Everything You Always Wanted to Know about Sarcopenia but Were Afraid to Ask: A Quick Guide for Radiation Oncologists (impAct oF saRcopeniA In raDiotherapy: The AFRAID Project)

Abstract

Sarcopenia (SP) is a syndrome characterized by age-associated loss of skeletal muscle mass and function. SP worsens both acute and late radiation-induced toxicity, prognosis, and quality of life. Myosteatosis is a pathological infiltration of muscle tissue by adipose tissue which often precedes SP and has a proven correlation with prognosis in cancer patients. Sarcopenic obesity is considered a “hidden form” of SP (due to large fat mass) and is independently related to higher mortality and worse complications after surgery and systemic treatments with worse prognostic impact compared to SP alone. The evaluation of SP is commonly based on CT images at the level of the middle of the third lumbar vertebra. On this scan, all muscle structures are contoured and then the outlined surface area is calculated. Several studies reported a negative impact of SP on overall survival in patients undergoing RT for tumors of the head and neck, esophagus, rectum, pancreas, cervix, and lung. Furthermore, several appetite-reducing side effects of RT, along with more complex radiation-induced mechanisms, can lead to SP through, but not limited to, reduced nutrition. In particular, in pediatric patients, total body irradiation was associated with the onset of SP and other changes in body composition leading to an increased risk of cardiometabolic morbidity in surviving adults. Finally, some preliminary studies showed the possibility of effectively treating SP and preventing the worsening of SP during RT. Future studies should be able to provide information on how to prevent and manage SP before, during, or after RT, in both adult and pediatric patients.

Sarcopenic Obesity in Cervical Carcinoma: A Strong and Independent Prognostic Factor beyond the Conventional Predictors (ESTHER Study—AFRAID Project)

“…In this study, we extended the investigation to include body composition-related parameters such as BMI, SP, and SO. These parameters have gained attention in recent years as potential prognostic factors in cancer treatment, including cervical cancer [ 11 , 12 ]. Previous studies have explored the impact of SP on outcomes in LACC patients undergoing CRT.…”

“…We found that patients with SO had significantly worse outcomes in terms of DFS and OS compared to those without this condition. This underscores the importance of evaluating both muscle mass and body fat in cancer prognostication, as SO represents a distinct phenotype with unique clinical implications [ 11 ].…”

“…These patients were part of an approved observational study known as the ESTHER study, which was conducted in accordance with the guidelines set by our local Ethical Committee (code CE 973/2020/Oss/AOUBo). Moreover, this analysis is part of our institutional AFRAID (impAct oF saRcopeniA In raDiotherapy) project [ 11 ]. All patients provided informed consent to participate in this study, and no specific exclusions were applied to ensure the real-world relevance of the research.…”

“… Delineation of the skeletal muscle area on a CT scan at the level of the third lumbar vertebra. Adapted from Medici F et al, 2022 [ 11 ]. …”

“…To improve the accuracy of outcome predictions and enable treatment customization based on prognostic profiles, recent studies have explored the use of various body composition-related parameters in cancer patients. In particular, there is a growing awareness of the impact of parameters such as body mass index (BMI), sarcopenia (SP), and sarcopenic obesity (SO) in cancer patients undergoing RT [11,12]. Also, in LACC, several studies have explored the impact of SP in patients treated with CRT.…”