Frequency and prognostic importance of the sarcopenia in patients with locally advanced or metastatic gastric cancer

Aim: Stomach cancer is the fifth most common malignancy in the world and also the third leading cause of cancer-related death. Stomach cancer is usually diagnosed in advanced stages and has a short survival rate of 5 years after diagnosis. Sarcopenia is defined as the loss of skeletal muscle mass characterized by skeletal muscle atrophy and deterioration in muscle tissue quality, which is led to decrease in muscle strength, easy fatigue, and various metabolic problems. Sarcopenia and cachexia occurring in oncology patients have important effects on the survival of patients and treatment side effects. Recent studies show that the presence of sarcopenia in patients with gastric cancer is an important risk factor for chemotherapy toxicity, and also overall survival time is shortened in sarcopenic patients. In this study, it was aimed to determine the frequency of sarcopenia in patients with advanced stage or metastatic gastric cancer and to investigate its effect on the prognosis of the disease. Materials and Methods: Patients with advanced stage or metastatic gastric cancer who applied to Ankara Yıldırım Beyazıt University Atatürk Training and Research Hospital and Ankara City Hospital Medical Oncology Department between January 2012 and June 2020 were included in our study. Early stage or operable patients were excluded from the study. After detection of the patients, the files of the patients are reviewed retrospectively and their demographic information (age, body mass index, height, weight, gender, etc.), prognostic information, pathological characteristics, treatments they received, metastasis status, and additional comorbidities were recorded. The mass of the muscles at the level of the 3rd lumbar vertebra was measured in cm2 by examining the CT and PET / CT images of the patients at the time of diagnosis and after treatment. Then, SI was calculated by dividing the total muscle mass by the square of the patients' height. According to the literature data, patients with SI below 52.4 cm2 / m2 for men and 38.5 cm2 / m2 for women were considered sarcopenic. The obtained data were analyzed by uploading to the SPSS database. Results: 59 patients diagnosed with gastric adenocarcinoma who met the inclusion criteria were included in our study. 43 (72.9%) of the patients were male, 16 (27.1%) were female. While the mean age at diagnosis of all patients was calculated as 59.75 ± 12.61 years; 33 patients (55.9%) were 60 years or older at the time of diagnosis. While the chemotherapy protocols received by the patients were included in the statistical calculations, those who received triple treatment regimes were classified as group 1, and those who received platin based double regimes or FOLFOX were classified as group 2. While 18 patients (34%) were receiving group-1 chemotherapy protocol, 35 patients (66.0%) were receiving group-2 protocol. When analyzed according to chemotherapy groups, there was no statistically significant difference between SI or muscle mass at the time of diagnosis and SI or muscle mass at intermediate measurement (p> 0.05). It was determined that 13 patients (22.0%) died during oncology follow-up. 35 patients (59.3%) were sarcopenic at the time of diagnosis. For all patients, muscle mass and SI values at the time of diagnosis were significantly higher than the values measured in the interim evaluation of the patients (p <0.05). Male patients had higher muscle mass and SI values measured at the time of diagnosis and in the interim evaluation. It was statistically significant. (p <0.05). The muscle mass and SI values of the male patients at the time of diagnosis were statistically significantly higher than the values measured in the post-treatment evaluation (t = 4,293; p = 0,000). When the average survival times of the patients were examined; the median duration for OS was 8,2 (months) and the median for PFS was 4,8 (months). There was no statistically significant relationship between sarcopenia status and age at diagnosis, OS (months) or PFS (months) values (p> 0.05). In the logistic regression analysis applied on the risk of sarcopenia, it was found that the risk of sarcopenia decreased by 34.1% as a result of one unit increase in BMI (kg / m2) (OR = 0.659; 95% CI = 0.524-0.829; p <0.05). Conclusion: According to the data presented in our study, more than half of the advanced stage or metastatic gastric cancer patients we diagnosed were sarcopenic. Although not statistically significant, in our study OS values of sarcopenic patients were lower than non-sarcopenic patients. It is obvious that sarcopenia has a negative effect on many issues such as drug side effects, surgical complications, and compliance with treatment, according to the studies in the literature. In our opinion; large-scale prospective studies are needed to fully determine the effects of sarcopenia on prognosis, treatment efficacy, side effects and quality of life in patients diagnosed with advanced or metastatic gastric cancer. Key Words: Sarcopenia, Gastric Cancer, Metastasis, Body Mass Index, Prognosis