Aims
Computed tomography (CT)-defined sarcopenia is a poor prognostic factor in patients with head and neck cancer (HNC). With evidence expanding, we aimed to determine the prognostic impact of CT-defined sarcopenia on overall survival, treatment completion and unplanned admissions in patients with HNC undergoing radiotherapy ± other treatment modality of curative intent.
Methods
A systematic review (January 2004-April 2021) was conducted in Medline, Embase, CINAHL, AMED and PubMed. Studies in adults (≥18 years) that evaluated sarcopenia using CT in patients who had completed radiotherapy of curative intent were included. Outcomes were overall survival, treatment completion and unplanned admissions. Study quality was assessed using the Quality In Prognosis Studies tool. HR or OR (95%CI) derived from multivariate analysis were extracted. Random effects meta-analysis was used to determine the pooled HR/OR for outcomes in patients with sarcopenia versus those without using RevMan (Version 5.3). The certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system.
Results
A total of 5,023 patients pooled from 19 studies (n=3,386) met the inclusion criteria. All studies defined sarcopenia as low muscle mass but varied in skeletal muscle index (SMI) thresholds applied, anatomical landmarking and ethnicity. The cumulative prevalence of sarcopenia was 40.2% (95%CI 38.9–48.6). Pre-treatment sarcopenia was associated with i)reduced overall survival (HR1.91; 95%CI, 1.6-2.3, p<0.0001, I2 63%); ii)chemotherapy dose-limiting toxicities (3 studies, n=449), (OR1.28, 95%CI, 0.8-2.1, p=0.33, I2 64%) and iii)Unplanned admissions (2, studies, n=269), (OR2.12, 95%CI, 0.4–10.2, p=0.35, I2 83%). The GRADE certainty of evidence was moderate, low and very low respectively.
Conclusions
CT-defined sarcopenia is independently associated with reduced overall survival in patients with HNC and holds clinically meaningful prognostic value. The certainty of evidence for treatment and admission-related outcomes may be strengthened through prospective studies. Methodological consensus and improved reporting guidelines for sarcopenia research are warranted.