Knowledge about breast cancer and hereditary breast cancer among nurses in a public hospital 1

OBJECTIVE: To assess the knowledge of nurses involved in the care of oncology patients in a public university hospital, regarding breast cancer and hereditary breast cancer, and to verify the use of such knowledge in their daily practice. METHODS: This is a descriptive cross-sectional study. Data were obtained through a structured, self-administered questionnaire. Out of 154 nurses, 137 (88.9%) agreed to participate in the study. Two questionnaires were excluded such that 135 questionnaires were analyzed. RESULTS: The global percentage of correct answers was not associated with age (p=0.173) or degree/specialization (p=0.815). Questions were classified into categories. In categories involving knowledge of established breast cancer risk factors and indicators of hereditary breast cancer, the rate of correct answers was 65.8% and 66.4%, respectively. On the practice of genetic counseling, 40.7% of those interviewed were not sure about the definition of genetic counseling and 78.5% reported never having identified or referred a patient at genetic risk for specialized risk assessment. Practice of educational actions regarding this subject was reported by 48.5% of those interviewed. CONCLUSION: This study reinforces the need to develop qualifying actions for nurses, so that strategies to control breast cancer become effective in their health care practice.


Introduction
Cancer is the leading cause of death due to nontransmitted diseases worldwide and thus an important public health problem both in developed countries and in underdeveloped or developing countries. Breast cancer is the most frequent type of cancer in women and the second cause of death in this population group worldwide (1) . In Brazil, it is the most frequent tumor in women of the Southeastern (69/100.000), Southern (65/100.000), Midwestern (48/100.000) and Northeastern regions (32/100.000) (2) . According to the Brazilian National Cancer Institute (INCA) (2) , estimates for 2012/2013 indicate that 52.680 new cases of female breast cancer will be identified, corresponding to the occurrence of 52 cases per 100.000 women. Despite being considered a tumor with good prognosis in most instances and if diagnosed and treated in time, breast cancer is still associated with a high mortality rate in Brazil. The most probable cause for this observation is that the disease is still being diagnosed in advanced stages, and multiple barriers to diagnosis and treatment exist for most women who rely on the public health care system (2)(3) .
Breast cancer is a multi-factorial disease in which genetic and environmental factors contribute to its occurrence (2) . In a small percentage of cases, a germline mutation in a high-penetrance cancer-predisposition gene is present, which can be a major determinant of the occurrence of the disease (4) . Sporadic breast cancer, which is not primarily caused by an inherited high-penetrance mutation, represents more than 90% of breast cancer cases throughout the world (5) . It is estimated that, on average, women who live until the age of 85 will have a chance of 1 in 9 of developing breast cancer (6) . Established risk factors for breast cancer include reproductive factors (early menarche, nulliparity, age at first pregnancy over 30 years, use of high-dose hormonal contraceptives, late menopause and hormone replacement therapy), increasing age, high breast tissue density and family history of cancer, especially breast cancer (2,(5)(6) . Additional factors that modulate breast cancer risk include nutritional factors, physical activity, history and duration of breast feeding, obesity in postmenopause, smoking, alcohol consumption, exposure to ionizing radiation and socio-economic level (2,(6)(7) .
Hereditary breast cancer corresponds to approximately 10-15% of all malignant breast tumors.
Among these are the tumors caused by highly penetrant germline mutations in the BRCA1 and BRCA2 genes.
Women with mutations in one of these genes present a cumulative risk of between 55% and 85% of developing breast cancer until the age of 70 and a 15% to 65% risk of developing ovarian cancer, depending of the type and location of the mutation (8)  There is no evidence to support breast self-examination (BSE) as an isolated strategy for early detection of breast cancer (2,7,9) .
Nurses have a central role in the multidisciplinary team involved in the care of patients with breast cancer, as well as those at increased risk for the disease.
Therefore, it is essential to invest in the education and training of nurses, both in the recognition of risk factors and in criteria for referral of patients to maximize risk-reducing practices, especially in highrisk individuals (10)(11) . Knowledge and identification of risk factors for sporadic breast cancer and focus on risk assessment for the genetic aspects of hereditary breast cancers are key challenges for health promotion and cancer prevention within nursing practice (12)(13) .

Discussion
The demographic data profile of participants in this study showed a predominance of professionals  (14) . Although one might expect that more mature professionals would have more knowledge in this area, we observed the opposite: more experienced professionals had lower performance in the questionnaire. This finding may reflect a lack of knowledge in older professionals due to deficiencies in undergraduate training and indicates the need for the ongoing education for nurses. This need was also highlighted in the previous study (14) .
An important fact that may explain the relative  approximately 30% knew only one factor (15) . A recent case-control study about women's knowledge of breast cancer risk factors performed in a regional university in the Brazilian state of Rio Grande do Sul (RS) observed that women with breast cancer had less previous knowledge about risk factors than women without the disease and concluded that information is an important means of reducing breast cancer incidence and enabling early diagnosis (13) .
Considering that primary prevention, which aims to prevent exposure to risk factors, especially modifiable ones, such as diet and physical activity, has the potential to reduce the incidence of cancer by up to 28%, health promotion is one of the fundamental strategies to empower women to understand and intervene in determinants of their own health (16) . Within that context, the nurse has a central role, considered by some authors as a duty, in promoting the development of such educational abilities, together with the female population.
Secondary prevention is also important in the control of breast cancer. An important finding of this study was the significant lack of knowledge regarding current guidelines for breast cancer screening proposed by the Ministry of Health (MH) in Brazil (2,9) . This observation allows us to infer that nurses might not be familiar with these protocols. The aforementioned study (14) (19) .
In relation to educational actions for the prevention  (4,8) . A study about the characteristics of women diagnosed with breast cancer attended in reference health services in north Minas Gerais, Brazil, indicated that 20.1% had a family history of breast cancer (21) .
Another study performed in an outpatient cancer-risk evaluation program located in a teaching hospital in the state of São Paulo showed that 35.3% of women with breast cancer also had a positive family history of the disease (22) . A study performed in Porto Alegre also found a relationship between breast cancer and family history (23) .
According to the study, a family history suggestive of hereditary breast cancer was identified in 6.2% of the cancer-unaffected women visiting basic health care units in the periphery of the city of Porto Alegre.
Timely identification of patients at risk for developing hereditary breast cancer allows implementation of multiple strategies aimed at prevention or early diagnosis, both in a proband and in his/her family members (24) . The nurse involved in the care of oncology patients can be the initial identifying agent of a highrisk patient, facilitating the referral to a specialist (11) .
Therefore, proper training of nurses in genetic risk identification and in the importance of referrals to highrisk programs, are crucial to enable timely referrals and use of proper risk reducing interventions (4) . Uncertainty