Abstract P5-13-06: Seasonal variation in onset of inflammatory breast cancer: Evidence of an infectious trigger

Abstract

Abstract Introduction: Inflammatory breast cancer (IBC) is a rare but extraordinarily aggressive disease with a number of studies indicating that environmental factors play the most important role. We have identified four reported clusters of IBC and our investigations thus far suggest that local toxic or infectious agents could be involved in the pathogenesis of the disease. IBC, like Burkitt's lymphoma (BL) has been reported to cluster and both have been implicated with infectious agents. Since BL has been reported to have a seasonal variation attributed to acute malaria symptoms as the precipitating agent, we decided to investigate the seasonality of IBC in two populations. Methods: For our analysis we used the datasets of two IBC referral groups. The first group consisted of a series of 163 consecutive cases of patients seen at Fox Chase Cancer Center (FCCC) almost all being from the Northeast U.S. (NE) and Canada. At the time of initial visit a detailed series of questions was specifically directed at identifying the accurate time of the first onset of symptoms/signs including skin rash, swelling, pain, nipple retraction and palpable mass. The second was the IBC registry (IBCR), established at the George Washington University with the purpose of collecting standardized clinical and epidemiologic data (including a detailed interview) and biospecimens from patients with IBC in the U.S and Canada. Complete data on patients in both groups were evaluated, including diagnostic workup, pathologic findings and treatment. Results: Of the 163 FCCC patients, 156 had the month of onset of symptoms clearly delineated. Of the 161 patients in the IBCR, 153 had month of symptomatic onset defined. In the combined groups, 181 NE patients were compared with 63 from the South. A seasonal pattern was noted in the NE patients, a bimodal pattern showing most patients with onset in March and July-Sept. No seasonal pattern was noted in patients from the South. Conclusion: The reports of IBC clusters are consistent with an acute triggering factor, possibly an infection. The seasonality we observed in NE patients but not in southern patients is consistent with this hypothesis. We are currently continuing to investigate clusters of IBC and are testing for specific candidate infectious agents as well as candidate environmental toxic agents to further understand possible triggers for this disease. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-13-06.