Background
Breast cancer is the most common cancer and the second principal cause of cancer deaths in women worldwide as well as in Nigeria [
1,
2]. The incidence of the disease appears to be rising faster in population groups that have hitherto enjoyed low incidence. The peak age of breast cancer in Nigerian women is about a decade earlier than Caucasians [
3‐
5]. For women with symptomatic breast cancer, prolonged delay, defined arbitrarily as an interval greater than 3 months from first detection to time of diagnosis and treatment has been shown to be associated with increased tumor size [
6,
7] and more advanced stage of disease [
7,
8] and with poor long-term survival [
6,
9]. An estimated 20–30% of Caucasian women wait for at least 3 months before seeking help for breast cancer symptoms [
10] compared with over 70% of Nigerian women presenting with advanced stages at which time little or no benefit is derived from any form of therapy [
3‐
5]; the 5-year survival of breast cancer in Nigeria is less than 10% [
3] compared with over 70% in Western Europe and North America. The recent fall in deaths from breast cancer in Western Nations is partly explained by earlier diagnosis as a result of early presentation. Understanding the factors that influence patient delay is a prerequisite for strategies to shorten delays [
11].
Although there is strong evidence suggesting that older women in the developed countries are more likely to delay their presentation with breast cancer, [
12], there is data suggesting that factors related to women's knowledge and beliefs about breast cancer and its management may contribute significantly to medical help-seeking behaviors [
13‐
15]. The three screening methods recommended for breast cancer includes breast self-examination (BSE), clinical breast examination (CBE), and mammography. Unlike CBE and mammography, which require hospital visit and specialized equipments and expertise, BSE is inexpensive and is carried out by women themselves. Several studies, based on breast cancer patient's retrospective self-report on their practices of the exam, have established that a positive association exists between performance of the exam and early detection of breast cancer [
16]. There is also evidence that most of the early breast tumors are self-discovered [
17] and that the majority of early self-discoveries are by BSE performers [
17].
Breast cancer presents most commonly as a painless breast lump and a smaller proportion with non-lump symptoms. For women to present early to hospital they need to be "breast aware"; they must be able to recognize symptoms of breast cancer through routine practice of practicable screening. At the present time, routine mammography cannot be recommended in developing countries due to financial constraints and the lack of accurate data on the burden of breast cancer in these countries. Few studies have examined the knowledge, attitude and practice of women towards breast cancer in Nigeria [
13,
18,
19]. These studies are often of small sample size and targeted women in special professions. We are unaware of any study that has examined these issues in community-dwelling women who constitute the majority of at risk women both for the disease and late presentation. This study recruiting 1000 community-dwelling women from an urban community in Nigeria was designed to evaluate the knowledge, attitude, and practice of these women towards breast cancer.
Methods
The study was designed to assess knowledge, attitude and practice towards breast cancer among 1000 community-dwelling women recruited from Egor local government area, a semi-urban community with a population of 229,681 comprising 115,550 males and 114,131 females in Edo State of Nigeria (1991 Population Census of Nigeria). Participants were recruited from randomly selected households using the 1991 National Population Census database listing of households in the local government area. For participants that declined participation, other households were randomly selected until the sample size of 1000 participants was achieved. University of Benin Research and Ethics Committee approved the study protocol and written informed consent was obtained from study participants prior to recruitment. Participants were recruited in their homes in January and February 2000.
Data collection was accomplished using interviewer-administered questionnaires designed to obtain relevant socio-demographic characteristics, knowledge, attitude and practice towards breast cancer. The questionnaire was developed by the authors based on information in the literature on risk-factors, common symptoms and signs of breast cancer, common methods of early detection, and current treatment modalities for the disease. The questionnaire was reviewed by a senior oncologist in our institution, who is not among the authors. The questionnaire was pre-tested on a convenient sample of 25 women drawn from the local community from whom study participants were recruited. As a result of this pretest, some of the items on the questionnaire were discarded mostly due to ambiguity of these questions. Some other questions were revised to ensure that vocabulary was within the comprehension of study participants while at the same time retaining the message of the question. Twenty core questions on knowledge of study participants on risk factors, common symptoms, methods of early detection, and treatment methods of breast cancer were retained out of the initial 31 items on the questionnaire. Except for the section of socio-demographic characteristics, most of the questions were designed to elicit "yes", "no" or "don't know" answers.
Participants were recruited by trained nurses, who had two days training session prior to commencement of study. Each respondent was identified by a study identification number. Socio-demographic information relating to age, educational status, religion, occupation, and marital status were collected in the first section of the questionnaire. In the second part, respondents were asked specific questions to elicit their knowledge of the common symptoms and signs of breast cancer, etiological factors, diagnostic procedures, and treatment options available for the disease. The third section examined participant's action and attitude towards breast cancer. Respondents were asked questions related to their practice of breast self examination (BSE), clinical breast examination (CBE) and mammography screening. Participants were also asked about specific actions they will take in the event of being diagnosed with breast cancer and acceptance of mastectomy as a treatment procedure.
Data analysis was carried using the Statistical Analysis Software (SAS) Version 8.2. Each respondent was scored based on the number of correct answers on 20 questions related to knowledge of common symptoms and signs of breast cancer, causal factors and available treatment options and percentage scores were computed. Pearson chi-square test was used to assess relationship between percentage scores and sociodemographic variables. We examined the practice of breast self examination (BSE) to determine factors that might influence this behavior. Variables considered for this analysis included education, age, marital status, and religion. Unconditional logistic regression models were used to assess the relationship of these variables with practice of BSE. Dummy variables were created for nominal categorical variables prior to the logistic regression. Univariate unconditional logistic regression models were first used to assess the relationship of these variables with practice of BSE; those with p > 0.25 were then dropped. Next, variables with p ≤ 0.25 were selectively added to the model, starting with the variable with the lowest p-value. Variables with p ≤ 0.10 were retained while those with p > 0.10 were dropped from the model. At the next stage variables with p > 0.05 were selectively removed from the model, one at time, beginning with the variable with the highest p-value. The model was then re-assessed, followed by dropping of the variable with the next highest p-value until all the variables with p > 0.05 were eliminated from the final multivariate model model. In addition, relationship between these variables and acceptance of mastectomy was similarly examined using unconditional logistic regression.
Discussion
The results of this study suggest that community-dwelling women in Nigeria have rather poor knowledge of breast cancer. This may partly explain the late presentation seen in over 70% of women with the disease [
3‐
5]. A mean knowledge score of 42.3% with only 22.9% scoring 50.0% and above portray the abysmal level of ignorance about risk factors and common symptoms of breast cancer in Nigerian women. Unlike previous studies on this subject in Nigerian women [
13,
18,
19], we have recruited community-dwelling women spanning a wide spectrum of age, occupation and educational status. The wide age coverage was deliberate as breast cancer shows a younger age profile in Nigerian women similar to reports in other populations of black descent in the Diaspora but contrary to the older age distribution in Caucasian women; the reported mean ages of 38, 44, and 48 years at presentation reported by various investigators [
3‐
5] in Nigeria support this proposition.
The low level of knowledge found in this study is in keeping with reports of other investigators [
13,
18,
19]. In a survey of breast cancer knowledge, Uche [
18] noted that only 32% of the respondents knew that a breast lump was a warning sign for breast cancer, 58.5% were unaware of most warning signs and only 9.8% knew of methods of detecting breast cancer. Our study showed that only 21.4% of community-dwelling women were aware of a painless breast lump as a common presentation of breast cancer and far less proportion of these women were able to identify non-lump presenting symptoms of breast cancer, while only 43.2% were aware of BSE as a screening tool for breast cancer. Even professional health workers such as nurses who are supposed to be leaders in "breast awareness", were reported to have similar low knowledge scores [
13]. Odusanya and Tayo [
13] found that only 27% of nurses in a tertiary health institution in Lagos, Nigeria could identify up to 3–4 risk factors for breast cancer. In addition, 51% of these nurses wrongly identified the use of fingertips in performing BSE.
These results in Nigerian women sharply contrast with reports from the Western world. In a study of women's knowledge and belief about breast cancer among British women, Grunfeld
et al, [
20] noted that 90%, 70%, and 60% respectively, were able to quantify the relative risk of breast cancer associated with family history, previous history of breast cancer, and smoking, respectively. The same authors found that over 70% of the surveyed women were able to identify painless breast lump, lump under the armpit and nipple discharge/bleeding as symptoms of breast cancer. It should however be noted that a much smaller proportion of these women were able to recognize other non-lump symptoms such as dimpling of the breast skin, inversion/pulling in of the nipple, and scaling/dry skin in the nipple region.
Our results indicate that education and employment in professional jobs significantly influenced knowledge of breast cancer. Women with education greater than High School and those employed in professional jobs such as nursing, teaching and sales had significantly higher knowledge scores compared with those employed in small businesses. Other demographic variables including age, marital status and religion were not significantly related to knowledge score. These results are in agreement with the findings of others but at variance with the report of others. Among a cross section of British women, Grunfeld
et al, [
20] found that older women demonstrated poorer knowledge of risk factors for breast cancer; they noted that this poorer knowledge was also apparent among women of lower social economic status (SES). Surveys in the US [
21], and Australia [
22] have demonstrated that older women have poorer knowledge of key risk factors for various cancers. It has been suggested that older women may attribute non-lump breast symptoms to the aging process, and therefore ignore these warning signs of breast cancer [
20]. Furthermore, it has been argued that older adults, who may have a number of symptoms of other illnesses, should not be expected to seek help for symptoms that are not causing them any pain or that have little effect on their functioning [
23].
Participants in our study had the right attitude towards breast cancer as majority indicated visiting the doctor for breast complaints. The use of screening methods was very low among our study subjects; only 34.9% practice BSE and only 9.1% had had CBE in the past year and none ever had a mammogram. Odusanya and Tayo [
13] reported that 89% of Nurses in Lagos, Nigeria practiced BSE and 34.3% had CBE although majority of their study participants did not know the correct time or technique for carrying out the procedure. Available data indicates that majority of women in the screening age group in the developed countries undergo routine screening using all three methods including monthly BSE, annual CBE, and annual mammography [
24,
25]. In a survey of practice of BSE among black women in the US, Jacobs
et al, [
26] found that 89% of respondents indicated practicing BSE during the past year, 74% indicated having done so during the past six months, and 39% indicated performing self exam monthly. Similar percentage of US women reporting practice of BSE monthly or more often have been reported by other investigators [
27].
Higher level of education and higher knowledge score were significant determinants of BSE practice in our study; age and other demographic variables were not significantly related to BSE practice. Similar to our findings, other investigators have reported that demographic characteristics such as higher levels of education and income, marital status, younger age, social support, knowledge and preventive attitudes, a history of breast diseases, a family history of breast cancer, having a regular physician, ethnic background and residence area are significant determinants of adherence to BSE practice [
14,
15,
28].
The guidelines for breast cancer screening recommended by a consortium of American medical organizations including the American Cancer Society, stipulates that: between the ages of 40 and 49 years, women should undergo a CBE and mammography every year or two; women older than 50 years should have an annual CBE as well as a mammogram [
29]. Mammography and CBE facilitate early detection and treatment of breast cancer, which is responsible for lower mortality rates [
30]. In a screening setting, about 10% of breast cancers will only be detected by CBE [
29].
The value of BSE is less established. While the findings of a clinical trial suggested that BSE results in no difference in risk of mortality from breast cancer, a review of case-control studies found that BSE might reduce this risk. Despite inconclusive evidence, it is thought that BSE makes women more "breast aware", which in turn may lead to earlier diagnosis of breast cancer [
30]. The rationale behind extending BSE practice as a screening test is the fact that breast cancer is frequently detected by women themselves without any other symptoms. A meta-analysis of studies investigating the possible benefits of BSE has shown that regular practice increases the probability of detecting breast cancer at an early stage [
14]. However, BSE is associated with other drawbacks including increased number of biopsies for benign breast lesions, [
31,
32] increased anxiety, and physician visits with consequent use of scarce health resources in addition to the distress, scarring and disfigurement that may be associated with breast biopsies.
Routine breast cancer screening is currently not being practiced in Nigeria. Even then, applying the recommended mammography screening guidelines in Nigeria will catch only a proportion of breast cancer cases as about 57% of breast cancer cases in Nigeria occur in women below the age of 50 years [
3]. In addition, some other factors militate against routine breast cancer screening in Nigeria. The actual burden of breast cancer in the population is unknown due to lack of adequate cancer statistics. The age specific incidence of the disease needs to be established to make a case for routine screening of women of specific age groups. Women need to be "breast aware" to stimulate their interest in screening. Health care spending for chronic diseases in Nigeria is competing with several basic needs including provision of basic amenities and infrastructure, and control of several endemic childhood infections and parasitic infestations; any money invested in breast cancer screening must be justified by the benefits to the population. Given the non-availability of adequate data to justify mammography screening and the high cost and skilled expertise required for the procedure, current efforts at breast cancer screening in Nigeria must rely on a combination of BSE and CBE. Women can be taught the techniques of monthly BSE and nurses, midwives, and other healthcare providers can be trained to augment physicians in the performance of clinical breast examinations (CBE).
As previously indicated, the interviewer-administered questionnaire developed by the authors was the only instrument employed for recruitment of study participants. Although, this may limit comparability of our findings with that of other investigators, it is important to note that efforts were made to ensure some measure of validity by pre-testing the questionnaire on a convenient sample before commencement of the study.
Competing interests
The author(s) declare that they have no competing interests.
Authors' contributions
MO, CB, UO, FO participated in conceptualization, design of the study and preparation of manuscript;
MO, CB, UO, FO participated in data analysis and preparation of the manuscript.
All the authors read and approved the final manuscript.