ABSTRACT

Breast cancer is the commonest site specific, malignancy affecting women and the most common cause of cancer mortality in women world wide. Our knowledge about breast cancer is evolving but it is still limited with respect to its etiology and biology and with respect to its features in individual countries and cultures.

The study was conducted to identify and determine the risk factors for breast cancer in a Tertiary hospital in Nigeria. A retrospective case control study was carried out in National Hospital Abuja. A total of 544samples were used in the work comprising of 272 cases and 272 controls . The data was obtained directly from patients case file. Information obtained were; Sex, Occupation, Weight, Height, Parity, Age, Religion, Marital Status, Smoking, Family history of breast cancer, Alcohol consumption, Menarche and Oral Contraceptive history. The data was entered and analyzed using SPSS 15 version. The P value accepted as significant was set at P < 0 .05 at 95% confidence level. Test statistics performed

were chi-square (x2) and odds ratio (OR) in order to obtain the association as well as level of risk of a given risk factor.

Females constituted 521 (95.8%) of the study population while males were 23(4.2%). Patients age ranged between 25-74 years with age groups 35-44 and 45-54 years constituting the highest frequencies of 158 (29.4%) and 160 (29.8%) respectively. Those who had early menarche were 257(51.1%) while normal menarche were 246 (48.9%). Population of women who used oral contraceptives were 110 (21.8%) while those who did not use were 395 (78.2%). Parity among

patients ranged between 0-10 children with those having 1-5 children having the highest frequency of 361 (72.8%). 264 (49.1%) of the patients consumed alcohol while 274 (50.9%) did not consume alcohol. Mother 60 (40.0%) and Sister 37 (24.7%) had the highest frequency for patient with family history. Civil servant 229 (43.5%) had the highest frequency for occupation of patients in the study. This was followed by those doing business 120 (22.8%). Housewives 96 (18.3%) Retiree 49 (9.3%) Student 18 (3.4%) and Farmers 14 (2.7%). 25 (4.6) of the patients smoked while 515 (95.4%) did not smoke. 47 (32.2%) of the patient were underweight while 99 (67.8%) were over weight. 459 (84.7%) of patients were Christians while 83 (15.3%) were practicing Islam. Finally 447 (82.9%) were married while 56(10.4%) were single and widows were 36 (6.7%) in the study.

In conclusion, Gender, Age, Parity, Early menarche, Use of oral contraceptives, Alcohol consumption, Occupation and family history of patients with breast cancer were identified as risk factors for breast cancer as well as had significant association for development of breast cancer. Smoking, Religion, Marital status and BMI of patients were not identified as risk factors for developing breast cancer in the study.

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CHAPTER ONE

1.0 INTRODUCTION

Breast Cancer constitutes a major public health issue globally with over 1 million new cases diagnosed annually, resulting in over 400,000 annual deaths and about 4.4 million women living with the disease. It is the commonest site specific malignancy affecting women and the most common cause of cancer mortality in

women worldwide.1,2

In Africa, Breast Cancer has overtaken cervical cancer as the commonest

malignancy affecting women and the incidence rates appear to be rising. 3,4 In Nigeria for example, incidence rate has increased from 13.8–15.3 per 100,000 in

the 1980s, to 33.6 per 100,000 in 1992 and 116 per 100,000 in 2001.5These increases in incidence are due to changes in the demography, socio-economic parameters, epidemiologic risk factors, better reporting and awareness of the disease.

There is an international/geographical variation in the incidence of Breast Cancer. Incidence rates are higher in the developed countries than in the developing countries and Japan. Incidence rates are also higher in urban areas than in the rural areas. While mortality rates are declining in the developed world (Americas, Australia and Western Europe) as a result of early diagnosis, screening, and improved cancer treatment programs, the converse is true in the developing world

as well as in eastern and central Europe 6,7

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Breast cancer and its treatment constitute a great physical, psychosocial and economic challenge in resource limited societies as found in Africa. The hallmark of the disease in Africa are patients presenting at advanced stage, lack of adequate mammography screening programs, preponderance of younger pre-menopausal

patients, and a high morbidity and mortality. 3,6

Pregnancy associated breast cancer is defined as breast cancer diagnosed during pregnancy or lactation or one year post partum. Breast cancer and pregnancy can be classified into three main situations; these are: breast cancer that is detected during the evolution of pregnancy; breast cancer that is detected during lactation or postpartum, and pregnancy in patients who have had a previous breast cancer. Cancer complicates approximately 1 per 1000 pregnancies and accounts for one-third of maternal deaths during gestation. The prevalence of breast cancer during pregnancy is increasing due to delayed onset of childbearing. Breast cancer is diagnosed in approximately 1 in 3000 pregnancies. The incidence ranges from 0.76% to 3.8% of breast cancer cases. The median age of pregnant women affected with breast cancer is 33 years. In a recent review in Nigeria, 12% of the patients with Breast Cancer were pregnant or lactating and 74% were premenopausal, making it the most frequently occurring malignancy during

pregnancy, along with cancer of the uterine cervix.5

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