Effect of Multimodal Prehabilitation vs Postoperative Rehabilitation on 30-Day Postoperative Complications for Frail Patients Undergoing Resection of Colorectal Cancer: A Randomized Clinical Trial.

Importance: Research supports use of prehabilitation to optimize physical status before and after colorectal cancer resection, but its effect on postoperative complications remains unclear. Frail patients are a target for prehabilitation interventions owing to increased risk for poor postoperative outcomes. Objective: To assess the extent to which a prehabilitation program affects 30-day postoperative complications in frail patients undergoing colorectal cancer resection compared with postoperative rehabilitation. Design, Setting, and Participants: This single-blind, parallel-arm, superiority randomized clinical trial recruited patients undergoing colorectal cancer resection from September 7, 2015, through June 19, 2019. Patients were followed up for 4 weeks before surgery and 4 weeks after surgery at 2 university-affiliated tertiary hospitals. A total of 418 patients 65 years or older were assessed for eligibility. Of these, 298 patients were excluded (not frail [n = 290], unable to exercise [n = 3], and planned neoadjuvant treatment [n = 5]), and 120 frail patients (Fried Frailty Index,≥2) were randomized. Ten patients were excluded after randomization because they refused surgery (n = 3), died before surgery (n = 3), had no cancer (n = 1), had surgery without bowel resection (n = 1), or were switched to palliative care (n = 2). Hence, 110 patients were included in the intention-to-treat analysis (55 in the prehabilitation [Prehab] and 55 in the rehabilitation [Rehab] groups). Data were analyzed from July 25 through August 21, 2019. Interventions: Multimodal program involving exercise, nutritional, and psychological interventions initiated before (Prehab group) or after (Rehab group) surgery. All patients were treated within a standardized enhanced recovery pathway. Main Outcomes and Measures: The primary outcome included the Comprehensive Complications Index measured at 30 days after surgery. Secondary outcomes were 30-day overall and severe complications, primary and total length of hospital stay, 30-day emergency department visits and hospital readmissions, recovery of walking capacity, and patient-reported outcome measures. Results: Of 110 patients randomized, mean (SD) age was 78 (7) years; 52 (47.3%) were men and 58 (52.7%) were women; 31 (28.2%) had rectal cancer; and 87 (79.1%) underwent minimally invasive surgery. There was no between-group difference in the primary outcome measure, 30-day Comprehensive Complications Index (adjusted mean difference, -3.2; 95% CI, -11.8 to 5.3; P = .45). Secondary outcome measures were also not different between groups. Conclusions and Relevance: In frail patients undergoing colorectal cancer resection (predominantly minimally invasive) within an enhanced recovery pathway, a multimodal prehabilitation program did not affect postoperative outcomes. Alternative strategies should be considered to optimize treatment of frail patients preoperatively. Trial Registration: ClinicalTrials.gov identifier: NCT02502760.

Diet composition as a source of variation in experimental animal models of cancer cachexia.

BACKGROUND: A variety of experimental animal models are used extensively to study mechanisms underlying cancer cachexia, and to identify potential treatments. The important potential confounding effect of dietary composition and intake used in many preclinical studies of cancer cachexia is frequently overlooked. Dietary designs applied in experimental studies should maximize the applicability to human cancer cachexia, meeting the essential requirements of the species used in the study, matched between treatment and control groups as well as also being generally similar to human consumption. METHODS: A literature review of scientific studies using animal models of cancer and cancer cachexia with dietary interventions was performed. Studies that investigated interventions using lipid sources were selected as the focus of discussion. RESULTS: The search revealed a number of nutrient intervention studies (n = 44), with the majority including n-3 fatty acids (n = 16), mainly eicosapentaenoic acid and/or docosahexaenoic acid. A review of the literature revealed that the majority of studies do not provide information about dietary design; food intake or pair-feeding is rarely reported. Further, there is a lack of standardization in dietary design, content, source, and overall composition in animal models of cancer cachexia. A model is proposed with the intent of guiding dietary design in preclinical studies to enable comparisons of dietary treatments within the same study, translation across different study designs, as well as application to human nutrient intakes. CONCLUSION: The potential for experimental endpoints to be affected by variations in food intake, macronutrient content, and diet composition is likely. Diet content and composition should be reported, and food intake assessed. Minimum standards for diet definition in cachexia studies would improve reproducibility of pre-clinical studies and aid the interpretation and translation of results to humans with cancer.

Optimal method for isolation of human peritoneal mesothelial cells from clinical samples of omentum.

INTRODUCTION: Human peritoneal mesothelial cells (HPMC) are a valuable research tool for understanding the molecular biology of several pathologies, in both monolayer and three dimensional models. We compared different methods of HPMC isolation and assessed their outcome as well as fibroblast contamination, a common problem encountered during isolation. METHODS: 1-3cm(3) samples of omentum were collected from 40 consenting patients undergoing elective gastrointestinal surgery. A total of 11 samples were incubated in 0.05% trypsin solution for 20 minutes at 37 degrees C (group A) and 29 in 0.25% trypsin (15 samples for 10 minutes (group B) and 14 for 20 minutes (group C)). Following digestion cells were re-suspended and cultured in supplemented Ham's F-12 medium containing 10% foetal calf serum (FCS), penicillin-streptomycin, glutamine, insulin, transferrin and hydrocortisone. Positive outcomes were absence of fibroblast contamination and satisfactory HPMC growth to confluence in a characteristic cobblestone pattern. Cytokeratins 5, 8, 18, Vimentin, Ber-Ep4 and Factor VIII were used to characterise HPMC and fibroblasts by immunohistochemistry. RESULTS: None of the 11 samples in group A yielded HPMC. 14 of 29 samples digested with 0.25% trypsin yielded HPMC: 10 of 14 yielded HPMC in group C versus four of 15 samples in group B (p = 0.02). Fibroblast contamination occurred in eight samples in group B versus three in group C. CONCLUSION: Optimal results are achieved with a 20 minute digestion in 0.25% trypsin. Fibroblast contamination could not be avoided completely. Other factors may minimise fibroblast contamination such as minimal tissue manipulation and early collection during surgery.