Association of Low Muscle Mass and Low Muscle Radiodensity With Morbidity and Mortality for Colon Cancer Surgery.

Importance: Given the risks of postoperative morbidity and its consequent economic burden and impairment to patients undergoing colon resection, evaluating risk factors associated with complications will allow risk stratification and the targeting of supportive interventions. Evaluation of muscle characteristics is an emerging area for improving preoperative risk stratification. Objective: To examine the associations of muscle characteristics with postoperative complications, length of hospital stay (LOS), readmission, and mortality in patients with colon cancer. Design, Setting, and Participants: This population-based retrospective cohort study was conducted among 1630 patients who received a diagnosis of stage I to III colon cancer from January 2006 to December 2011 at Kaiser Permanente Northern California, an integrated health care system. Preliminary data analysis started in 2017. Because major complication data were collected between 2018 and 2019, the final analysis using the current cohort was conducted between 2019 and 2020. Exposures: Low skeletal muscle index (SMI) and/or low skeletal muscle radiodensity (SMD) levels were assessed using preoperative computerized tomography images. Main Outcomes and Measures: Length of stay, any complication (≥1 predefined complications) or major complications (Clavien-Dindo classification score ≥3), 30-day mortality and readmission up to 30 days postdischarge, and overall mortality. Results: The mean (SD) age at diagnosis was 64.0 (11.3) years and 906 (55.6%) were women. Patients with low SMI or low SMD were more likely to remain hospitalized 7 days or longer after surgery (odds ratio [OR], 1.33; 95% CI, 1.05-1.68; OR, 1.39; 95% CI, 1.05-1.84, respectively) and had higher risks of overall mortality (hazard ratio, 1.40; 95% CI, 1.13-1.74; hazard ratio, 1.44; 95% CI, 1.12-1.85, respectively). Additionally, patients with low SMI were more likely to have 1 or more postsurgical complications (OR, 1.31; 95% CI, 1.04-1.65) and had higher risk of 30-day mortality (OR, 4.85; 95% CI, 1.23-19.15). Low SMD was associated with higher odds of having major complications (OR, 2.41; 95% CI, 1.44-4.04). Conclusions and Relevance: Low SMI and low SMD were associated with longer LOS, higher risk of postsurgical complications, and short-term and long-term mortality. Research should evaluate whether targeting potentially modifiable factors preoperatively, such as preserving muscle mass, could reverse the observed negative associations with postoperative outcomes.

Muscle mass at the time of diagnosis of nonmetastatic colon cancer and early discontinuation of chemotherapy, delays, and dose reductions on adjuvant FOLFOX: The C-SCANS study.

BACKGROUND: For many chemotherapy regimens dosed based on body surface area (BSA), patients experience dose reductions or delays or discontinue treatment, thereby reducing survival. Consideration of body composition may be useful in individualizing chemotherapy dosing, but to the authors' knowledge few studies to date have examined the association of body composition with chemotherapy tolerance in patients with colon cancer. METHODS: The authors identified patients with nonmetastatic colon cancer who were diagnosed from 2006 through 2011 at Kaiser Permanente and who received leucovorin calcium/calcium folinate, 5-fluorouracil, and oxaliplatin (FOLFOX) as initial adjuvant chemotherapy (533 patients). Patients' muscle mass was quantified using clinically acquired computed tomography scans. The authors quantified chemotherapy doses, treatment dates, and related toxicities using the electronic medical record. In logistic regression models adjusting for age, sex, and American Joint Committee on Cancer stage of disease, the authors examined associations of muscle tertiles with early treatment discontinuation (<6 cycles), treatment delay (>3 days off schedule for ≥3 times), and/or dose reduction (relative dose intensity ≤ 0.70, based on planned treatment). RESULTS: The average age of the patients at the time of diagnosis was 58.7 years; BSA was 1.9 m2 and body mass index was 28.7 kg/m2 . Compared with the highest sex-specific tertile of muscle mass, patients in the lowest tertile were more likely to experience toxicities and had twice the risk of adverse outcomes while receiving FOLFOX; for early discontinuation, the odds ratio (OR) was 2.34 (95% confidence interval [95% CI], 1.04-5.24; P for trend = .03), whereas the ORs were 2.24 (95% CI, 1.37-3.66; P for trend = .002) for treatment delay and 2.28 (95% CI, 1.19-4.36; P for trend = .01) for dose reduction. CONCLUSIONS: Lower muscle mass is associated with greater toxicity and poor chemotherapy adherence among patients receiving FOLFOX. Many chemotherapy drugs are dosed based on BSA, but treatment may be better individualized if muscle mass is considered. Cancer 2017;123:4868-77. © 2017 American Cancer Society.