Epidemiological study of aromatase inhibitors in women diagnosed with breast cancer: evaluation and management of secondary effects

Abstract

Aromatase inhibitors (AI) are one of the main therapies to treat estrogen-receptor positive breast cancer. AI use is associated with several side effects that affects patient’s quality of life and reduces treatment adherence. Hence, it is necessary to make further efforts in elucidating and diminishing the AI-related side effects. In this line, this thesis provided new and additional evidence for this purpose. Starting by the importance of assessing vitamin D levels during AI treatment, especially to those who underwent to chemotherapy. We also studied the bone health evolution at the end and one-year after AI cessation, and the impact of oral bisphosphonates (BP). Moreover, we analyzed the arthralgia (VAS score) and health-related quality of life in osteoporosis (ECOS-16 score) progression during the AI treatment until one- year post-treatment. Then, fracture incidence and risk during AI therapy compared to tamoxifen (TAM) was analyzed, as well as the protective effect of BP. Finally, we studied the cardiovascular and thromboembolic risk, and overall survival benefit of AI compared to TAM. Our research leads us to state that bone health and circulant vitamin D levels monitoring, plus calcium and vitamin D supplementation is key for the clinical management of AI patients. BP treatment is proved to diminish bone loss and fracture risk, but cannot reverse risk levels towards patients at low fracture risk. Furthermore, prior TAM treatment enhances the odds to withdraw during the first year, increases bone loss during

AI treatment, and restricts the recovery in lumbar spine location at one-year post-treatment. On the other hand, since there are no differences in cardiovascular and thromboembolic risk between AI and TAM users, but AI users have lower all-cause mortality, AI should be the preferable choice. In summary, it is mandatory to clinical monitoring AI patients, especially those who were previously treated with TAM, including fracture risk and related risk factors assessments. These would reduce early cessation of treatment and improve patients’ quality of life.