The incidence, mortality, and survival rates for BC vary across the world's regions because of underlying differences in known risk factors, access to effective treatment, and the availability of organized screening programs [2]. Fatality rates tend to be higher in low-resource countries [1].

In Egypt, cancer registries reveal that BC is the most frequently occurring cancer among women, representing 18.9% of the total cancer cases (35.1% in women and 2.2% in men), with an age-adjusted rate of 49.6 per 100.000 persons [3]. BC among Egyptian patients has a younger age distribution, with the majority of cases occurring at 30–60 years of age. The median age at diagnosis is 49 years, 1 decade younger than the corresponding age in Europe and North America [4].

The etiology of BC is multi-factorial and cannot be directly linked to any single factor. The epidemiological literature supports a highly complex interplay between different exposures and host characteristics and between exogenous and endogenous hormones and an individual's genetic makeup [5]. A woman's age is the strongest risk factor for BC, and older women have a 10 times increased risk compared with younger women. Reproductive risk factors associated with the risk of BC include: menarche before the age of 11 years, menopause after the age of 54 years, and an age greater than 40 years at first full-term pregnancy [6]. The higher the number of full-term pregnancies, the greater the protection. Women who breastfeed have a reduced risk compared with women who do not breastfeed [7]. Current knowledge suggests that oral contraceptive use is one of the weakest risk factors for BC [5].

Prevention or identification of BC at an early stage is of paramount importance in saving and improving the quality of life. Breast health awareness appears to be a pragmatic method for this. Creating breast health awareness appears to be an important prerequisite for early detection of BC in low-income countries [8]. Although breast awareness has long been advocated as a health promotion intervention in many parts of the world, evidence suggests that women in general are still not breast aware.

Methods for early detection must be considered the best second choice for reducing the mortality, amongst which breast self-examination (BSE), clinical breast examination (CBE) by the treating physician, as well as ultrasound and mammography, are the secondary preventive methods used for screening in the early detection of BC [9]. According to the American Cancer Society (ACS), BSE is an option for women starting from the early 20's [10].

The combination of BSE and CBE seems to be an important available alternative in slum areas [11]. In areas where access to CBE and mammograms is difficult, BSE still detects BC early enough for treatment options.

BC is usually diagnosed at an advanced stage in Egypt, and studies revealed that population screening is rarely practiced in Egypt [9, 12, 13, 14]. Women living in slum areas suffer from the unavailability of services and poor health [15].

The present findings illustrate the unsatisfactory basic knowledge of the sampled women on BC risk factors prior to the intervention. This may be due to the shortage of BC-related health education programs in primary health care facilities and in the media [21]. Women's limited knowledge on BC has been identified elsewhere in developed and developing countries [22].

Similar to the present findings, many studies from both developing and developed countries illustrated the effectiveness of intervention programs in increasing the knowledge on BC, its risk factors and the awareness for BC screening [23, 24]. The pre-intervention mean opinion score of some protective factors like breastfeeding was relatively high, reflecting cultural and religious factors encouraging breastfeeding [25].

The participants showed poor understanding of some BC risk factors, specifically obesity and early menarche. This may be explained by the local culture where obesity and early menarche are seen as signs of fecundity and good health.

Although the effectiveness of BSE remains controversial [26], it holds some promise of early detection of BC, especially in areas where secondary intervention facilities are scarce [27].