Targeting PARG induces tumor cell growth inhibition and antitumor immune response by reducing phosphorylated STAT3 in ovarian cancer.

BACKGROUND: Ovarian cancer is the most lethal gynecological malignancy, with limited treatment options after failure of standard therapies. Despite the potential of poly(ADP-ribose) polymerase inhibitors in treating DNA damage response (DDR)-deficient ovarian cancer, the development of resistance and immunosuppression limit their efficacy, necessitating alternative therapeutic strategies. Inhibitors of poly(ADP-ribose) glycohydrolase (PARG) represent a novel class of inhibitors that are currently being assessed in preclinical and clinical studies for cancer treatment. METHODS: By using a PARG small-molecule inhibitor, COH34, and a cell-penetrating antibody targeting the PARG's catalytic domain, we investigated the effects of PARG inhibition on signal transducer and activator of transcription 3 (STAT3) in OVCAR8, PEO1, and Brca1-null ID8 ovarian cancer cell lines, as well as in immune cells. We examined PARG inhibition-induced effects on STAT3 phosphorylation, nuclear localization, target gene expression, and antitumor immune responses in vitro, in patient-derived tumor organoids, and in an immunocompetent Brca1-null ID8 ovarian mouse tumor model that mirrors DDR-deficient human high-grade serous ovarian cancer. We also tested the effects of overexpressing a constitutively activated STAT3 mutant on COH34-induced tumor cell growth inhibition. RESULTS: Our findings show that PARG inhibition downregulates STAT3 activity through dephosphorylation in ovarian cancer cells. Importantly, overexpression of a constitutively activated STAT3 mutant in tumor cells attenuates PARG inhibitor-induced growth inhibition. Additionally, PARG inhibition reduces STAT3 phosphorylation in immune cells, leading to the activation of antitumor immune responses, shown in immune cells cocultured with ovarian cancer patient tumor-derived organoids and in immune-competent mice-bearing mouse ovarian tumors. CONCLUSIONS: We have identified a novel antitumor mechanism underlying PARG inhibition beyond its primary antitumor effects through blocking DDR in ovarian cancer. Furthermore, targeting PARG activates antitumor immune responses, thereby potentially increasing response rates to immunotherapy in patients with ovarian cancer.

Explainable artificial intelligence analysis of brachytherapy boost receipt in cervical cancer during the COVID-19 era.

PURPOSE: Brachytherapy is a critical component of the standard-of-care curative radiotherapy regimen for women with locally advanced cervical cancer (LACC). However, existing literature suggests that many patients will not receive the brachytherapy boost. We used machine learning (ML) and explainable artificial intelligence to characterize this disparity. MATERIALS AND METHODS: Patients with LACC diagnosed from 2004 to 2020 who received definitive radiation were identified in the National Cancer Database. Five ML models were trained to predict if a patient received a brachytherapy boost. The best-performing model was explained using SHapley Additive exPlanation (SHAP) values. To identify trends that may be attributable to the coronavirus disease 2019 (COVID-19) pandemic, the previous analysis was repeated and limited to 2019 to 2020. RESULTS: A total of 37,564 patients with LACC were identified; 5799 were diagnosed from 2019 to 2020 (COVID cohort). Of these patients, 59.3% received a brachytherapy boost, with 76.4% of patients diagnosed in 2019 to 2020 receiving a boost. The random forest model achieved the best performance for both the overall and COVID cohorts. In the overall cohort, the most important predictive features were the year of diagnosis, stage, age, and insurance status. In the COVID cohort, the most important predictive features were FIGO stage, age, insurance status, and hospital type. Of the 26 patients who tested positive for COVID-19 during their course of radiotherapy, 19 (73.1%) received a brachytherapy boost. CONCLUSIONS: A gradual increase in brachytherapy boost utilization has been noted, which did not seem to be significantly impacted by the onset of the COVID-19 pandemic. ML could be considered to identify patient populations where brachytherapy is underutilized, which can provide actionable feedback for improving access.

POLD1 DEDD Motif Mutation Confers Hypermutation in Endometrial Cancer and Durable Response to Pembrolizumab.

BACKGROUND: Mutations in the DNA polymerase delta 1 (POLD1) exonuclease domain cause DNA proofreading defects, hypermutation, hereditary colorectal and endometrial cancer, and are predictive of immunotherapy response. Exonuclease activity is carried out by two magnesium cations, bound to four highly conserved, negatively charged amino acids (AA) consisting of aspartic acid at amino acid position 316 (p.D316), glutamic acid at position 318 (p.E318), p.D402, and p.D515 (termed DEDD motif). Germline polymorphisms resulting in charge-discordant AA substitutions in the DEDD motif are classified as variants of uncertain significance (VUSs) by laboratories and thus would be considered clinically inactionable. We hypothesize this mutation class is clinically pathogenic. METHODS: A review of clinical presentation was performed in our index patient with a POLD1(p.D402N) heterozygous proband with endometrial cancer. Implications of this mutation class were evaluated by a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-guided systematic review, in silico analysis with orthogonal biochemical confirmation, and whole-exome and RNA sequencing analysis of the patient's tumor and engineered cell lines. RESULTS: Our systematic review favored a Mendelian disease mutation class associated with endometrial and colorectal cancers. In silico analysis predicted defective protein function, confirmed by biochemical assay demonstrating loss of nuclease activity. A POLD1-specific mutational signature was found in both the patient's tumor and POLD1(p.D402N) overexpressing cell. Furthermore, paired whole-exome/transcriptome analysis of endometrial tumor demonstrated hypermutation and T cell-inflamed gene expression profile (GEP), which are joint predictive biomarkers for pembrolizumab. Our patient showed a deep, durable response to immune checkpoint inhibitor (ICI). CONCLUSION: Charge-discordant AA substitution in the DEDD motif of POLD1 is detrimental to DNA proofreading and should be reclassified as likely pathogenic and possibly predictive of ICI sensitivity.

Feasibility of combining pelvic reconstruction with gynecologic oncology-related surgery.

INTRODUCTION AND HYPOTHESIS: At our institution, every patient seen by the gynecologic oncology service is screened for pelvic floor dysfunction. This study was aimed at determining if a combined surgical approach by gynecologic oncology and urogynecology services at our institution was feasible and safe for this patient population. METHODS: We performed a retrospective review of patients undergoing combined surgery by gynecologic oncology and urogynecology services at our institution from 2013 to 2021. Perioperative variables, postoperative adverse events, and long-term outcomes were assessed, and descriptive statistics were performed. RESULTS: From 20 December 2013 to 29 January 2021, a total of 102 patients underwent concurrent surgical repair of pelvic organ prolapse and/or stress urinary incontinence. Seventy-three patients (71.6%) had normal/benign pathologic conditions, and 29 (28.4%) had premalignant/malignant pathologic conditions. Ten patients (9.8%) had a postoperative complication, including reoperation for exposed midurethral sling (4.9%), urinary retention requiring midurethral sling release (2.9%), reoperation for hemoperitoneum (1.0%), and anemia requiring blood transfusion (1.0%). Nine complications occurred in patients with benign/normal pathologic conditions (12.3%), and one complication occurred in patients with pre-malignant/malignant pathologic conditions (3.4%). CONCLUSIONS: In our single-institution experience, concurrent gynecologic oncology and pelvic floor reconstructive surgery were safe and feasible in combination with no reported major morbidity events.

Niraparib-induced STAT3 inhibition increases its antitumor effects.

Recently, poly(ADP-ribosyl)ation polymerase inhibitors (PARPis), which induce synthetic lethality of tumor cells with DNA damage repair defects, have emerged as a promising therapy for ovarian, breast, and pancreatic cancer. Although the PARPi Olaparib is limited to treating cancer patients with DNA repair deficiencies, the PARPi Niraparib is FDA approved to treat ovarian cancer patients regardless of their status in DNA repair pathways. Despite differences in the affinity to PARP enzymes, the rationale behind the clinical use of Niraparib in patients without DNA repair deficiencies is still lacking. Moreover, only Olaparib has been approved for pancreatic ductal adenocarcinoma (PDAC) patients with BRCA mutations, accounting for only 5-7% of total PDACs. It remains unclear whether Niraparib could be beneficial to PDACs without BRCA mutations. We found that Niraparib inhibits ovarian and PDAC tumor cell growth, regardless of BRCA mutational status, more effectively than Olaparib. Unlike Olaparib, which is known to activate STAT3, Niraparib inhibits STAT3 activity in ovarian and PDAC cancer cell lines and patient tumors. Moreover, Niraparib regulates the expression of several STAT3 downstream genes involved in apoptosis. Overexpression of a constitutively activated STAT3 mutant rescues Niraparib-induced cancer cell apoptosis. Our results suggest that Niraparib inhibits pSTAT3 by interfering with SRC tyrosine kinase. Collectively, our studies provide a mechanism underlying Niraparib's ability to induce tumor cell apoptosis without BRCA mutations, suggesting the potential use of Niraparib for treating PDAC patients regardless of BRCA status.

Phase I trial of daily subcutaneous SPL-108 injections in combination with paclitaxel in patients with platinum resistant CD44+ advanced ovarian epithelial cancer.

OBJECTIVE: Preclinical evidence and early clinical trials have demonstrated the activity of SPL-108, a targeted agent that inhibits CD44 mediated induction of multidrug resistance specifically to paclitaxel and platinum agents. We conducted a phase I, open label, dose escalation study of the safety and tolerability of the combination of SPL-108 with weekly paclitaxel in patients with platinum resistant CD44+ ovarian, primary peritoneal, or fallopian tube cancer. METHODS: Patients with platinum resistant histologically proven epithelial ovarian, primary peritoneal, or fallopian tube cancers and measurable disease according to RECIST (Response Evaluation Criteria in Solid Tumours) version 1.1 were selected. Tumors were tested for CD44 expression for eligibility, defined as strong (+++) or moderate (++) staining in ≥20% of the tumor tissue or diffuse + staining. Patients were treated with daily and then twice daily SPL-108 subcutaneous injections and weekly intravenous paclitaxel on days 1, 8, and 15 of a 28 day cycle. Endpoints included safety, determination of maximum tolerated dose, and efficacy. Tumors underwent comprehensive genomic profiling, and cell lines and western blotting were used to study markers of response. RESULTS: We screened 16 patients, and 14 were enrolled based on CD44+ expression. A total of 86% of patients had high grade serous tumors and all had received multiple prior therapies. There were no grade 4-5 toxicities. One patient had grade 3 peripheral sensory neuropathy attributed to paclitaxel and one patient developed presumed colonic perforation attributed to the study drug. No dose reductions or treatment discontinuations were required. All patients tolerated the maximum planned dose; no maximum tolerated dose was reached. Overall response rate was 36%; 5 (36%) patients had partial response and 5 (36%) patients had stable disease. CONCLUSIONS: The combination of SPL-108 with weekly paclitaxel was safe and well tolerated. Encouraging antitumor activity was observed, with 72% of patients deriving a clinical benefit. TRIAL REGISTRATION: NCT03078400.

Thirty-day Postoperative Adverse Events in Minimally Invasive versus Open Abdominal Radical Hysterectomy for Early-stage Cervical Cancer.

STUDY OBJECTIVE: To identify the incidence, type, and grade of postoperative adverse events in minimally invasive radical hysterectomy vs abdominal radical hysterectomy (ARH) for patients with early-stage cervical cancer and determine risk factors associated with these adverse events. DESIGN: The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) was queried to identify patients with early-stage cervical cancer undergoing radical hysterectomy. Multivariable logistic regression was used to assess risk factors associated with adverse postoperative outcomes among patients undergoing radical hysterectomy. SETTING: ACS NSQIP participating institutions within the United States. PATIENTS: Patients were collected from the ACS NSQIP databases (2014-2017) undergoing radical hysterectomy for early-stage cervical cancer. INTERVENTIONS: N/A MEASUREMENTS AND MAIN RESULTS: ARH had a significantly increased incidence of any 30-day postoperative adverse event compared with minimally invasive radical hysterectomy (31.2% vs 19.9%, p <.001). There was a higher incidence of surgical site infection, both deep and superficial, and blood transfusions in ARH. On multivariable logistic regression, the abdominal surgical approach was the only risk factor significantly associated with any postoperative adverse event (odds ratio, 1.4; confidence interval, 1.1-1.9; p = .018; 95% CIs). CONCLUSIONS: In this study, the abdominal surgical approach for radical hysterectomy in early-stage cervical cancer was associated with a higher incidence of postoperative adverse events than the minimally invasive approach.

PIPAC for the Treatment of Gynecologic and Gastrointestinal Peritoneal Metastases: Technical and Logistic Considerations of a Phase 1 Trial.

BACKGROUND: Peritoneal metastases (PM) from ovarian, gastric, appendiceal, or colorectal origin can be treated via cytoreductive surgery with or without the addition of hyperthermic intraperitoneal chemotherapy (HIPEC) for selected patients. Unfortunately, not all patients are candidates for aggressive surgical debulking. For these patients, pressurized intraperitoneal aerosolized chemotherapy (PIPAC) has emerged as an alternative method for intraperitoneal (IP) chemotherapy administration. This report presents the design and implementation of the first phase 1 trial to evaluate the safety and efficacy of PIPAC in the United States. METHODS: This is an ongoing prospective phase 1 clinical trial of PIPAC for patients who have histologically confirmed ovarian, uterine, gastric, appendiceal, or colorectal cancer with PM and have progressed to at least one evidence-based chemotherapeutic regimen. The trial has two clinical arms. The patients in arm 1 have gynecologic and gastric malignancies treated with IP cisplatin and doxorubicin, and the arm 2 patients have colorectal and appendiceal malignancies treated with intravenous fluorouracil and leucovorin followed by IP oxaliplatin. All the patients are monitored for dose-limiting toxicities and adverse events. RESULTS: Practical and technical considerations for the phase 1 PIPAC trial are presented. These considerations include patient selection, operating room setup, and technical details for successful aerosolized chemotherapy delivery. The phase 1 study results will be reported separately at completion of the trial. CONCLUSIONS: The PIPAC treatment is a feasible, minimally invasive approach that permits IP delivery of chemotherapy. Once completed, the ongoing phase 1 trial will help to provide safety and initial efficacy data.

PARP Inhibition Activates STAT3 in Both Tumor and Immune Cells Underlying Therapy Resistance and Immunosuppression In Ovarian Cancer.

Despite the promising activity of poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) in many cancer types with defects in the DNA damage response the majority of the treated patients acquire PARPi resistance and succumb to their diseases. Consequently, there is an urgent need to identify the mechanisms of PARPi resistance. Here, we show that PARPi treatment promotes STAT3 activation in ovarian cancer cells, tumor-associated immune cells and fibroblasts, resulting in PARPi resistance and immunosuppression. Comparison of ovarian cancer patient-matched tumor biopsies before and after PARPi therapy revealed that STAT3 activity was significantly higher in tumor cells and tumor-associated immune cells and fibroblasts post PARPi treatment. Moreover, one-time PARPi treatment activated STAT3 both in tumor cells as well as diverse immune subsets and fibroblasts. PARPi-treated immune cells exhibited decreased expression of immunostimulatory interferon (IFN)-γ and Granzyme B while increasing immunosuppressive cytokine IL-10. Finally, we demonstrate that the acquisition of PARPi resistance in ovarian cancer cells was accompanied by increased STAT3 activity. Ablating STAT3 inhibited PARPi-resistant ovarian tumor cell growth and/or restored PARPi sensitivity. Therefore, our study has identified a critical mechanism intrinsic to PARPi that promotes resistance to PARPi and induces immunosuppression during PARPi treatment by activating STAT3 in tumor cells and tumor-associated immune cells/fibroblasts.

Criminal Justice Involvement and Abnormal Cervical Cancer Screening Results Among Women in an Urban Safety Net Hospital.

OBJECTIVE: The aim of the study was to elucidate the risk factors underlying abnormal cytology-based cervical cancer screening (Pap testing) in justice-involved women (JIW) compared with non-JIW in an urban safety net hospital. METHODS: Retrospective chart review of women with a history of correctional involvement who received care at Grady Health System between 2010 and 2018 and had a Pap test was performed (n = 191). An age-matched cohort of women with no correctional involvement and had a Pap test at Grady served as the control (n = 394). Variables of interest were age, HIV, smoking, race, mental health history, and history of incarceration. Outcomes of interests were rate of abnormal Pap tests and follow-up. χ2 and logistic regression models evaluated associations between the variables of interest and outcomes. RESULTS: Rates of abnormal Pap tests were significantly higher in JIW (35.6%) than controls (18.5%, p < .0001). Compared with controls, JIW were significantly more likely to have high-grade cervical cytology (odds ratio [OR] = 3.89, p < .0005) and be lost to gynecologic follow-up (OR = 8.75, p < .0001) and a history of severe mental illness (29.5% vs 4.3%, p < .0001). Those with abnormal Pap tests were likely to be HIV-positive (OR = 20.7, p < .001) and have a history of incarceration (OR = 2.33, p < .001). Predictors of high-grade Pap test were smoking history (OR = 0.16, p = .014), HIV-positive (OR = 3.66, p = .025), and history of incarceration (OR = 3.96, p < .0005). CONCLUSIONS: Justice-involved women represent a high-risk subpopulation with significantly increased rates of high-grade cytology and lost to follow-up. This underscores the need for attention to screening programs and follow-up interventions for JIW.

Do High Rates of Atypical Glandular Cells Correlate With Higher Incidence of Disease in a Large Safety Net Hospital.

OBJECTIVE: The aim of the study was to describe the incidence and correlates of atypical glandular cell (AGC) Pap tests in a low socioeconomic status, underserved population. MATERIALS AND METHODS: Medical records of patients with AGC Pap tests at a single institution were reviewed from January 2013 to August 2019. Baseline characteristics were extracted including age, body mass index, birth control, abnormal uterine bleeding, and human papillomavirus (HPV). All colposcopy and endometrial biopsies were classified into negative/low-risk (polyps, tubular metaplasia, microglandular hyperplasia, cervical intraepithelial neoplasia 1) and high-risk (HR) lesions (cervical intraepithelial neoplasia 2/3, adenocarcinoma in situ, endometrial hyperplasia, cervical cancer, endometrial cancer). Logistic regression identified significant associations. Sixty-eight randomly selected AGC cytology slides from the cohort and 32 non-AGC slides outside the cohort were blindly reviewed by 6 pathologists. Fleiss κ interrater agreement was assessed. RESULTS: Seven hundred forty patients with AGC Pap tests were identified (0.8% of all Pap tests performed during this time). After excluding for incomplete data, 478 patients were included. Sixty-three patients had HR lesions (13.3%). Patients with HR lesions had increased odds of abnormal uterine bleeding (odds ratio = 4.32, p < .001) and HPV positivity (odds ratio = 10.89, p < .001) when compared with patients with low-risk lesions. The κ agreement was 0.21 for all cases and 0.18 for AGC alone. CONCLUSIONS: This population falls within the national averages for AGC Pap tests. There was an increased risk of HR lesions in patients with abnormal uterine bleeding and HPV positivity. The rate of HR lesions among AGC Pap tests was at the lower end of values in the literature. After blinded pathologist review, interobserver κ agreement was low for AGC Pap tests.

Primary colonic extrauterine endometrial stromal sarcoma: A case and review of the literature.

•Primary colonic extrauterine endometrial stromal sarcoma is a rare entity and diagnosis of this tumor can be challenging.•There is a common gene translocation specific to the tumors, our case was confirmed by identifying it.•Classifying these tumors correctly is important for treatment.

Evaluating unplanned readmission and prolonged length of stay following minimally invasive surgery for endometrial cancer.

OBJECTIVE: To evaluate risk factors for 30-day unplanned readmission and increased length of stay (LOS) following minimally invasive surgery (MIS) for endometrial cancer. METHODS: This was a retrospective, case-control study using the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP). Multivariable logistic regression was used to assess perioperative variables associated with readmission and increased LOS after MIS for endometrial cancer. RESULTS: The study population included 10,840 patients who met the criteria of having undergone MIS with a resultant endometrial malignancy confirmed on postoperative pathology. Common reasons for readmission included organ/space surgical site infection (65 cases), sepsis/septic shock (19 cases), and venous thromboembolism (20 cases). Notable risk factors for readmission included (Odds Ratio, Confidence Interval, p-value): dialysis dependence (6.77, 2.51-17.80, <0.01), increased length of stay (3.00, 2.10-4.10, <0.01), and preoperative weight loss (2.80, 1.06-7.17, 0.03); notable risk factors for increased LOS: ascites (8.51, 2.00-36.33, <0.01), operation duration >5 h (6.93, 5.29-9.25, <0.01), and preoperative blood transfusion (5.37, 2.05-14.04, <0.01). CONCLUSIONS: Identification of risk factors for adverse postoperative outcomes is necessary to inform and improve standards of care in MIS for endometrial cancer. Using nationally reported data from the ACS NSQIP, this study identifies independent risk factors for unplanned readmission and prolonged LOS, and in doing so, highlights potential avenues for quality improvement.

Morbidity and Mortality Risk Assessment in Gynecologic Oncology Surgery Using the American College of Surgeons National Surgical Quality Improvement Program Database.

INTRODUCTION: Gynecologic oncology patients represent a distinct patient population with a variety of surgical risks. The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database provides an opportunity to analyze large cohorts of patients over extended periods with high accuracy. Our goal was to develop a postoperative risk assessment calculator capable of providing a standardized, objective means of preoperatively identifying high-risk patients in the gynecologic oncology population. METHODS: We queried the ACS NSQIP database for gynecologic oncology patients from 2005 to 2013. Multivariate logistic regression was performed to generate predictive models specific for 30-day postoperative mortality and major morbidity. RESULTS: There were 12,831 patients with a primary gynecologic malignancy identified: 7847 uterine, 3366 adnexal, 1051 cervical, and 567 perineum cancers. In this cohort, 125 (0.97%) patients died, and 784 (6.11%) major morbidity events were recorded within 30 days of their surgery. For 30-day mortality, the mean calculated predictive probability was 0.128 (SD, 0.219) compared with 0.009 (SD, 0.027) in patients alive 30 days postoperatively (P < 0.0001). The mean predictive probability of major morbidity was 0.097 (SD, 0.095) compared with 0.059 (SD, 0.043) in patients who did not experience major morbidity 30 days postoperatively (P < 0.0001). CONCLUSIONS: Using NSQIP data, these predictive models will help to determine patients at risk for 30-day mortality and major morbidity. Further clinical validation of these models is required.

Ogilvie's Syndrome after Robotic-Assisted Radical Hysterectomy for Cervical Cancer.

Acute colonic pseudo-obstruction (ACPO), also known as Ogilvie's syndrome, is defined by poor peristaltic activity of the colon that mimics mechanical obstruction in the absence of any mechanical occlusive gut lesion. This case report is the first to be published on ACPO occurring after robotic-assisted radical hysterectomy. Given that robotic-assisted laparoscopic surgery has become the next major stage of advancement for a range of operations, especially in gynecologic oncology surgery, this report emphasizes the importance of recognizing precipitating factors associated with this syndrome, including minimally invasive surgery.

Patient-specific risk factors are predictive for postoperative adverse events in colorectal surgery: an American College of Surgeons National Surgical Quality Improvement Program-based analysis.

BACKGROUND: Pay-for-performance measures incorporate surgical site infection rates into reimbursement algorithms without accounting for patient-specific risk factors predictive for surgical site infections and other adverse postoperative outcomes. METHODS: Using American College of Surgeons National Surgical Quality Improvement Program data of 67,445 colorectal patients, multivariable logistic regression was performed to determine independent risk factors associated with various measures of adverse postoperative outcomes. RESULTS: Notable patient-specific factors included (number of models containing predictor variable; range of odds ratios [ORs] from all models): American Society of Anesthesiologists class 3, 4, or 5 (7 of 7 models; OR 1.25 to 1.74), open procedures (7 of 7 models; OR .51 to 4.37), increased body mass index (6 of 7 models; OR 1.15 to 2.19), history of COPD (6 of 7 models; OR 1.19 to 1.64), smoking (6 of 7 models; OR 1.15 to 1.61), wound class 3 or 4 (6 of 7 models; OR 1.22 to 1.56), sepsis (6 of 7 models; OR 1.14 to 1.89), corticosteroid administration (5 of 7 models; OR 1.11 to 2.24), and operation duration more than 3 hours (5 of 7 models; OR 1.41 to 1.76). CONCLUSIONS: These findings may be used to pre-emptively identify colorectal surgery patients at increased risk of experiencing adverse outcomes.

Unique risks for mortality in patients with end-stage renal disease undergoing nonemergent colorectal surgery.

BACKGROUND: The aim of this study was to identify unique risk factors for mortality in patients with end-stage renal disease undergoing nonemergent colorectal surgery. METHODS: A multivariate logistic regression model predicting 30-day mortality was constructed for patients with end-stage renal disease undergoing nonemergent colorectal procedures. Data were obtained from the National Surgical Quality Improvement Program (2005-2010). RESULTS: Among the 394 patients analyzed, those with serum creatinine levels >7.5 mg/dL had .07 times the adjusted mortality risk of those with levels <3.5 mg/dL. For colorectal surgery patients, the average serum creatinine level was 5.52 ± 2.6 mg/dL, and mortality was 13% (n = 50). CONCLUSIONS: High serum creatinine was associated with a lower risk for mortality in patients with end-stage renal disease, even though creatinine is often considered a risk factor for surgery. These results show how variables from a patient-centered subpopulation can differ in meaning from the general population.