An affair of the heart.

In 1950, patients with Hodgkin lymphoma had a median survival time of 4 years and a 5-year relative survival rate of 29% (1). Since the introduction of radiation therapy and chemotherapy for Hodgkin lymphoma in the 1960s and 1970s, the 5-year relative survival rate is more than 85% (2), and these patients can now expect a long lymphoma-free life. However, the price for this phenomenal success has been high. " Radiation-induced heart disease " was recognized in the 1960s (3) and radiation-induced cancers somewhat later (4 – 6). Multidrug chemotherapy was introduced in the 1970s (i.e., combination chemotherapy with mechlorethamine, vincristine, procarbazine, and prednisone) (7); however, one of these drugs, nitrogen mustard (mechlorethamine), appeared to carry a high risk of leukemia (8). Over the years, other drug combinations that were equally effective but less leuke mogenic were introduced, such as doxorubicin, bleomycin, vinblastine, and dacarbazine. Unfortunately, the anthracycline doxorubicin carried an increased risk of cardiac toxicity (9). In a sense, one type of late effect, leukemia, was being replaced by another, heart disease. Although the risk of new malignancies among Hodgkin lymphoma patients has been well studied and the relationship between the development of a subsequent cancer and radiation dose to specifi c organs characterized (4 – 6 , 10), it is only relatively recently that large studies have attempted to quantify the risk of late cardiac toxicity among these patients. In this issue of the Journal, Swerdlow et al. (11) provide important new information on the risk of dying from myocardial infarction following curative treatment for Hodgkin lymphoma. They report that among 7033 patients who were treated from 1967 through 2000 (median follow up of 9.9 years), 166 deaths from myocardial infarction occurred, and the increased risk of death from myocardial infarc-tion remained high for at least 25 years after fi rst treatment. The overall standardized mortality ratio (SMR) was 2.5, and the absolute excess risk was approximately 0.13% per year (125.8 per 100 000 person-years). On a relative scale, the risk of death from myocardial infarction was highest among patients who were younger than 25 years at fi rst treatment and within the fi rst year of treatment. On an absolute scale, however, risk was highest among patients who were older than 45 years at fi rst treatment because of the higher rates of heart disease that occur at older ages. The high risks associated with mediastinal radiotherapy …