Exposición laboral a factores de riesgo de cáncer de mamatrabajo nocturno en personal de enfermería

  1. Javier Fagundo Rivera
Supervised by:
  1. Juan Gómez Salgado Director

Defence university: Universidad de Huelva

Year of defence: 2021

  1. Octavio Vázquez Aguado Chair
  2. Luciano Rodríguez Díaz Secretary
  3. Emilia Isabel Martins Texeira da Costa Committee member

Type: Thesis


Introduction Breast cancer is a disease which is commonly diagnosed in women and whose incidence worldwide has increased in recent decades. Its etiopathology has been linked to multiple carcinogenic factors that converge in the working environment. Among these factors, the increased incidence of occupational breast cancer has potentially been associated with circadian misalignment and sleep pattern disorders caused by shift-work and night work, something common in a society that organizes many of its professions around 24 hours a day. These working conditions make the labour of nurses particularly stressful and other spheres, such as private or family, can also be altered due to time incompatibilities and lifestyle mismatches. In fact, nurses may stay away from healthy lifestyles because of their presence in irregular shifts that make it impossible for them to have physical and food routines. It is therefore a priority to assess the impact of short- and long-term night work on the nurses' group and their risk profile for the development of breast cancer. Objectives The objective of this study was to analyze the relationship between shift work, especially night work, and the risk of breast cancer in the nurses of Spain. To do this, the incidence and prevalence of occupational breast cancer in nurses were analyzed and the possible association between consecutive shifts and nights, lifestyle type, and risk of breast cancer were assessed. Among the specific objectives, this study assessed the subjective self-perception of the own health, psychosomatic manifestations related to the stress and job satisfaction of nurses. Methodology An observational, descriptive, cross-sectional, and quantitative study was performed to meet the objectives. To this end, a description and identification of available evidence on breast cancer and shift work in nurse samples was first made through an analysis of the literature. In the next phase, a field study was conducted with a sample of 966 Spanish nurses between February and September 2020, using a self-administered questionnaire containing sociodemographic variables, occupational variables, a scale of self-assessment of health, the Spanish version of the Psychosomatic Problem Questionnaire and an adaptation of the SF21/26 Job Satisfaction questionnaire. A descriptive analysis of the variables was performed, and the relationship was tested using the OR independence and χ2 test. Mann Whitney U-test analyzed the differences between subgroups in relation to health self-perception. The use of data mining techniques, using classification trees, and multivariate analysis allowed to draw a tight profile of professionals with breast cancer. Results Most of the evaluated studies found a clear association between breast cancer and prolongation of night rotating shifts over time. Similarly, relationships have been found regarding the alteration of certain markers of circadian rhythm, such as melatonin, or markers of epigenetic alteration such as telomere length. Among the most significant risk variables of the field study, they were the number of years worked, the number of nights worked throughout life, and years of work performing more than 3 nights per month. In this way, exceeding the 16 years worked was presented as the most significant variable for women and men, and when the time worked was shorter than 16 years, the number of cases increased when there were family history of cancer and more than 500 nights had been worked. Overall health was perceived as good in the sample, although lower values were present in those with breast cancer. In addition, other psychosomatic manifestations such as insomnia, palpitations or extreme tiredness were highlighted in cancer cases. Among the most appreciated aspects of generating job satisfaction, the relationship with co-workers was underlined. Discussion This study has provided a closer look to the possible interaction of occupational factors and personal factors that may influence the risk of breast cancer in nurses. In this way, caring for dependents at home, taking medication to sleep, having a demanding physical work activity, and being passively exposed to tobacco smoke at home and at work were especially significant in cases of breast cancer, possibly indicating the emergence of conflicts between personal life, family life and the pace of work of nurses. On the other hand, the level of job satisfaction has shown associations with perceived sleep quality and the overall health and has also been linked to the importance of partnership relations, making it visible that nurses find an important support network in co-workers. Institutional support for workplace adaptation could also be highlighted in this study, as it has been observed that those nurses with breast cancer worked on rotating and night shifts in a smaller proportion than the sample free of disease. Conclusions Rotating shift work can cause multiple clinical alterations and can lead to problems related to family conciliation, self-care, or wellness. High-intensity night work seems more harmful at an early age, especially if hereditary factors interfere, although the accumulation of years and nights of work increases the risk of breast cancer when factors such as sleep disturbance, physical stress or family responsibilities come together.While more experimentation is still needed to demonstrate the biometric factors of circadian disruption and the mechanism of development of breast cancer from the exposure to night work, certain preventive measures could reduce many negative effects on nurses and prevent the onset of other risk factors. In this way, 24h breaks after each night shift are recommended, favoring personal time and family conciliation. Emphasis is also placed on the need for smoke-protected spaces and occupational health care services that assess carcinogenic risk factors periodically.