ABSTRACT
Background: Breast cancer is the most common malignancy in women in Nigeria. Women previously treated for ipsilateral breast cancer have increased risk of developing contalateral breast cancer (CBC); the chance of which increases with longer period of survival and is associated with worse prognosis. Reports from Nigeria are few on this. The aim of this study was to assess the prevalence; predisposition; presentation; and outcome of management of bilateral breast cancer (BBC) in a population; South-western Nigeria.Methods: A review of bio-data of all patients with BBC seen in LTH; Osogbo; Nigeria between 2001 and 2008 was done. Age; parity; age at menarche and first child birth; family history; duration of symptoms; tumour characteristics and exposure to cigarette; oral contraceptive pills (O.C Pills) and outcome of treatment were also assessed.Results: BBC constituted 4.6of the 256 breast cancer patients. Eight (73) were metachronous and 91were infiltrating ductal carcinoma. Patients' mean age; mean age at menarche and first child birth were 39; 14.5+3 and 22.5yrs respectively. Mean parity was 3.5 child birth; 91were premenopausal and all have menstruated for 12-31yrs. None had positive family history while only 1 and 3 had insignificant exposure to cigarette and O.C pills respectively. The mean interval between the 2 onsets was 18mths (0-68mths). 91of all tumours were advance; while 81of the first tumours were on the right. Mean duration before presentation for the first and second tumours were 261 and 111 days respectively. One patient has survived for 2 years thus far.Conclusion: The incidence of BBC was 4.26. Most patients were young and premenopausal with mostly infiltrating ductal carcinoma (NOS) and presenting with late stage disease; hence poor prognosis. Aggressive follow-up of patients with ipsilateral cancer will aid early detection of CBC