The evaluation of the effect of adjuvant chemotherapy on sarcopenia in breast cancer patients

Purpose: Breast Cancer is one of the most diagnosed and it represents the number one cause of cancer-related deaths in women. Lately, due to early diagnosis, improvement in prognosis outcome and higher life expectancy has been observed. The fact that the cure rate of this disease is high means that the long-term complications are important. Sarcopenia; is an important health problem in malignant patients and is related to disease-free survival, postoperative complications, treatment response, treatment toxicity, and general survival. This study aims to find the frequency of sarcopenia and the short and long term effect of adjuvant chemotherapy and hormone therapy on sarcopenia in breast cancer patients. Method: Patients diagnosed with breast cancer who applied to the medical oncology outpatient clinic at Adnan Menderes University Faculty of Medicine, Department of Internal Medicine, Oncology Department between 01.01.2015-31.12.2019, were included in the study. Patients with early breast cancer and non-regional lymph node involvement without any other organ metastases were included in the study. The group receiving adjuvant chemotherapy consisted of 33 patients. the other group consisted of 20 patients who received only hormonal therapy without adjuvant chemotherapy. In this study, patients were examined with PET CT / CT imaging for diagnosis and follow-up from the MIA-MED automation system. The sarcopenia index was calculated by measuring the cross-sectional areas of the psoas, erector spinae, quadratus lumborum, rectus abdominis, transversus abdominis-external, and internal oblique muscles measured at the L3 vertebra level. Results: The average age of the patient group receiving chemotherapy was 51.88 ± 11.71, while the average of the patient group who did not receive chemotherapy was 62.35 ± 7.27 (p <0.001). When the relationship between BMI and sarcopenia was examined in patients, sarcopenia was observed in 50% of patients with normal weight, 27.8% of overweight patients, and 0% of obese patients at the start of treatment. This difference was statistically significant (p 0.002). When the presence of sarcopenia was examined in all patient groups, 21.2% of patients who received chemotherapy had sarcopenia at the beginning of treatment, while 20% of patients who did not receive chemotherapy had sarcopenia. The difference was not statistically significant. In the second year follow-up of patients, 27.3% sarcopenia was observed in the group receiving chemotherapy, while 25% sarcopenia in the group not receiving chemotherapy. The difference was not statistically significant. When the total muscle mass change of the patients who received chemotherapy before, shortly after and after the 2nd year of chemotherapy was examined, the mean of the total muscle mass, was found to be 110.68±12.04 cm2 in the period before chemotherapy, 111.74±11.75 cm2 in the post-chemotherapy period and 110.49±12.40 cm2 in the long term, and there was no statistically significant difference. When the start of treatment and the change of total muscle mass in the second year of patients who received only hormone therapy without chemotherapy were examined, the average of total muscle mass was 112.37±18.18 cm2 at the beginning of the treatment, while it was found to be 109.08 ± 16.80 cm2 in the second year. There was a decrease in total muscle mass in the follow-up and this difference was found statistically significant (p <0.001) Conclusion: In the light of clinical data, the importance of muscle mass has come to the fore with numerous studies emphasizing the importance of disease-free survival, treatment response, chemotherapy-related toxicities, and overall survival. When the course of sarcopenia with chemotherapy was examined, it was not shown that sarcopenia increased in patients receiving chemotherapy. In patients receiving only hormone therapy without chemotherapy, an increase in the sarcopenia rate could not be observed, but a marked decrease was observed in the muscle cross-section areas. Although an increase in sarcopenic obesity rates was observed with the treatment, we could not reach statistical significance with our study. There was no difference in the sarcopenia index in patients receiving different hormone therapy agents such as aromatase inhibitor and tamoxifen.