The pattern of prognostic indicators among women with breast cancer undergoing modified radical mastectomy at Muhimbili National Hospital (MNH) and Tumaini hospital, Dar es salaam Tanzania

Abstract

Background: Breast cancer represents the most common cancer in women in the world. It is the second most common malignancy among females in sub-Saharan African countries including Tanzania, the leading cancer being that of uterine cervix. Worldwide, the incidence of breast cancer is 1, 000,000 cases per year and causes approximately 373,000 deaths yearly. Prognostic indicators in breast cancer have been found to influence use of adjuvant therapy following mastectomy by predicting patients with risks on survival and recurrence. In Tanzania, data on prognostic indicators is lacking. The main objective of the study was to determine the pattern of prognostic indicators among women with breast cancer undergoing modified radical mastectomy (MRM) at Muhimbili National Hospital and Tumaini Hospital, Dar es Salaam. Methodology: A hospital-based prospective cross-sectional study was carried out that included female patients undergoing MRM from April 2011 to January 2012 with calculated minimum sample size of 84 patients. Patients with clinical stage I-III disease were enrolled in the study after being scheduled for mastectomy. Patients with evidence of distant metastasis after a chest x-ray and abdomino-pelvic ultrasound i.e. stage IV were excluded. The surgical specimen consisting of mastectomy tissue and axillary lymphnodes was submitted to the histopathology laboratory to determine grade, type, nodal status and margins status. Data collection was done using a structured questionnaire and analyzed using SPSS software. Results: During 10 months of study, 348 patients were admitted with breast cancer. Eighty six (86) patients met the inclusion criteria to the study. Age at diagnosis was 28-79yrs with mean age of 52.08years. Ten percent (10.6%) were ≤35years, 55% were 36 -55 years and 33.1% were above 55years. Eighty nine percent (89%) of study population attained menarche above the age of 11yrs, with mean age of 14.3years. About fifty six percent (56%) were postmenopausal with 22.9% attaining menopause at the age of 55yrs or more. Majority (78%) were multipara and only 7.1% nulliparous. ix Most (87.3%) of them had their first live birth below the age of 30years. Family history of breast cancer was reported in 14.1% of patients and 37.6% reported use of hormonal contraceptives. Among the study population, 5.9% were smokers and 27.1% were social alcohol drinkers. Most of our patients (61%) had T4b disease, 75.6% had positive axillary nodes where 42.7% had 4-9 (N2 disease).The commonest histological type was invasive ductal carcinoma (91.9%). Lobular carcinoma, medullary and mucinous carcinoma together accounted for only 8.1%. Eighty three percent (83.7%) of our patients presented with stage III, 16.3% with stage II disease, and none at stage I. The intermediate and high grade tumor accounted for 73.5%. Twenty five percent (25%) of our patients had positive surgical margins with 25% positive base following MRM. Conclusion: Most breast cancer patients treated surgically at MNH present with a stage III disease and have been shown to have unfavorable prognostic indicators. The presentation is of primary tumor size with skin infiltration, positive axillary lymph nodes and a risky histological grade i.e. intermediate and high grade. Despite locally advanced disease the majority have negative surgical margins following modified radical mastectomy. Recommendation: A sustainable screening program to diagnose patients at early stage of disease is mandatory. Public education on breast self examination is required to involve women in early diagnosis of disease. A follow up study is needed to determine how these patients fare after treatment to allow individualized type of management.