Photo by Rhoda Baer
Young adult with cancer receiving chemotherapy
A new study suggests Hodgkin lymphoma (HL) survivors have a high risk of developing a second malignancy, particularly if they have a family history of that malignancy.
The research showed that HL survivors in Sweden were roughly 2.4 times more likely than individuals in the country’s general population to develop a second cancer.
The risk for HL survivors remained high 30 years after treatment, and the risk was even greater in HL survivors who had a family history of specific cancers.
“The vast majority of patients with Hodgkin lymphoma are cured with a combination of chemotherapy and radiotherapy,” said study author Amit Sud, MBChB, of The Institute of Cancer Research, London in the UK.
“Our research has shown that these patients are at substantially increased risk of a second cancer later in life and particularly if they have a family history of cancer.”
Dr Sud and his colleagues described this research in the Journal of Clinical Oncology.
The team analyzed data from the Swedish Family-Cancer Project Database. They identified 9522 HL patients diagnosed between 1965 and 2013. During a median follow-up of 12.6 years, there were 1215 second cancers in 1121 HL patients (12%).
Compared to the general population, the HL patients had a significantly higher risk of all second malignancies, with a standardized incident ratio (SIR) of 2.39 and an absolute excess risk of 71.2 cases per 10,000 person-years.
Cancer types
HL patients had a significantly increased risk of several malignancies. The overall SIRs were as follows:
- NHL—7.99
- Leukemia—6.46
- Connective tissue cancer—5.73
- Thyroid cancer—5.13
- Squamous cell carcinoma—4.44
- Lung cancer—3.61
- Pharyngeal cancer—3.52
- Esophageal cancer—2.62
- Brain cancer—2.58
- Breast cancer—2.52
- Colon cancer—2.21
- Pancreatic cancer—2.09
- Melanoma—2.08
- Colorectal cancer—1.85
- Stomach cancer—1.78
- Bladder cancer—1.57
- Prostate cancer—1.21.
The researchers calculated SIRs over time and found the risk for many of the cancers remained high over 30 years following HL treatment.
Family history
The researchers identified 28,277 first-degree relatives of the HL survivors. Thirty percent of HL survivors (n=2785) had 1 or more first-degree relatives with a family history of cancer.
The SIR for cancers was 1.02 in the relatives. The SIR for second cancers was 2.83 for HL survivors who had first-degree relatives with cancer and 2.16 for HL survivors who did not have any first-degree relatives with cancer.
The researchers said the increased risk of second malignancy was correlated with the number of first-degree relatives with cancer.
The SIR was 2.67 for HL patients who had a single first-degree relative with cancer and 3.40 for HL patients who had 2 or more first-degree relatives with cancer.
The SIRs for different cancer types (for HL patients with at least 1 first-degree relative with cancer and no first-degree relatives with cancer, respectively) were as follows:
- NHL—14.43 vs 7.83
- Leukemia—14.31 vs 6.37
- Squamous cell carcinoma—10.85 vs 4.30
- Lung cancer—11.24 vs 3.39
- Breast cancer—4.36 vs 2.36
- Colorectal cancer—3.71 vs 1.76.
Sex and age
The researchers found significant differences in the SIRs for second cancers between HL patients diagnosed before the age of 35 and those diagnosed after age 35.
For men, the SIRs were:
- All cancers—4.26 for <35, 2.08 for ≥ 35
- Colorectal cancer—4.07 for < 35, 1.73 for ≥35
- Lung cancer—6.16 for < 35, 3.20 for ≥35
- Breast cancer—12.60 for < 35, 4.58 for ≥35
- Squamous cell carcinoma—5.89 for < 35, 3.96 for ≥35
- NHL—15.9 for < 35, 6.93 for ≥35
- Leukemia—12.15 for < 35, 5.57 for ≥35.
For women, the SIRs were:
- All cancers—4.61 for <35, 1.73 for ≥ 35
- Colorectal cancer—1.31 for < 35, 1.65 for ≥35
- Lung cancer—8.84 for < 35, 2.50 for ≥35
- Breast cancer—6.00 for < 35, 1.14 for ≥35
- Squamous cell carcinoma—6.37 for < 35, 4.87 for ≥35
- NHL—6.23 for < 35, 6.55 for ≥35
- Leukemia—10.36 for < 35, 4.51 for ≥35.
“Younger women who have been treated with radiotherapy to the chest for Hodgkin lymphoma are already screened for breast cancer, but our study suggests that we should be looking at ways of monitoring survivors for other forms of cancer too, and potentially offering preventative interventions,” Dr Sud said.
“After patients are cured, they no longer encounter oncologists, so it’s important that other healthcare providers are aware of the increased risk to Hodgkin lymphoma survivors to improve early diagnosis of second cancers.”
