Breast cancer is the most common malignant tumour in women around the world. The objective of this study was to quantify the number of non-haematological adverse reactions associated with chemotherapy, as well as to assess the effect of the sense of coherence, optimism-pessimism and the quality of the doctor-patient relationship on the quality of life of breast cancer patients. To this end, a cross-sectional descriptive study was conducted involving 110 breast cancer patients who were treated with docetaxel, epirubicin, and cyclophosphamide during the period 2012-2014. The difference in the quality of life in patients who have five or fewer toxicities compared to those with more than six is highlighted. This difference is not as important when comparing patients with 6 to 10 toxicities and those with more than 10. The multivariate model used in this study corroborates the direct implication of the sense of coherence on the quality of life and adds the number of adverse reactions as a new construct. This has virtually the same impact on the quality of life of these patients, but in reverse. In conclusion, to improve the quality of life of breast cancer patients it would be necessary to have an impact on the number of adverse reactions involved in chemotherapeutic treatment, as well as on psychological interventions, with the sense of coherence as a possible starting point.
Keywords: breast cancer; health-related quality of life; optimism; sense of coherence; toxicities.