Clinical and pathologic features of breast cancers in women treated for Hodgkin's disease: a case-control study

The goal of this study was to assess whether there are clinical or pathologic differences between radiation-associated breast cancers developing after treatment for Hodgkin's disease and spontaneously arising breast cancers. Clinical and pathologic data were reviewed for 26 Hodgkin's disease patients who received irradiation and subsequently developed breast cancer (cases) and 26 age- and stage-matched patients with sporadic breast cancers (controls). The median age at diagnosis of Hodgkin's disease was 21 years (range 11-40 years), and the median interval between Hodgkin's disease and breast cancer diagnosis was 15 years (range 4-27 years). There were no differences between cases and controls with regard to clinical factors. Cases had a lower frequency of histologic grade III tumors (38% versus 65%, p = 0.09) and moderate to marked mononuclear inflammatory cell reaction (11% versus 35%, p = 0.03). When these covariates were combined, grade III tumors in conjunction with mononuclear inflammatory cell reaction were also seen less frequently in the case group than in the control group (11% versus 31%, p = 0.06). Seven cases developed additional cancers, but no additional cancers developed in the control group (p = 0.01). Patients who developed breast cancers after Hodgkin's disease did not differ from patients with spontaneous breast cancers, with regard to clinical factors. However, the lower frequency of high-grade tumors and moderate to marked mononuclear inflammatory cell reaction among the cases suggests that radiation-associated breast cancers may differ from spontaneously arising cancers in their pathogenesis. Cases appeared to be at increased risk of developing additional cancers, but we cannot exclude surveillance as a possible contributing factor.