Distance Traveled and Disparities in Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: The impact of distance traveled on cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) outcomes needs further investigation. METHODS: This retrospective study reviewed a prospectively managed single-center CRS/HIPEC 1992-2022 database. Zip codes were used to calculate distance traveled and to obtain data on income and education via census data. Patients were separated into three groups based on distance traveled in miles (local: ≤50 miles, regional: 51-99 miles, distant: ≥100 miles). Descriptive statistics, Kaplan-Meier method, and Cox regression were performed. RESULTS: The 1614 patients in the study traveled a median distance of 109.5 miles (interquartile range [IQR], 53.36-202.29 miles), with 23% traveling locally, 23.9% traveling regionally, and 53% traveling distantly. Those traveling distantly or regionally tended to be more white (distant: 87.8%, regional: 87.2%, local: 83.2%), affluent (distant: $61,944, regional: $65,014, local: $54,390), educated (% without high school diploma: distant: 10.6%, regional: 11.5%, local: 13.0%), less often uninsured (distant: 2.3%, regional: 4.6%, local: 5.2%) or with Medicaid (distant: 3.3%, regional: 1.3%, local: 9.7%). They more often had higher Peritoneal Carcinomatosis Index (PCI) scores (distant: 15.4, regional: 15.8, local: 12.7) and R2 resections (distant: 50.3%, regional: 52.2%, local: 40.5%). Median survival did not differ between the groups, and distance traveled was not a predictor of survival. CONCLUSION: More than 50% of the patients traveled farther than 100 miles for treatment. Although regionalization of CRS/HIPEC may be appropriate given the lack of survival difference based on distance traveled, those who traveled further had fewer health care disparities but higher PCI scores and more R2 resections, which raises concerns about access to care for the underserved, time to treatment, and surgical quality.

Quality-of-Life Outcomes for Patients Taking Opioids and Psychotropic Medications Before Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: The impact of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) on quality of life (QoL) for patients taking opioids and psychotropic medications preoperatively is unclear. METHODS: This study retrospectively reviewed a CRS-HIPEC single-center prospectively maintained database for 2012-2016. Demographics and clinical data on opioids/psychotropic medication use were collected via chart review. The study collected QoL outcomes at baseline, then 3, 6, and 12 months postoperatively via the Center for Epidemiologic Studies Depression Scale (CES-D), Brief Pain Inventory, Functional Assessment of Cancer Therapy, and 36-Item Short-Form Health Survey. Differences in QoL between the groups were calculated using repeated measures analysis of variance regression. Descriptive statistics and Kaplan-Meier analyses were performed. RESULTS: Of 388 patients, 44.8% were taking opioids/psychotropic medications preoperatively. At baseline, those taking opioids/psychotropic medications preoperatively versus those not taking these medications had significantly worse QoL. By 1 year postoperatively, the QoL measures did not differ significantly except for emotional functioning (e.g., no medications vs. opioids/psychotropic medications: CES-D, 5.6 vs. 10.1). Median survival did not differ significantly (opioids/psychotropic medications vs. no medications: 52.3 vs. 60.6 months; p = 0.66). At 1 year after surgery, a greater percentage of patients were taking opioids, psychotropic medications, or both than at baseline (63.2% vs. 44.8%; p < 0.001). CONCLUSION: Despite worse baseline QoL, patients who took opioids/psychotropic medications had QoL scores 1 year postoperatively similar to the scores of those who did not except in the emotional domains. These data point to the potential utility of a timed psychosocial intervention to enhance emotional adaptation and further support the role of CRS-HIPEC in improving QoL.

Cisplatin exhibits superiority over MMC as a perfusion agent in a peritoneal mesothelioma patient specific organoid HIPEC platform.

Peritoneal mesothelioma (PM) is a rare malignancy with poor prognosis, representing about 10-15% of all mesothelioma cases. Herein we apply PM patient-derived tumor organoids (PTOs) in elucidating personalized HIPEC responses to bypass rarity of disease in generating preclinical data. Specimens were obtained from PM patients undergoing cytoreductive surgery with HIPEC. PTOs were fabricated with tumor cells suspended in ECM-hydrogel and treated with HIPEC regimen parameters. Viability and characterization analyses were performed post-treatment. Treatment efficacy was defined as ≥ 50% viability reduction and p < 0.05 compared to controls. From October 2020 to November 2022, 17 tumors from 7 patients were biofabricated into organoids, with 16/17 (94.1%) sites undergoing comparative 37° and 42° treatments with cisplatin and mitomycin C (MMC). Hyperthermic cisplatin and MMC enhanced cytotoxicity which reduced treatment viability by 25% and 22%, respectively, compared to normothermia. Heated cisplatin displayed the greatest cytotoxicity, with efficacy in 12/16 (75%) tumors and an average viability of 38% (5-68%). Heated MMC demonstrated efficacy in 7/16 (43.8%) tumors with an average treatment viability of 51% (17-92.3%). PTOs fabricated from distinct anatomic sites exhibited site-specific variability in treatment responses. PM PTOs exhibit patient and anatomic location treatment responses suggestive of underlying disease clonality. In PM organoids cisplatin is superior to MMC in HIPEC.

Survival Outcomes of Optimally Treated Colorectal Metastases: The Importance of R0 Status in Surgical Treatment of Hepatic and Peritoneal Surface Disease.

BACKGROUND: Although colorectal hepatic metastases (HM) and peritoneal surface disease (PSD) are distinct biologic diseases, they may have similar long-term survival when optimally treated with surgery. METHODS: This study retrospectively reviewed prospectively managed databases. Patients undergoing R0 or R1 resections were analyzed with descriptive statistics, the Kaplan-Meier method, and Cox regression. Survival was compared over time for the following periods: 1993-2006, 2007-2012, and 2013-2020. RESULTS: The study enrolled 783 HM patients undergoing liver resection and 204 PSD patients undergoing cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC). Compared with PSD patients, HM patients more often had R0 resections (90.3% vs. 32.4%), less often had pre-procedure chemotherapy (52.4% vs. 92.1%), and less often were functionally independent (79.7% vs. 95.6%). The 5-year overall survival for HM was 40.9%, with a median survival period of 45.8 months versus 25.8% and 33.4 months, respectively, for PSD (p < 0.05). When stratified by resection status, R0 HM and R0 PSD did not differ significantly in median survival (49.0 vs. 45.4 months; p = 0.83). The median survival after R1 resection also was similar between HM and PSD (32.6 vs. 26.9 months; p = 0.59). Survival between the two groups again was similar over time when stratified by resection status. The predictors of survival for HM patients were R0 resection, number of lesions, intraoperative transfusion, age, and adjuvant chemotherapy. For the PSD patients, the predictors were peritoneal cancer index (PCI) score, estimated blood loss (EBL), and female gender. CONCLUSION: The study showed that R0 resections are associated with improved outcomes and that median survival is similar between HM and PSD patients when it is achieved. Surveillance and treatment strategies that facilitate R0 resections are needed to improve results, particularly for PSD.

Long-Term Survival in Patients Treated with Cytoreduction and Heated Intraperitoneal Chemotherapy for Peritoneal Mesothelioma at a Single High-Volume Center.

BACKGROUND: Malignant peritoneal mesothelioma (MPM) is a rare diagnosis with a dismal prognosis if untreated. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is shown to significantly improve survival. Our institution is uniquely positioned to report long-term outcomes in MPM with CRS-HIPEC, due to our robust peritoneal surface disease program existing over the past three decades. METHODS: Our prospectively maintained, single-institution database of CRS-HIPEC cases was reviewed, identifying 111 consecutive patients with MPM over 28 years (1993-2021). Prognostic, operative, and pathologic factors were reviewed. Overall survival (OS) and conditional survival (CS) analyses were performed. RESULTS: The average age was 55.1 years; 58.6% of patients were male; 17 of 111 patients (15.3%) had a second CRS-HIPEC. At first CRS-HIPEC, the average PCI score was 18.7, and the perfusate drugs were platinum-based (72.1%) and mitomycin C (27.9%). The resection status at first CRS-HIPEC was R2a (46.4%), followed by R0-1 (29.1%), and R2b-c (24.5%). Median OS was 3.3 years for the entire cohort, with 75th and 25th percentiles at 10.7 months and 10.6 years. Median CS was improved if patients survived to the 1-year postoperative mark (4.9 years, p < 0.01) and trended toward further improvement with each passing year. If 3-year postoperative survival was achieved, the median CS improved to 6.1 years. CONCLUSIONS: This represents one of the largest and lengthiest, single-center, longitudinal, case series of peritoneal mesothelioma treated with CRS-HIPEC. The OS suggests efficacy for CRS-HIPEC for MPM. Long-term survival improves significantly after patients achieve the 1-year, postoperative mark.

Utilizing Patient-Derived Organoids in the Management of Colorectal Cancer with Peritoneal Metastases: A Review of Current Literature.

INTRODUCTION: Treatment of colorectal cancer-derived peritoneal carcinomatosis (CRC-PC) is challenging due to cellular heterogeneity that exhibits variable degrees of resistance to systemic as well as intraperitoneal chemotherapy. Therefore, it is not a surprise that the majority of patients undergoing cytoreductive surgery with HIPEC will experience recurrence. Patient-derived tumor organoids (PTOs) may be potentially capable of informing clinical treatment decisions at the level of the individual patient. In this study, we review the current landscape of CRC-PC PTO literature. METHODS: PubMed was queried for peer-reviewed publications studying CRC-PC organoids. Original articles which harnessed organoids as a research platform to study CRC-PC were included for review. Xenograft organoid studies were excluded. RESULTS: A total of 5 articles met inclusion criteria published between 2017 and 2022 and underwent complete analysis. Study topics included optimization of current therapies, identification of novel drug applications, and identification of disease mechanisms. Current therapies studied included systemic chemotherapy, targeted inhibitors, and HIPEC regimens. CONCLUSIONS: Patient-derived tumor organoids are a valuable personalized research tool that can complement real-time clinical settings. Additional research is needed to optimize methodologies of organoid incorporation in patients with colorectal cancer with peritoneal carcinomatosis.

Exposure to Neoadjuvant Oxaliplatin-Containing Chemotherapy, Does it Effect Intraperitoneal Hyperthermic Chemotherapy Perfusion?

INTRODUCTION: Patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) are commonly exposed to oxaliplatin neoadjuvant chemotherapy (NAT) regimens. The impact of systemic exposure to oxaliplatin prior to HIPEC with oxaliplatin is unknown. METHODS: We conducted a retrospective review of our institutional registry of CRS/HIPEC cases who received oxaliplatin-containing NAT, and compared patients who underwent HIPEC with oxaliplatin versus cases perfused with mitomycin C. The primary outcome was survival, defined by overall survival (OS) and disease-free survival (DFS). Subgroup analysis was performed based on primary tumor etiology and completeness of cytoreduction. RESULTS: A total of 333 cases satisfied the selection criteria-159 appendiceal primaries (all high-grade disease) and 174 colorectal cases. Thirty-one cases (9.3%) underwent HIPEC with oxaliplatin, with the remaining 302 cases (90.7%) receiving mitomycin C. Both cohorts were identical in regard to baseline characteristics, and both groups were alike in regard to NAT regimens and oxaliplatin exposure. There was no difference in survival outcomes. OS times were 2.9 (± 2.8) and 2.8 ( ± 3.6) years for oxaliplatin and mitomycin C perfusions, respectively (p = 0.94), and the 5-year OS rates were also similar at 9.7 and 18.5% (odds ratio [OR] 0.49, 95% confidence interval [CI] 0.14-1.67, p = 0.24) for oxaliplatin and mitomycin cases, respectively. Likewise, DFS findings were similar, with survival of 2.5 (± 4.5) and 1.8 (± 2.4) years for oxaliplatin and mitomycin perfusions, respectively (p = 0.21). There was no difference in 5-year DFS rates, at 10.5 and 7.8% (OR 1.39, 95% CI 0.30-6.56, p = 0.68) for oxaliplatin and mitomycin C, respectively. Subgroup analysis found minimal discordant findings from the main results. CONCLUSION: This analysis found no discernable association with NAT oxaliplatin exposure in regard to survival outcomes following CRS/HIPEC stratified out by perfusion agent.

Impact of myometrium invasion on survival outcomes following cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC).

INTRODUCTION: Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is an effective surgical intervention for peritoneal surface malignancy. The effect of myometrium invasion on outcomes is unknown. METHODS: Retrospective review of our institutional registry with analysis of CRS-HIPEC cases involving a hysterectomy. Compared cases with myometrium invasion versus those without invasion. Primary outcome was survival as measured by overall survival (OS) and disease-free survival (DFS). Secondary outcome was the evaluation of risk factors for myometrium invasion based on multivariate analysis. RESULTS: A total of 126 cases of CRS-HIPEC involving a hysterectomy were identified. Ninety-seven cases (76.9%) had no myometrium invasion and the remaining 29 cases (23.1%) had malignant invasion. The presence of myometrial invasion was a significant negative survival prognostic factor. The OS was halved with mean survival times of 2.8 (±2.3) versus 5.8 (±4.7) years for cases with and without invasion, respectively (p = 0.002). Five-year OS rates were also inferior with myometrium invasion at 17.4% versus 53.8% (odds ratio [OR] = 0.181, 95% confidence interval [CI]: 0.057-0.580, p = 0.002). A similar trend was present with DFS with mean survival times of 1.4 (±0.9) versus 3.7 (±3.9) years for noninvasion and invasion cases (p = 0.009). The 5-year DFS rates were 0% versus 34.8% (OR = 0.652, 95% CI: 0.549-0.775, p = 0.004). Secondary analysis significantly associated several risk factors with myometrium invasion to include lymph node positivity (OR = 2.539, 95% CI: 1.074-6.003, p = 0.012), colorectal primary tumors (OR = 2.248, 95% CI: 1.094-5.161, p = 0.035), and high-grade tumors (OR = 2.160, 95% CI: 1.080-4.820, p = 0.038). CONCLUSION: Myometrium invasion is a significant negative prognostic factor for survival following CRS-HIPEC. Several risk factors are potentially predictive of identifying those at high-risk for myometrium invasion.

Timing of Repeat Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy for Recurrent Low-Grade Appendiceal Mucinous Neoplasms.

BACKGROUND: Low-grade appendiceal mucinous neoplasm (LAMN) with peritoneal involvement is a common indication for cytoreductive surgery with heated intraperitoneal chemotherapy (CRS/HIPEC). With peritoneal recurrence, patients are increasingly being offered repeat CRS/HIPECs, however optimal timing for a second CRS/HIPEC remains unknown. METHODS: A prospectively maintained 30-year database at our high-volume HIPEC center was analyzed retrospectively for patients with LAMNs and peritoneal recurrence receiving one or two CRS/HIPECs. Kaplan-Meier survival analysis, linear regression modeling, and Cox proportional hazards regression analyses were performed. RESULTS: Overall, 143 patients with LAMNs who underwent CRS/HIPECs had confirmed postoperative peritoneal recurrence. Of these patients, 85 underwent one CRS/HIPEC and 58 underwent two CRS/HIPECs. The groups had significant differences in age, with younger patients more likely to undergo a second CRS/HIPEC (48.5 vs. 58.0 years; p < 0.001). The median overall survival (OS) for the group undergoing two CRS/HIPECs was approximately four times longer compared with the group undergoing one CRS/HIPEC (227.1 vs. 54.5 months; p < 0.0001). The time from recurrence to the second CRS/HIPEC was not significantly associated with OS from the time of the first operation. Instead, a shorter time between the first CRS/HIPEC and recurrence was significantly associated with shorter OS from the time of the first operation (p = 0.037). CONCLUSION: In peritoneal LAMNs with recurrence, receiving two CRS/HIPECs was associated with better OS compared with receiving one CRS/HIPEC. Longer time to recurrence was a good prognostic factor. Delay between recurrence and second CRS/HIPEC had no apparent impact on OS from the first CRS/HIPEC; thus, immediate or delayed reoperative intervention are both reasonable approaches.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Management of Colorectal Cancer with Peritoneal Dissemination: 30 Years of Experience at a Single Institution.

BACKGROUND: Cytoreductive surgery (CRS) is at the forefront of treatment for colorectal cancer with peritoneal metastasis or "carcinomatosis" (CRC-PC). We report outcomes of the operative management of CRC-PC at a single center. STUDY DESIGN: We retrospectively reviewed our database from 1992 through 2021. The Kaplan-Meier method was used to estimate survival. Proportional hazards regression and multivariable models were used for assessments. RESULTS: This study included 345 patients with mean age 53.5 years. Multivariate analysis revealed performance and resection status were associated with overall survival (OS; p < 0.001). Within the R0/R1 group, adverse impact on OS was found with increasing Peritoneal Cancer Index (PCI) score starting at 9 (hazard ratio [HR] = 1.98, CI 1.39-2.82, p = 0.0001) with the most significant hazard noted at PCI >14 (HR = 2.35, CI 1.52-3.63, p = 0.0001). Incomplete resection (R2) had significantly worse OS compared with complete CRS 33.4 (n = 206) vs R2: 12.7 months (n = 139; p < 0.0001. When stratified by PCI for the R0/R1 group, median OS for PCI less than 10, 10 to 15, and greater than 15 was 38.2, 19.7, and 22.2 m, respectively (p = 0.0007 comparing PCI less than 10 and greater than 15). Ten-year increments-1991 through 2000, 2001 through 2010, 2011 through 2020-revealed improvement in median OS (13.4 [n = 66], 19.3 [n = 139], and 29.1 months [n = 140]). However, by resection status, median OS remained stable for R0/R1 (32.3 [n = 23], 31.1 [n = 76], and 34.1 months [n = 107]) and improved for R2 (5.2 [n = 43], 14.4 [n = 63], and 14.6 months [n = 33]). Clavien-Dindo complication rate (greater than or equal to grade III) was 29.4%. CONCLUSION: CRS improves outcomes for CRC-PC compared with historic outcomes with nonoperative management. This benefit is greatest with complete resection and lower disease burden. Results of CRS (with or without heated intraperitoneal chemotherapy) are improving, and surgery for CRC-PC should be routinely considered.

Repeat Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy for Cancers with Peritoneal Metastasis: A 30-year Institutional Experience.

BACKGROUND: Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) improves survival in abdominal cancer patients with metastatic disease limited to the peritoneal cavity. Patients are increasingly being offered repeat CRS-HIPECs for peritoneal recurrence. However, in this rare clinical scenario, the survival benefit of performing repeat CRS-HIPEC operations remains unclear. METHODS: A retrospective review of the CRS-HIPEC database at Wake Forest Baptist Medical Center was performed over a 30-year timespan. From 1547 patients with appendix cancers, colorectal cancers, mesotheliomas, and other miscellaneous cancers, 156 received more than one CRS-HIPEC. Kaplan-Meier survival analysis was performed using overall survival (OS) from the time of surgery as the primary endpoint. Multi-variable Cox proportional hazards regression modelling was performed on pertinent clinical variables. RESULTS: Patients who received multiple CRS-HIPECs had significantly better median OS (10.7 years) versus those who received one CRS-HIPEC (2.5 years), with appendix cancers faring best (12.9 years). Resection status R2a or better was achieved in 76.4% of repeat CRS-HIPECs. There were no significant changes in complication rates after repeat CRS-HIPEC. On multivariate analysis of repeat CRS-HIPEC, patients with appendix and colorectal cancers, heart disease, and poor functional status were independently associated with poor OS. Factors not independently associated with OS were age, sex, body mass index, race, diabetes, lung disease, smoking history, and systemic chemotherapy between CRS-HIPECs. CONCLUSIONS: Performing multiple CRS-HIPEC operations on appropriate surgical candidates may significantly prolong survival. Appendix cancers derived the greatest benefit. Satisfactory resection margins and complication rates are comparable to first cases and achievable in repeat CRS-HIPEC procedures.

Utility of Neoadjuvant Chemotherapy for Peritoneal Carcinomatosis Secondary to High-Grade Appendiceal Neoplasms for Patients Undergoing Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy.

INTRODUCTION: Neoadjuvant chemotherapy (NAT) is frequently utilized before cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) for high-grade appendiceal neoplasms. The proposed benefits of NAT do not correlate with the limited literature. METHODS: Retrospective review of our CRS-HIPEC registry. Primary outcomes were the effect of NAT on disease burden, cytoreduction scores, overall survival (OS), disease-free survival (DFS), and recurrence patterns. RESULTS: A total of 126 cases of high-grade disease met selection criteria; 73 cases received NAT before referral, and 53 cases received no therapy before referral and went directly to CRS-HIPEC. For those cases who received NAT 89% received a FOLFOX-based regimen. Mean PCI scores were 16.47 and 16.07 (P = 0.843) with complete cytoreductions rates of 79.5% and 75% (P = 0.556) for NAT and non-NAT cases, respectively. NAT cases were associated with significantly decreased OS and DFS rates. Mean OS was 3.6 and 2.5 years (P = 0.005) with actual 5-year OS rates of 24.2% versus 5% (P = 0.017) for non-NAT and NAT cases respectively. Mean DFS was 2.8 and 1.7 years (P = 0.015) with actual 5-year DFS rates of 18.6% versus 5.7% (P = 0.048) for non-NAT and NAT cases respectively. Lastly, the use of NAT had no impact on recurrence patterns (P = 0.221). CONCLUSIONS: This is the largest study to evaluate high-grade appendiceal neoplasms in regard to CRS-HIPEC and NAT. NAT had no impact in regard to disease burden, cytoreduction, or recurrence patterns. Utilization of NAT was associated with decreased OS and DFS.

Utility of hyperthermic intraperitoneal chemotherapy in cases of incomplete cytoreductive surgery.

INTRODUCTION: Hyperthermic intraperitoneal chemotherapy (HIPEC) during cytoreductive surgery (CRS) is typically reserved for a complete or optimal cytoreduction. There is the potential for therapeutic effect of HIPEC with an incomplete cytoreduction, particularly for near optimal cytoreductions. METHODS: Retrospective review of incomplete cytoreductions (R2b, R2c) for appendiceal and colorectal primaries. Primary endpoints were overall survival (OS) and progression-free survival (PFS). Subgroup analysis for primary etiology and specific cytoreductive score. RESULTS: A total of 121 cases of incomplete CRS, 74 CRS alone, and 47 CRS-HIPEC. For the entire study group there was a survival benefit with HIPEC. OS and PFS were 2.3 versus 1.4 (p = 0.001) and 1.6 versus 0.7 (p < 0.0001) respectively for cases with and without HIPEC. Subgroup analysis of appendiceal neoplasms, 43 CRS-HIPEC and 50 CRS alone, found HIPEC benefit persisted; OS and PFS were 2.4 versus 1.5 (p = 0.016) and 1.7 versus 0.8 (p < 0.0001), respectively for cases with and without HIPEC. Benefit most pronounced in low-grade cases with doubling of the OS and PFS (p = 0.004). With colorectal primary cases, 10 CRS-HIPEC and 18 CRS alone, no difference in OS and PFS. When stratifying out by cytoreduction scores, R2b and R2c, HIPEC only provided a benefit for R2b cases; OS and PFS for R2b cases were 2.28 versus 1.01 (p = 0.011) and 1.67 versus 0.75 (p = 0.001), respectively for cases with and without HIPEC. CONCLUSION: HIPEC has utility for incomplete cytoreductions with appendiceal neoplasms, greatest effect with low-grade appendiceal neoplasms. HIPEC is only beneficial for near optimal cytoreductions (R2b).

Organoid Platform in Preclinical Investigation of Personalized Immunotherapy Efficacy in Appendiceal Cancer: Feasibility Study.

PURPOSE: Immunotherapy efficacy data on appendiceal cancer from clinical trials does not exist, due to appendiceal cancer incidence of 0.97 per 100,000. The goal of this study was to preclinically explore the application of immunotherapy in treating appendiceal cancer in a personalized organoid model. EXPERIMENTAL DESIGN: Patient tumor organoids (PTO) were fabricated using unsorted tumor cells with and without enrichment with patient-matched immune components derived from peripheral blood leukocytes, spleen, or lymph nodes [immune-enhanced PTOs (iPTO)]. Organoids were cultured for 7 days, followed by treatment with immunotherapy (pembrolizumab, ipilimumab, nivolumab), and assessed for treatment efficacy. RESULTS: Between September 2019 and May 2021, 26 patients were enrolled in the study. Successful testing was conducted in 19 of 26 (73.1%) patients, with 13 of 19 (68.4%) and 6 of 19 (31.6%) patients having low-grade appendiceal (LGA) and high-grade appendiceal (HGA) primaries, respectively. Immunotherapy response, with increased expression of granzyme B and cleaved caspase 3 and decreased expression of CK20 and ATP activity, was exhibited in 4 of 19 (21.1%) pembrolizumab-treated and 2 of 19 (10.5%) nivolumab-treated iPTOs. Post-immunotherapy cellular viability, in responding HGA organoids to pembrolizumab, decreased to less than 15% (P < 0.05). LGA iPTO treatment responses were observed in pembrolizumab and nivolumab, with an 8%-47.4% (P < 0.05) viability compared with controls. Ipilimumab showed no efficacy in the examined cohort. CONCLUSIONS: Immunotherapy shows measurable efficacy in appendiceal cancer organoids. Information derived from immunocompetent organoids may be applied in selecting patients for clinical trial enrollment in rare diseases where preclinical models of disease are lacking.

Prognostic Impact and Utility of Immunoprofiling in the Selection of Patients with Colorectal Peritoneal Carcinomatosis for Cytoreductive Surgery (CRS) and Heated Intraperitoneal Chemotherapy (HIPEC).

BACKGROUND: Recent studies have shown an association in non-metastatic colorectal cancer between patient survival and immunoprofiling (expression of CD3, CD4, CD8, CD45, and FOXP3 T cells at the invasive margin (IM) and the tumor center (TC)) regardless of stage. Patients with peritoneal carcinomatosis have a dismal prognosis, but survival can be significantly improved in selected patients who undergo cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC). However, current patient selection for CRS/HIPEC is suboptimal. The purpose of this study is to evaluate immune profiles of patients with peritoneal carcinomatosis and their correlation with overall survival (OS). METHODS: The study cohort included patients from a prospectively maintained database of adults with colorectal peritoneal carcinomatosis who underwent CRS/HIPEC. Immunohistochemistry (IHC) using antibodies to CD3, CD4, CD8, CD45RO, and FOXP3 T cells was performed. IHC image density was calculated using ImageJ software, and an immunoscore was determined. RESULTS: Eighty tumors were evaluated from 66 patients. These included 14 primary sites and 66 metastatic sites. R0/R1 resection was achieved in 44 (66.7%) patients. Known prognostic factors including resection status (HR 1.99, p = 0.004) and lymph node status (HR 3.49, p = 0.002) were associated with overall survival. On multivariate analysis, increased CD3/CD4 IM (HR 0.54, p = 0.03) ratio positively was associated with improved OS. DISCUSSION: This is the first study to assess the utility of subtypes of T cells as prognostic markers in patients with colorectal peritoneal carcinomatosis, which may play a role in patients with low-volume disease. Further studies into immune mechanisms may improve patient selection for cytoreductive surgery and HIPEC as well as provide novel pathways for effective immunotherapy.