Skeletal muscle loss (SML) is highly prevalent in the first three months following gastrointestinal (GI) cancer surgery, significantly impacting patients' quality of life and increasing postoperative complications, according to a new study. The prospective study, published in Changes in Skeletal Muscle Mass in the First 3 Months Following Gastrointestinal Cancer Surgery, highlights the need for routine assessment and monitoring of skeletal muscle mass (SMM) in GI cancer patients undergoing surgical treatment.
The study, conducted at a single center in China, followed 483 patients undergoing gastric, esophageal, or colorectal cancer surgery. Researchers assessed SMM using bioelectrical impedance analysis (BIA) at four time points: before surgery, 7 days after surgery, 1 month after surgery, and 3 months after surgery. They also collected data on patient demographics, clinical characteristics, biomarkers, postoperative complications, and quality of life using the EORTC QLQ-C30 questionnaire.
High Prevalence of Postoperative SML
The study found that 92% of patients experienced SML within the first three months after surgery. The median change in SMI (skeletal muscle index) was -2.5% at 7 days, -5.3% at 1 month, and -5.6% at 3 months. Only 7.9% of participants did not experience SML at any timepoint during the study period.
Distinct Patterns of Muscle Change
Growth mixture modeling (GMM) identified four distinct classes of muscle change patterns:
- Class 1 (16.1%): Low SMM before surgery with further SML after surgery (moderate SML).
- Class 2 (23.1%): SML at 7 days and 1 month after surgery, but above-normal SMM at all times with a recovery trend at 3 months (mild SML).
- Class 3 (27.3%): Just-above-normal SMM before surgery with consistent SML after surgery (severe SML).
- Class 4 (33%): Just-above-normal SMM that remained at a similar level throughout the study period (mild SML).
Classes 2 and 4 were grouped as mild SML, class 1 as moderate SML, and class 3 as severe SML.
Impact on Health Outcomes
Patients with moderate or severe SML experienced significantly higher prevalences of total (p < 0.001) and severe (p = 0.016) postoperative complications compared to those with mild SML. They also reported significantly lower quality of life regarding global health status and physical function at all timepoints, as well as worse role, emotional, and social functioning, and more severe symptoms like fatigue, pain, and insomnia.
Predictors of Postoperative Muscle Loss
Multivariate logistic regression analysis identified advanced age (≥65 years), preoperative sarcopenia, low prognostic nutrition index (PNI), and advanced cancer stage (III and IV) as independent predictors of moderate/severe postoperative muscle loss. The model demonstrated good predictive ability with an AUC of 0.896 (95% CI: 0.854, 0.937).
Clinical Implications
"Our results highlight the importance of recognizing different patterns of postoperative muscle change and assessment and monitoring of SMM after GI cancer surgical treatment," the authors stated. They recommend that healthcare professionals incorporate regular assessments of SMM and function into routine practice, starting as early as 7 days and 1 month after surgery. Patient-reported quality of life measurement should also be incorporated, given the relationship between quality of life and SML.
The study's findings provide a foundation for developing targeted intervention programs to actively manage SML and enhance the overall well-being of patients undergoing GI cancer surgery. Future research should explore long-term survival outcomes and investigate nutrition- and physical-activity-related factors to better understand the underlying mechanisms of SML.
