Mismatch Repair and Microsatellite Testing for Individuals With Colorectal Cancer.

This cohort study examines the institution-level and patient-level factors associated with mismatch repair and microsatellite testing for individuals with colorectal cancer.

The Rise of Patients Declining Rectal Cancer Surgery in the Era of Total Neoadjuvant Therapy.

BACKGROUND: The treatment landscape for rectal cancer is rapidly evolving, particularly with the increasing use of neoadjuvant therapies. Still, up to 50% of patients with stage II-III disease require surgical resection post-neoadjuvant therapy to achieve the best oncologic outcomes. Many patients, however, hope to avoid surgery. This study aimed to assess trends and factors associated with declining recommended oncologic resection after systemic therapy nationally and in our institution. PATIENTS AND METHODS: This is a retrospective analysis using the National Cancer Database from 2009 to 2021 and an institutional cohort at an academic center between 2009 and 2022 including adults with stage I-III rectal adenocarcinoma who underwent neoadjuvant therapy and were suitable for surgery. RESULTS: Of 96,997 patients nationally, the rate of declining surgery increased from 2.3% in 2009 to 6.3% in 2021, a trend mirrored in our institutional cohort of 365 patients (0% in 2009/2010 to approximately 6-12% in 2021/2022). Locally, patients who declined surgery had higher rates of tobacco use, temporary loss to follow-up during therapy, and a more robust, albeit incomplete, tumor response to neoadjuvant therapy compared with controls who underwent surgery. Despite a stoma being the most cited reason for declining surgery, 30.4% of patients who declined oncologic resection died with a stoma. CONCLUSIONS: Our findings underscore a notable trend of patients declining oncologic resections following neoadjuvant therapy for rectal cancer. By shedding light on the outcomes of patients who opt against surgery, we address a critical gap in the literature essential for informing patients about potential risks.

Comparative analysis of short-term outcomes after semielective and elective surgery for sigmoid volvulus.

BACKGROUND: Data to guide surgical timing after colonic decompression for sigmoid volvulus are limited. Thus, we compared the postoperative outcomes of patients with sigmoid volvulus who underwent semielective (during index hospitalization after decompression) and elective surgery (subsequent elective hospitalization). METHODS: We performed a retrospective review of 100% Medicare Provider Analysis and Review Files from 2016 to 2019, including Medicare beneficiaries aged ≥65 years who were urgently/emergently admitted for their index episode of volvulus and underwent colonic decompression followed by surgery. RESULTS: The mean age of 2,053 patients was 78 (standard deviation 8 years); 7% had elective surgery and 93% had semielective surgery (including 12.5% on the same day as decompression). In a bivariate analysis, elective surgery was associated with greater rates of minimally invasive surgery (32.8% vs 12.6%, P < .001), lower rates of ostomy formation (2.9% vs 36.0%, P < .001), and greater rates of discharge home (89.8% vs 47.4%, P < .001) with similar cumulative length of stay (8 vs 9 days, not significant) compared with semielective surgery. In a multivariable logistic regression, elective surgery was associated with reduced odds of morbidity (odds ratio, 0.60; 95% confidence interval, 0.49-0.74) and similar odds of mortality (odds ratio, 0.79; 95% confidence interval, 0.50-1.25) compared with semielective surgery, which remained consistent after excluding patients with surgery on the same day as decompression. CONCLUSIONS: After colonic decompression for sigmoid volvulus, elective surgery appears safe and is associated with favorable outcomes compared with semielective surgery. With the potential severe consequences of volvulus recurrence, these findings underscore the need for algorithms to predict recurrence risk to help guide careful patient selection for elective surgery.

Systematic Review of Surgical Care in the Incarcerated Population: Identifying Knowledge Gaps for Future Research.

Objective: This study, examining literature up to December 2023, aims to comprehensively assess surgical care for incarcerated individuals, identifying crucial knowledge gaps for informing future health services research and interventions. Background: The US prison system detains around 2 million individuals, mainly young, indigent males from ethnic and racial minorities. The constitutional right to healthcare does not protect this population from unique health challenges and disparities. The scarcity of literature on surgical care necessitates a systematic review to stimulate research, improve care quality, and address health issues within this marginalized community. Methods: A systematic review, pre-registered with the International Prospective Register of Systematic Reviews (CRD42023454782), involved searches in PubMed, Embase, and Web of Science. Original research on surgical care for incarcerated individuals was included, excluding case reports/series (<10 patients), abstracts, and studies involving prisoners of war, plastic surgeries for recidivism reduction, transplants using organs from incarcerated individuals, and nonconsensual surgical sterilization. Results: Out of 8209 studies screened, 118 met inclusion criteria, with 17 studies from 16 distinct cohorts reporting on surgical care. Predominantly focusing on orthopedic surgeries, supplemented by studies in emergency general, burns, ophthalmology, and kidney transplantation, the review identified delayed hospital presentations, a high incidence of complex cases, and low postoperative follow-up rates. Notable complications, such as nonfusion and postarthroplasty infections, were more prevalent in incarcerated individuals compared with nonincarcerated individuals. Trauma-related mortality rates were similar, despite lower intraabdominal injuries following penetrating abdominal injuries in incarcerated patients. Conclusion: While some evidence suggests inferior surgical care in incarcerated patients, the limited quality of available studies underscores the urgency of addressing knowledge gaps through future research. This is crucial for patients, clinicians, and policymakers aiming to enhance care quality for a population at risk of surgical complications during incarceration and postrelease.

New Onset Geriatric Syndromes and One-year Outcomes Following Elective Gastrointestinal Cancer Surgery.

OBJECTIVE: To assess whether older adults who develop geriatric syndromes following elective gastrointestinal surgery have poorer 1-year outcomes. BACKGROUND: Within 10 years, 70% of all cancers will occur in older adults ≥65 years old. The rise in older adults requiring major surgery has brought attention to age-related complications termed geriatric syndromes. However, whether postoperative geriatric syndromes are associated with long-term outcomes is unclear. METHODS: A population-based retrospective cohort study using the New York State Cancer Registry and the Statewide Planning and Research Cooperative System was performed including patients >55 years with pathologic stage I-III esophageal, gastric, pancreatic, colon, or rectal cancer who underwent elective resection between 2004 and 2018. Those aged 55 to 64 served as the reference group. The exposure of interest was a geriatric syndrome [fracture, fall, delirium, pressure ulcer, depression, malnutrition, failure to thrive, dehydration, or incontinence (urinary/fecal)] during the surgical admission. Patients with any geriatric syndrome within 1 year of surgery were excluded. Outcomes included incident geriatric syndrome, 1-year days alive and out of the hospital, and 1-year all-cause mortality. RESULTS: In this study, 37,998 patients with a median age of 71 years without a prior geriatric syndrome were included. Of those 65 years or more, 6.4% developed a geriatric syndrome. Factors associated with an incident geriatric syndrome were age, alcohol/tobacco use, comorbidities, neoadjuvant therapy, ostomies, open surgery, and upper gastrointestinal cancers. An incident geriatric syndrome was associated with a 43% higher risk of 1-year mortality (hazard ratio, 1.43; 95% confidence interval, 1.27-1.60). For those aged 65+ discharged alive and not to hospice, a geriatric syndrome was associated with significantly fewer days alive and out of hospital (322 vs 346 days, P < 0.0001). There was an indirect relationship between the number of geriatric syndromes and 1-year mortality and days alive and out of the hospital after adjusting for surgical complications. CONCLUSIONS: Given the increase in older adults requiring major surgical intervention, and the establishment of geriatric surgery accreditation programs, these data suggest that morbidity and mortality metrics should be adjusted to accommodate the independent relationship between geriatric syndromes and long-term outcomes.

Metabolic syndrome and surgical complications: a systematic review and meta-analysis of 13 million individuals.

BACKGROUND: Metabolic syndrome (MetS) is characterised by the presence of at least three of the five following components: insulin resistance, obesity, chronic hypertension, elevated serum triglycerides, and decreased high-density lipoprotein cholesterol concentrations. It is estimated to affect 1 in 3 people around the globe and is reported to affect 46% of surgical patients. For people with MetS who undergo surgery, an emerging body of literature points to significantly poorer postoperative outcomes compared with nonaffected populations. The aim of this study is to review the current evidence on the risks of surgical complications in patients with MetS compared to those without MetS. METHODS: Systematic review and meta-analysis using PRISMA and AMSTAR reporting guidelines. RESULTS: The meta-analysis included 63 studies involving 1 919 347 patients with MetS and 11 248 114 patients without MetS. Compared to individuals without the condition, individuals with MetS were at an increased risk of mortality (OR 1.75 95% CI: 1.36-2.24; P <0.01); all surgical site infection types as well as dehiscence (OR 1.64 95% CI: 1.52-1.77; P <0.01); cardiovascular complications (OR 1.56 95% CI: 1.41-1.73; P <0.01) including myocardial infarction, stroke, cardiac arrest, cardiac arrythmias and deep vein thrombosis; increased length of hospital stay (MD 0.65 95% CI: 0.39-0.9; P <0.01); and hospital readmission (OR 1.55 95% CI: 1.41-1.71; P <0.01). CONCLUSION: MetS is associated with a significantly increased risk of surgical complications including mortality, surgical site infection, cardiovascular complications, increased length of stay, and hospital readmission. Despite these risks and the high prevalence of MetS in surgical populations there is a lack of evidence on interventions for reducing surgical complications in patients with MetS. The authors suggest prioritising interventions across the surgical continuum that include (1) preoperative screening for MetS; (2) surgical prehabilitation; (3) intraoperative monitoring and management; and (4) postoperative rehabilitation and follow-up.

A Scoping Review of Quality-of-Life Assessments Employed in Abdominal Wall Reconstruction.

INTRODUCTION: Surgeons use several quality-of-life instruments to track outcomes following abdominal wall reconstruction (AWR); however, there is no universally agreed upon instrument. We review the instruments used in AWR and report their utilization trends within the literature. METHODS: This scoping review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis extension for Scoping Reviews guidelines using the PubMed, Embase, Web of Science, ClinicalTrials.gov, and Cochrane databases. All published articles in the English language that employed a quality-of-life assessment for abdominal wall hernia repair were included. Studies which focused solely on aesthetic abdominoplasty, autologous breast reconstruction, rectus diastasis, pediatric patients, inguinal hernia, or femoral hernias were excluded. RESULTS: Six hernia-specific tools and six generic health tools were identified. The Hernia-Related Quality-of-Life Survey and Carolinas Comfort Scale are the most common hernia-specific tools, while the Short-Form 36 (SF-36) is the most common generic health tool. Notably, the SF-36 is also the most widely used tool for AWR outcomes overall. Each tool captures a unique set of patient outcomes which ranges from abdominal wall functionality to mental health. CONCLUSIONS: The outcomes of AWR have been widely studied with several different assessments proposed and used over the past few decades. These instruments allow for patient assessment of pain, quality of life, functional status, and mental health. Commonly used tools include the Hernia-Related Quality-of-Life Survey, Carolinas Comfort Scale, and SF-36. Due to the large heterogeneity of available instruments, future work may seek to determine or develop a standardized instrument for characterizing AWR outcomes.

Practice Patterns for Organ Preservation in US Patients With Rectal Cancer, 2006-2020.

Importance: In March 2023, the National Comprehensive Cancer Network endorsed watch and wait for those with complete clinical response to total neoadjuvant therapy. Neoadjuvant therapy is highly efficacious, so this recommendation may have broad implications, but the current trends in organ preservation in the US are unknown. Objective: To describe organ preservation trends among patients with rectal cancer in the US from 2006 to 2020. Design, Setting, and Participants: This retrospective, observational case series included adults (aged ≥18 years) with rectal adenocarcinoma managed with curative intent from 2006 to 2020 in the National Cancer Database. Exposure: The year of treatment was the primary exposure. The type of therapy was chemotherapy, radiation, or surgery (proctectomy, transanal local excision, no tumor resection). The timing of therapy was classified as neoadjuvant or adjuvant. Main Outcomes and Measures: The primary outcome was the absolute annual proportion of organ preservation after radical treatment, defined as chemotherapy and/or radiation without tumor resection, proctectomy, or transanal local excision. A secondary analysis examined complete pathologic responses among eligible patients. Results: Of the 175 545 patients included, the mean (SD) age was 63 (13) years, 39.7% were female, 17.4% had clinical stage I disease, 24.7% had stage IIA to IIC disease, 32.1% had stage IIIA to IIIC disease, and 25.7% had unknown stage. The absolute annual proportion of organ preservation increased by 9.8 percentage points (from 18.4% in 2006 to 28.2% in 2020; P < .001). From 2006 to 2020, the absolute rate of organ preservation increased by 13.0 percentage points for patients with stage IIA to IIC disease (19.5% to 32.5%), 12.9 percentage points for patients with stage IIIA to IIC disease (16.2% to 29.1%), and 10.1 percentage points for unknown stages (16.5% to 26.6%; all P < .001). Conversely, patients with stage I disease experienced a 6.1-percentage point absolute decline in organ preservation (from 26.4% in 2006 to 20.3% in 2020; P < .001). The annual rate of transanal local excisions decreased for all stages. In the subgroup of 80 607 eligible patients, the proportion of complete pathologic responses increased from 6.5% in 2006 to 18.8% in 2020 (P < .001). Conclusions and Relevance: This case series shows that rectal cancer is increasingly being managed medically, especially among patients whose treatment historically relied on proctectomy. Given the National Comprehensive Cancer Network endorsement of watch and wait, the increasing trends in organ preservation, and the nearly 3-fold increase in complete pathologic responses, international professional societies should urgently develop multidisciplinary core outcome sets and care quality indicators to ensure high-quality rectal cancer research and care delivery accounting for organ preservation.

Development and validation of multivariable predictive models for recurrence and mortality following nonoperative management of sigmoid volvulus.

AIM: Sigmoid volvulus is a challenging condition, and deciding between elective surgery or expectant management can be complex. The aim of this study was to develop a tool for predicting the risk of recurrent sigmoid volvulus and all-cause mortality within 1 year following initial nonoperative management. METHOD: This is a retrospective cohort study using Medicare claims data from 2016 to 2018 of beneficiaries admitted urgently/emergently for volvulus, undergoing colonic decompression and discharged alive without surgery (excluding those discharged to hospice). The primary outcomes were recurrent sigmoid volvulus and all-cause mortality within 1 year. Proportional hazards models and logistic regression were employed to identify risk factors and develop prediction equations, which were subsequently validated. RESULTS: Among the 2078 patients managed nonoperatively, 36.1% experienced recurrent sigmoid volvulus and 28.6% died within 1 year. The prediction model for recurrence integrated age, sex, race, palliative care consultations and four comorbidities, achieving area under the curve values of 0.63 in both the training and testing samples. The model for mortality incorporated age, palliative care consultations and nine comorbidities, with area under the curve values of 0.76 in the training and 0.70 in the testing sample. CONCLUSION: This study provides a straightforward predictive tool that utilizes easily accessible data to estimate individualized risks of recurrent sigmoid volvulus and all-cause mortality for older adults initially managed nonoperatively. The tool can assist clinicians and patients in making informed decisions about such risks. While the accuracy of the calculator was validated, further confirmation through external validation and prospective studies would enhance its clinical utility.

Is there an outcome benefit? Patient engagement technology in addition to the electronic medical record patient portal following elective colorectal surgery.

BACKGROUND: Patient engagement technologies (PET) are an area of growing innovation and investment, but whether PET use in the setting of electronic medical record (EMR) supported patient portals are associated with improved outcomes is unknown. Therefore, we assessed PET and EMR activation among patients undergoing elective colorectal surgery on an enhanced recovery pathway. METHODS: We identified adults undergoing elective colorectal surgery between 1/2017 and 7/2021. EMR activations were assessed and patients were considered PET users if they used a proprietary PET application. Multivariable logistic regression was used to identify factors associated with PET use and determine whether the level of engagement (percentage of messages read by the patient) was associated with 30-day outcomes. RESULTS: 484 patients (53.5% PET users, 81.6% with an activated EMR patient portal, 30.8% ≥ 70 years of age) were included. PET users were younger, more likely to have their EMR portal activated and had decreased odds of prolonged length of stay [odds ratio (OR) 0.5, 95% confidence interval (CI) 0.4-0.8]. Among patients ≥ 70 years, PET users had reduced odds of readmissions (OR 0.2, 95% CI 0.1-0.9) compared to PET non-users. The most engaged PET users had decreased morbidity (OR 0.2, 95% CI 0.1-0.8) and readmissions (OR 0.3, 95% CI 0.1-0.8) compared to the least engaged PET users. CONCLUSION: When controlling for EMR activation, patients who use PET, specifically those with higher levels of engagement or aged ≥ 70, have improved outcomes following elective colorectal surgery. Interventions aimed at increasing the adoption of PET among older adults may be warranted.

New insights into the responder/nonresponder divide in rectal cancer: Damage-induced Type I IFNs dictate treatment efficacy and can be targeted to enhance radiotherapy.

Rectal cancer ranks as the second leading cause of cancer-related deaths. Neoadjuvant therapy for rectal cancer patients often results in individuals that respond well to therapy and those that respond poorly, requiring life-altering excision surgery. It is inadequately understood what dictates this responder/nonresponder divide. Our major aim is to identify what factors in the tumor microenvironment drive a fraction of rectal cancer patients to respond to radiotherapy. We also sought to distinguish potential biomarkers that would indicate a positive response to therapy and design combinatorial therapeutics to enhance radiotherapy efficacy. To address this, we developed an orthotopic murine model of rectal cancer treated with short course radiotherapy that recapitulates the bimodal response observed in the clinic. We utilized a robust combination of transcriptomics and protein analysis to identify differences between responding and nonresponding tumors. Our mouse model recapitulates human disease in which a fraction of tumors respond to radiotherapy (responders) while the majority are nonresponsive. We determined that responding tumors had increased damage-induced cell death, and a unique immune-activation signature associated with tumor-associated macrophages, cancer-associated fibroblasts, and CD8+ T cells. This signature was dependent on radiation-induced increases of Type I Interferons (IFNs). We investigated a therapeutic approach targeting the cGAS/STING pathway and demonstrated improved response rate following radiotherapy. These results suggest that modulating the Type I IFN pathway has the potential to improve radiation therapy efficacy in RC.

Are postoperative opioid stewardship protocols sustainable? Results from a 2-year quality improvement project.

BACKGROUND: Opioid stewardship protocols reduce opioid overprescription, but many require corrective action within 1 year. Because there are limited data on the sustainability of opioid reduction protocols, we sought to evaluate prescribing trends beyond 1 year. METHODS: We reviewed prescribing data from a tertiary care center to establish a consensus discharge opioid-prescribing guideline. Subsequently, we performed a prospective quality-improvement study for patients on an enhanced recovery protocol undergoing elective colectomies, proctectomies, and stoma-related procedures. We gathered process (protocol compliance), balance (rates of patient-controlled analgesia and nerve blocks, inpatient opioid utilization, pain scores within 48 hours of discharge), and clinical measures (median discharge opioid pills, postdischarge day 7 satisfaction). RESULTS: In total, 1,049 patients with similar ages, operative indications, and rates of substance use pre- and postintervention were included. Over 2 years, compliance was 88.6%, and there was a 43.6% reduction in the total discharge number of opioid pills. Phone calls for opioid refills were stable (10.2% pre- vs 7.8% postintervention, P = .16), and the following all decreased significantly: intraoperative nerve blocks, patient-controlled analgesia use, and final 48-hour and total median inpatient opioid use. There was a clinically negligible, statistically significant reduction in pain scores within 48 hours of discharge. Fifty patients provided satisfaction data, and 92% were satisfied or somewhat satisfied with their analgesia. CONCLUSION: Over 2 years, reduced opioid prescribing was maintained without escalating resources. Sustainability suggests that after successfully implementing an opioid reduction protocol, institutions may safely redeploy quality improvement resources elsewhere.

Epidemiology and healthcare utilization for rectal foreign bodies in United States adults, 2012-2021.

INTRODUCTION: Presentations to the emergency department for rectal foreign bodies are common, but there is little epidemiologic information on this condition. This limits the ability to provide evidence-based education to trainees regarding the populations affected, the types and frequency of foreign bodies, and factors associated with hospitalization. To address this, we analyzed national estimates of emergency department presentations for rectal foreign bodies from 2012 to 2021 in the US. METHODS: We queried the National Electronic Injury Surveillance System for any injury to the 'pubic region' or 'lower trunk' with an accompanying diagnosis of foreign body, puncture, or laceration. Two authors manually reviewed all clinical narratives to identify cases of rectal foreign bodies. National estimates were determined using weighting and strata variables, incidence rates calculated using census data, trends assessed by linear regression, and factors associated with hospitalization identified by multivariable logistic regression. RESULTS: From 885 cases, there were an estimated 38,948 (95% CI, 32,040-45,856) emergency department visits for rectal foreign bodies among individuals ≥15 years from 2012 to 2021. The average age was 43, 77.8% were male, 55.4% of foreign bodies were sexual devices, and 40.8% required hospitalization. The annual incidence of presentations for rectal foreign bodies increased from 1.2 in 2012 to 1.9 per 100,000 persons in 2021 (R2 = 0.84, p < 0.01). Males have a bimodal age distribution peaking in the fifth decade, while females have a right-skewed age distribution peaking in the second decade. Female sex (odds ratio [OR] 0.4; 95% confidence interval [CI], 0.2-0.6) and, compared to sexual devices, balls/marbles (OR 0.2; 95% CI, 0.05-0.6) or drugs/paraphernalia (OR 0.1; 95% CI, 0.05-0.4) are associated with a reduced odds of hospitalization. CONCLUSIONS: Presentations to the emergency department for rectal foreign bodies increased for males and females from 2012 to 2021 in the United States. These epidemiologic estimates for a complex form of anorectal trauma provide preclinical information for emergency medicine, surgery, and radiology trainees.

Could meeting the standards of the National Accreditation Program for Rectal Cancer in the National Cancer Database improve patient outcomes?

AIM: The National Accreditation Program for Rectal Cancer (NAPRC) was developed to improve rectal cancer patient outcomes in the United States. The NAPRC consists of a set of process and outcome measures that hospitals must meet in order to be accredited. We aimed to assess the potential of the NAPRC by determining whether achievement of the process measures correlates with improved survival. METHODS: The National Cancer Database was used to identify patients undergoing curative proctectomy for non-metastatic rectal cancer from 2010 to 2014. NAPRC process measures identified in the National Cancer Database included clinical staging completion, treatment starting <60 days from diagnosis, carcinoembryonic antigen level measured prior to treatment, tumour regression grading and margin assessment. RESULTS: There were 48 669 patients identified with a mean age of 62 ± 12.9 years and 61.3% of patients were men. The process measure completed most often was assessment of proximal and distal margins (98.4%) and the measure completed least often was the serum carcinoembryonic antigen level prior to treatment (63.8%). All six process measures were completed in 23.6% of patients. After controlling for age, gender, comorbidities, annual facility resection volume, race and pathological stage, completion of all process measures was associated with a statistically significant mortality decrease (Cox hazard ratio 0.88, 95% CI 0.81-0.94, P < 0.001). CONCLUSION: Participating institutions provided complete datasets for all six process measures in less than a quarter of patients. Compliance with all process measures was associated with a significant mortality reduction. Improved adoption of NAPRC process measures could therefore result in improved survival rates for rectal cancer in the United States.

Implementation of a new definition for acute kidney injury in the National Surgical Quality Improvement Project: What is the impact?

BACKGROUND: The National Surgical Quality Improvement Project is the preeminent surgical quality database, but it undercaptures acute kidney injury. Recently, the National Surgical Quality Improvement Project lowered the thresholds for acute kidney injury for the first time, so we assessed the impact of implementing the definition change on the rate of acute kidney injuries. METHODS: For this interrupted time series analysis, we assembled 2 institutional National Surgical Quality Improvement Project files to identify adults undergoing inpatient noncardiac nonvascular surgery. The acute kidney injury definition changed on July 1, 2021, so patients were stratified by their operative date into 12-month pre and post groups. Weighted covariate propensity score matching and logistic regression were used to balance the periods and compare outcomes. RESULTS: In total, 4,784 adults were eligible (55% pre and 45% post change). The overall rate of postoperative outcomes was similar, aside for acute kidney injury (pre 0.3%, post 5.6%, P < .0001). Regardless of the period, patients with acute kidney injuries had significantly longer lengths of stay and morbidity and mortality rates compared to those without an acute kidney injury. After the definition change, 81% of acute kidney injuries were stage I, and none were identified by urine output alone. After matching, surgery after the definition change was associated with an increased weighted odds of an acute kidney injury compared to surgery before the change (odds ratio 26.2; 95% confidence interval, 12.1-56.8). CONCLUSION: In the year after the definition change, there was a 1,700% relative increase in the rate of reported acute kidney injuries. Newly identified acute kidney injuries are associated with high complication rates, and this definition change has implications for patient counseling, research, and quality reporting.

A Novel Use for Pelvic MRI Scans to Estimate Lean Body Mass and Screen for Sarcopenia in Patients With Rectal Cancer.

BACKGROUND: Sarcopenia, the combination of low lean body mass and decreased muscle strength, is associated with significant morbidity and mortality among patients with colorectal cancer. Standard methods for assessing lean body mass and muscle strength, such as bioelectric impedance analysis and handgrip dynamometry, are rarely obtained clinically. Per National Cancer Center Network recommendations, pelvic MRI is routinely collected for staging and surveillance among patients with rectal cancer. However, there are no data assessing the relationship of pelvic MRI lean body mass measurements at the fifth lumbar vertebrae with bioelectric impedance analysis, handgrip strength, or abdominal CT in patients with rectal cancer. Therefore, we aimed to assess whether pelvic MRI lean body mass correlates with a standard for lean body mass measurement (bioelectric impedance analysis), muscle function (handgrip strength), and an imaging modality frequently used in the literature to identify sarcopenia (abdominal CT at the third lumbar vertebrae). IMPACT OF INNOVATION: Lean body mass measurements from routinely collected pelvic MRI at the fifth lumbar vertebrae accurately and reproducibly estimate lean body mass and modestly correlate with handgrip strength. Rectal cancer pelvic MRI may be repurposed for identifying sarcopenia without increasing inconvenience, ionizing radiation exposure, or expenditure to patients with rectal cancer. TECHNOLOGY, MATERIALS, AND METHODS: Patients with locally advanced rectal cancer with pretreatment bioelectric impedance analysis and handgrip strength measurements within 3 months of their staging pelvic MRI were eligible. Axial skeletal muscle areas were segmented using T1-weighted series pelvic MRI at the fifth lumbar vertebrae and abdominal CT at the third lumbar vertebrae using Slice-O-Matic (Tomovision, Montreal, Canada). Lean body mass (kilograms) was derived from skeletal muscle area with standard equations. Handgrip strength (kilograms) was the maximum of 3 dominant hand attempts in the standing anatomical position. The primary outcome was the agreement between lean body mass measured by pelvic MRI (at the fifth lumbar vertebrae) and bioelectric impedance analysis. Secondary outcomes included the concordance of pelvic MRI lean body mass (at the fifth lumbar vertebrae) with abdominal CT (at the third lumbar vertebrae) and handgrip strength. Additionally, the intra- and interobserver validity, internal consistency, and the mean difference (bias) between lean body mass measurements by pelvic MRI and bioelectric impedance analysis were evaluated. PRELIMINARY RESULTS: Sixteen patients were eligible. The average lean body mass was similar and consistent across 2 observers between bioelectric impedance analysis and pelvic MRI. There was a strong correlation between lean body mass measured on pelvic MRI, bioelectric impedance analysis, and abdominal CT. The reliability of 2 pelvic MRI lean body mass measurements (2 weeks apart by blinded observers) and the correlation of lean body mass between pelvic MRI and bioelectric impedance analysis was strong. Inter- and intraobserver correlation, reliability, and internal consistency were strong for the entire cohort. There was a moderate correlation between pelvic MRI lean body mass and handgrip strength. CONCLUSIONS: Lean body mass measured at the fifth lumbar vertebrae on pelvic MRI is reproducible and correlates strongly with measurements from bioelectric impedance analysis (standard) and abdominal CT at the third lumbar vertebrae and modestly with handgrip strength. These data suggest that MRI lean body mass measurements may be a method to screen patients with rectal cancer for sarcopenia. FUTURE DIRECTIONS: Future studies may evaluate changes in lean body mass on serial pelvic MRI studies among patients with rectal cancer.