In an international study of lung cancer after Hodgkin lymphoma (HL), dose to the specific location in the lung where cancer developed was estimated. Quantitative data on both chemotherapy and tobacco use were obtained from medical records. The estimated excess relative risk (ERR) of lung cancer per Gy was 0.15 (95% CI: 0.06-0.39). There was an interaction between radiation and chemotherapy and between radiation and smoking.
A study of breast cancer following radiotherapy for HL found that a radiation dose of 4 Gy or more delivered to the breast was associated with a 3.2-fold increased risk, compared with the risk in patients who received lower doses and no alkylating agents. Increased risks persisted for 25 or more years following radiotherapy. Treatment with alkylating agents alone resulted in a reduced risk of breast cancer, and combined alkylating agents and radiotherapy in a slightly increased risk. The high radiation-related risk, which did not diminish at the highest doses or the longest follow-up, suggests the need for lifetime surveillance and programs of patient and public awareness.
The cumulative absolute risk of breast cancer following HL was computed, using modified standardized incidence ratios to relate cohort breast cancer risks to those in the general population, enabling application of population-based breast cancer rates, and allowing for competing risks mortality rates in female HL survivors. Breast cancer projections varied considerably by type of HL therapy, time since HL diagnosis, and age at end of follow-up. These estimates are applicable to HL survivors treated with regimens of the past and can be used to counsel such patients and plan management and preventive strategies. Projections should be used with caution, however, in patients treated with more recent approaches, including limited-field radiotherapy and/or ovary-sparing chemotherapy.
The risk of developing acute myeloid leukemia (AML) after treatment for Hodgkin lymphoma (HL) has decreased over the last three decades. To determine whether patients treated after 1984 have decreased risks for AML, the researchers analyzed data on more than 35,000 1-year Hodgkin lymphoma survivors who were reported to population-based cancer registries in North America and in Nordic countries between 1970 and 2001. The risks were higher for patients over age 35 at the time of their HL treatment, and if that treatment occurred between 1970 and 1984 (versus 1985-2001). The decline over time in the risk of secondary AML was particularly apparent among HL survivors who initially received any chemotherapy. The analysis showed that excess absolute risk for secondary AML was highest during the first 10 years after HL diagnosis but remained elevated thereafter.