Normal CEA Levels After Neoadjuvant Chemotherapy and Cytoreduction with Hyperthermic Intraperitoneal Chemoperfusion Predict Improved Survival from Colorectal Peritoneal Metastases.

BACKGROUND: Normal carcinoembryonic antigen (CEA) levels (≤ 2.5 ng/ml) after resection of localized colorectal cancer or liver metastases are associated with improved survival, however, these trends are understudied for colorectal peritoneal metastases (CRPM). PATIENTS AND METHODS: We conducted a retrospective single-institution study of patients with CRPM undergoing cytoreductive surgery with hyperthermic intraperitoneal chemoperfusion (CRS/HIPEC) with and without neoadjuvant chemotherapy (NACT). CEA was measured before and after NACT and within 3 months after CRS/HIPEC. RESULTS: A total of 253 patients (mean age 55.3 years) with CRPM undergoing CRS/HIPEC had complete CEA data and 191 also underwent NACT with complete data. The median peritoneal carcinomatosis index score (PCI) of the overall cohort was 12 and 82.7% of patients had complete cytoreduction (CC0). In total, 64 (33.5%) patients had normal CEA levels after NACT with a median overall survival (OS) of 45.2 months compared with those with an elevated CEA (26.4 months, p = 0.004). Patients with normal CEA after NACT had a lower PCI found at the time of surgery than those with elevated CEA (10 versus 14, p < 0.001), 68 (26.9%) patients with an elevated preoperative CEA level experienced normalization after CRS/HIPEC, and 118 (46.6%) patients had elevated CEA after CRS/HIPEC. Patients who experienced normalization demonstrated similar OS to patients that had normal CEA levels pre- and post-surgery and improved OS compared with those with elevated postop CEA (median 41.9 versus 47 months versus 17.1 months, respectively, p < 0.001). CONCLUSIONS: Normal CEA levels after NACT and/or CRS/HIPEC are associated with improved survival for patients with CRPM. Patients that normalize CEA levels after surgery have similar survival to those with normal preoperative levels.

Insight into Predictors of Cytoreduction Score Following Cytoreductive Surgery-Hyperthermic Intraperitoneal Chemotherapy for Gastric Peritoneal Carcinomatosis Improves Patient Selection and Prognostic Outcomes.

BACKGROUND: Peritoneal metastases due to gastric adenocarcinoma (GCPM) carry a dismal prognosis. A promising treatment strategy is cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC), but clear eligibility criteria for GCPM are lacking. We sought to identify factors associated with overall survival (OS) following CRS-HIPEC for GCPM to help optimize patient selection and clinical outcomes. PATIENTS AND METHODS: In this single-center retrospective cohort study, we examined CRS-HIPEC outcomes for patients with GCPM between 2001 and 2021. After analyzing patient demographic, clinicopathologic, and perioperative variables, we applied multivariable Cox hazard models to assess factors associated with OS. We then assessed associations between baseline predictors and prognostically important variables using multivariable logistic regression. RESULTS: We analyzed 55 patients with GCPM who underwent CRS-HIPEC. Median age was 54 years and 42% were female. Median peritoneal carcinomatosis index (PCI) was 8, and 75% of patients achieved a cytoreduction completeness score (CC score) of 0. Median progression-free survival (PFS) was 6.9 months, and median OS was 14.1 months. On adjusted analysis, a CC score > 0 (HR 2.3, p = 0.02) was significantly associated with worse OS. A peritoneal carcinomatosis index greater than 13 (OR 52.6, p = 0.001) and fewer lymph nodes (especially < 18) resected with the primary tumor (OR 0.86, p = 0.042) in the metachronous setting were significantly associated with incomplete macroscopic cytoreduction (CC score > 0). CONCLUSIONS: We demonstrated that PCI > 13 and primary lymph nodes harvested < 18 in metachronous tumors are associated with CC score > 0, which in turn portends a worse OS. Although these results warrant prospective validation, they provide insight into improved selection of patients with GCPM for CRS-HIPEC.

Targeted Next-Generation Sequencing Improves the Prognostication of Patients with Disseminated Appendiceal Mucinous Neoplasms (Pseudomyxoma Peritonei).

BACKGROUND: Appendiceal mucinous neoplasms (AMNs) with disseminated disease (pseudomyxoma peritonei) are heterogeneous tumors with variable clinicopathologic behavior. Despite the development of prognostic systems, objective biomarkers are needed to stratify patients. With the advent of next-generation sequencing (NGS), it remains unclear if molecular testing can improve the evaluation of disseminated AMN patients. METHODS: Targeted NGS was performed for 183 patients and correlated with clinicopathologic features to include American Joint Committee on Cancer/World Health Organization (AJCC/WHO) histologic grade, peritoneal cancer index (PCI), completeness of cytoreduction (CC) score, and overall survival (OS). RESULTS: Genomic alterations were identified for 179 (98%) disseminated AMNs. Excluding mitogen-activated protein kinase genes and GNAS due to their ubiquitous nature, collective genomic alterations in TP53, SMAD4, CDKN2A, and the mTOR genes were associated with older mean age, higher AJCC/WHO histologic grade, lymphovascular invasion, perineural invasion, regional lymph node metastasis, and lower mean PCI (p < 0.040). Patients harboring TP53, SMAD4, ATM, CDKN2A, and/or mTOR gene alterations were found to have lower OS rates of 55% at 5 years and 14% at 10 years, compared with 88% at 5 years and 88% at 10 years for patients without the aforementioned alterations (p < 0.001). Based on univariate and multivariate analyses, genomic alterations in TP53, SMAD4, ATM, CDKN2A, and/or the mTOR genes in disseminated AMNs were a negative prognostic factor for OS and independent of AJCC/WHO histologic grade, PCI, CC score, and hyperthermic intraperitoneal chemotherapy treatment (p = 0.006). CONCLUSIONS: Targeted NGS improves the prognostic assessment of patients with disseminated AMNs and identifies patients who may require increased surveillance and/or aggressive management.

Socioeconomic Barriers to CRS HIPEC for Appendiceal Cancer within a Regional Academic Hospital System.

BACKGROUND: Appendiceal cancer with peritoneal metastases (ACPM) is a complex disease requiring multidisciplinary care. Cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion (CRS HIPEC) can significantly improve survival but requires evaluation by a surgical oncologist and significant treatment endurance. The impacts of socioeconomic status (SES) and other social determinants of health on rates of surgical evaluation and treatment have not been examined. METHODS: We conducted a retrospective cohort study examining all patients with ACPM from 2010 to 2018 in a regional healthcare system. Patient characteristics, oncologic details, treatment strategies, and survival were examined. The primary outcomes of interest were referral to Surgical Oncology, receipt of CRS HIPEC, and survival. RESULTS: Of 194 patients identified, 94% had synchronous ACPM. The majority of patients (95%) were referred to surgical oncology. Advanced age was the only predictor of nonreferral (p < 0.001). A total of 147 patients (76%) ultimately underwent CRS HIPEC. After adjusting for medical and tumor characteristics, CRS HIPEC was less likely for patients who were unmarried [odds ratio (OR) 0.253, p = 0.004] or of low SES (OR 0.372, p = 0.03). On subanalysis of patients undergoing CRS HIPEC, median overall survival was worse for patients of low SES [51 months versus not reached (NR), p = 0.05], and this disparity persisted on multivariate analysis [hazard ratio (HR) = 2.278, p = 0.001]. CONCLUSIONS: This analysis is the first to evaluate barriers to CRS HIPEC for ACPM. While most patients were evaluated by a multidisciplinary team, nonmedical factors may play a role in the treatment received and ultimate outcomes. Addressing these disparities is crucial for ensuring equitable outcomes and improving patient care.

Failure to Thrive Following Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy: Causes and Consequences.

BACKGROUND: Failure to thrive (FTT) is a complex syndrome of nutritional failure and functional decline. Readmission for FTT following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS HIPEC) is common but underexamined. This study aims to determine features, risk factors, and prognostic significance of FTT following CRS HIPEC. PATIENTS AND METHODS: We reviewed patients who underwent CRS HIPEC from 2010 to 2018 at our institution. Patients were categorized into no readmission, FTT readmission, and other readmission. FTT was determined by coding and chart review. We compared baseline characteristics, oncologic data, perioperative outcomes, and survival among the three cohorts. RESULTS: Of 1068 discharges examined, 379 patients (36%) were readmitted within 90 days, of which 134 (12.5%) were labeled as FTT. Patients with FTT readmission had worse preoperative functional status, higher rates of malnutrition, more complex resections, longer hospital stays, and more postoperative complications (all p < 0.001). Ostomy creation [relative risk ratio (RRR) 4.06], in-hospital venous thromboembolism (VTE), discharge to nursing home (RRR 2.48), pre-CRS HIPEC chemotherapy (RRR 1.98), older age (RRR 1.84), and female gender (RRR 1.69) were all independent predictors for FTT readmission on multinomial regression (all p < 0.01). FTT readmission was associated with worse median overall survival on multivariate analysis [hazard ratio (HR) 1.60, p < 0.001] after controlling for oncologic, perioperative, and baseline factors. CONCLUSIONS: FTT is common following CRS HIPEC and appears to be associated with baseline patient characteristics, operative burden, and postoperative complications. Perioperative strategies for improving nutrition and activity, along with early recognition and intervention in FTT may improve patient outcomes.

Glucose deprivation-induced endoplasmic reticulum stress response plays a pivotal role in enhancement of TRAIL cytotoxicity.

Abnormalities of the tumor vasculature result in insufficient blood supply and development of a tumor microenvironment that is characterized by low glucose concentrations, low extracellular pH, and low oxygen tensions. We previously reported that glucose-deprived conditions induce metabolic stress and promote tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced cytotoxicity. In this study, we examined whether the metabolic stress-associated endoplasmic reticulum (ER) stress response pathway plays a pivotal role in the enhancement of TRAIL cytotoxicity. We observed no significant cytotoxicity when human colorectal cancer SW48 cells were treated with various doses of TRAIL (2-100 ng/ml) for 4 h or glucose (0-25 mM) for 24 h. However, a combination of TRAIL and low glucose-induced dose-dependent apoptosis through activation of caspases (-8, -9, and -3). Studies with activating transcription factor 4 (ATF4), C/EBP-homologous protein (CHOP), p53 upregulated modulator of apoptosis (PUMA), or death receptor 5 (DR5)-deficient mouse embryonic fibroblasts or HCT116 cells suggest that the ATF4-CHOP-PUMA axis and the ATF4-CHOP-DR5 axis are involved in the combined treatment-induced apoptosis. Moreover, the combined treatment-induced apoptosis was completely suppressed in BH3 interacting-domain death agonist (Bid)- or Bcl-2-associated X protein (Bax)-deficient HCT116 cells, but not Bak-deficient HCT116 cells. Interestingly, the combined treatment-induced Bax oligomerization was suppressed in PUMA-deficient HCT116 cells. These results suggest that glucose deprivation enhances TRAIL-induced apoptosis by integrating the ATF4-CHOP-PUMA axis and the ATF4-CHOP-DR5 axis, consequently amplifying the Bid-Bax-associated mitochondria-dependent pathway.

Impact of Socioeconomic Status on Presentation and Outcomes in Colorectal Peritoneal Metastases Following Cytoreduction and Chemoperfusion: Persistent Inequalities in Outcomes at a High-Volume Center.

BACKGROUND: Cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion (CRS HIPEC) can offer significant survival advantage for select patients with colorectal peritoneal metastases (CRPM). Low socioeconomic status (SES) is implicated in disparities in access to care. We analyze the impact of SES on postoperative outcomes and survival at a high-volume tertiary CRS HIPEC center. PATIENTS AND METHODS: We conducted a retrospective cohort study examining patients who underwent CRS HIPEC for CRPM from 2000 to 2018. Patients were grouped according to SES. Baseline characteristics, perioperative outcomes, and survival were examined between groups. RESULTS: A total of 226 patients were analyzed, 107 (47%) low-SES and 119 (53%) high-SES patients. High-SES patients were younger (52 vs. 58 years, p = 0.01) and more likely to be White (95.0% vs. 91.6%, p = 0.06) and privately insured (83% vs. 57%, p < 0.001). They traveled significantly further for treatment and had lower burden of comorbidities and frailty (p = 0.01). Low-SES patients more often presented with synchronous peritoneal metastases (48% vs. 35%, p = 0.05). Following CRS HIPEC, low-SES patients had longer length of stay and higher burden of postoperative complications, 90-day readmission, and 30-day mortality. Median overall survival following CRS HIPEC was worse for low-SES patients (17.8 vs. 32.4 months, p = 0.02). This disparity persisted on multivariate survival analysis (low SES: HR = 1.46, p = 0.03). CONCLUSIONS: Despite improving therapies for CRPM, low-SES patients remain at a significant disadvantage. Even patients who overcome barriers to care experience worse short- and long-term outcomes. Improving access and addressing these disparities is crucial to ensure equitable outcomes and improve patient care.

Definition and Prediction of Early Recurrence and Mortality Following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Colorectal Peritoneal Metastases: Towards Predicting Oncologic Futility Preoperatively.

INTRODUCTION: Early recurrence (ER) is a significant challenge for patients with colorectal peritoneal metastases (CRPM) following cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS HIPEC). Preoperative risk stratification for ER would improve preoperative decision making. METHODS: We conducted a retrospective study examining patients who underwent CRS HIPEC for CRPM from 2000 to 2018. Optimal definition of ER was determined via minimum p-value approach based on differentiation of post-recurrence survival. Risk factors for ER were assessed in a derivation cohort by uni- and multivariate logistic regression. A predictive score for ER was generated using preoperative variables and validated in an independent cohort. RESULTS: 384 patients were analyzed, 316 (82%) had documented recurrence. Optimal length of post-operative RFS to distinguish ER (n = 144, 46%) vs. late recurrence (LR) (n = 172, 63%) was 8 mos (p<0.01). ER patients had shorter median OS post-CRS-HIPEC (13.6 vs. 39.4 mos, p<0.01). Preoperative BMI (OR 1.88), liver lesions (OR 1.89), progression on chemotherapy (OR 2.14), positive lymph nodes (OR 2.47) and PCI score (16-20: OR 1.7; >20: OR 4.37) were significant predictors of ER (all p<0.05). Using this model, patients were assigned risk scores from 0 to 9. Intermediate (scores 4-6) and high-risk patients (score 7-9) had observed rates of ER of 56% and 79% and overall 2-year survival rates of 27% and 0% respectively. The model showed fair discrimination (AUC 0.72) and good calibration (Hosmer-Lemeshow GOF p = 0.68). CONCLUSIONS: ER predicts markedly worse OS following surgery. Preoperative factors can accurately stratify risk for ER and identify patients in whom CRS-HIPEC for CPRM is futile.

Predischarge Prediction of Readmission After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: Derivation and Validation of a Risk Prediction Score.

BACKGROUND: Ninety-day hospital readmission rates following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) range from 20 to 40%. OBJECTIVE: The aim of this study was to develop and validate a simple score to predict readmissions following CRS/HIPEC. STUDY DESIGN: Using a prospectively maintained database, we retrospectively reviewed clinicopathologic, perioperative, and day-of-discharge data for patients undergoing CRS/HIPEC for peritoneal surface malignancies between 2010 and 2018. In-hospital mortalities and discharges to hospice were excluded. Multivariate logistic regression was utilized to identify predictors of unplanned readmission, with three-quarters of the sample randomly selected as the derivation cohort and one-quarter as the validation cohort. Using regression coefficient-based scoring methods, we developed a weighted 7-factor, 10-point predictive score for risk of readmission. RESULTS: Overall, 1068 eligible discharges were analyzed; 379 patients were readmitted within 90 days (35.5%). Seven factors were associated with readmission: stoma creation, Peritoneal Cancer Index score ≥ 15, hyponatremia, in-hospital major complication, preoperative chemotherapy, anemia, and discharge to nursing home. In the validation cohort, 25 patients (9.2%) were categorized as high risk for readmission, with a predicted rate of readmission of 69.3% and an observed rate of 76.0%. The score had fair discrimination (area under the curve 0.70) and good calibration (Hosmer-Lemeshow goodness-of-fit p-value of 0.77). CONCLUSION: Our proposed risk score, easily obtainable on day of discharge, distinguishes patients at high risk for readmission over 90 days following CRS/HIPEC. This score has the potential to target high-risk individuals for intensive follow-up and other interventions.

Ferroptotic agent-induced endoplasmic reticulum stress response plays a pivotal role in the autophagic process outcome.

Ferroptosis has been reported as a unique form of cell death. However, in recent years, researchers have increasingly challenged the uniqueness of ferroptosis compared to other types of cell death. In this study, we examined whether ferroptosis shares cell death pathways with other types of cell death, especially autophagy, via the autophagic process. Here, we observed that ferroptosis inducers (artesunate [ART] and erastin [ERA]) and autophagy inducers (bortezomib [BOR] and XIE62-1004) led to autophagosome formation via the endoplasmic reticulum (ER) stress response. Unlike XIE62-1004, ART, ERA, and BOR, which affect glutathione production or utilization, induced oxidative stress responses-an increase in the levels of heme oxygenase-1 and lipid peroxidation. Oxidative stress responses were attenuated by deletion of autophagy-related gene-5 or treatment with autophagy inhibitors (bafilomycin and chloroquine). Our studies provide an overview of common death pathways-the ER stress response-associated autophagic process in ferroptosis and autophagy. We also highlight the role played by glutathione redox system in the outcome of the autophagic process.

BAX-dependent mitochondrial pathway mediates the crosstalk between ferroptosis and apoptosis.

Ferroptosis is considered a distinctive form of cell death compared to other types of death such as apoptosis. It is known to result from iron-dependent accumulation of lipid peroxides rather than caspase activation. However, we reported recently that ferroptosis interplays with apoptosis. In this study, we investigated a possible mechanism of this interplay between ferroptosis and apoptosis. Results from our studies reveal that combined treatment of the ferroptotic agent erastin and the apoptotic agent TRAIL effectively disrupted mitochondrial membrane potential (ΔΨm) and subsequently promoted caspase activation. The alterations of mitochondrial membrane potential are probably due to an increase in oligomerization of BAX and its accumulation at the mitochondria during treatment with erastin and TRAIL. Interestingly, the combined treatment-promoted apoptosis was effectively inhibited in BAX-deficient HCT116 cells, but not BAK-deficient cells. These results indicate that the BAX-associated mitochondria-dependent pathway plays a pivotal role in erastin-enhanced TRAIL-induced apoptosis.

Outcomes After Adjuvant Hyperthermic Intraperitoneal Chemotherapy for High-Risk Primary Appendiceal Neoplasms After Complete Resection.

INTRODUCTION: Appendiceal neoplasms are uncommon tumors. Optimal treatment for patients with perforation or high-grade pathology after initial resection is unknown. This study evaluated patients with increased risk for peritoneal dissemination after primary resection, but no evidence of peritoneal disease, who underwent adjuvant hyperthermic intraperitoneal chemotherapy (HIPEC). METHODS: This multi-institutional cohort study evaluated 56 patients with high-risk (HR) appendiceal neoplasms with a peritoneal carcinomatosis index of 0 who underwent HIPEC. The patients were divided into two groups: perforated low-grade appendiceal (LGA) carcinoma and HR neoplasms, which included perforated high-grade appendiceal carcinoma, positive margins after initial resection, minimal macroscopic peritoneal disease that was previously resected or completely responded to systemic chemotherapy prior to HIPEC, goblet cell carcinoma, and adenocarcinoma with signet ring cell features. Overall survival (OS) and recurrence-free survival (RFS) were estimated by Kaplan-Meier analysis. RESULTS: Thirty-eight percent of patients had perforated LGA and 68% had HR features. Five-year OS probability was 82.1% for the entire cohort, and 100% and 70.1% for patients with perforated LGA and HR features, respectively (p = 0.024). Five-year RFS probability was 79.3% for the entire cohort, and 90.0% and 72.4% for patients with perforated LGA and HR features, respectively (p = 0.025). Eight patients recurred after HIPEC and their OS was significantly worse (p < 0.001). CONCLUSION: While adjuvant HIPEC is both safe and feasible, there appears to be little benefit over close surveillance when outcomes are compared with historical and prospective studies, especially for perforated LGA carcinoma.

Correction to: Postoperative Complications Independently Predict Cancer-Related Survival in Peritoneal Malignancies.

In the original article, the Comprehensive Complication Index (CCI) was incorrectly identified as the Comprehensive Comorbidity Index. Wherever CCI appears, it refers to the Comprehensive Complication Index.

Postoperative Complications Independently Predict Cancer-Related Survival in Peritoneal Malignancies.

BACKGROUND: The authors hypothesized that postoperative complications after cytoreductive surgery-hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC) have a negative impact on perioperative and oncologic outcomes and that the novel Comprehensive Comorbidity Index (CCI) would be a better predictor of such outcomes than the traditional Clavien-Dindo classification (CDC). METHODS: The study used a prospective database of 1296 patients with peritoneal metastases (PM) undergoing CRS-HIPEC between 2001 and 2016. The Kaplan-Meier method was used to estimate survival. Multivariate analyses identified associations with perioperative and oncologic outcomes. The Akaike information criterion and the Schwarz (Bayesian information) criterion were used to compare model fitting for CCI versus CDC. RESULTS: In this study, CRS-HIPEC was performed for malignant mesothelioma (12%) and PM from appendix (50%), colorectal (30%), and ovarian (8%) cancers. Major postoperative in-hospital complications (CDC grades 3-4) occurred for 24% of the patients. However, a range of CCI scores was calculated for each CDC grade because 36% of the patients experienced multiple complications. After a median follow-up period of 55 months, the median progression-free survival was 15 months, and the median overall survival was 39 months. In the multivariate Cox proportional hazards models, postoperative in-hospital complications (measured by CDC or CCI) were independent prognostic factors for 30-day post-discharge morbidity and readmission, as well as for survival. The CCI scores demonstrated higher prognostic sensitivity for these outcomes than CDC grades. CONCLUSIONS: Reduction of postoperative complications after CRS-HIPEC is essential for optimal short- and long-term outcomes. For assessing total burden of postoperative complications per patient, CCI is superior to CDC and more sensitive for assessing surgery- and cancer-related outcomes after CRS-HIPEC.

Effectiveness of Hepatic Artery Infusion (HAI) Versus Selective Internal Radiation Therapy (Y90) for Pretreated Isolated Unresectable Colorectal Liver Metastases (IU-CRCLM).

BACKGROUND: In the era of modern effective systemic chemotherapy, the comparative effectiveness of hepatic artery infusion (HAI) versus selective internal radiation therapy (yttrium-90 [Y90]) for pretreated patients with isolated unresectable colorectal liver metastasis (IU-CRCLM) remains unknown. This study sought to compare the overall survival (OS) after HAI versus Y90 for IU-CRCLM patients treated with modern chemotherapy and to perform a cost analysis of both regional methods. METHODS: This study retrospectively reviewed patients receiving HAI or Y90 in combination with modern chemotherapy as second-line therapy for IU-CRCLM. Overall survival was calculated from the time of IU-CRCLM diagnosis. Uni- and multivariate models were constructed to identify independent predictors of survival. RESULTS: The inclusion criteria were met by 97 patients (48 HAI patients and 49 Y90 patients). Both groups were similar in terms of age, gender, body mass index (BMI), synchronous disease, carcinoembryonic antigen (CEA), liver tumor burden, and chemotherapy-related characteristics including use of biologics and lines of chemotherapy (all p > 0.05). The HAI group had a better OS than the Y90 group (31.2 vs. 16.3 months; p < 0.001). A trend toward reduced cost favored the HAI group (median, $29,479 vs. $39,092; p = 0.296). The multivariate analysis showed that receipt of HAI (hazard ratio 0.465) and number of chemotherapy lines (HR 0.797) were associated with improved OS from the date of IU-CRCLM diagnosis. CONCLUSIONS: This is the first study to evaluate the comparative effectiveness of HAI versus Y90 in the era of modern chemotherapy, and the findings suggests that HAI is associated with better survival than Y90 for patients with pretreated IU-CRCLM.

Fitbit step counts during inpatient recovery from cancer surgery as a predictor of readmission.

Background: Postoperative ambulation is encouraged to promote timely recovery but is rarely monitored objectively or examined as a predictor of clinical outcomes, despite growing availability of wearable devices that allow passive quantification and remote real-time monitoring of the number of steps taken during recovery. Purpose: To determine whether the number of steps taken during inpatient recovery predicts 30- and 60-day readmission risk after metastatic cancer surgery. Methods: Patients diagnosed with metastatic peritoneal cancer and scheduled for surgical resection were enrolled in this observational cohort study at their preoperative clinic visit. Fitbits were placed on patients' wrists upon transfer from the ICU following surgery and worn for the duration of their inpatient stay. Information about hospital readmission was extracted from electronic medical records. Results: Seventy-one patients participated in the study (mean age = 57.14, range = 31-80 years; 42% female; 51% diagnosed with appendiceal cancer). Mean steps per day were calculated for each participant over the entire inpatient recovery period (mean stay = 12.12 days, 4-37 days). Readmission within 30 and 60 days was medically indicated for 34% and 39% of patients, respectively. After statistically adjusting for age, body mass index, comorbidity, and length of postoperative stay, higher mean steps per day predicted lower 30-day and 60-day readmission risk. Conclusions: Higher Fitbit step counts during inpatient recovery predicted lower risk of 30- and 60-day readmission after surgery for metastatic peritoneal cancer. Results suggest that passively monitoring perioperative ambulation may identify patients at risk for readmission and highlight opportunities for behavioral intervention.