colleagues wrote.
“... In this large cohort of patients diagnosed with childhood Hodgkin lymphoma and followed for more than 25 years, we identified subgroups of patients with Hodgkin lymphoma at highest risk of developing specific solid subsequent malignant neoplasms,” they added. “The results of the current study also provide evidence for screening parameters in these high-risk subgroups, both with respect to Hodgkin lymphoma diagnosis as well as the attained age of the survivor of Hodgkin lymphoma.”
Because survivors of pediatric Hodgkin lymphoma face an increased risk for subsequent malignant neoplasms, Bhatia and colleagues conducted an extended follow-up of the Late Effects Study Group — initiated in 1979 as a multinational group of children diagnosed with Hodgkin lymphoma and other cancers between 1955 and 1979 when aged 16 years or younger —to identify patients at highest risk to support risk-based screening recommendations.
As only one hematologic malignancy had been reported since a prior update, the current update mainly analyzed solid secondary malignancies.
Researchers determined risk for solid subsequent malignant neoplasms by comparing the number of person-years at risk under observation with standardized incidence ratios they calculated based on SEER rates.
Median follow-up was 26.6 years.
The analysis included 1,136 patients diagnosed with Hodgkin lymphoma when aged younger than 17 years (median age, 11 years; range, birth-16) who the researchers followed for 23,212 person-years after diagnosis.
Of these patients, 162 developed 196 solid subsequent malignant neoplasms, including 54 patients with breast cancer, 34 with basal cell carcinoma, 30 with thyroid cancer, 15 with colorectal cancer, 11 with lung cancer and 40 with other malignancies.
Researchers calculated a cumulative incidence of any solid subsequent malignant neoplasm of 26.4% (95% CI, 22.4-30.5) at 40 years after Hodgkin lymphoma diagnosis and 27.2% (95% CI, 23.2-31.5) at 50 years after diagnosis.
Compared with the general population, the study group appeared to be at 14 times (SIR = 14; 95% CI, 12-16.3) the risk for developing a solid subsequent malignant neoplasm.
Results of a multivariable analysis showed an increased risk for solid subsequent malignant neoplasm among women (HR = 1.8; 95% CI, 1.3-2.5) and after radiation (HR = 4.8; 95% CI, 1.8-19.7).
Researchers then sought to define high-risk groups. They found that females diagnosed with Hodgkin lymphoma when aged 10 to 16 years (HR = 9; 95% CI, 2.8-55.4) and who were treated with chest radiotherapy (HR = 5; 95% CI, 1.5-30.7) were at the greatest risk for subsequent breast cancer; males who underwent chest radiotherapy at age 10 years or younger had the highest risk for lung cancer; those who received high-dose alkylating agents (HR = 5.1; 95% CI, 1.3-33.6) or abdominal/pelvic radiotherapy (HR = 3.6; 95% CI, 1.1-16.1) were at increased risk for colorectal cancer; and females (HR = 2.1; 95% CI, 1-4.4) and those treated when aged younger than 10 years (HR = 3; 95% CI, 1.4-6.7) were at greatest risk for thyroid cancer.
In these specific high-risk subgroups, cumulative incidence rates by age 50 years were 45.3% for breast cancer, 4.2% for lung cancer, 9.5% for colorectal cancer and 17.3% for thyroid cancer.
“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,” Bhatia said in a press release. “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.”– by Jennifer Byrne
Disclosures : The authors report no relevant financial disclosures.