The Significance of the Morphological Appearance of Peritoneal Lesions on Imaging in Patients With Peritoneal Malignancies-A Report From Phase 1 of the PRECINCT Study.

BACKGROUND AND AIM: This is a report from Phase 1 of the prospective, observational, PRECINCT (Pattern of peritoneal dissemination and REsponse to systemic Chemotherapy IN Common and uncommon peritoneal Tumours) study, in which we studied the incidence of disease at pathological evaluation in different morphological appearances of peritoneal malignancies (PM) on imaging. METHODS: Radiological findings were captured in a specific format that included a description of the morphological appearance of PM and a correlation performed with pathological findings. RESULTS: In 630 patients enroled at seven centres (September 2022-December 2023), 24 morphological terms were used. Among prespecified terms (N = 8 used in 6350 [92.2%] regions), scalloping was pathologically positive in 93.5%, confluent disease in 78.8%, tumour nodules in 69.6%, thickening in 66.1%, infiltration in 56.3%. Among unspecified appearances (N = 16) for 540 (7.8%) regions, 'enhancement' was positive in 41.5%, micronodules in 65.3% and nodularity in 60.2%. Hierarchal clustering placed gastric cancer and rare tumours together and colorectal cancer, ovarian cancer and peritoneal mesothelioma in one cluster. CONCLUSIONS: The incidence of disease at pathological evaluation for most morphological appearances was high (> 50%). Morphological description should be provided in routine radiology reports. A set of standardized terms with their description should be developed by a consensus among experienced radiologists.

Impact of Previous Abdominal Surgery and Timing of Peritoneal Metastases on Accuracy of Imaging in Predicting the Surgical PCI: A Report From the PRECINCT Study.

BACKGROUND AND AIM: In this report from Phase 1 of the prospective, observational, PRECINCT (Pattern of peritoneal dissemination and REsponse to systemic Chemotherapy IN Common and uncommon peritoneal Tumours) study, a correlation was performed between the radiological PCI (peritoneal cancer index; rPCI) and surgical PCI (sPCI). The impact of timing of peritoneal malignancy (PM) and previous abdominal surgery was also studied. METHODS: The rPCI and sPCI were considered the 'same' if they differed by ≤ 3 points. The agreement was assessed using Bland-Altman analysis and the strength of the agreement was assessed using the concordance correlation coefficient (CCC). The extent of prior surgery was classified according to prior surgical score (PSS). RESULTS: In 707 (79.4%) patients, rPCI and sPCI concurred in 280 (39.6%). In the Bland-Altman analysis, < 40% patients were in the ±3 PCI points limit of acceptable difference. The average difference between the two scores was 4.5 points (95% CI- -5.16 to -3.92). The CCC- was 0.59 for the whole cohort ('moderate' concordance) and was not influenced by imaging modality, timing of PM or PSS. CONCLUSIONS: The rPCI underestimated sPCI by an average of 4.5 points. The role of peritoneal MRI in patients undergoing iterative procedures and the performance of imaging according to sites of recurrence need further evaluation.

Review of 2022 PSOGI/RENAPE Consensus on HIPEC.

The 2022 PSOGI (Peritoneal Surface Oncology Group International) and RENAPE (French Network for Rare Peritoneal Malignancies) consensus on hyperthermic intraperitoneal chemotherapy (HIPEC) was a comprehensive effort aimed at standardizing treatment protocols for various peritoneal malignancies. This initiative is critical due to the wide range of technical variations in HIPEC procedures and the resulting need for standardization to ensure consistent and effective patient care and meaningful audit of multicenter data.

Acute kidney injury after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy - A systematic review.

The use of nephrotoxic chemotherapeutic agents during hyperthermic intraperitoneal chemotherapy (HIPEC), carries the risk of postoperative acute kidney injury (AKI). The available evidence on this subject is sparse with variability in the reported incidence of AKI. In this systematic review, the aim was to analyse the incidence, risk factors, and preventive measures for AKI after cytoreductive surgery and HIPEC. A systematic literature search was conducted using the terms 'Acute kidney injury', 'Acute kidney failure', 'Acute renal failure', 'Acute renal impairment', 'HIPEC Surgery', 'Cytoreductive Surgery', 'Heated Chemotherapy' on PubMed, Scopus, clinical trial.gov, POPLINE and Google Scholar. Randomized controlled trials, cohort studies and observational studies published from January 2000-December 2020 were included. The systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42021247781). Data from 16 articles, which included 1622 patients, was included. The incidence AKI by any definition, was 23.36 %. The highest incidence of AKI (45.45 %) was reported after paclitaxel-HIPEC. The incidence of AKI after cisplatin-HIPEC was 34.7 %. Cisplatin HIPEC was the most common factor associated with AKI in 7/16 studies followed by pre-existing comorbidities and low intraoperative diuresis in 4 and 3 studies respectively. The perioperative use of sodium thiosulfate and amifostine led to a significant reduction in the incidence of AKI. The reported incidence of AKI after CRS-HIPEC is high. Identifying preoperative risk factors, optimising comorbidities, maintaining perioperative haemodynamic stability, perioperative use of sodium thiosulfate, maintaining adequate diuresis could reduce the incidence of AKI.

Correlation of Morphological Appearance of Peritoneal Lesions at Laparotomy and Disease at Pathological Assessment in Patients Undergoing Cytoreductive Surgery for Peritoneal Malignancy: Results of Phase I of the PRECINCT Study in 707 Patients.

BACKGROUND: The PRECINCT (Pattern of peritoneal dissemination and REsponse to systemic Chemotherapy IN Common and uncommon peritoneal Tumors) is a prospective, multicenter, observational study. This report from phase I of PRECINCT outlines variations in recording the surgical peritoneal cancer index (sPCI) at experienced peritoneal malignancy centers and the incidence of pathologically confirmed disease in morphologically different peritoneal lesions (PL). METHODS: The sPCI was recorded in a prespecified format that included the morphological appearance of PL. Six prespecified morphological terms were provided. The surgical and pathological findings were compared. RESULTS: From September 2020 to December 2021, 707 patients were enrolled at 10 centers. The morphological details are routinely recorded at two centers, structure bearing the largest nodule, and exact size of the largest tumor deposit in each region at four centers each. The most common morphological terms used were normal peritoneum in 3091 (45.3%), tumor nodules in 2607 (38.2%) and confluent disease in 786 (11.5%) regions. The incidence of pathologically confirmed disease was significantly higher in 'tumor nodules' with a lesion score of 2/3 compared with a lesion score of 1 (63.1% vs. 31.5%; p < 0.001). In patients receiving neoadjuvant chemotherapy, the incidence of pathologically confirmed disease did not differ significantly from those undergoing upfront surgery [751 (47.7%) and 532 (51.4%) respectively; p = 0.069]. CONCLUSIONS: The sPCI was recorded with heterogeneity at different centers. The incidence of pathologically confirmed disease was 49.2% in 'tumor nodules'. Frozen section could be used more liberally for these lesions to aid clinical decisions. A large-scale study involving pictorial depiction of different morphological appearances and correlation with pathological findings is indicated.

Two-stage cytoreductive surgery for 'extensive' pseudomyxoma peritonei: A legitimate alternative or salvage strategy?

BACKGROUND AND AIM: Two-stage cytoreductive surgery (CRS) has been proposed as an alternative to one-stage surgery in patients who have 'extensive' pseudomyxoma peritonei (PMP) and/or are unfit for very extensive surgery, to reduce morbidity. We review current evidence on two-stage CRS focusing on patient selection, interval between procedures, extent of surgery, use of HIPEC, perioperative and oncological outcomes. METHODS: This is a narrative review. A literature search on PubMed and Embase was performed using keywords- 'Two-stage cytoreductive surgery', 'pseudomyxoma peritonei', 'high-volume PMP', 'huge PMP', 'cytoreductive surgery', 'HIPEC', 'staged surgery' and 'extensive pseudomyxoma peritonei'. RESULTS: Five studies reported outcomes in a total of 114 patients. The indications for two-stage CRS were: in two studies, patients undergoing an incomplete cytoreduction due to undue surgical risk were reevaluated for a second surgery during routine surveillance; severe comorbidities in one; extensive disease with PCI>28 in another and in one, only HIPEC was performed as a second procedure due to intraoperative hemodynamic instability (the two-stage procedure was performed in interest of patient's safety). Major morbidity ranged from 0 to 37.5 % (first-stage) and 25%-38.9 % (second-stage). Short term follow-up demonstrated equivalent short-term oncological outcomes compared to historical data. Long term follow-up and quality-of-life data were not available. CONCLUSIONS: The published studies showed different interpretations and applications of the two-stage CRS concept. The reported morbidity was similar to that after single-stage CRS for extensive PMP. Though short-term survival outcomes are acceptable, long-term follow-up is needed. Planned two-stage CRS should currently be reserved for highly selected clinical situations.

Perioperative outcomes and platinum resistant recurrence in patients undergoing systematic, protocol-based, total parietal peritonectomy during interval cytoreductive surgery for advanced ovarian cancer: results of the TORPEDO study.

OBJECTIVE: The TORPEDO (CTRI/2018/12/016789) is the single-arm, prospective, interventional study evaluating the role of a total parietal peritonectomy (TPP) in patients undergoing interval cytoreductive surgery (iCRS). In this manuscript, we report the perioperative outcomes and platinum resistant recurrence (PRR) in 218 patients enrolled in the study. METHODS: A TPP was performed in all patients undergoing iCRS irrespective of the residual disease extent. hyperthermic intraperitoneal chemotherapy (HIPEC) was performed as per the clinician's discretion with 75 mg/m² of cisplatin. Maintenance therapy was also used at the discretion of the treating clinicians. RESULTS: From 9th December 2018 to 31st July 2022 (recruitment complete), 218 patients were enrolled at 4 medical centers in India. The median surgical peritoneal cancer index was 14 and a complete gross resection was achieved in 95.8%. HIPEC was performed in 130 (59.6%) patients. The 90-day major morbidity was 17.4% and 2.7% patients died within 90 days of surgery. Adjuvant chemotherapy was delayed beyond 6 weeks in 7.3%. At a median follow-up of 19 months (95% confidence interval [CI]=15.9-35 months), 101 (46.3%) recurrences and 19 (8.7%) deaths had occurred. The median progression-free survival was 22 months (95% CI=17-35 months) and the median overall survival (OS) not reached. Platinum resistant recurrence was observed in 6.4%. The projected 3-year OS was 81.5% and in 80 patients treated before may 2020, it was 77.5%. CONCLUSION: The morbidity and mortality of TPP with or without HIPEC performed during iCRS is acceptable. The incidence was of PRR is low. Early survival results are encouraging and warrant conduction of a randomized controlled trial comparing TPP with conventional surgery.

Descriptive review of current practices and prognostic factors in patients with ovarian cancer treated by pressurized intraperitoneal aerosol chemotherapy (PIPAC): a multicentric, retrospective, cohort of 234 patients.

Introduction: Ovarian cancer (OC) is the primary cause of mortality in women diagnosed with gynecological cancer. Our study assessed pressurized intraperitoneal aerosol chemotherapy (PIPAC) as treatment for peritoneal surface metastases (PSM) from recurrent or progressive OC and conducted survival analyses to identify prognostic factors. Material and methods: This retrospective cohort study, conducted across 18 international centers, analyzed the clinical practices of patients receiving palliative treatment for PSM from OC who underwent PIPAC. All patients were initially treated appropriately outside any clinical trial setting. Feasibility, safety, and morbidity were evaluated along with objective endpoints of oncological response. Multivariate analysis identified prognostic factors for OS and PFS. Results: From 2015-2020, 234 consecutive patients were studied, from which 192 patients were included and stratified by platinum sensitivity for analysis. Patients with early recurrence, within one postoperative month, were excluded. Baseline characteristics were similar between the groups regarding platinum sensitivity (platinum sensitive (PS) and resistant (PR)), but chemotherapy frequency differed, as did PCI before PIPAC. Median PCI decreased in both groups after three cycles of PIPAC (PS 16 vs. 12, p < 0.001; PR 24 vs. 20, p = 0.009). Overall morbidity was 22%, with few severe complications (4-8%) or mortality (0-3%). Higher pathological response and longer OS (22 vs. 11m, p = 0.012) and PFS (12 vs. 7m, p = 0.033) were observed in the PS group. Multivariate analysis (OS/PFS) identified ascites (HR 4.02, p < 0.001/5.22, p < 0.001), positive cytology at first PIPAC (HR 3.91, p = 0.002/1.96, p = 0.035), and ≥ 3 PIPACs (HR 0.30, p = 0.002/0.48, p = 0.017) as independent prognostic factors of overall survival/progression-free survival. Conclusions: With low morbidity and mortality rates, PIPAC is a safe option for palliative treatment of advanced ovarian cancer. Promising results were observed after 3 PIPAC, which did improve the peritoneal burden. However, further research is needed to evaluate the potential role of PIPAC as an independent prognostic factor.

The 2022 PSOGI International Consensus on HIPEC Regimens for Peritoneal Malignancies: Epithelial Ovarian Cancer.

BACKGROUND AND AIM: We report the results of an international consensus on hyperthermic intraperitoneal chemotherapy (HIPEC) regimens for epithelial ovarian cancer (EOC) performed with the following goals: To define the indications for HIPEC To identify the most suitable HIPEC regimens for each indication in EOC To identify areas of future research on HIPEC To provide recommendations for some aspects of perioperative care for HIPEC METHODS: The Delphi technique was used with two rounds of voting. There were three categories of questions: evidence-based recommendations [using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system with the patient, intervention, comparator, and outcome (PICO) method], an opinion survey, and research recommendations. RESULTS: Seventy-three (67.5%) of 108 invited experts responded in round I, and 68 (62.9%) in round II. Consensus was achieved for 34/38 (94.7%) questions. However, a strong positive consensus that would lead to inclusion in routine care was reached for only 6/38 (15.7%) questions. HIPEC in addition to interval cytoreductive surgery (CRS) received a strong positive recommendation that merits inclusion in routine care. Single-agent cisplatin was the only drug recommended for routine care, and OVHIPEC-1 was the most preferred regimen. The panel recommended performing HIPEC for a minimum of 60 min with a recommended minimum intraabdominal temperature of 41°C. Nephroprotection with sodium thiosulfate should be used for cisplatin HIPEC. CONCLUSIONS: The results of this consensus should guide clinical decisions on indications of HIPEC and the choice and various parameters of HIPEC regimens and could fill current knowledge gaps. These outcomes should be the basis for designing future clinical trials on HIPEC in EOC.

Long-Term Survival in Patients Treated by Cytoreductive Surgery with or Without HIPEC for Peritoneal Surface Malignancies-A report from the Indian HIPEC Registry.

A previous report from the Indian HIPEC registry showed acceptable early survival and morbidity in patients undergoing cytoreductive surgery (CRS) + / - hyperthermic intraperitoneal chemotherapy (HIPEC). The goal of this retrospective study was to evaluate the long-term outcomes in these patients. Three hundred seventy-four patients treated from December 2010 to December 2016 and enrolled in the Indian HIPEC registry were included. All patients had completed 5 years from the date of surgery. The 1-, 3-, 5- and 7-year progression-free (PFS) and overall survival (OS) and factors affecting these were evaluated. The histology was epithelial ovarian cancer in 209 (46.5%), pseudomyxoma peritonei (PMP) in 65 (17.3%) and colorectal cancer in 46 (12.9%) patients. The peritoneal cancer index (PCI) was ≥ 15 in 160 (42.8%). A completeness of cytoreduction (CC) score of 0/1 resection was obtained in 83% (CC-0-65%; CC-1-18%). HIPEC was performed in 59.2%. At a median, follow-up of 77 months (6-120 months), 243 (64.9%) patients developed recurrence, and 236 (63%) died of any cause; 138 (36.9%) were lost to follow-up. The median OS was 56 months (95% CI 53.42-61.07), and the median PFS was 28 months (95% CI 37.5-44.4). The 1-, 3-, 5- and 7-year OS was 97.6%, 63%, 37.7% and 24% respectively. The 1-, 3-, 5- and 7-year PFS was 84.8%, 36.5%, 27.3% and 22% respectively. The use of HIPEC (p = 0.03) and PMP of appendiceal origin (p = 0.01) was independent predictors of a longer OS. CRS + / - /HIPEC may achieve long-term survival in patients with PM from different primary sites in the Indian scenario. More prospective studies are needed to confirm these findings and identify factors influencing long-term survival. Supplementary Information: The online version contains supplementary material available at 10.1007/s13193-023-01727-7.

A Descriptive Analysis of Patients Undergoing Cytoreductive Surgery for the First Peritoneal Recurrence from Adult Granulosa Cell Tumours: Focus on Disease Distribution, Morphology of Peritoneal Disease and the Role of HIPEC - a Retrospective Study by INDEPSO.

The aim of the present study was to report the clinical outcome and factors affecting survival in patients with first recurrence of AGC treated with cytoreductive surgery with or without HIPEC. The second aim was to study the disease distribution in the peritoneal cavity according to the peritoneal carcinomatosis index (PCI) and the morphology of peritoneal deposits. In this retrospective multicentric study, all patients of adult granulosa cell tumor with peritoneal recurrence were treated with CRS with or without HIPEC. Relevant clinical and demographic data were captured. Multivariable logistic regression was performed to evaluate the factors affecting recurrence after CRS ± HIPEC. Factors affecting survival and second recurrences were evaluated in addition to studying the disease distribution at first recurrence. In the period from January 2013 to December 2021, 30 consecutive patients of recurrent adult type granulosa cell tumor of the ovary undergoing CRS ± HIPEC were included in this study. The median follow-up duration was 55 months [12-96 months]. The median rPFS and rOS were both not reached. HIPEC (p = 0.015) was the only factor independently associated with a longer rPFS. CRS with or without HIPEC can be performed with an acceptable morbidity in patients with the first recurrence from adult granulosa cell tumours. The role of HIPEC, patterns of peritoneal spread and impact of other prognostic factors on the treatment outcome all need further evaluation in larger series of patients.

Rare Variants of Malignant Peritoneal Mesothelioma: a Literature Review.

Primary peritoneal mesothelioma (PM) is a rare and aggressive malignancy that arises from the peritoneum and classified into diffuse malignant peritoneum mesothelioma (DMPM) and borderline variants, viz. multicystic peritoneal mesothelioma (MCPM) and well-differentiated papillary peritoneal mesothelioma (WDPPM). The borderline variants are rarer than conventional DMPM, are less aggressive form accounting for 3-5% of all cases of peritoneal mesothelioma. In this narrative review article, we have discussed the pathogenesis, clinical presentation, natural history, and management of these rarer variants of PM, viz. MCPM and WDPPM. Histologically, MCPM typically consists of small cysts composed of mesothelial epithelium with benign bland cuboidal cells with clear fluids; cells lack cellular atypia and have increased number of mitoses. WDPPM has specific papillary component with myxoid plump cores and single layer of bland mesothelial cells. Both the variants commonly present as incidental finding or symptoms of chronic abdominal pain, chronic pelvic inflammatory disease, pelvic mass, and infertility. In the absence of treatment, these diseases are slow growing with major concerns being that both the variants have malignant transformation capabilities and a high rate of recurrence. In the light of current evidences, it is recommended that MCPM and WDPPM patients should be offered a complete cytoreductive surgery and hyperthermic intraperitoneal chemotherapy consisting of cisplatin and doxorubicin. Collaborative multi-institutional studies are needed to generate more data and formulate robust guidelines.

Histopathological Evaluation and Molecular Diagnostic Tests for Peritoneal Metastases with Unknown Primary Site-a Review.

Cancer of unknown primary (CUP) is a well-studied entity with guidelines available for the management of patients with CUP. The peritoneum represents one of the metastatic sites in CUP, and peritoneal metastases (PM) could present as CUP. PM of unknown origin remains a poorly studied clinical entity. There is only one series of 15 cases, one population-based study, and few other case reports on this subject. Studies on CUP, in general, cover some common tumour histological types like adenocarcinomas and squamous carcinomas. Some of these tumours may have a good prognosis though majority have high-grade disease with a poor long-term outcome. Some of the histological tumour types commonly seen in the clinical scenario of PM like mucinous carcinoma have not been studied. In this review, we divide PM into five histological types-adenocarcinomas, serous carcinomas, mucinous carcinomas, sarcomas and other rare varieties. We provide algorithms to identify the primary tumour site using immunohistochemistry when imaging, and endoscopy fails to establish the primary tumour site. The role of molecular diagnostic tests for PM or unknown origin is also discussed. Current literature on site-specific systemic therapy based on gene expression profiling does not show a clear benefit of this approach over empirical systemic therapies.

Bilateral Thoracic Cytoreductive Surgery for Pseudomyxoma Peritonei of Appendiceal Origin.

Pleural spread occurs in pseudomyxoma peritonei (PMP) in less than 10% of the patients and is treated by thoracic cytoreductive surgery with or without hyperthermic intrathoracic chemotherapy (HITOC). It is performed both for symptom palliation and disease control and includes pleurectomy and decortication and wedge and segmental lung resections. So far, only unilateral spread treated with a thoracic cytoreductive surgery (CRS) has been reported in literature. We report a patient with bilateral thoracic PMP following a complete abdominal CRS and hyperthermic intraperitoneal chemotherapy (HIPEC) who was treated with bilateral staged thoracic CRS and subsequently had a 4th CRS for abdominal disease. The staged procedure was performed as she was symptomatic due to the thoracic disease and there was disease on all pleural surfaces. HITOC was not performed. Both procedures were uneventful with no major morbidity. The patient is currently disease free nearly 84 months after the first abdominal CRS and 60 months after the second thoracic CRS. Thus, an aggressive CRS in the thorax in patients with PMP can result in a prolongation of survival while preserving the quality of life if the abdominal disease is controlled. A thorough understanding of the disease biology and surgical expertise are both essential for selecting the right patients for these complex procedures and achieving good short- and long-term outcomes.