Abstract Objectives: Inflammatory Breast Cancer (IBC) is a rapidly developing and very lethal form of breast cancer. IBC is relatively rare in the US, accounting for only 1-2% of all breast cancer cases. It is associated with a much lower 3-year survival rate as well as a younger mean age of onset than non-IBC, with higher incidence and younger mean age in African American women than Whites. Though little research has been conducted on IBC internationally, a few studies have reported a higher frequency and a more aggressive form of the disease in Egypt, Tunisia, and Morocco. No information is available about breast cancer or IBC in native Sub-Saharan African populations. The purpose of this study was to describe the clinical and reproductive factors of breast cancer and to determine the proportion of IBC in Tanzania. The study also aimed at investigating pathological and molecular features of breast tumors, such as the presence of dermal lymphatics and overexpression of RhoC and E-Cadherin. Methods: Data was abstracted from the medical records of all breast cancer patients attending Ocean Road Cancer Institute (ORCI) in Dar Es Salaam, Tanzania for a 2-year period from July 2007 to June 2009. Tumor tissue samples were collected for those patients with symptoms suggestive of IBC as well as for non-IBC patients. Slides were cut from each paraffin block and one from each set was H & E stained. Results: Preliminary results of 223 breast cancer cases show that the average age at diagnosis is lower than that in the US at approximately 48 years (std. dev≈12) and that the average duration of symptoms is greater than 1 year. The majority of the clinical TNM diagnoses fall into the T4 category, with less than 3% diagnosed as T4d (IBC) clinically at some point in the record. Greater than 50% of cases are diagnosed as ductal carcinoma of the breast. The defining symptoms of IBC, erythema, edema, and peau d'orange, account for a minority of symptoms recorded and it is even rarer for a single patient to have all three symptoms present. 71 cases were analyzed for ER/PR status of which 53% were ER negative and 59% were PR negative. 88% of those that were ER positive were also PR positive. Conclusions: The proportion of IBC in Tanzania is not high and most cases are diagnosed at advanced disease stages. ER/PR results suggest that hormonal therapy would be valuable to approximately half of breast cancer cases. The descriptive and molecular analysis conducted could provide valuable insight into IBC both internationally and in the US as there are no standard histopathological diagnostic criteria to date. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5744.