Are risk factors for breast cancer similar in women with inflammatory breast cancer and in those with non-inflammatory breast cancer?

PURPOSE: The aim of the study was to compare reproductive factors in patients with inflammatory breast cancer (IBC), and with non-inflammatory breast cancer (non-IBC). The study was performed in two centers: one French including 49 IBC patients and 140 non-IBC and another Tunisian including 97 IBC and 139 non-IBC. Unconditional logistic regression was used for the analyses. PATIENTS AND METHODS: The French IBC patients had a lower educational level, a higher body mass index and a longer cumulative duration of breast-feeding, and they included a greater proportion of non-European women, than the non-IBC patients. In the multivariate analysis, only breast-feeding duration remained associated with the IBC status (P=10(-3)). These results could not be verified in the Tunisian series, because the duration of breast-feeding was unavailable in this center. RESULTS: This study suggests that the etiology of IBC might be different of that of non-IBC.

Dermal lymphatic emboli in inflammatory and noninflammatory breast cancer: a French-Tunisian joint study in 337 patients.

BACKGROUND: We studied whether dermal lymphatic emboli (DLE) add independent prognostic information to the clinical definition of inflammatory breast cancer (IBC). PATIENTS AND METHODS: The study was performed in 2 centers, one each in France and Tunisia. For every patient with IBC, 1-3 patients with noninflammatory breast cancer (non-IBC) were included. All patients were to have a surgical tumor biopsy, including a sample of the skin surrounding the tumor. The endpoint was the risk of a relapse at 2 years, which was estimated using univariate and multivariate Cox models. RESULTS: Three hundred thirty-seven patients were included (150 in France and 187 in Tunisia). The IBC status was divided into 2 clinical categories according to the extent of inflammation in the breast (localized IBC, which was defined as clinical inflammation in the tumor area, vs. diffuse IBC, which was defined as inflammation of at least two thirds of the breast). In total, 57 patients presented with localized IBC, 71 with diffuse IBC, and 209 with non-IBC. Dermal lymphatic emboli were found in 7% of non-IBC cases, in 25% of localized IBC cases, and in 45% of diffuse IBC cases. We found a significant interaction between the presence of DLE and diffuse IBC (P = 0.01). In patients with diffuse IBC, the presence of DLE increased the risk of relapse 3-fold. Conversely, DLE were not associated with the risk of relapse in patients with non-IBC, nor in patients with localized IBC. In patients with diffuse IBC and no DLE, the risk of relapse was similar to that of patients with localized IBC. CONCLUSION: A DLE status might be a useful prognostic indicator exclusively in patients with diffuse IBC. However, because all patients with localized and diffuse IBC generally receive similar types of treatment, additional information on the presence or absence of DLE will not have an impact on treatment practice.