Should We Be Doing Cytoreductive Surgery with HIPEC for Signet Ring Cell Appendiceal Adenocarcinoma? A Study from the US HIPEC Collaborative

Predicting Survival in Mucinous Adenocarcinoma of the Appendix: Demographics, Disease Presentation, and Treatment Methodology

BACKGROUND

Mucinous adenocarcinoma of the appendix (MACA) follows a complex disease course with variable survival. Large-scale predictive modeling may determine subtle yet important prognostic factors otherwise unseen in smaller cohort analyses.

METHODS

Patients with MACA were identified from the Surveillance, Epidemiology, and End Results (SEER) Research Plus database (2005-2019). Primary, secondary, and tertiary outcomes were disease-specific survival (DSS), overall survival (OS), and average annual percent change (AAPC) in incidence.

RESULTS

Among 4,258 included patients, MACA was most frequently diagnosed at 50 to 69 years (52.0%), with female preponderance (55.9%). MACA incidence AAPC was 3.8 (95% confidence interval [CI] 1.9-5.9). For patients with exclusive, first-diagnosis MACA included in survival analysis (3,222 patients), median DSS and OS were 118 and 88 months, respectively. In DSS-based multivariable analysis, worse prognosis was associated with non-Hispanic Black background (HR 1.36, 95% CI 1.02-1.82; p = 0.036), high grade (grade 3 HR 3.10, 95% CI 2.44-3.92; p < 0.001), lymphatic spread (HR 2.73, 95% CI 2.26-3.30; p < 0.001), and distant metastasis (HR 5.84, 95% CI 3.86-8.83; p < 0.001). In subcohort analysis of patients with rationale for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC, 2,387 patients), CRS-HIPEC was associated with survival benefit compared with surgery alone but only for moderate-grade tumors (median DSS/OS 138/138 vs. 116/87 months; p < 0.001).

CONCLUSIONS

Mucinous adenocarcinoma of the appendix incidence is increasing in the United States. Survival rates are affected by both demographics and classical risk factors, and CRS-HIPEC-associated survival benefit predominantly occurs in moderate-grade tumors. Further exploration of biologic and clinicopathologic features may enhance risk stratification for this disease.

Patterns of Recurrence in Appendix Cancer After Complete Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

It is thought that low-grade (LG) appendiceal cancer (AC) demonstrates predominantly intraperitoneal recurrence (IPR) after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC), whereas high-grade (HG) tumors progress both intra- and extraperitoneally (EPR). However, evidence supporting this conception is lacking; therefore, we assessed recurrence in various AC histologies.

METHODS

A retrospective, cohort study was conducted by using a single-center database (1998-2022). Recurrence patterns (IPR, EPR, combined) were identified for LG, HG, high-grade with signet ring cells (SRC), and goblet cell carcinoma (GCC).

RESULTS

We included 432 complete (CC-0/1) CRS/HIPECs: 200 LG, 114 HG, 72 SRC, and 46 GCC. Median follow-up was 78 (95% confidence interval [CI] 70-86) months. Overall, 34% (n = 148) of patients recurred. IPR was the most common (LG 16%, HG 27%, SRC 36%, GCC 26%) with median time to recurrence (MTR) of 21 (IQR: 12-40) months. EPR (liver, lung, pleura, lymph nodes, or bones) occurred in LG 3%, HG 9%, SRC 22%, and GCC 7%. MTR was 11 (IQR: 4-16) months. Combined pattern occurred in LG 0%, HG 8%, SRC 7%, and GCC 0%. MTR was 13 (IQR: 7-18) months. Iterative surgery was performed in 53% IPR, 18% EPR, and 51% combined. Median post-recurrence survival was longer after IPR compared with EPR and combined recurrence: 36 (95% CI 25-47) versus 13 (95% CI 7-19) and 18 (95% CI 6-30) months (p < 0.01).

CONCLUSIONS

After complete CRS/HIPEC, IPR was the predominant pattern in all AC histologies and occurred later. Post-recurrence survival after IPR was longer. Knowing AC recurrence patterns can help to understand its biology and plan follow-up and post-relapse management.

Defining a role for systemic chemotherapy in local and advanced appendix adenocarcinoma

BACKGROUND

Appendix adenocarcinomas (AAs) are rare tumours that often present late, with a propensity for peritoneal metastases (PMs). This study aimed to evaluate outcomes of AA patients undergoing cytoreductive surgery (CRS) with curative intent and determine the role of systemic chemotherapy.

MATERIALS AND METHODS

Data were collected from a prospective database and classified according to World Health Organization (WHO) 2019 classification. Tumour clearance from CRS was described using a completeness of cytoreduction (CC) score ranging from 0 [no residual disease (RD)] to 3 (>2.5 cm RD). Patients with CC0-2 CRS received hyperthermic intraperitoneal chemotherapy (HIPEC). Systemic chemotherapy was categorised as 'prior' (>6 months before), 'neoadjuvant' (<6 months before), 'adjuvant' (<6 months after CC0-1 CRS) or 'palliative' (after CC2-3 CRS). Analyses used Kaplan-Meier and Cox regression methods.

RESULTS

Between January 2005 and August 2021, 216 AA patients were identified for inclusion. Median age was 59 years (21-81 years). CRS/HIPEC was carried out in 182 (84%) patients, of whom 164/182 (76%) had mitomycin C HIPEC. CC0-1 was achieved in 172 (80%) patients. Systemic chemotherapy was given to 97 (45%) patients from the whole cohort and to 37/46 (80%) patients with positive nodes. Median overall survival (OS) was 122 months (95% confidence interval 61-182 months). After multivariate analysis, patients with acellular and lower-grade PM had similar OS to those with localised (M0) disease (P = 0.59 and P = 0.19). For patients with positive nodes, systemic chemotherapy was associated with reduced risk of death compared to no chemotherapy (P < 0.0019).

CONCLUSION

This study identifies AA patients with positive lymph nodes derive the most benefit from systemic chemotherapy. We confirm the prognostic importance of stage and peritoneal grade, with excellent outcomes in patients with acellular mucin and lower-grade PM.

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.

Appendiceal Mucinous Neoplasms: From Clinic to Pathology and Prognosis

Appendiceal mucinous neoplasms have been classified differently over time causing confusion when comparing results between working groups in this field and establishing a prognosis of the disease. A historical perspective of the different classification systems of these tumors is essential for the understanding of the evolution of concepts and histopathological definitions that have led up to the present moment. We carried out a systematic review of the pathological classifications of appendiceal mucinous tumors and how they have included the new criteria resulting from clinical and pathological research. The latest classifications by PSOGI and AJCC 8th edition Cancer Staging have made a great effort to incorporate the new pathological descriptions and develop prognostic groups. The introduction of these new classification systems has posed the challenge of verifying how they adapt to our casuistry and which one defines best the prognosis of our patients. We reclassified our series of patients treated for mucinous appendiceal tumors with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy following the PSOGI and the AJCC 8th edition criteria and concluded that both classifications correspond well with the OS and DFS of these patients, with some advantage relative to the PSOGI classification due to a better histopathological description of the different groups.

Prolonged Survival in Peritoneal Metastatic Appendiceal Carcinoma Patients Treated With Combined Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

INTRODUCTION

Primary treatment for peritoneal dissemination of appendiceal cancer is the combination of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. The endpoints were overall survival and evaluation of prognostic factors.

METHODS

Clinicopathological and treatment-related factors were obtained from a prospective database. A total of 84 patients, 55 (65%) primary and 29 (35%) recurrent malignant appendiceal carcinomas with synchronous and metachronous peritoneal metastases, underwent multimodal treatment between 2011 and 2021. The endpoints of the study were overall survival and evaluation of prognostic factors.

RESULTS

The median follow-up was 4.8 y; the mean age was 54.5 y (range 25-77), with a sex distribution of 69% female and 31% male. The mean peritoneal cancer index was 11.3. The proportion of mucinous, intestinal-type, signet ring cell, and goblet cell carcinoma was 56%, 23%, 11%, and 10%, respectively. The 5-y survival rate of the whole cohort was 56.7%. In primary and recurrent diseases, the overall median survival was 8.4 and 4.9 y. Significantly improved survival was detected after complete cytoreduction resection (hazard ratio [HR] for CCR-2 versus CCR-0: 9.388, 95% confidence interval [CI] 3.026-29.124, P = 0.001) and initial local operation with undelayed admission to the center (HR 0.262, 95% CI 0.089-0.773; P = 0.015). The five independent factors in Kaplan-Meier analysis and univariable Cox regression analysis associated with significant adverse survival were cancer antigen (CA) 19-9 over 37 IU/mL, signet ring cell and intestinal-type histology, positive nodal status, grading, and peritoneal cancer index >20. Neoadjuvant chemotherapy administration did not impact survival (HR 1.220, 95% CI 0.612-2.432, P = 0.571).

CONCLUSIONS

With multimodal treatment, prolonged survival is attainable in stage IV primary and recurrent appendiceal carcinoma with peritoneal dissemination. Direct referral to specialized centers after confirmation of peritoneal metastasis is recommended because prompt definitive treatment may significantly improve survival.

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.

The contemporary management of peritoneal metastasis: A journey from the cold past of treatment futility to a warm present and a bright future

Peritoneal metastasis (PM) is often regarded as a less frequent pattern of spread; however, collectively across all spectra of primary tumors, the consequences of PM impact a large population of patients annually. Unlike other modes of metastasis, symptoms at presentation or during the treatment course are common, representing an additional challenge in the management of PM. Early efforts with chemotherapy and incomplete surgical interventions transiently improved symptoms, but durable symptom control and survival extension were rare, which established a perspective of treatment futility for PM through most of the 20th century. Notably, the continued development of better systemic therapy combinations, optimization of cytoreductive surgery (CRS), and rigorous investigation of combining regional therapy-specifically hyperthermic intraperitoneal chemotherapy-with CRS, have resulted in more effective multimodal treatment options for patients with PM. In this article, the authors provide a comprehensive review of the data establishing the contemporary approach for tumors with a high frequency of PM, including appendix, colorectal, mesothelioma, and gastric cancers. The authors also explore the emerging role of adding hyperthermic intraperitoneal chemotherapy to the well established paradigm of CRS and systemic therapy for advanced ovarian cancer, as well as the recent clinical trials identifying the efficacy of poly(adenosine diphosphate ribose) polymerase maintenance therapy. Finally, recent data are included that explore the role of precision medicine technology in PM management that, in the future, may help further improve patient selection, identify the best systemic therapy regimens, detect actionable mutations, and identify new targets for drug development.

Adjuvant chemotherapy for high-grade appendiceal cancer after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy

INTRODUCTION

There are no available data on the efficacy of adjuvant chemotherapy (ACT) in stage IVA/B high-grade mucinous appendiceal cancer treated with CRS/HIPEC. We evaluated the association between ACT and survival in this cohort.

MATERIALS AND METHODS

A single-institution retrospective cohort study using a prospective database was conducted. Stage IVA/B high-grade mucinous appendiceal cancer patients who underwent CRS/HIPEC with CC-0/1 were included. Survival was compared between ACT and no chemotherapy (NoCT) patients. Subgroup analysis was performed with adjustment for confounding variables.

RESULTS

We identified 180 patients: 77 ACT and 103 NoCT. ACT regimens included 5-FU/capecitabine (13%), oxaliplatin-based (63%), and irinotecan-based (21%), combined with bevacizumab in 27% of cases. Median number of cycles was 9 (IQR: 6-12). Median overall survival (OS) did not significantly differ between ACT and NoCT (53 vs 75 months, p = 0.566). Multivariable Cox regression showed no OS benefit for ACT vs NoCT in patients with neoadjuvant chemotherapy (HR 1.14; 95%CI: 0.38-3.39) or without it (HR 1.33; 95%CI: 0.69-2.57), with signet ring cell (HR 0.89; 95%CI: 0.38-2.06) or other histologies (HR 1.11; 95%CI: 0.50-2.46), positive lymph nodes (HR 1.60; 95%CI: 0.74-3.49), or peritoneal cancer index ≥20 (HR 1.08; 95%CI: 0.55-2.11) after adjusting for other factors.

CONCLUSIONS

In our cohort, colon-type ACT was not associated with better OS in stage IVA/B mucinous appendiceal cancer after CRS/HIPEC, even after adjusting for confounders. This may be due to different tumor biology than colon cancer or small sample size. Prospective collaborative studies are needed.

A Metastatic Breast Tumor of an Appendiceal Signet Ring Cell Carcinoma

A 54-year-old woman with pseudomyxoma peritonei from an appendiceal signet ring cell carcinoma was referred to our hospital. Right massive effusion with cytology-proven malignant cells was controlled with thoracentesis. Pathological study after intraperitoneal (IP) chemotherapy, hyperthermic IP chemotherapy, and cytoreductive surgery showed no malignant cells in the abdomen except for the appendix and greater omentum. Although the patient noticed a right breast mass, mammography (MMG) showed no abnormality. Ultrasonography showed right breast masses consisting of hypo- and hyper-echoic areas without clear tumor margins. Magnetic resonance imaging (MRI) with contrast medium showed multiple lesions showing persistent enhancement pattern. Pathological study of the vacuum-assisted biopsy specimen showed signet ring cells growing in diffuse, trabecular, and linear fashions, leading to the diagnosis of metastatic breast tumors from the appendiceal signet ring cell carcinoma. Positron emission tomography (PET)/computed tomography (CT) showed no fluorodeoxyglucose uptake in the breasts. The patient was treated with simple mastectomy for local control. Pathological study of the resected breast showed predominant localization of the metastatic breast tumors deep in the mammary gland and lymphovascular invasion. Metastatic breast tumors from appendiceal signet ring cell carcinomas are extremely rare and can sometimes be difficult to detect with MMG and PET/CT. General surgeon should note that appendiceal signet ring cell carcinomas can metastasize to the breast, presumably through lymphatic permeation from malignant pleural effusion, without abnormal MMG and PET/CT findings.

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.

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

BACKGROUND

Appendiceal cancer with peritoneal metastases (ACPM) is a complex disease requiring multidisciplinary care. Cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion (CRS HIPEC) can significantly improve survival but requires evaluation by a surgical oncologist and significant treatment endurance. The impacts of socioeconomic status (SES) and other social determinants of health on rates of surgical evaluation and treatment have not been examined.

METHODS

We conducted a retrospective cohort study examining all patients with ACPM from 2010 to 2018 in a regional healthcare system. Patient characteristics, oncologic details, treatment strategies, and survival were examined. The primary outcomes of interest were referral to Surgical Oncology, receipt of CRS HIPEC, and survival.

RESULTS

Of 194 patients identified, 94% had synchronous ACPM. The majority of patients (95%) were referred to surgical oncology. Advanced age was the only predictor of nonreferral (p < 0.001). A total of 147 patients (76%) ultimately underwent CRS HIPEC. After adjusting for medical and tumor characteristics, CRS HIPEC was less likely for patients who were unmarried [odds ratio (OR) 0.253, p = 0.004] or of low SES (OR 0.372, p = 0.03). On subanalysis of patients undergoing CRS HIPEC, median overall survival was worse for patients of low SES [51 months versus not reached (NR), p = 0.05], and this disparity persisted on multivariate analysis [hazard ratio (HR) = 2.278, p = 0.001].

CONCLUSIONS

This analysis is the first to evaluate barriers to CRS HIPEC for ACPM. While most patients were evaluated by a multidisciplinary team, nonmedical factors may play a role in the treatment received and ultimate outcomes. Addressing these disparities is crucial for ensuring equitable outcomes and improving patient care.

The role of chemotherapy in the treatment of advanced appendiceal cancers: summary of the literature and future directions

Appendiceal cancer is rare and encompasses a diverse group of tumours ranging from low-grade appendiceal mucinous neoplasms to high-grade adenocarcinomas. Appendiceal cancers often spread to the peritoneal cavity causing extensive mucinous dissemination and peritoneal metastases. Prognosis varies with histological subtype. Cytoreductive surgery and heated intraperitoneal chemotherapy is well-established as the most effective treatment achieving long-term survival in some patients. Chemotherapy regimens used to treat appendiceal cancer are extrapolated from the colorectal cancer setting, but disease biology differs and outcomes are inferior. The role of chemotherapy in the treatment of appendiceal cancer remains poorly defined. There is an urgent need to develop novel tailored treatment strategies in the perioperative and unresectable setting. This review aims to evaluate the literature for patients who received intraperitoneal and systemic chemotherapy for appendiceal cancers.

Iterative Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy for Recurrent Mucinous Adenocarcinoma of the Appendix

BACKGROUND

Recurrence after cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) for appendiceal tumors (AT) with mucinous carcinomatosis peritonei (MCP) is common. The evidence favoring iterative procedures (iCRS/HIPEC) is limited, and its benefit is not clear for all patients.

METHODS

Retrospective (1998-2020) cohorts of AT patients with MCP recurrence after the first CRS/HIPEC were analyzed. Outcomes were compared within tumor grades between iCRS/HIPEC patients and matched control patients without iCRS/HIPEC using propensity score matching (1:1). Post-recurrence survival (PRS) was measured from the date of recurrence after the first CRS/HIPEC to death or last contact.

RESULTS

Overall, 55 iCRS/HIPEC patients were identified: 36 low-grade (LGMCP) patients, 13 high-grade (HGMCP) patients, and 6 HGMCP patients with signet-ring features (HGMCP-S). Nine patients had a third CRS/HIPEC. The median peritoneal cancer index (PCI) scores were 33, 19 and 10, with CC-0/1 achieved for 94.4%, 78.2% and 88.9% of the patients after the first, second, and third CRS/HIPEC, respectively. No 90-day postoperative mortality occurred. The median progression-free survival from the first CRS/HIPEC was 19.7 months for the iCRS/HIPEC patients versus 14.2 months for the matched control patients (p = 0.43). The median PRS was 80.2 months for iCRS/HIPEC versus 36.2 for the control patients (p < 0.001). For the iCRS/HIPEC versus the matched control patients, the median PRS by tumor grade was 174.1 versus 51.9 (p < 0.001) for the LGMCP, 42.0 versus 12.4 (p = 0.02) for the HGMCP, and 15.4 versus 8.1 months (p = 0.61) for the HGMCP-S patients, respectively.

CONCLUSIONS

Selected low- and high-grade appendiceal cancer patients with MCP recurrence able to undergo iterative CRS/HIPEC procedures showed favorable outcomes and such patients should be considered for surgery when feasible. This survival benefit with iCRS/HIPEC is not evidenced in recurrent MCP with signet ring cell morphology.

The Landmark Series: Appendiceal Primary Peritoneal Surface Malignancy

Appendiceal primary peritoneal surface malignancies are rare and include a broad spectrum of pathologies ranging from indolent disease to aggressive disease. As such, the data that drive the management of appendiceal peritoneal surface malignancies is generally not based on prospective clinical trial data, but rather consists of level 1 data based on retrospective studies and high-volume institutional experiences. Complete surgical debulking typically offers the best chance for long-term survival. This review highlights the landmark articles on which management of primary appendiceal peritoneal surface malignancies are based.

Risk of Intraoperative Hyperthermia and Outcomes in Adults Undergoing Cytoreductive Surgery (CRS) with Hyperthermic Intraperitoneal Chemotherapy (HIPEC)

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) is commonly used to treat peritoneal surface malignancies. We aimed to identify risk factors of intraoperative patient hyperthermia and the postoperative outcome of adults undergoing HIPEC PATIENTS AND METHODS: A retrospective, IRB approved, single center cohort study was conducted. Adults treated with cytoreductive surgery and HIPEC between 2006 and 2021 were included. The primary outcome was bladder hyperthermia during perfusion, stratified by severity and duration. Secondary outcomes were postoperative complications and recurrence-free (RFS) and overall (OS) survival. Multivariable logistic regression models were fit to estimate the effects of important covariates.

RESULTS

Out of 214 patients, 114 had mild hyperthermia (≥ 38 °C) at any time, and in 73 of these it lasted for ≥ 30 min. Independent prognostic factors of mild hyperthermia ≥ 30 min were age (OR = 0.958, 95% CI 0.933-0.984), body mas index (BMI; OR = 0.959 95% CI 0.917-1.002), gender (OR = 0.199, 95% CI 0.092-0.431), and type of chemotherapy [cisplatin versus mitomycin (OR = 0.186, 95% CI 0.070-0.491; oxaliplatin versus mitomycin (OR = 0.430, 95% CI 0.163-1.139)]. Prognostic factors of moderate-to-severe hyperthermia (≥ 39 °C) at any time were perfusion duration (OR = 1.094, 95% CI 1.018-1.177) and blood transfusion (OR = 5.689, 95% CI 1.784-18.137). Intraoperative hyperthermia was not associated with increased postoperative complications but was associated with better RFS and OS.

CONCLUSIONS

Our study demonstrates age, gender, BMI, and chemotherapy type to be associated with hyperthermia ≥ 38 °C for ≥ 30 min, whereas longer perfusion time and blood transfusion were associated with hyperthermia ≥ 39 °C. Mild hyperthermia at the end of perfusion is associated with better RFS and OS.

Impact of Ketamine on Opioid Use and Persistent Pain After Cytoreductive Surgery with Hyperthermic Chemotherapy

Background

Persistent pain and opioid use can be devastating after cytoreductive surgery (CRS) and hyperthermic intraoperative chemotherapy (HIPEC).

Methods

We conducted a retrospective study to investigate the impact of ketamine use on postoperative complications and persistent and chronic pain after CRS-HIPEC.

Results

Ketamine reduced perioperative opioid use before and after implementation of recovery after surgery programs. Ketamine did not impact the formation of persistent and chronic pain formation and long-term opioid use. Postoperative complications and postoperative re-operations were independent predictors of persistent pain. Interestingly, the risk of having a complication was increased by 1% for every doubling in opioids used intraoperatively.

Conclusion

Ketamine use reduces perioperative opioid consumption in patients undergoing CRS-HIPEC, but it is not associated with improvements in long-term opioid use and chronic pain.

A rare case of synchronous appendiceal and cecal cancer

Primary appendiceal cancer is rare, and difficult to diagnose pre-operatively because lack of specific symptoms. This report presents a rare case of synchronous colon and appendiceal cancer. A 50-year-old man was referred to our hospital due to endoscopic submucosal resection (ESD) for early cecal cancer. ESD was performed, and the pathological examination revealed tubular adenocarcinoma with deep submucosal invasion. Laparoscopic ileocecal resection was performed as additional resection after ESD of cecal cancer. There were no obvious abnormalities around the ileocecal region in the preoperative examination. Postoperative pathological examination incidentally revealed a mucosal papillary adenocarcinoma of the appendix, with no residual lesion in the ESD scar. The patient was discharged on the seventh postoperative day. Synchronous appendiceal and colon cancer is extremely rare in past reports. Here, we report the case details and review previous case reports.

Defining stage in mucinous tumours of the appendix with peritoneal dissemination: the importance of grading terminology: systematic review

BACKGROUND

Mucinous appendiceal neoplasms with peritoneal dissemination (PD) show a wide spectrum of clinical behaviour. Histological grade has been correlated with prognosis, but no universally accepted histological grading has been established. The aim of this systematic review was to provide historical insight to understand current grading classifications, basic histopathological features of each category, and to define which classification correlates best with prognosis.

METHODS

MEDLINE and the Cochrane Library were searched for studies that reported survival across different pathological grades in patients with mucinous neoplasm of the appendix with PD treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. PRISMA guidelines were followed.

RESULTS

Thirty-eight studies were included. Ronnett's classification was the most common (9 studies). Classifications proposed by the Peritoneal Surface Oncology Group International (PSOGI) (6 studies) and the seventh or eighth edition of the AJCC (7 studies) are gaining in popularity. Nine studies supported a two-tier, 12 a three-tier, and two a four-tier classification system. Three studies demonstrated that acellular mucin had a better prognosis than low-grade pseudomyxoma peritonei in the PSOGI classification or M1bG1 in the eighth edition of the AJCC classification. Four studies demonstrated that the presence of signet ring cells was associated with a worse outcome than high-grade pseudomyxoma peritonei in the PSOGI classification and M1bG2 in the eighth edition of the AJCC.

CONCLUSION

There is a great need for a common language in describing mucinous neoplasms of the appendix with PD. Evolution in terminology as a result of pathological insight turns the four-tiered PSOGI classification system into a coherent classification option.

A multi-institutional analysis of Textbook Outcomes among patients undergoing cytoreductive surgery for peritoneal surface malignancies

BACKGROUND

While recent studies have introduced the composite measure of a textbook outcome (TO) for measuring postoperative outcomes, the incidence of a TO has not been characterized among patients undergoing cytoreductive surgery (CRS) for peritoneal surface malignancies (PSM).

STUDY DESIGN

All patients who underwent CRS ± hyperthermic intraperitoneal chemotherapy (HIPEC) between 1999 and 2017 from 12 institutions were included. A TO was defined as the absence of any of the following criteria: completeness of cytoreduction >1, reoperation within 90-days, readmission within 90-days, mortality within 90-days, any grade ≥2 complication, hospital stay >75th percentile, and non-home discharge.

RESULTS

Among 1904 patients who underwent CRS, only 30.9% achieved a TO while 69.1% failed to achieve a TO most commonly because of postoperative complications. On multivariable analysis, factors associated with achieving a TO were age <65 years (OR: 1.5), albumin ≥3.5 g/dl (OR: 5.7), receipt of HIPEC (OR: 4.5), PCI ≤14 (OR: 2.2), intravenous fluid volume ≤10,000 ml (OR: 2.1), blood loss ≤1000 ml (OR: 4.2) and operative time <7 h (OR: 1.9); while receipt of neoadjuvant therapy (OR: 0.7) and liver resection (OR: 0.4) were associated with not achieving a TO (all p < 0.05). TO was associated with improved overall survival (median 159 months vs 56 months, p < 0.01) even after controlling for confounders on Cox regression (hazard ratio: 2.5, p < 0.01).

CONCLUSION

Among patients undergoing CRS ± HIPEC for PSM, failure to achieve a TO is common and independently associated with worse overall survival.

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

BACKGROUND

Cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion (CRS HIPEC) can offer significant survival advantage for select patients with colorectal peritoneal metastases (CRPM). Low socioeconomic status (SES) is implicated in disparities in access to care. We analyze the impact of SES on postoperative outcomes and survival at a high-volume tertiary CRS HIPEC center.

PATIENTS AND METHODS

We conducted a retrospective cohort study examining patients who underwent CRS HIPEC for CRPM from 2000 to 2018. Patients were grouped according to SES. Baseline characteristics, perioperative outcomes, and survival were examined between groups.

RESULTS

A total of 226 patients were analyzed, 107 (47%) low-SES and 119 (53%) high-SES patients. High-SES patients were younger (52 vs. 58 years, p = 0.01) and more likely to be White (95.0% vs. 91.6%, p = 0.06) and privately insured (83% vs. 57%, p < 0.001). They traveled significantly further for treatment and had lower burden of comorbidities and frailty (p = 0.01). Low-SES patients more often presented with synchronous peritoneal metastases (48% vs. 35%, p = 0.05). Following CRS HIPEC, low-SES patients had longer length of stay and higher burden of postoperative complications, 90-day readmission, and 30-day mortality. Median overall survival following CRS HIPEC was worse for low-SES patients (17.8 vs. 32.4 months, p = 0.02). This disparity persisted on multivariate survival analysis (low SES: HR = 1.46, p = 0.03).

CONCLUSIONS

Despite improving therapies for CRPM, low-SES patients remain at a significant disadvantage. Even patients who overcome barriers to care experience worse short- and long-term outcomes. Improving access and addressing these disparities is crucial to ensure equitable outcomes and improve patient care.

Exploring the prognostic and therapeutic utility of expanded mutation profiling in appendix peritoneal metastasis managed with CRS/HIPEC

INTRODUCTION

Interrogation of cancers with next-generation sequencing (NGS) mutation panels has become widely utilized, identifying prognostic and actionable mutations. This study explored the value of expanded mutation analysis in appendix peritoneal metastases (APM).

METHODS

Forty-eight APM patients treated 2013-2018 were retrospectively collected from a registry. Fifty-gene NGS analysis was performed in CLIA approved lab to obtain mutation profiles. All patients underwent cytoreductive surgery (CRS)/hyperthermic intraperitoneal chemotherapy (HIPEC) with mitomycin C. Peritoneal cancer index (PCI), optimal CRS, survival (overall survival [OS] and progression-free survival [PFS]) data were collected. Survival analyses were performed on all APM, high-grade (HG), and low grade (LG) subsets, evaluating the impact of specific mutations on the outcome.

RESULTS

Eighty-three percent of APM had a mutation identified. KRAS was most frequent, 65% (88% LG 42% HG) with GNAS identified in 92% of LG-APM. SMAD4 and/or TP53 mutations occurred in 25% of APM with observed decreased OS (46 vs. 81 months p = .0029); worse in HG-APM (26 vs. 49 months p = .0451). SMAD4 was associated with the most significant reduction in PFS in APM (p = .0085). Actionable mutations were identified in 73% of APM patients.

CONCLUSIONS

Most frequent mutations were KRAS, TP53, and SMAD4, and actionable mutation detection was common. SMAD4 and TP53 were associated with decreased OS. NGS mutation profiling has potential utility in APM.

Current Management of Appendiceal Neoplasms

Appendiceal neoplasms include a heterogeneous group of epithelial and nonepithelial tumors that exhibit varying malignant potential. This review article summarizes current diagnostic criteria, classification systems, and optimal therapeutic strategies for the five main histopathologic subtypes of appendiceal neoplasms. In particular, the management of epithelial appendiceal neoplasms has evolved. Although their treatment has historically been extrapolated from colon cancer, improved understanding of their unique histopathologic and molecular characteristics and a growing body of published clinical data support a more nuanced approach to their management.

The Role of Hyperthermic Intraperitoneal Chemotherapy for Non-colorectal Peritoneal Surface Malignancies

BACKGROUND

Peritoneal carcinomatosis, from a variety of gastrointestinal and gynecological malignancies, has been historically challenging to treat and there remains a wide range of biologic aggressiveness in these patients. Malignancies commonly associated with PC include those of colorectal, appendiceal, gastric, ovarian, sarcoma, small intestinal, and primary peritoneal origin among others. Advances in our understanding of this unique disease process have led to significant interest in cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) as an emerging treatment option. The goal of CRS-HIPEC is to remove all visible macroscopic disease while preserving organ function, and then treat microscopic disease through perfusion of the peritoneal cavity with heated chemotherapy.

PURPOSE

Although recent reviews have focused on the management of peritoneal carcinomatosis secondary to colorectal cancer given the publication of several recent randomized controlled trials, the purpose of the current review is to summarize the evidence on CRS-HIPEC for non-colorectal peritoneal surface malignancies, including appendiceal neoplasms, malignant peritoneal mesothelioma, gastric cancer, and ovarian cancer.

RESULTS

While retrospective studies have clarified the importance of prognostic factors such as the peritoneal carcinomatosis index, completeness of cytoreduction, histopathological characteristics, and lymph node positivity, the lack of convincing level 1 evidence for the use of CRS-HIPEC has led to it remaining a highly controversial topic.

CONCLUSION

The decision to utilize CRS-HIPEC should involve a multidisciplinary team approach and evaluation of prognostic factors to balance the short-term morbidity of the operation with maximum long-term benefits. Large, multi-institutional groups and ongoing trials hold promise for clarifying the role of CRS-HIPEC in peritoneal surface malignancies.

CRS/HIPEC with Major Organ Resection in Peritoneal Mesothelioma Does not Impact Major Complications or Overall Survival: A Retrospective Cohort Study of the US HIPEC Collaborative

INTRODUCTION

CRS/HIPEC is thought to confer a survival advantage for patients with malignant peritoneal mesothelioma (MPM). However, the impact of nonperitoneal organ resection is not clearly defined. We evaluated the impact of major organ resection (MOR) on postoperative outcomes and overall survival (OS).

PATIENTS AND METHODS

The US HIPEC collaborative database (2000-2017) was reviewed for MPM patients who underwent CRS/HIPEC. MOR was defined as total or partial resection of diaphragm, stomach, spleen, pancreas, small bowel, colon, rectum, kidney, ureter, bladder, and/or uterus. MOR was categorized as 0, 1, or 2+ organs.

RESULTS

A total of 174 patients were identified. Median PCI was 16 (3-39). The distribution of patients with MOR-0, MOR-1, and MOR-2+ was 94, 45, and 35 patients, respectively. MOR-1 and MOR-2+ groups had a higher frequency of any complication compared with MOR-0 (57.8%, 74.3%, and 48.9%, respectively, p = 0.035), but Clavien 3/4 complications were similar. Median length of stay was slightly higher in the MOR-1 and MOR-2+ groups (10 and 11 days) compared with the MOR-0 cohort (9 days, p = 0.005). Incomplete cytoreduction, ASA class 4, and male gender were associated with increased mortality on unadjusted analysis; however, their impact on OS was attenuated on multivariable analysis. MOR was not associated with OS based on these data (MOR-1: HR 1.67, 95% CI 0.59-4.74; MOR-2+ : HR 0.77, 95% CI 0.22-2.69).

CONCLUSIONS

MOR was not associated with an increase in major complications or worse OS in patients undergoing CRS/HIPEC for MPM and should be considered, if necessary, to achieve complete cytoreduction for MPM patients.

Outcomes of neoadjuvant chemotherapy before CRS-HIPEC for patients with appendiceal cancer

BACKGROUND

Cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) is indicated for patients with peritoneal dissemination of appendiceal cancer. The role of neoadjuvant chemotherapy (NAC) before CRS-HIPEC remains controversial.

METHODS

A retrospective review of adult patients who underwent CRS ± HIPEC for metastatic appendiceal cancer between 2000-2017 was performed. Patients who received NAC followed by surgery were compared with those who underwent surgery first (SF) with and without 1:1 propensity score matching (PSM).

RESULTS

Among 803 patients with appendiceal cancer who underwent CRS ± HIPEC, 225 (28%) received NAC, and 578 (72%) underwent SF. After PSM (n = 186), median overall survival (OS) did not differ (NAC: 40 vs SF: 56 months; P = .210) but recurrence-free survival (RFS) was worse among patients who received NAC (14 vs 22 months; P = .007). NAC was independently associated with worse OS (hazards ratio [HR], 1.81; 95% confidence interval [CI], 1.03-3.18) and RFS (HR, 1.93; 95% CI, 1.25-2.99).

CONCLUSION

In this multi-institutional retrospective analysis of patients with peritoneal dissemination from appendiceal cancer, the use of NAC before CRS-HIPEC was associated with worse OS and RFS even after PSM and multivariable regression. Immediate surgery should be considered for patients with disease amenable to complete cytoreduction.