The 2022 PSOGI International Consensus on HIPEC Regimens for Peritoneal Malignancies: Methodology.

BACKGROUND: A group of experts from the Peritoneal Surface Oncology Group International (PSOGI) and the BIG-RENAPE group carried out a consensus among surgeons experienced in treating peritoneal malignancies from around the world to derive recommendations on indications of hyperthermic intraperitoneal chemotherapy (HIPEC), choice and details of HIPEC regimens, and areas for future research. This manuscript describes the methodology of achieving this consensus and the degree of participation of experts. METHODS: The Delphi technique was used and the questionnaire comprised three categories: evidence-based recommendations using the GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) system with the PICO (patient, intervention, comparison, and outcome) method, an opinion survey, and research recommendations. A consensus was achieved if any one option had >50% of votes, or positive or negative recommendations combined had > 70% of votes. RESULTS: Of the 145 experts solicited, 71.1% in round I and 72.2% in round II took the survey. Participation was highest among surgeons treating both gastrointestinal and gynecological malignancies. Of 113 questions, after round I, a consensus was achieved for 72 (63.7%) questions, and after the second round, consensus was achieved for another 22 (19.4%) questions, making a total of 94 (83.1%) questions for which a consensus was achieved. CONCLUSION: This consensus was carried out using a thorough review of literature and robust rating of evidence, and included key experts and opinion leaders from across the world. The results could guide clinicians on the use of HIPEC, both in their day-to-day clinical practice and in designing clinical trials.

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.

Role of Hyperthermic Intraperitoneal Chemotherapy Combined with Cytoreductive Surgery as Consolidation Therapy for Advanced Epithelial Ovarian Cancer.

BACKGROUND: Patients with advanced epithelial ovarian cancer who undergo incomplete surgery followed by six cycles of chemotherapy could benefit from second-look or consolidation cytoreductive surgery (CCRS). The primary goal of this study was to evaluate the overall survival (OS) in patients undergoing complete CCRS and the factors affecting survival. The secondary goal was to study the benefit of hyperthermic intraperitoneal chemotherapy (HIPEC) in these patients. METHODS: This was a retrospective analysis of 173 patients with CCRS with (n = 118) or without (n = 55) HIPEC treated at 12 French centers. Only patients having a completeness of cytoreduction (CC) 0/1 resection and a minimum of 5 years of follow-up were included. HIPEC was performed systematically for all patients except those treated at the four centers that did not perform HIPEC. RESULTS: The median Peritoneal Cancer Index was 6 (range 0-33). Closed HIPEC was performed in 59 (34.1%) patients and open HIPEC was performed in 56 (32.3%) patients. Grade 3-4 complications occurred in 64 (36.9%) patients. The median OS was 35.67 months (95% confidence interval [CI] 29.8-46.1) and was significantly longer for CCRS + HIPEC (31.4 months without HIPEC and 42.5 months with HIPEC; p = 0.022). On multivariate analysis, closed HIPEC (hazard ratio [HR] 0.46, 95% CI 0.29-0.73; p < 0.001) resulted in a longer OS, and age > 65 years (HR 2.17, 95% CI 1.14-4.11; p = 0.018) and bowel resection (HR 1.98, 95% CI 1.27-3.08; p = 0.020) led to a shorter OS. On multivariate logistic regression analysis, closed HIPEC (odds ratio 0.18; p = 0.001) was associated with a lower risk of dying at 5 years. CONCLUSIONS: CCRS was performed with an acceptable morbidity and resulted in good overall survival. The role of HIPEC in addition to CCRS should be evaluated in prospective, randomized studies and the closed technique prospectively compared with the open technique.

Total Parietal Peritonectomy Can Be Performed with Acceptable Morbidity for Patients with Advanced Ovarian Cancer After Neoadjuvant Chemotherapy: Results From a Prospective Multi-centric Study.

BACKGROUND: Total parietal peritonectomy (TPP) removes areas of "normal-appearing" parietal peritoneum bearing microscopic residual disease and has the potential to improve survival of patients undergoing interval cytoreductive surgery (CRS) for advanced serous epithelial ovarian cancer. This report presents the morbidity outcomes for the first 50 patients enrolled in TORPEDO (CTRI/2018/12/016789), a prospective study. METHODS: All the patients underwent a TPP during interval CRS. A surgical protocol that includes a description of the boundaries for each of the five peritonectomies was followed. The common toxicology criteria for adverse events (CTCAE) classification was used to record 90-day morbidity and mortality. RESULTS: The median Peritoneal Cancer Index (PCI) for 50 patients was 15 (range, 5-37). A complete cytoreduction (CC-0 resection) was obtained in 80%, a CC-1 resection in 16%. A bowel resection was performed in 70% of the patients. Grade 3 or 4 complications were seen in 11 patients (22%), and one patient died within 90 days after surgery due to intraperitoneal hemorrhage. The most common complications were postoperative fluid collection requiring aspiration (n = 5), intraperitoneal hemorrhage (n = 2), abdominal wound dehiscence (n = 2), pseudo-obstruction (n = 1), urinary sepsis (n = 2), and ileostomy-related complications (n = 2). No bowel fistulas or anastomotic leaks occurred. Microscopic disease in 'normal appearing' peritoneum adjacent to tumor nodules was observed in 46% of the patients, and in regions given a lesion score of 0 in 34%. The parietal peritoneal regions (0-8) had a higher incidence of residual disease (p < 0.001) and occult disease (p < 0.001). CONCLUSIONS: During interval CRS, TPP can be performed with acceptable morbidity and mortality. The pathologic findings further support this therapeutic rationale. Survival outcomes should determine the future role of such a procedure in routine clinical practice.

HIPEC Methodology and Regimens: The Need for an Expert Consensus.

BACKGROUND: Hyperthermic intraperitoneal chemotherapy (HIPEC) is performed with a wide variation in methodology, drugs, and other elements vital to the procedure. Adoption of a limited number of regimens could increase the collective experience of peritoneal oncologists, make comparison between studies more meaningful, and lead to a greater acceptance of results from randomized trials. This study aimed to determine the possibility of standardizing HIPEC methodology and regimens and to identify the best method of performing such a standardization. METHODS: A critical review of preclinical and clinical studies evaluating the pharmacokinetic aspects of different HIPEC drugs and drug regimens, the impact of hyperthermia, and the efficacy of various HIPEC regimens as well as studies comparing different regimens was performed. RESULTS: The preclinical and clinical data were limited, and studies comparing different regimens were scarce. Many of the regimens were neither supported by preclinical rationale or data nor validated by a dose-escalating formal phase 1 trial. All the regimens were based on pharmacokinetic data and did not take chemosensitivity of peritoneal metastases into account. Personalized medicine approaches such as patient-derived tumor organoids could offer a solution to this problem, although clinical validation is likely to be challenging. CONCLUSIONS: Apart from randomized trials, more translational research and phases 1 and 2 studies are needed. While waiting for better preclinical and clinical evidence, the best way to minimize heterogeneity is by an expert consensus that aims to identify and define a limited number of regimens for each indication and primary site. The choice of regimen then can be tailored to the patient profile and its expected toxicity and the methodology according regional factors.

Clinical and Radiologic Predictors of a Pathologic Complete Response to Neoadjuvant Chemotherapy (NACT) in Patients Undergoing Cytoreductive Surgery for Colorectal Peritoneal Metastases: Results of a Prospective Multi-center Study.

BACKGROUND: Patients undergoing cytoreductive surgery for colorectal peritoneal metastases who have a pathologic complete response (pCR) to neoadjuvant chemotherapy experience a significantly longer survival than those with residual disease. This response is known only after surgery. This study aimed to examine clinical and radiologic predictors of a pCR. METHODS: From July 2018 to December 2019, the study prospectively enrolled 120 patients. The clinical and radiologic findings were compared between patients with and without a pCR. A protocol for pathologic evaluation was followed. RESULTS: A pCR was observed in 34 patients (28.3%). Receiver operating characteristic (ROC) curves showed that patients with a surgical Peritoneal Cancer Index (sPCI) of 3 or lower had an 80% probability of experiencing a pCR, and that patients with a radiologic PCI (rPCI) of 2 or lower had a 70% probability of experiencing a pCR. A pCR was correctly predicted for 47% of the patients by imaging and for 44.4% of the patients by surgical evaluation. The site of primary tumor, the timing of peritoneal metastasis (PM), histology, tumor marker positivity, and mutations in known poor prognostic genes (KRAS) did not differ between the patients with and those without pCR. The primary tumor showed residual disease in 23.5% and regional nodes in 26.4% of the patients with pCR. CONCLUSIONS: The rPCI and sPCI concurred with a pCR in less than 50% of the patients. The patients with a lower PCI had greater concordance. An sPCI of 3 or lower was predictive of a pCR in 80% of the patients. The impact of KRAS mutations on pCR should be evaluated in a larger series. The predictors of pCR and response to systemic chemotherapy should be incorporated in prognostic scores used to select patients for surgery.

Implications of Pathologic Findings in Cytoreductive Surgery Specimens on Treatment of Colorectal Peritoneal Metastases: Results of a Prospective Multicentric Study.

BACKGROUND: A surgical peritoneal cancer index of >20 is often used to exclude patients from cytoreductive surgery for colorectal peritoneal metastases. The pathologic peritoneal cancer index in these patients may be <20. OBJECTIVE: The purpose of this study was to compare the pathologic and surgical findings and to look at potential pathologic prognostic factors. DESIGN: This is a prospective observational study including patients undergoing cytoreductive surgery. SETTINGS: The study was carried out at 3 peritoneal surface malignancy centers, 1 in France and 2 in India. PATIENTS: One-hundred patients were included from July 1, 2018, to June 30, 2019. MAIN OUTCOME MEASURES: The pathologic peritoneal cancer index, peritoneal disease distribution, pathologic response to chemotherapy, factors affecting them and their relation with surgical findings, and potential prognostic value were explored. RESULTS: Ninety percent had colonic primaries. Fifty-one percent had left-sided tumors. The median surgical peritoneal cancer index was 4 (range, 0-35). Upper regions were involved in 32% and small bowel regions in 26%, and their involvement increased with a higher peritoneal cancer index (p < 0.001). The median pathologic peritoneal cancer index was 2 (range, 0-27) and was less than the surgical peritoneal cancer index in 57%. A pathologic complete response was obtained in 25%. Patients with pathologic complete response received more antiepidermal growth factor receptor therapy (p = 0.008); more leucovorin, 5-fluorouracil, and oxaliplatin; and folinic acid, fluorouracilirin, irinotecan hydrochloride, and oxaliplatin (p < 0.001). In 7 patients with a surgical peritoneal cancer index of >20, pathologic peritoneal cancer index was <20 in 4 patients. Disease in the primary tumor/anastomotic site was found in ≈80%. LIMITATIONS: Survival outcomes are not available. CONCLUSIONS: Surgical peritoneal cancer index of >20 should not be the sole factor to exclude patients from surgery, especially in responders to systemic therapies. The pathologic peritoneal cancer index, pathologic response to systemic chemotherapy, and disease distribution in the peritoneal cavity should be meticulously documented. Correlation with survival will define their future prognostic value. The primary anastomotic site is a common site for peritoneal disease and should be carefully evaluated in all patients. See Video Abstract at http://links.lww.com/DCR/B490. IMPLICACIONES DE LOS HALLAZGOS PATOLÓGICOS EN MUESTRAS DE CIRUGÍA CITORREDUCTORA EN EL TRATAMIENTO DE METÁSTASIS PERITONEALES COLORRECTALES: RESULTADOS DE UN ESTUDIO PROSPECTIVO MULTICÉNTRICO: Una ICP quirúrgica de >20 se utiliza a menudo para excluir a los pacientes de la cirugía citorreductora por metástasis peritoneales colorrectales. La PCI patológica en estos pacientes puede ser <20.Comparar los hallazgos patológicos y quirúrgicos y observar los posibles factores pronósticos patológicos.Se trata de un estudio observacional prospectivo que incluye a pacientes sometidos a cirugía citorreductora.El estudio se llevó a cabo en tres centros de malignidad de la superficie peritoneal, 1 en Francia y 2 en India.Se incluyeron 100 pacientes desde el 1 de julio de 2018 al 30 de junio de 2019.No hubo intervención terapéutica.Se exploró la ICP patológica, la distribución de la enfermedad peritoneal, la respuesta patológica a la quimioterapia, los factores que la afectan y su relación con los hallazgos quirúrgicos y el valor pronóstico potencial.El noventa por ciento tenía lesiones primarias colónicas. El 51% tenía tumores del lado izquierdo. La mediana de la ICP quirúrgica 4 [0-35]. Las regiones superiores estuvieron involucradas en el 32% y las regiones del intestino delgado en un 26% y su participación aumentó con una ICP más alta (p <0,001). La mediana de la ICP patológica fue 2 [0-27] y fue menor que la ICP quirúrgica en el 57%. Se obtuvo respuesta patológica completa en el 25%. Los pacientes con respuesta patológica completa recibieron más terapia anti-EGFR (p = 0,008) y más FOLFOX y FOLFIRINOX (p <0,001). En 7 pacientes con una ICP quirúrgica de> 20, la ICP patológica fue menor de 20 en 4 pacientes. Se encontró enfermedad en el tumor primario/anastomósis en casi el 80%.Los resultados de supervivencia no están disponibles.La ICP quirúrgica de> 20 no debería ser el único factor para excluir a los pacientes de la cirugía, especialmente en los que responden a las terapias sistémicas. La PCI patológica, la respuesta patológica a la quimioterapia sistémica y la distribución de la enfermedad en la cavidad peritoneal deben documentarse meticulosamente. La correlación con la supervivencia definirá su valor pronóstico futuro. El sitio anastomótico primario es un sitio común de enfermedad peritoneal y debe evaluarse cuidadosamente en todos los pacientes. Consulte Video Resumen en http://links.lww.com/DCR/Bxxx. (Traducción-Dr. Gonzalo Hagerman).

Extent of Peritoneal Resection for Peritoneal Metastases: Looking Beyond a Complete Cytoreduction.

Completeness of cytoreduction is one of the most important prognostic factors impacting outcomes of cytoreductive surgery (CRS). To what extent the surrounding normal peritoneum needs to be removed is not known. We hypothesized that the extent of peritoneal resection should be different for different tumors and performed this study to find evidence to support this rationale. To determine the extent of resection of surrounding tissue for any tumor, the mechanisms of tumor development and spread, tumor morphology, the possibility of finding disease in the surrounding normal tissue, and the pattern of lymph node metastases should be known. Surgical resections also depend on patterns of recurrence and the impact of varying extent of resection on survival. We performed a review of literature pertaining to pathways and patterns of peritoneal cancer spread to determine the scientific basis for the extent of peritonectomy. We also reviewed studies comparing less and more extensive peritoneal resection. There is no consensus on the extent of lymphadenectomy required for most PM. Based on this review, we provide recommendations for the extent of peritoneal resection and the extent of lymph node dissection that should be performed for some common peritoneal tumors and identify areas that require further research. We propose that a systematic method of synoptic reporting of pathological specimens of CRS should be developed to capture information regarding the disease distribution within the peritoneal cavity and morphology of PM from different tumors. This can in future be used to establish standard guidelines for such resections.

The Pathologic Peritoneal Cancer Index (PCI) Strongly Differs From the Surgical PCI in Peritoneal Metastases Arising From Various Primary Tumors.

BACKGROUND: The surgical peritoneal cancer index (sPCI) is calculated based on a subjective evaluation of the extent of peritoneal disease during surgery. The pathologic PCI (pPCI) may be a more accurate and objective method for determining the PCI. This study aimed to compare the sPCI and pPCI and to study the potential pitfalls and clinical implications of using the pPCI. METHODS: This prospective study (July to December 2018) included all patients undergoing cytoreductive surgery (CRS). The pPCI was calculated for each patient and compared with the sPCI. The impact of potential confounding factors on the difference between pPCI and sPCI was evaluated. RESULTS: Among 191 patients undergoing CRS at four centers, the pPCI and sPCI were concordant for 37 patients (19.3%). The pPCI was lower than the sPCI for 125 patients (65.4%) and higher for 29 patients (15.1%). The concordance between the two groups was maximum for gastric cancer (38.8%) and colorectal cancer (27.6%) and least for mesothelioma (6.7%) and rare primary tumors (5.6%) (p = 0.04). The difference was 0 to 3 points for 119 patients (62.3%), 4 to 5 points for 27 patients (14.1%), and more than 5 points for 45 patients (23.5%). The rate of concordance was not influenced by the use of neoadjuvant chemotherapy (NACT) (p = 0.4), but the difference was greater when NACT was used (p = 0.03). CONCLUSIONS: The pPCI strongly differs from the sPCI for patients undergoing CRS for peritoneal disease and may provide a more accurate evaluation of the peritoneal disease extent. Further studies are needed to determine its prognostic value compared with sPCI, and consensus guidelines are needed for calculating it.

Treading the beaten path with old and new obstacles: a report from the Indian HIPEC registry.

BACKGROUND: The Indian HIPEC registry is a self-funded registry instituted by a group of Indian surgeons for patients with peritoneal metastases (PM) undergoing surgical treatment. This work was performed to • Evaluate outcomes of cytoreductive surgery ± HIPEC in patients enrolled in the registry. • Identify operational problems. METHODS: A retrospective analysis of patients enrolled in the registry from March 2016 to September 2017 was performed. An online survey was performed to study the surgeons' attitudes and existing practices pertaining to the registry and identify operational problems. RESULTS: During the study period, 332 patients were enrolled in 8 participating centres. The common indication was ovarian cancer for three centres and pseudomyxoma peritonei for three others. The median PCI ranged from 3 to 23. A CC-0/1 resection was obtained in 94.7%. There was no significant difference in the morbidity (p = .25) and mortality (p = .19) rates between different centres. There was a high rate of failure-to-rescue (19.3%) patients with complications and the survival in patients with colorectal PM was inferior. A lack of dedicated personnel for data collection and entry was the main reason for only 10/43 surgeons contributing data. The other problem was the lack of complete electronic medical record systems at all centres. CONCLUSIONS: These results validate existing practices and identify country-specific problems that need to be addressed. Despite operational problems, the registry is an invaluable tool for audit and research. It shows the feasibility of fruitful collaboration between surgeons in the absence of any regulatory body or funding for the project.

Outcomes of cytoreductive surgery and HIPEC for pseudomyxoma peritonei of appendiceal origin from two Indian centers: A preliminary five-year experience.

PURPOSE: To evaluate the short-term outcomes of patients of pseudomyxoma peritonei (PMP) of appendiceal origin treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) at two tertiary Indian centers. METHODS: Data was prospectively collected from January 2011 to January 2016. Palliative procedures were excluded. HIPEC was performed by the coliseum technique using either a mitomycin or oxaliplatin-based regimen. RESULTS: 77 procedures were performed on 71 patients. The average time interval between diagnosis and CRS was 15.3 months. Of the tumors, 22.1% were high grade, 77.9% low grade and 24.6% intermediate grade. The median peritoneal carcinomatosis index (PCI) was 26 (<25 in 70.1% and >30 in 38.9%). Completeness of cytoreduction score (CCS)-1 was achieved in 75.3% (CC-0 in 42.9%). The mean number of bowel anastomoses was 1.1 and the mean number of organs resected per patient was 3.3. Of the 77 patients, 71% had resection of 3 or more organs and 50.6% had resection of 4 or more organs. Grade 3-4 complications occurred in 42.9% of the patients and the perioperative mortality was 5.2%. The projected 5-year overall survival (OS) was 62.3% and the 3-year disease-free survival (DFS) was 71% at a median follow up of 13 months. CONCLUSION: CRS and HIPEC can be used to treat PMP with an acceptable morbidity and mortality in Indian patients. Lack of early referrals leads to a large portion of patients presenting with extensive disease and an inferior survival which should improve with increasing awareness about the procedure and its results.