Emerging therapeutic approaches for peritoneal metastases from gastrointestinal cancers

Peritoneal metastases from gastrointestinal malignancies present difficult management decisions, with options consisting primarily of systemic chemotherapy or major surgery with or without hyperthermic intraperitoneal chemotherapy. Current research is investigating expanding therapeutic modalities, and the aim of this review is to provide an overview of the existing and emerging therapies for the peritoneal metastases from gastrointestinal cancers, primarily through the recent literature (2015 and newer). These include the current data with systemic therapy and cytoreduction with hyperthermic intraperitoneal or pressurized intraperitoneal aerosol chemotherapy, as well as novel promising modalities under investigation, including dominating oncolytic viral therapy and adoptive cellular, biologic, and bacteria therapy, or nanotechnology. The novel diverse strategies, although preliminary and preclinical in murine models, individually and collectively contribute to the treatment of peritoneal metastases, offering hope for improved outcomes and quality of life. We foresee that these evolving treatment approaches will facilitate the transfer of knowledge and data among studies and advance discovery of new drugs and optimized treatments for patients with peritoneal metastases.

Recurrence patterns after complex multimodality therapy and hepatic arterial infusion for colorectal liver metastases: A reflection of biology and technique

BACKGROUND AND METHODS

We characterized colorectal liver metastasis recurrence and survival patterns after surgical resection and intraoperative ablation ± hepatic arterial infusion pump (HAIP) placement. We estimated patterns of recurrence and survival in patients undergoing contemporary multimodal treatments. Between 2017 and 2021, patient, tumor characteristics, and recurrence data were collected. Primary outcomes included recurrence patterns and survival data based on operative intervention.

RESULTS

There were 184 patients who underwent hepatectomy and intraoperative ablation. Sixty patients (32.6%) underwent HAIP placement. A total of 513 metastases were ablated, median total of 2 ablations per patient. Median time to recurrence was 31 [22-40] months. Recurrence patterns included tumor at ablative margin on first scheduled postoperative imaging (8, 4.3%), local tumor recurrence at ablative site (69, 37.5%), and non-ablated liver tumor recurrence (38, 20.6%). In patients who underwent HAIP placement, the rate of liver recurrence was reduced (45% vs 70.9%, p = 0.0001). Median overall survival was 64 [41-58] months and prolonged survival was associated with HAIP treatment (85 [66-109] vs 60 [51-70] months.

CONCLUSIONS AND DISCUSSION

Hepatic recurrence is common and combination of intraoperative ablation and HAIP treatments were associated with prolonged survival. These data may reflect patient selection however, future work will clarify preoperative tumor and patient characteristics that may better predict recurrence expectations.

Weekend Discharge Is Not Associated With Increased Readmission After Hyperthermic Intraperitoneal Chemotherapy

INTRODUCTION

We explored the association between weekend discharge and 30- and 90-d readmission rates in patients undergoing hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) for peritoneal carcinomatosis.

METHODS

The US HIPEC Collaborative database, comprised of a longitudinal cohort of patients undergoing CRS/HIPEC for peritoneal carcinomatosis at twelve academic institutions between 2000 and 2017, was queried for date of discharge information. Patients were retrospectively divided into weekday and weekend/holiday discharge groups. Patients <18 y old, lacking day of discharge information, or who experienced intraoperative/in-hospital mortality were excluded. Comparisons were made between patients discharged on a weekday versus those discharged on a weekend or major holiday.

RESULTS

1415 patients met inclusion criteria for the study: 1108 (78%) patients with a weekday discharge and 308 (22%) with a weekend/holiday discharge. Median age at time of surgery was 55 y (Interquartile Range: 46-63); 59% (n = 841) patients were female, 25% (n = 328) of patients had high volume disease (defined as a peritoneal cancer index >20 intraoperatively), and 92% (n = 1210) of patients had a complete cytoreduction (defined as a completeness of cytoreduction score of 0 or 1). Overall, 15% (n = 218) of patients were readmitted within 30 d and 19% (n = 265) within 90 d. In a linear mixed effects model, weekend discharge was not associated with higher 30- or 90-d readmissions (P = 0.291, P = 0.743).

CONCLUSIONS

Weekend discharges are safe following CRS/HIPEC. Length of stay initiatives should focus on discharging the patient when medically ready, rather than avoiding weekend discharge out of an abundance of caution.

Impact of Sodium Thiosulfate on Prevention of Nephrotoxicities in HIPEC: An Ancillary Evaluation of Cisplatin-Induced Toxicities in Ovarian Cancer

PURPOSE

Hyperthermic intraperitoneal chemotherapy (HIPEC) with cisplatin confers a survival benefit in epithelial ovarian cancer (EOC) but is associated with renal toxicity. Sodium thiosulfate (ST) is used for nephroprotection for HIPEC with cisplatin, but standard HIPEC practices vary.

METHODS

A prospective, nonrandomized, clinical trial evaluated safety outcomes of HIPEC with cisplatin 75 mg/m2 during cytoreductive surgery (CRS) in patients with EOC (n = 34) and endometrial cancer (n = 6). Twenty-one patients received no ST (nST), and 19 received ST. Adverse events (AEs) were reported according to CTCAE v.5.0. Serum creatinine (Cr) was collected preoperatively and postoperatively (Days 5-8). Progression-free survival (PFS) was followed. Normal peritoneum was biopsied before and after HIPEC for whole transcriptomic sequencing to identify RNAseq signatures correlating with AEs.

RESULTS

Forty patients had HIPEC at the time of interval or secondary CRS. Renal toxicities in the nST group were 33% any grade AE and 9% grade 3 AEs. The ST group demonstrated no renal AEs. Median postoperative Cr in the nST group was 1.1 mg/dL and 0.5 mg/dL in the ST group (p = 0.0001). Median change in Cr from preoperative to postoperative levels were + 53% (nST) compared with - 9.6% (ST) (p = 0.003). PFS did not differ between the ST and nST groups in primary or recurrent EOC patients. Renal AEs were associated with downregulation of metabolic pathways and upregulation of immune pathways.

CONCLUSIONS

ST significantly reduces acute renal toxicity associated with HIPEC with cisplatin in ovarian cancer patients. As nephrotoxicity is high in HIPEC with cisplatin, nephroprotective agents should be considered.

Prediction of Early Recurrence Following CRS/HIPEC in Patients With Disseminated Appendiceal Cancer

INTRODUCTION

In patients with disseminated appendiceal cancer (dAC) who underwent cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC), characterizing and predicting those who will develop early recurrence could provide a framework for personalizing follow-up. This study aims to: (1) characterize patients with dAC that are at risk for recurrence within 2 y following of CRS ± HIPEC (early recurrence; ER), (2) utilize automated machine learning (AutoML) to predict at-risk patients, and (3) identifying factors that are influential for prediction.

METHODS

A 12-institution cohort of patients with dAC treated with CRS ± HIPEC between 2000 and 2017 was used to train predictive models using H2O.ai's AutoML. Patients with early recurrence (ER) were compared to those who did not have recurrence or presented with recurrence after 2 y (control; C). However, 75% of the data was used for training and 25% for validation, and models were 5-fold cross-validated.

RESULTS

A total of 949 patients were included, with 337 ER patients (35.5%). Patients with ER had higher markers of inflammation, worse disease burden with poor response, and received greater intraoperative fluids/blood products. The highest performing AutoML model was a Stacked Ensemble (area under the curve = 0.78, area under the curve precision recall = 0.66, positive predictive value = 85%, and negative predictive value = 63%). Prediction was influenced by blood markers, operative course, and factors associated with worse disease burden.

CONCLUSIONS

In this multi-institutional cohort of dAC patients that underwent CRS ± HIPEC, AutoML performed well in predicting patients with ER. Variables suggestive of poor tumor biology were the most influential for prediction. Our work provides a framework for identifying patients with ER that might benefit from shorter interval surveillance early after surgery.

Neighborhood-Level Socioeconomic Disadvantage Predicts Outcomes in Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Malignancy

BACKGROUND

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) improves survival in select patients with peritoneal metastases (PM), but the impact of social determinants of health on CRS/HIPEC outcomes remains unclear.

PATIENTS AND METHODS

A retrospective review was conducted of a multi-institutional database of patients with PM who underwent CRS/HIPEC in the USA between 2000 and 2017. The area deprivation index (ADI) was linked to the patient's residential address. Patients were categorized as living in low (1-49) or high (50-100) ADI residences, with increasing scores indicating higher socioeconomic disadvantage. The primary outcome was overall survival (OS). Secondary outcomes included perioperative complications, hospital/intensive care unit (ICU) length of stay (LOS), and disease-free survival (DFS).

RESULTS

Among 1675 patients 1061 (63.3%) resided in low ADI areas and 614 (36.7%) high ADI areas. Appendiceal tumors (n = 1102, 65.8%) and colon cancer (n = 322, 19.2%) were the most common histologies. On multivariate analysis, high ADI was not associated with increased perioperative complications, hospital/ICU LOS, or DFS. High ADI was associated with worse OS (median not reached versus 49 months; 5 year OS 61.0% versus 28.2%, P < 0.0001). On multivariate Cox-regression analysis, high ADI (HR, 2.26; 95% CI 1.13-4.50; P < 0.001), cancer recurrence (HR, 2.26; 95% CI 1.61-3.20; P < 0.0001), increases in peritoneal carcinomatosis index (HR, 1.03; 95% CI 1.01-1.05; P < 0.001), and incomplete cytoreduction (HR, 4.48; 95% CI 3.01-6.53; P < 0.0001) were associated with worse OS.

CONCLUSIONS

Even after controlling for cancer-specific variables, adverse outcomes persisted in association with neighborhood-level socioeconomic disadvantage. The individual and structural-level factors leading to these cancer disparities warrant further investigation to improve outcomes for all patients with peritoneal malignancies.

Safety and Efficacy of Oxaliplatin Pressurized Intraperitoneal Aerosolized Chemotherapy (PIPAC) in Colorectal and Appendiceal Cancer with Peritoneal Metastases: Results of a Multicenter Phase I Trial in the USA

BACKGROUND

Pressurized intraperitoneal aerosolized chemotherapy (PIPAC) is a laparoscopic locoregional treatment for peritoneal metastases (PM) from colorectal cancer (CRC) or appendiceal cancer (AC) in patients who cannot undergo cytoreductive surgery (CRS). While PIPAC has been studied in Europe and Asia, it has not been investigated in the USA.

PATIENTS AND METHODS

We evaluated PIPAC with 90 mg/m2 oxaliplatin alone (cycle 1) and preceded by systemic chemotherapy with fluorouracil (5-FU) and leucovorin (LV) (cycle 2-3) as a multicenter prospective phase I clinical trial (NCT04329494). The primary endpoint was treatment-related adverse events (AEs). Secondary endpoints included survival and laparoscopic, histologic, and radiographic response.

RESULTS

12 patients were included: 8 with CRC and 4 with AC. Median prior chemotherapy cycles was 2 (interquartile range (IQR) 2-3). All patients were refractory to systemic oxaliplatin-based chemotherapy. Median peritoneal carcinomatosis index (PCI) was 28 (IQR 19-32). Six (50%) of twelve patients completed three PIPAC cycles. No surgical complications or dose-limiting toxicities were observed. Two patients developed grade 3 treatment-related toxicities (one abdominal pain and one anemia). Median overall survival (OS) was 12.0 months, and median progression-free survival (PFS) was 2.9 months. OS was correlated with stable disease by Response Evaluation Criteria in Solid Tumors (RECIST) criteria but not with laparoscopic response by PCI or histologic response by peritoneal regression grading system (PRGS).

CONCLUSIONS

This phase I trial in the USA demonstrated safety, feasibility, and early efficacy signal of PIPAC with oxaliplatin and chemotherapy in patients with PM from AC or CRC who are refractory to standard lines of systemic chemotherapy.

Validation of the AJCC 8th Edition Staging System for Disseminated Appendiceal Cancer Patients Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: A Multi-institutional Analysis

BACKGROUND

The AJCC 8th edition stratifies stage IV disseminated appendiceal cancer (dAC) patients based on grade and pathology. This study was designed to externally validate the staging system and to identify predictors of long-term survival.

METHODS

A 12-institution cohort of dAC patients treated with CRS ± HIPEC was retrospectively analyzed. Overall survival (OS) and recurrence-free survival (RFS) were analyzed by using Kaplan-Meier and log-rank tests. Univariate and multivariate cox-regression was performed to assess factors associated with OS and RFS.

RESULTS

Among 1009 patients, 708 had stage IVA and 301 had stage IVB disease. Median OS (120.4 mo vs. 47.2 mo) and RFS (79.3 mo vs. 19.8 mo) was significantly higher in stage IVA compared with IVB patients (p < 0.0001). RFS was greater among IVA-M1a (acellular mucin only) than IV M1b/G1 (well-differentiated cellular dissemination) patients (NR vs. 64 mo, p = 0.0004). Survival significantly differed between mucinous and nonmucinous tumors (OS 106.1 mo vs. 41.0 mo; RFS 46.7 mo vs. 21.2 mo, p < 0.05), and OS differed between well, moderate, and poorly differentiated (120.4 mo vs. 56.3 mo vs. 32.9 mo, p < 0.05). Both stage and grade were independent predictors of OS and RFS on multivariate analysis. Acellular mucin and mucinous histology were associated with better OS and RFS on univariate analysis only.

CONCLUSIONS

AJCC 8th edition performed well in predicting outcomes in this large cohort of dAC patients treated with CRS ± HIPEC. Separation of stage IVA patients based on the presence of acellular mucin improved prognostication, which may inform treatment and long-term, follow-up strategies.

Complete Pathologic Response to PARP Inhibitor Olaparib in a Patient with Stage IVB Recurrent Endometrioid Endometrial Adenocarcinoma

Treatment for endometrial cancer is rapidly evolving with the increased use and integration of somatic tumor RNA sequencing in clinical practice. There is a paucity of data regarding PARP inhibition in endometrial cancer given that mutations in homologous recombination genes are rare, and currently no FDA approval exists. A 50-year-old gravida 1 para 1 woman with a diagnosis of stage IVB poorly differentiated endometrioid endometrial adenocarcinoma presented to our comprehensive cancer center. Following surgical staging, she was placed on adjuvant chemotherapy with carboplatin/paclitaxel which was held multiple times due to poor performance status and complications. CT scan of the abdomen and pelvis following cycles 3 of adjuvant chemotherapy showed recurrent progressive disease. She received one cycle of liposomal doxorubicin but discontinued it due to severe cutaneous toxicity. Based on the BRIP1 mutation identified, the patient was placed on compassionate use of Olaparib in January 2020. Imaging during this surveillance period showed a significant decrease in hepatic, peritoneal, and extraperitoneal metastases, and eventually the patient had a clinical complete response in a year. The most recent CT A/P in December 2022 showed no sites of active recurrent or metastatic disease in the abdomen or pelvis. We present a unique case of a patient with recurrent stage IVB poorly differentiated endometrioid endometrial adenocarcinoma with multiple somatic gene mutations including BRIP1, who had a pathologic complete response following compassionate use of Olaparib for 3 years. To our knowledge, this is the first reported case of high grade endometrioid endometrial cancer that has shown a pathologic complete response to a PARP inhibitor.

Influence of insurance status on the postoperative outcomes of cytoreductive surgery and HIPEC

BACKGROUND

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is increasingly performed for peritoneal surface malignancies but remains associated with significant morbidity. Scant research is available regarding the impact of insurance status on postoperative outcomes.

METHODS

Patients undergoing CRS/HIPEC between 2000 and 2017 at 12 participating sites in the US HIPEC Collaborative were identified. Univariate and multivariate analyses were used to compare the baseline characteristics, operative variables, and postoperative outcomes of patients with government, private, or no insurance.

RESULTS

Among 2268 patients, 699 (30.8%) had government insurance, 1453 (64.0%) had private, and 116 (5.1%) were uninsured. Patients with government insurance were older, more likely to be non-white, and comorbid (p < 0.05). Patients with government (OR: 2.25, CI: 1.50-3.36, p < 0.001) and private (OR: 1.69, CI: 1.15-2.49, p = 0.008) insurance had an increased risk of complications on univariate analysis. There was no independent relationship on multivariate analysis. An American Society of Anesthesiologists score of 3 or 4, peritoneal carcinomatosis index score >15, completeness of cytoreduction score >1, and nonhome discharge were factors independently associated with a postoperative complication.

CONCLUSION

While there were differences in postoperative outcomes between the three insurance groups on univariate analysis, there was no independent association between insurance status and postoperative complications after CRS/HIPEC.

Tumor extent impacts survival benefit in minimally invasive colectomy for T4 colon cancer: A propensity matched national cohort analysis

BACKGROUND

T4 colon cancers have been underrepresented in randomized trials comparing minimally invasive colectomy (MC) versus open colectomy (OC). Retrospective studies suggest improved survival with MC versus OC, but have not addressed the impact of tumor extent.

METHODS

Using the National Cancer Database (NCDB), we analyzed patients undergoing colectomy for T4 colon adenocarcinoma from 2010 to 2014. Propensity score matching was performed between MC and OC patients. Tumor extent was defined by zones based on adjacent organ involvement.

RESULTS

Of the 19 178 eligible patients, 6564 (34%) underwent MC. After matching, MC was associated with improved overall survival (hazard ratios: 0.71, 95% confidence interval: 0.67-0.76; median OS 59 vs. 42 months, p < 0.001). Compared to MC patients, those undergoing OC had: a higher margin positive rate (p = 0.009); lower median nodes examined (p < 0.001); a lower rate of adjuvant chemotherapy (p < 0.001); and a longer median time to chemotherapy (p < 0.001). Stratified survival analyses demonstrated that MC was associated with improved overall survival compared to OC in all zones except zone 3 and 4.

CONCLUSIONS

Compared to OC, MC for T4 colon cancer is associated with improved oncologic outcomes when performed for zone 0-2 tumors. For, zone 3 and 4 tumors MC and OC have similar oncologic outcomes and patients should be cautiously selected.

Conditional Survival Following Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Surface Malignancies: An Analysis from the US HIPEC Collaborative

INTRODUCTION

The long-term prognosis of patients who undergo cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal surface malignancies (PSM) varies considerably on the basis of histological and operative factors. While overall survival (OS) estimates are used to inform adjuvant therapy and surveillance strategies, conditional survival may provide more clinically relevant estimates of prognosis by accounting for disease-free time elapsed.

PATIENTS AND METHODS

All patients from 12 academic institutions who underwent CRS ± HIPEC for PSM from 2000 to 2017 were retrospectively analyzed. OS and disease-free survival (DFS) rates were calculated using the Kaplan-Meier method while conditional overall (COS) and conditional disease-free survival (CDFS) rates were calculated at 1, 2, or 3 years from surgery for different tumor histologies.

RESULTS

Overall, 1610 patients underwent CRS ± HIPEC. Among patients with benign appendiceal mucinous tumors (N = 460), 5-year OS and COS at 3 years were 92.1% and 96.3% (Δ4.2%), respectively. For patients with well-differentiated appendiceal cancers (N = 400), 5-year OS and COS at 3 years were 76.3% and 88.3% (Δ12.0%), respectively. For patients with high-grade appendiceal cancers (N = 258), 5-year OS and COS at 3 years were 43.8% and 75.4% (Δ31.6%), respectively. For patients with colorectal cancers (N = 362), 5-year OS and COS at 3 years were 31.8% and 67.3% (Δ35.5%), respectively. For patients with peritoneal mesothelioma (N = 130), 5-year OS and COS at 3 years were 67.6% and 89.7% (Δ22.1%), respectively. Similar trends were observed for DFS/CDFS.

CONCLUSION

The conditional survival of patients undergoing CRS ± HIPEC for PSM is associated with tumor histology. COS and CDFS provide a more accurate, dynamic estimate of survival than OS and DFS, especially for patients with more aggressive histologies.

Medicare Advantage: A Disadvantage for Complex Cancer Surgery Patients

PURPOSE

Nearly half of all Medicare beneficiaries are enrolled in privatized Medicare insurance plans (Medicare Advantage [MA]). Little comparative information is available about access, outcomes, and cost of inpatient cancer surgery between MA and Traditional Medicare (TM) beneficiaries. We set out to assess and compare access, postoperative outcomes, and estimated cost of inpatient cancer surgery among MA and TM beneficiaries.

METHODS

Retrospective cohort analysis of MA or TM beneficiaries undergoing elective inpatient cancer surgery (for cancers located in lung, esophagus, stomach, pancreas, liver, colon, or rectum) was performed using the Office of Statewide Health Planning Inpatient Database linked to California Cancer Registry from 2000 to 2020. For each cancer site, risk-standardized access to high-volume hospitals, postoperative 30-day mortality, complications, failure to rescue, and surgery-specific estimated costs were compared between MA and TM beneficiaries.

RESULTS

This analysis of 76,655 Medicare beneficiaries (median age 74 years, 51% female, 39% MA) included 31,913 colectomies, 10,358 proctectomies, 4,604 hepatectomies, 2,895 pancreatectomies, 3,639 gastrectomies, 1,555 esophagectomies, and 21,691 lung resections. Except for colon surgery, MA beneficiaries were less likely to receive care at a high-volume hospital. Mortality was significantly higher among MA beneficiaries (v TM) for gastrectomy (adjusted risk difference [ARD], 1.5%; 95% CI, 0.01 to 2.9; P = .036), pancreatectomy (ARD, 2.0%; CI, 0.80 to 3.3; P = .002), and hepatectomy (ARD, 1.4%; 95% CI, 0.1 to 2.9; P = .04). By contrast, compared with TM, MA beneficiaries incurred lower estimated hospital costs.

CONCLUSION

Enrollment in MA plan is associated with lower estimated hospital costs. However, compared with TM, MA beneficiaries had lower access to high-volume hospitals and increased 30-day mortality for stomach, pancreas, or liver surgery.

Multicenter dose-escalation Phase I trial of mitomycin C pressurized intraperitoneal aerosolized chemotherapy in combination with systemic chemotherapy for appendiceal and colorectal peritoneal metastases: rationale and design

Objectives

Peritoneal metastasis (PM) from appendiceal cancer or colorectal cancer (CRC) has significant morbidity and limited survival. Pressurized intraperitoneal aerosolized chemotherapy (PIPAC) is a minimally invasive approach to treat PM. We aim to conduct a dose-escalation trial of mitomycin C (MMC)-PIPAC combined with systemic chemotherapy (FOLFIRI) in patients with PM from appendiceal cancer or CRC.

Methods

This is a multicenter Phase I study of MMC-PIPAC (NCT04329494). Inclusion criteria include treatment with at least 4 months of first- or second-line systemic chemotherapy with ineligibility for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). Exclusion criteria are: progression on chemotherapy; extraperitoneal metastases; systemic chemotherapy intolerance; bowel obstruction; or poor performance status (ECOG>2). Escalating MMC-PIPAC doses (7-25 mg/m2) will be administered in combination with standard dose systemic FOLFIRI. Safety evaluation will be performed on 15 patients (dose escalation) and six expansion patients: 21 evaluable patients total.

Results

The primary endpoints are recommended MMC dose and safety of MMC-PIPAC with FOLFIRI. Secondary endpoints are assessment of response (by peritoneal regression grade score; Response Evaluation Criteria in Solid Tumors [RECIST 1.1], and peritoneal carcinomatosis index), progression free survival, overall survival, technical failure rate, surgical complications, conversion to curative-intent CRS-HIPEC, patient-reported outcomes, and functional status. Longitudinal blood and tissue specimens will be collected for translational correlatives including pharmacokinetics, circulating biomarkers, immune profiling, and single-cell transcriptomics.

Conclusions

This Phase I trial will establish the recommended dose of MMC-PIPAC in combination with FOLFIRI. Additionally, we expect to detect an early efficacy signal for further development of this therapeutic combination.

Do Lymph Node Metastases Matter in Appendiceal Cancer with Peritoneal Carcinomatosis? A US HIPEC Collaborative Study

BACKGROUND

Whether formal regional lymph node (LN) evaluation is necessary for patients with appendiceal adenocarcinoma (AA) who have peritoneal metastases is unclear. The aim of this study was to evaluate the prognostic value of LN metastases on survival in patients treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC).

METHODS

A retrospective analysis of the US HIPEC collaborative, a multi-institutional consortium comprising 12 high-volume centers, was performed to identify patients with AA who underwent CRS-HIPEC with adequate LN sampling (≥ 12 LNs).

RESULTS

Two hundred-fifty patients with AA who underwent CRS-HIPEC were included. Outcomes were compared between LN - and LN + disease. Baseline patient characteristics between groups were similar, with most patients undergoing complete cytoreduction (0/1: 86.0% vs. 76.8%, p = 0.08), respectively. More adverse tumor factors were found in patients with LN + disease, including poor differentiation, signet ring cells, and lymphovascular invasion. Multivariate analysis of overall survival (OS) found LN + disease was independently associated with worse OS (HR: 2.82 95%CI: 1.25-6.34, p = 0.01), even after correction for receipt of systemic therapy. On Kaplan-Meier analysis, median OS was lower in patients with LN + disease (25.9 months vs. 91.4 months, p < 0.01). LN + disease remained associated with poor OS following propensity score matching (HR: 4.98 95%CI: 1.72-14.40, p < 0.01) and in patients with PCI ≥ 20 (HR: 3.68 95%CI: 1.54-8.80, p < 0.01).

CONCLUSIONS

In this large multi-institutional study of patients with AA undergoing CRS-HIPEC, LN status remained associated with worse OS even in the setting of advanced peritoneal carcinomatosis. Formal LN evaluation should be performed for most patients with AA undergoing CRS-HIPEC.

Feasibility of perioperative remote monitoring of patient-generated health data in complex surgical oncology

BACKGROUND

The feasibility of remote perioperative telemonitoring of patient-generated physiologic health data and patient-reported outcomes in a high risk complex general and urologic oncology surgery population is evaluated.

METHODS

Complex general surgical/urologic oncology patients wore a pedometer, completed ePROs (electronic patient-reported outcome surveys) and record their vitals (weight, pulse, pulse oximetry, blood pressure, and temperature) via a telehealth app platform. Feasibility (% adherence) was assessed as the primary outcome measure.

RESULTS

Twenty-one patients with a median age 58 (32-82) years were included. The readmission rate was 33% and the incidence of ≥Grade 3a morbidity was 24%. Adherence to vital sign and ePRO measurements was 95% before surgery, 91% at discharge, and 82%, 68%, and 64% at postdischarge d2, 7, 14, and 30, respectively. There was significant worsening of mobility, self-care and usual daily activity at postdischarge d2 compared to preoperative baseline (p < 0.05). Median daily preoperative steps taken by patients with <Grade 3a versus ≥Grade 3a postoperative morbidity was 6062 versus 4166 (p < 0.05). Of those interviewed, 87% (13/15) viewed vital sign devices as helpful in recovery.

CONCLUSIONS

Telemonitoring is feasible in a general surgical and urologic oncology setting. Future studies will ascertain optimal patient selection, duration, and extent of perioperative monitoring.

Immunotherapy-Based Neoadjuvant Treatment of Advanced Microsatellite Instability-High Gastric Cancer: A Case Series

Despite the use of first-line therapies like fluoropyrimidine and platinum-based cytotoxic chemotherapy, gastric cancer (GC) continues to carry a poor prognosis. Recent subgroup analyses of first-line phase III trials have demonstrated that patients with microsatellite instability-high (MSI-H) metastatic GC derive significant improvement in survival rates when immune checkpoint inhibitors (ICIs) are combined with chemotherapy compared with chemotherapy alone. However, it remains to be seen whether the success of ICIs in the metastatic setting can be translated into earlier stages of GC with resectable disease. We report 6 cases of locally advanced, nonmetastatic MSI-H GC that all demonstrated favorable response following treatment with pembrolizumab in addition to neoadjuvant chemotherapy. With the exception of immune-related colitis in one patient, pembrolizumab was well-tolerated. To our knowledge, this is the first reported US case series of patients treated with an ICI in combination with neoadjuvant chemotherapy for advanced, nonmetastatic, resectable or unresectable MSI-H GC.

Abstract 6342: Pan-cancer analysis of promoter or promoter-proximal somatic mutations defines transcription-replication conflict mutational signature

Introduction: While the nature of somatic mutations in cancer exomes has been described, mutations in non-coding regions are less well-characterized. Compared to the rest of the genome, promoter or promoter-proximal (PPP) regions are more susceptible to mutagenesis and distinct mutational processes [e.g., transcription-replication conflicts (TRCs)]. We sought to investigate the nature of mutations in PPP regions across human cancer types and to define a novel TRC mutational signature.

Methods: Whole genome and RNA sequencing data for untreated primary cancers were downloaded from the International Cancer Genome Consortium repository. PPP regions were defined as 1kb upstream of transcription start sites. We quantified the number of mutations in 1) PPP regions, 2) PPP regions of highly transcribed genes (HTGs; ≥75th percentile), and 3) common fragile sites (CFS).

Results: A total of 835 patients across 12 tumor types were included in our analysis. Our data show significant variation in PPP mutations across cancer types with liver, pancreatic, and ovarian cancers demonstrating the highest burden of PPP mutations (Table 1). These same cancer types also possessed high numbers of PPP mutations specifically in HTGs. Since PPP mutations may be caused by TRCs, we proposed that liver, pancreatic, and ovarian cancers exhibited a strong TRC mutational signature. Therefore, we examined the correlation between the signature and CFS mutations—known to be caused by TRCs—to validate our results. The data show a positive correlation across tumor types; this correlation was strongest for cancer types where a TRC signature was more prevalent [correlation coefficient (R): liver: 0.985, pancreas: 0.991, ovary: 0.964].

Conclusions: Our analysis of PPP and CFS mutations suggests that transcription-dependent genome instability is more prevalent in liver, pancreatic, and ovarian cancers. Further, PPP in HTGs may be a novel TRC mutational signature.

Medians and interquartile ranges of mutations by disease type. PPP: promoter or promoter-proximal Disease type Number of patients Mutations in PPP regions Mutations in PPP regions of highly transcribed genes (≥75%ile) Mutations in common fragile sites Bladder 23 4 (2-8) 2 (1-5) 12 (7-17) Bone 49 5 (2-12) 2 (0-3) 14 (7-43) Breast 89 1 (0-2) 0 (0-2) 5 (2-7) Cervix 20 1 (0-2) 1 (0-1) 3 (2-5) Colorectal 43 2 (1-14) 1 (0-5) 11 (6-81) Liver 227 54 (37-75) 13 (9-18) 264 (180-368) Lung 38 3 (1-6) 1 (0-2) 9 (4-24) Ovary 102 41 (3-68) 36 (16-52) 148 (7-213) Pancreas 140 31 (15-45) 25 (19-37) 113 (66-161) Prostate 19 0 (0-0) 0 (0-0) 1 (0-1) Stomach 34 2 (1-3) 1 (0-2) 8 (3-17) Uterus 51 1 (0-4) 1 (0-3) 6 (3-21)

Citation Format: Marc A. Attiyeh, Fan Meng, Yilun Liu, Nicholas Banovich, Mustafa Raoof. Pan-cancer analysis of promoter or promoter-proximal somatic mutations defines transcription-replication conflict mutational signature [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6342.

Cisplatin-induced nephrotoxicity in hyperthermic intraperitoneal chemotherapy (HIPEC) is mitigated by sodium thiosulfate: Clinical and toxicotranscriptomic results of a prospective trial

5570

Background: Hyperthermic intraperitoneal chemotherapy (HIPEC) with cisplatin confers a survival benefit in epithelial ovarian cancer (EOC). Unfortunately, cisplatin is associated with significant renal toxicities. Sodium thiosulfate (ST) has been suggested as a nephroprotectant for patients undergoing HIPEC with cisplatin. Methods: A feasibility trial ( ClinicalTrials.gov: NCT01970722) evaluated safety outcomes of HIPEC with cisplatin 75 mg/m2 during optimal cytoreductive surgery (CRS) in patients with EOC and endometrial cancer (n = 40), with or without ST. Twenty-one patients received no sodium-thiosulfate (nST group), and nineteen patients received sodium thiosulfate (ST group). Toxicities were reported according to CTCAE v. 5. Progression-free survival was followed. Normal tissue biopsies were collected intra-operatively immediately following HIPEC and cisplatin exposure in a subset of patients (n = 21), and profiled with transcriptomic sequencing to identify RNAseq signatures correlating with toxicities. Hierarchical cluster analyses identified distinct transcriptomic signatures in post-HIPEC normal samples of patients with renal AEs (rAEs) compared to no renal AEs (nrAEs). KEGG pathway analysis identified up- or downregulated gene sets using GSEA. Results: Forty patients had HIPEC at time of optimal CRS. Renal toxicities were higher in the nST group (no sodium thiosulfate) compared to the ST group. nST patients had 17% any grade, and 9% Grade 3 AEs for acute and chronic kidney injuries. In contrast, ST patients suffered 0% renal AEs. rAE patients demonstrated upregulation of immune signaling pathways (Toll-like receptor, Natural killer cell, Nod-like receptor); and downregulation of metabolic pathways. Top upregulated genes in rAE patients included immune (e.g. neutrophil) related genes, while downregulated genes included metabolism genes. Kaplan-Meier curves demonstrated improved PFS in primary ovarian cancer patients undergoing HIPEC who were treated with ST vs no ST (p = 0.04, NR vs 13.4 mo). Conclusions: HIPEC with cisplatin results in significant renal toxicities. The mechanisms of cisplatin-induced nephrotoxicity in HIPEC are immune-related and reflect reduced metabolism. Sodium thiosulfate abrogated renal toxicities and did not decrease PFS. Clinical trial information: NCT01970722.

Is CRS-HIPEC Still Indicated in Patients With Extraperitoneal Disease?

INTRODUCTION

The role of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with extraperitoneal disease (EPD) is controversial.

METHODS

Among patients with peritoneal metastases from appendiceal cancer (AC) and colorectal cancer (CRC) who underwent CRS-HIPEC, those with EPD (liver, lung, or retroperitoneal lymph nodes [RP LN]) were retrospectively compared to those without EPD. Overall (OS) and recurrence-free survival (RFS) analyses were performed before/after propensity score matching (PSM).

RESULTS

Among 1341 patients with AC (64%) or CRC (36%) who underwent CRS ± HIPEC, 134 (10%) had EPD whereas 1207 (90%) did not. EPD was located in the lungs (47%), RP LN (28%), liver (18%), or multiple (6%). Patients with EPD experienced worse median OS (34 versus 63 mo; P = 0.002) and RFS (12 versus 19 mo; P < 0.001). On a multivariable analysis, EPD was associated with worse RFS (P = 0.003), but not OS (P = 0.071). After PSM, the association of EPD with OS (P = 0.204) and RFS (P = 0.056) was no longer significant. In the multivariable analysis of the PSM cohort, EPD was not associated with OS (P = 0.157) or RFS (P = 0.110).

CONCLUSIONS

The findings of this large retrospective multi-institutional study suggest that EPD alone, while a negative prognostic indicator, should not be considered an absolute contraindication to CRS ± HIPEC for otherwise well-selected patients with peritoneal surface malignancies. Further research is needed to delineate whether location of EPD influences OS and RFS following CRS-HIPEC.

Development and Validation of an Explainable Machine Learning Model for Major Complications After Cytoreductive Surgery

Importance

Cytoreductive surgery (CRS) is one of the most complex operations in surgical oncology with significant morbidity, and improved risk prediction tools are critically needed. Machine learning models can potentially overcome the limitations of traditional multiple logistic regression (MLR) models and provide accurate risk estimates.

Objective

To develop and validate an explainable machine learning model for predicting major postoperative complications in patients undergoing CRS.

Design, Setting, and Participants

This prognostic study used patient data from tertiary care hospitals with expertise in CRS included in the US Hyperthermic Intraperitoneal Chemotherapy Collaborative Database between 1998 and 2018. Information from 147 variables was extracted to predict the risk of a major complication. An ensemble-based machine learning (gradient-boosting) model was optimized on 80% of the sample with subsequent validation on a 20% holdout data set. The machine learning model was compared with traditional MLR models. The artificial intelligence SHAP (Shapley additive explanations) method was used for interpretation of patient- and cohort-level risk estimates and interactions to define novel surgical risk phenotypes. Data were analyzed between November 2019 and August 2021.

Exposures

Cytoreductive surgery.

Main Outcomes and Measures

Area under the receiver operating characteristics (AUROC); area under the precision recall curve (AUPRC).

Results

Data from a total 2372 patients were included in model development (mean age, 55 years [range, 11-95 years]; 1366 [57.6%] women). The optimized machine learning model achieved high discrimination (AUROC: mean cross-validation, 0.75 [range, 0.73-0.81]; test, 0.74) and precision (AUPRC: mean cross-validation, 0.50 [range, 0.46-0.58]; test, 0.42). Compared with the optimized machine learning model, the published MLR model performed worse (test AUROC and AUPRC: 0.54 and 0.18, respectively). Higher volume of estimated blood loss, having pelvic peritonectomy, and longer operative time were the top 3 contributors to the high likelihood of major complications. SHAP dependence plots demonstrated insightful nonlinear interactive associations between predictors and major complications. For instance, high estimated blood loss (ie, above 500 mL) was only detrimental when operative time exceeded 9 hours. Unsupervised clustering of patients based on similarity of sources of risk allowed identification of 6 distinct surgical risk phenotypes.

Conclusions and Relevance

In this prognostic study using data from patients undergoing CRS, an optimized machine learning model demonstrated a superior ability to predict individual- and cohort-level risk of major complications vs traditional methods. Using the SHAP method, 6 distinct surgical phenotypes were identified based on sources of risk of major complications.

AHPBA guidelines for managing VTE prophylaxis and anticoagulation for pancreatic surgery

BACKGROUND

Major abdominal surgery and malignancy lead to a hypercoagulable state, with a risk of venous thromboembolism (VTE) of approximately 3% after pancreatic surgery. No guidelines exist to assist surgeons in managing VTE prophylaxis or anticoagulation in patients undergoing elective pancreatic surgery for malignancy or premalignant lesions. A systematic review specific to VTE prophylaxis and anticoagulation after resectional pancreatic surgery is herein provided.

METHODS

Six topic areas are reviewed: pre- and perioperative VTE prophylaxis, early postoperative VTE prophylaxis, extended outpatient VTE prophylaxis, management of chronic anticoagulation, anti-coagulation after vascular reconstruction, and treatment of VTE. A Medline and PubMED search was completed with systematic medical literature review for each topic. Level of evidence was graded and strength of recommendation ranked according to the GRADE (Grades of Recommendation Assessment, Development and Evaluation) system for practice guidelines.

RESULTS

Levels of evidence and strength of recommendations are presented.

DISCUSSION

While strong data exist to guide management of chronic anticoagulation and treatment of VTE, data for anticoagulation after reconstruction is inconclusive and support for perioperative chemoprophylaxis with pancreatic surgery is similarly limited. The risk of post-pancreatectomy hemorrhage often exceeds that of thrombosis. The role of universal chemoprophylaxis must therefore be examined critically, particularly in the preoperative setting.

Hyperthermic Intraperitoneal Chemotherapy-Induced Molecular Changes in Humans Validate Preclinical Data in Ovarian Cancer

Hyperthermic intraperitoneal chemotherapy (HIPEC) confers a survival benefit in epithelial ovarian cancer (EOC) and in preclinical models. However, the molecular changes induced by HIPEC have not been corroborated in humans.

Promoting antibody-dependent cellular phagocytosis for effective macrophage-based cancer immunotherapy

Macrophages are essential in eliciting antibody-dependent cellular phagocytosis (ADCP) of cancer cells. However, a satisfactory anticancer efficacy of ADCP is contingent on early antibody administration, and resistance develops along with cancer progression. Here, we investigate the mechanisms underlying ADCP and demonstrate an effective combinatorial strategy to potentiate its efficacy. We identified paclitaxel as a universal adjuvant that efficiently potentiated ADCP by a variety of anticancer antibodies in multiple cancers. Rather than eliciting cytotoxicity on cancer cells, paclitaxel polarized macrophages toward a state with enhanced phagocytic ability. Paclitaxel-treated macrophages down-regulated cell surface CSF1R whose expression was negatively correlated with patient survival in multiple malignancies. The suppression of CSF1R in macrophages enhanced ADCP of cancer cells, suggesting a role of CSF1R in regulating macrophage phagocytic ability. Together, these findings define a potent strategy for using conventional anticancer drugs to stimulate macrophage phagocytosis and promote the therapeutic efficacy of clinical anticancer antibodies.

Safety and efficacy of pressurized intraperitoneal aerosolized chemotherapy in appendiceal and colorectal cancer patients with peritoneal carcinomatosis: A first-in-US phase I study

125

Background: Pressurized intraperitoneal aerosolized chemotherapy (PIPAC) is being evaluated as a novel minimally invasive palliative treatment of peritoneal metastases (PM). Prior studies have established the feasibility and safety of repeated PIPAC treatments in gastrointestinal and gynecologic cancers. The goal of the present phase 1 trial was to establish the safety and feasibility of PIPAC oxaliplatin in a highly chemotherapy refractory colorectal and appendiceal cancer patient population. Methods: Patients with biopsy-proven peritoneal metastases from colorectal or appendiceal cancer underwent up to three PIPAC treatments using oxaliplatin (92 mg/m2) with a six-week interval at two academic centers. Patients with bowel obstruction, extra-peritoneal metastases, or poor performance status (ECOG>2) were excluded. PIPAC was nebulized over 5 min with a 30 min aerosol dwell time. Apart from the first PIPAC cycle, the patients also received a sensitizing dose of 5FU/LV (400mg/m2) within 24 hours of the procedure. Primary end point was safety as assessed by dose limiting toxicities within 6 weeks of the first PIPAC. Secondary endpoints included safety with the addition of 5FU/LV, efficacy, surgical morbidity, technical failure rate, progression-free and overall survival, pharmacokinetics (PK), and quality of life assessment. Results: A total of 8 patients were included: 5 colorectal; and 3 appendiceal. Median number of prior chemotherapy cycles was 2 (Interquartile range – IQR; 1.5-3.5). All patients were refractory to systemic oxaliplatin-based chemotherapy. Median time from diagnosis to PIPAC was 16 months (IQR; 5.6, 17.5) and Peritoneal Carcinomatosis Index was 29 (IQR; 20.5, 31.5). Five (62.5%) patients completed 3 PIPAC cycles while in 3 (37.5%) patients PIPAC was discontinued due to disease progression within the peritoneal cavity. No surgical complication or dose limiting toxicity was observed. Only one patient developed grade 3 treatment-related toxicity after first PIPAC (anemia), and another patient after second PIPAC (abdominal pain and anemia). At the completion of PIPAC treatment 5 patients had stable disease and 3 had disease progression. Pharmacokinetic, histologic response and preliminary survival data will be presented at the meeting. Conclusions: PIPAC with oxaliplatin is safe and feasible in a highly chemotherapy refractory cohort of appendiceal and colorectal carcinomatosis patients with or without sensitizing 5-FU/ LV. Clinical trial information: NCT04329494.

Prognostic Significance of Preoperative Tumor Markers in Pseudomyxoma Peritonei from Low-Grade Appendiceal Mucinous Neoplasm: a Study from the US HIPEC Collaborative

BACKGROUND

Tumor markers are commonly utilized in the diagnostic evaluation, treatment decision making, and surveillance of appendiceal tumors. In this study, we aimed to determine the prognostic significance of elevated preoperative tumor markers in patients with pseudomyxoma peritonei secondary to low-grade appendiceal mucinous neoplasm who underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

METHODS

Using a multi-institutional database, eligible patients with measured preoperative tumor markers [carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA 19-9), or cancer antigen 125 (CA-125)] were identified. Univariate and multivariate Cox-proportional hazards regression analysis assessed relationships between normal and elevated serum tumor markers with progression-free and overall survival in the context of multiple clinicopathologic variables.

RESULTS

zTwo hundred and sixty-four patients met criteria. CEA was the most commonly measured tumor marker (97%). Patients who had any elevated tumor marker had a higher peritoneal carcinomatosis index (PCI) as compared to those with normal range markers. Elevated CEA and CA 19-9 levels were individually associated with longer inpatient length of stay, requirement for intraoperative transfusion, and incomplete cytoreduction. Utilization of neoadjuvant chemotherapy, increased PCI score, elevated CA 19-9 (p = 0.007), and CA-125 levels (p = 0.01) were predictive of decreased progression-free survival on univariate analysis. However, in a multivariate model, only elevated PCI was a statistically significant predictor of progression-free survival.

CONCLUSION

Elevated preoperative tumor markers indicate a higher burden of disease but are not independently associated with survival in this retrospective multi-institutional cohort. Further prospective studies are needed to clarify the utility of these markers in this patient population.

Racial and Ethnic Bias Impact Perceptions of Surgeon Communication

OBJECTIVE

To evaluate patient satisfaction scores as a function of physician and patient race and sex.

BACKGROUND

Patient satisfaction is increasingly used as a surrogate for physician performance. How patient and surgeon race and ethnicity affect perceptions of surgeon communication and care is not widely explored.

METHODS

Press Ganey patient satisfaction surveys collected from January 2019 to September 2020 were studied. Multivariate logistic regressions were used to identify factors associated with favorable surgeon performance as a function of patient and surgeon demographics.

RESULTS

A total of 4732 unique outpatient satisfaction survey responses were analyzed. The majority of patients were White (60.5%), followed by Asian (8.6%), Black (4.2%), and Hispanic (4.3%). URM accounted for 8.9% of the 79 surgeons evaluated, and 34% were female. Black, Hispanic, and Asian patients were more likely to report unfavorable experiences than their White counterparts (P < 0.01). Spanish-speaking patients were most likely to perceive that surgeon show less respect for patient concerns (13.9% vs 9.3%, P = 0.004) and inadequate time spent explaining health concerns (12.6% vs 9.2%, P < 0.001). Female surgeons were more likely to achieve the highest overall ratings for effective communication, whereas Asian surgeons received lower scores. Asian surgeons were more likely than non-Asian surgeons to receive lower scores in explanation (37.3% vs 44.1%, P = 0.003). After adjusting for confounding factors, Asian surgeons had 26% lower odds of receiving favorable scores for overall communication (odds ratio: 0.736, 95% confidence interval: 0.619-0.877, P = 0.001).

CONCLUSIONS

Both patient and surgeon race and sex drive negative perceptions of patient-physician communication. As URM report more negative experiences, further studies should focus on effects of surgeon cultural awareness on underrepresented patient satisfaction.

Medicare Advantage Networks and Access to High-volume Cancer Surgery Hospitals

OBJECTIVE

To determine how Medicare Advantage (MA) health plan networks impact access to high-volume hospitals for cancer surgery.

BACKGROUND

Cancer surgery at high-volume hospitals is associated with better short- and long-term outcomes. In the United States, health insurance is a major detriment to seeking care at high-volume hospitals. A third of older (>65 years) Americans are enrolled in privatized MA health plans. The impact of MA plan networks on access to high-volume surgery hospitals is unknown.

METHODS

We analyzed in-network hospitals for MA plans offered in Los Angeles county during open enrollment of 2015. For the purposes of this analysis, MA network data from provider directories were linked to hospital volume data from California Office of Statewide Health Planning and Development. Volume thresholds were based on published literature.

RESULTS

A total of 34 MA plans enrolled 554,754 beneficiaries in Los Angeles county during 2014 open enrollment for coverage starting in 2015 (MA penetration ∼43%). The proportion of MA plans that included high-volume cancer surgery hospital varied by the type of cancer surgery. While most plans (>71%) included at least one high-volume hospital for colon, rectum, lung, and stomach; 59% to 82% of MA plans did not include any high-volume hospitals for liver, esophagus, or pancreatic surgery. A significant proportion of beneficiaries in MA plans did not have access to high-volume hospitals for esophagus (93%), stomach (44%), liver (39%), or pancreas (70%) surgery. In contrast, nearly all MA beneficiaries had access to at least one high-volume hospital for lung (93%), colon (100%), or rectal (100%) surgery. Overall, Centers for Medicare & Medicaid Services plan rating or plan popularity were not correlated with access to high-volume hospital (P > 0.05).

CONCLUSIONS

The study identifies lack of high-volume hospital coverage in MA health plans as a major detriment in regionalization of cancer surgery impacting at least a third of older Americans.

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.

Patterns of Whole Exome Sequencing in Resected Cholangiocarcinoma

Simple Summary

Cholangiocarcinomas are rare cancers that harbor a significant number of potentially targetable mutations. In this study, we assessed the frequency of genomic profiling for resected cholangiocarcinomas. We found that, over the past decade, a third of patients underwent tumor genomic profiling, among whom 89% harbored a targetable mutation. Mutations were associated with a median of one approved drug. A quarter of eligible sequenced patients were treated with therapy targeting tumor-specific mutations.

Abstract

Background: With minimally effective chemotherapy options, cholangiocarcinoma patients have 5 year survival rate of 10%. Tumor genetic profiling (TGP) can identify mutations susceptible to targeted therapies. We sought to describe the use of TGP and frequency of actionable results in resected cholangiocarcinoma. Methods: A retrospective review of patients undergoing curative intent resection at a comprehensive cancer center (2010–2020). Clinicopathologic and partial or whole exome sequencing data were reviewed. Results: 114 patients (mean age 65 ± 11 years, 45% female) underwent resection of cholangiocarcinoma (46% poorly differentiated, 54% intrahepatic, 36% node positive, 75% margin negative). Additionally, 32% of patients underwent TGP, yielding a mean of 3.1 actionable mutations per patient (range 0–14). Mutations aligned with a median of one drug per patient (range 0–11). Common mutations included TP53 (33%), KRAS (31%), IDH1/2 (14%), FGFR (14%), and BRAF (8%). Targeted therapies were administered in only 4% of patients (23% of eligible sequenced patients). After a median 22 months, 23% had recurrence and 29% were deceased. Discussion: TGP for cholangiocarcinoma has increased over the last decade with targeted therapies identified in most sequenced tumors, impacting treatment in a quarter of eligible patients. Precision medicine will play a central role in the future care of cholangiocarcinoma.

A Quantitative Analysis of Surgical Smoke Exposure as an Occupational Hazard

OBJECTIVE

We hypothesized that OR airborne PM was different in quantity and mutagenic potential than office air and cigarette smoke.

SUMMARY OF BACKGROUND DATA

Exposure to surgical smoke has been equated to cigarette smoking and thought to be hazardous to health care workers despite limited data.

METHODS

PM was measured during 15 operations in ORs with 24.8 ± 2.0 air changes/h, and in controls (cigarettes, office air with 1.9-2.9 air changes/h). Mutagenic potential was assessed by gamma Histone 2A family member X staining of DNA damage in small airway epithelial cells co-cultured with PM.

RESULTS

Average PM concentration during surgery was 0.002 ± 0.002 mg/m3 with maximum values at 1.08 ± 1.30 mg/m3. Greater PM correlated with more diathermy (ρ = 0.69, P = 0.006). Values were most often near zero, resulting in OR average values similar to office air (0.002 ± 0.001 mg/m3) (P = 0.32). Cigarette smoke average PM concentration was significantly higher, 4.8 ± 5.6 mg/m3 (P < 0.001). PM collected from 14 days of OR air caused DNA damage to 1.6% ± 2.7% of cultured cells, significantly less than that from office air (27.7% ± 11.7%, P = 0.02), and cigarette smoke (61.3% ± 14.3%, P < 0.001).

CONCLUSIONS

The air we breathe during surgery has negligible quantities of PM and mutagenic potential, likely due to low frequency of diathermy use coupled with high airflow. This suggests that exposure to surgical smoke is associated with minimal occupational risk.

Robotic minor hepatectomy: optimizing outcomes and cost of care

BACKGROUND

The advantages of robotic liver surgery are strongest for minor resections, where incision size drives recovery time, but cost remains a concern. We hypothesized that patients who underwent robotic minor liver resections would have superior peri-operative outcomes resulting in decreased cost.

METHODS

We queried the medical record and cost data for patients who underwent open or robotic minor (1-2 segment) liver resection from 1/2016-8/2019. Financial data were normalized to Medicare reimbursements.

RESULTS

There were 87 patients who underwent minor liver resections (robotic n = 46, open n = 41). Specimen size (173 ± 203 vs 257 ± 481 cm³), surgical duration (233 ± 87 vs 227 ± 83 min), estimated blood loss (187 ± 236 vs 194 ± 165 mL), and margin status (89% vs 93% R0) were similar for robotic and open resections respectively, yet complications (3/46, 7% vs 10/41, 24%, p = 0.02) and length of stay (2.2 ± 2.2 vs 6.2 ± 2.9, p < 0.001) were significantly lower for patients who underwent robotic resection. These factors contributed to minor robotic liver resections costing $534 less than open resections ($3597 ± 1823 vs $4131 ± 1532, p = 0.03).

CONCLUSION

Patients undergoing robotic minor hepatectomy had superior peri-operative outcomes resulting in lower total cost of care when compared to open minor hepatectomy. Financial considerations should not adversely influence selection of a robotic approach for minor hepatectomy.

Management of disappearing colorectal liver metastases: an international survey

BACKGROUND

Improved chemotherapy response rates have lead to "disappearing" colorectal liver metastases (dCRLM). We aim to assess management patterns of dCRLM from an international body of hepatobiliary surgeons.

METHODS

A survey was designed, tested for item relevance, readability and content validity, and distributed to the AHPBA, IHPBA and ANZHPBA.

RESULTS

The majority of 226 respondents were <15 years from training (69%), practiced in academia (82%) and devoted >50% of their practice to hepatobiliary (75%). Surgeons utilize CT(45%) or MRI(47%) for preoperative planning with a preferred imaging interval of <6 weeks. Nearly all have experienced dCRLM (99%) and 63% of surgeons have waited a few months to assess for durability of response prior to definitive surgical/ablative therapy. Only 24% place fiducial markers for lesions <1-cm prior to neoadjuvant chemotherapy. Intra-operatively, 97% of surgeons perform ultrasound, and 71% ablation. When a tumor has "disappeared," 49% elect for observation and 31% resect if the dCRLM is superficial. Of those electing observation, 87% believe there is effective treatment with progression on surveillance imaging.

CONCLUSIONS

Nearly all surgeons have experienced dCRLM with half choosing observation over intervention due to the belief that these lesions may be re-addressed in the future.

Effect of cabazitaxel on macrophages improves CD47-targeted immunotherapy for triple-negative breast cancer

Background

Limited therapeutic options are available for triple-negative breast cancer (TNBC), emphasizing an urgent need for more effective treatment approaches. The development of strategies by targeting tumor-associated macrophages (TAMs) to stimulate their ability of Programmed Cell Removal (PrCR) provides a promising new immunotherapy for TNBC treatment.

Methods

CD47 is a critical self-protective “don’t eat me” signal on multiple human cancers against macrophage immunosurveillance. Using human and mouse TNBC preclinical models, we evaluated the efficacy of PrCR-based immunotherapy by blocking CD47. We performed high-throughput screens on FDA-approved anti-cancer small molecule compounds for agents potentiating PrCR and enhancing the efficacy of CD47-targeted therapy for TNBC treatment.

Results

We showed that CD47 was widely expressed on TNBC cells and TAMs represented the most abundant immune cell population in TNBC tumors. Blockade of CD47 enabled PrCR of TNBC cells, but the efficacy was not satisfactory. Our high-throughput screens identified cabazitaxel in enhancing PrCR-based immunotherapy. A combination of CD47 blockade and cabazitaxel treatment yielded a highly effective treatment strategy, promoting PrCR of TNBC cells and inhibiting tumor development and metastasis in preclinical models. We demonstrated that cabazitaxel potentiated PrCR by activating macrophages, independent of its cytotoxicity toward cancer cells. When treated with cabazitaxel, the molecular and phenotypic signatures of macrophages were polarized toward M1 state, and the NF-kB signaling pathway became activated.

Conclusion

The combination of CD47 blockade and macrophage activation by cabazitaxel synergizes to vastly enhance the elimination of TNBC cells. Our results show that targeting macrophages is a promising and effective strategy for TNBC treatment.