Women who develop breast cancer after having had Hodgkin's lymphoma are more likely than other breast cancer patients to have bilateral disease and to die from other causes, say researchers from Memorial Sloan-Kettering Cancer Center in New York City, New York in a study report published in the May 16 online edition of the Journal of Clinical Oncology.
"Our results are mostly relevant to patients treated for Hodgkin's lymphoma in the era when radiation therapy alone was the dominant form of curative therapy and was used with high radiation doses that almost always included both breasts and the heart," the researchers explain, referring to the "radical radiotherapy" received by patients 30 to 50 years ago. "However, our findings are informative for the thousands of Hodgkin's lymphoma survivors who remain at risk of long-term complications from their original treatment.”
In conducting the study, Joachim Yahalom, MD and his colleagues compared the characteristics and outcomes of breast cancer in 253 women with a history of radiation therapy for Hodgkin's lymphoma and 741 women with sporadic breast cancer and no history of Hodgkin's lymphoma matched by age, race, and year of breast cancer diagnosis. Subjects in the former group were more likely to have their breast cancer detected by screening mammography (40% versus 33% for sporadic cancers), more likely to be diagnosed with early-stage disease (61% versus 42%), and less likely to have axillary lymph node involvement (25% versus 39%).
However, the researchers found, women who developed breast cancer after Hodgkin's lymphoma were three times as likely to have bilateral disease (6% versus 2% for sporadic cancers), less than half as likely to have a lumpectomy (23% versus 55%), and far less likely to receive radiation as part of their breast cancer treatment (8% versus 61%).
Additionally, event-free breast cancer survival and breast cancer-specific survival rates proved similar for women in the Hodgkin's lymphoma and sporadic breast cancer groups. However, the Hodgkin's lymphoma survivors were more than four times likelier to develop metachronous contralateral tumors. Women with breast cancer after Hodgkin's lymphoma were nearly twice as likely to die as a result of any cause, compared with sporadic breast cancer patients, even after adjusting for patient and disease characteristics and breast cancer treatment. Overall, women in whom breast cancer had been detected by screening were only half as likely to die as women whose breast cancer had been self-detected or found by clinicians.