Malnutrition in Head and Neck Free Flap Reconstruction as a Predictor of Adverse Outcomes.

INTRODUCTION: Malnutrition is associated with increased mortality in patients with head and neck (H&N) cancer. Because albumin levels are used as a surrogate for nutritional status, the purpose of this study is to assess whether malnutrition is associated with adverse postoperative outcomes in H&N free flap reconstruction. MATERIALS AND METHODS: The 2006-2018 National Surgical Quality Improvement Program Database was queried for patients undergoing flap procedures of the H&N based on Current Procedure Terminology codes. Patients were included if they were operated on by an otolaryngologist or when the primary surgical site was H&N. Nutritional status was categorized as malnourished (preoperative albumin level <3.5 g/dL) or normal (preoperative albumin level ≥3.5 g/dL). Major complications included pulmonary complications, cardiac complications, deep vein thrombosis/pulmonary embolism, and sepsis/septic shock. Minor complications included surgical infection, urinary tract infection, bleeding, and dehiscence. Data were analyzed via univariate chi-square and multivariate regression analyses. RESULTS: Of the patients, 2532 (83.3%) had normal albumin and 506 (16.7%) had hypoalbuminemia. Patients with hypoalbuminemia were more likely to have smoking history (P = 0.008), pulmonary comorbidity (P < 0.001), renal comorbidity (P = 0.018), disseminated cancer (P < 0.001), steroid use (P < 0.001), recent weight loss (P < 0.001), bleeding disorder (P = 0.023), and preoperative transfusion (P < 0.001). After adjustment for preoperative variance, malnourished patients were more likely to experience death (P < 0.001), return to operating room (P < 0.001), free flap failure (P = 0.008), pulmonary complication (P < 0.001), deep vein thrombosis/pulmonary embolism (P = 0.019), wound disruption (P = 0.042), intraoperative transfusion (P < 0.001), minor complication (P < 0.001), major complication (P < 0.001), and extended length of stay (P < 0.001). Of the patients with normal albumin, 2.1% experienced flap failure compared with 6.3% of patients with hypoalbuminemia. It should be noted that malnourished patients were 3.370 times more likely to experience flap failure (95% confidence interval, 1.383-8.212; P = 0.008) and 3.975 times more likely to experience death (95% confidence interval, 1.700-9.626; P = 0.001) than those with normal albumin. CONCLUSION: Malnutrition is associated with death, flap failure, minor complications, and other major complications following H&N free flap surgery, even after controlling for preoperative variance. Optimizing preoperative nutrition status before free flap procedures may ameliorate morbidity and mortality in H&N patients.

Platelet microRNAs inhibit primary tumor growth via broad modulation of tumor cell mRNA expression in ectopic pancreatic cancer in mice.

We investigated the contributions of platelet microRNAs (miRNAs) to the rate of growth and regulation of gene expression in primary ectopic tumors using mouse models. We previously identified an inhibitory role for platelets in solid tumor growth, mediated by tumor infiltration of platelet microvesicles (microparticles) which are enriched in platelet-derived miRNAs. To investigate the specific roles of platelet miRNAs in tumor growth models, we implanted pancreatic ductal adenocarcinoma cells as a bolus into mice with megakaryocyte-/platelet-specific depletion of mature miRNAs. We observed an ~50% increase in the rate of growth of ectopic primary tumors in these mice compared to controls including at early stages, associated with reduced apoptosis in the tumors, in particular in tumor cells associated with platelet microvesicles-which were depleted of platelet-enriched miRNAs-demonstrating a specific role for platelet miRNAs in modulation of primary tumor growth. Differential expression RNA sequencing of tumor cells isolated from advanced primary tumors revealed a broad cohort of mRNAs modulated in the tumor cells as a function of host platelet miRNAs. Altered genes comprised 548 up-regulated transcripts and 43 down-regulated transcripts, mostly mRNAs altogether spanning a variety of growth signaling pathways-notably pathways related to epithelial-mesenchymal transition-in tumor cells from platelet miRNA-deleted mice compared with those from control mice. Tumors in platelet miRNA-depleted mice showed more sarcomatoid growth and more advanced tumor grade, indicating roles for host platelet miRNAs in tumor plasticity. We further validated increased protein expression of selected genes associated with increased cognate mRNAs in the tumors due to platelet miRNA depletion in the host animals, providing proof of principle of widespread effects of platelet miRNAs on tumor cell functional gene expression in primary tumors in vivo. Together, these data demonstrate that platelet-derived miRNAs modulate solid tumor growth in vivo by broad-spectrum restructuring of the tumor cell transcriptome.