Comparison of the Peritoneal Cancer Index and Dutch region count as tools to stage patients with peritoneal metastases of colorectal cancer.

BACKGROUND: Extent of peritoneal metastases (PM) is among the most powerful prognostic factors for survival after cytoreductive surgery (CRS). This study aimed to compare the Peritoneal Cancer Index (PCI) and the Dutch region count as tools for staging PM of colorectal cancer. The Dutch region count is a simpler classification that distinguishes seven rather than 13 abdominal regions. Presence or absence of PM is recorded. METHODS: This was a retrospective cohort study in two tertiary referral centres in the Netherlands. Consecutive patients with colorectal PM who were intentionally treated with CRS and subsequent hyperthermic intraperitoneal chemotherapy in 2016 and 2017 were included. The PCI and Dutch region count were both recorded during laparotomy. Correlation between scoring tools was calculated using Spearman's rank correlation coefficient. Diagnostic values were calculated for different cut-off values of the PCI, alongside the Dutch region count. The correlation of both scores was determined for the exploration and validation cohorts separately. RESULTS: In the exploration and validation cohorts, 73 and 85 patients respectively were included. Spearman's correlation coefficients of 0·897 and 0·961 were observed for continuous scores of the Dutch region count and PCI in the exploration and validation group respectively. A cut-off value of 20 for the PCI score and 5 for the Dutch region count showed 91·9 and 94·5 per cent sensitivity, and 81·8 and 91·7 per cent specificity, respectively. CONCLUSION: The Dutch region count correlated well with the PCI score, and may help to simplify reporting of the extent of peritoneal disease.

ANTECEDENTES: La extensión de las metástasis peritoneales (peritoneal metastases, PM) es uno de los factores pronósticos más importantes para la supervivencia después de la cirugía citorreductora (cytoreductive surgery, CRS). El objetivo de este estudio fue comparar el índice de carcinomatosis peritoneal (Peritoneal Cancer Index, PCI) y el recuento holandés por regiones como herramientas para la estadificación de las PM del cáncer colorrectal. El recuento holandés por regiones es una clasificación más simple que distingue 7 regiones abdominales en lugar de 13. En dichas regiones abdominales se registró la presencia o ausencia de PM. MÉTODOS: Se llevó a cabo un estudio de cohortes retrospectivo en dos centros de referencia terciarios en los Países Bajos. Se incluyeron pacientes consecutivos con PM de origen colorrectal que fueron tratados con CRS seguida de quimioterapia intraperitoneal hipertérmica (hyperthermic intraperitoneal chemotherapy, HIPEC) en 2016 y 2017. Durante la laparotomía se recogieron datos del índice PCI y de la clasificación de las regiones abdominales. Se utilizó el coeficiente de correlación de Spearman para analizar la correlación entre estas dos herramientas de puntuación. Se calculó la precisión diagnóstica en función de diferentes umbrales del índice PCI junto con los datos del recuento por regiones. Asimismo, se calcularon las correlaciones entre ambas puntuaciones en las cohortes de exploración y validación por separado. RESULTADOS: Se incluyeron 73 pacientes en la cohorte de exploración y 85 en la de validación. Los coeficientes de correlación de Spearman eran de 0,987 para puntuaciones continuas del recuento holandés por regiones abdominales y del PCI en la cohorte de exploración y de 0,961 en la cohorte de validación. Los umbrales de corte de 20 para el índice PCI y de 5 para el recuento por regiones demostraron sensibilidades de 91,9% y 94,5%, y especificidades de 81,8% y 91,7%, respectivamente. CONCLUSIÓN: El recuento holandés por regiones abdominales se correlacionó bien con el PCI y puede ser útil para simplificar la extensión de la enfermedad peritoneal.

Effect of intraperitoneal chemotherapy concentration on morbidity and survival.

BACKGROUND: Selected patients with colorectal peritoneal metastases are treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The concentration of intraperitoneal chemotherapy reflects the administered dose and perfusate volume. The aim of this study was to calculate intraperitoneal chemotherapy concentration during HIPEC and see whether this was related to clinical outcomes. METHODS: An observational multicentre study included consecutive patients with colorectal peritoneal metastases who were treated with CRS-HIPEC between 2010 and 2018 at three Dutch centres. Data were retrieved from prospectively developed databases. Chemotherapy dose and total circulating volumes of carrier solution were used to calculate chemotherapy concentrations. Postoperative complications, disease-free and overall survival were correlated with intraoperative chemotherapy concentrations. Univariable and multivariable logistic regression, Cox regression and survival analyses were performed. RESULTS: Of 320 patients, 220 received intraperitoneal mitomycin C (MMC) and 100 received oxaliplatin. Median perfusate volume for HIPEC was 5·0 (range 0·7-10·0) litres. Median intraperitoneal chemotherapy concentration was 13·3 (range 7·0-76·0) mg/l for MMC and 156·0 (91·9-377·6) mg/l in patients treated with oxaliplatin. Grade III or higher complications occurred in 75 patients (23·4 per cent). Median overall survival was 36·9 (i.q.r. 19·5-62·9) months. Intraperitoneal chemotherapy concentrations were not associated with postoperative complications or survival. CONCLUSION: CRS-HIPEC was performed with a wide variation in intraperitoneal chemotherapy concentrations that were not associated with complications or survival.

ANTECEDENTES: Ciertos pacientes seleccionados con metástasis peritoneales de cáncer colorrectal (peritoneal metastases, PM) se tratan con cirugía citorreductora (cytoreductive surgery, CRS) y quimioterapia intraperitoneal hipertérmica (hyperthermic intraperitoneal chemotherapy, HIPEC). La concentración de quimioterapia intraperitoneal refleja la dosis administrada y el volumen perfundido. El objetivo de este estudio fue calcular la concentración de quimioterapia intraperitoneal durante HIPEC y evaluar si ello se relacionaba con los resultados clínicos. MÉTODOS: Estudio observacional multicéntrico en el que se incluyeron pacientes consecutivos con PM de cáncer colorrectal que fueron tratados con CRS-HIPEC entre 2010 y 2018 en tres centros holandeses. Se obtuvieron los datos a partir de bases de datos mantenidas de forma prospectiva. La dosis de quimioterapia y los volúmenes circulantes totales de solución de perfusión se usaron para calcular las concentraciones de quimioterapia. Las complicaciones postoperatorias y las supervivencias libre de enfermedad y global se correlacionaron con las concentraciones de quimioterapia intraoperatoria. Se realizaron regresiones logísticas univariable y multivariable, regresión de Cox y análisis de supervivencia. RESULTADOS: De 320 pacientes, 220 recibieron mitomicina C intraperitoneal (MMC) y 100 oxaliplatino (OXA). El volumen medio de perfusión para HIPEC fue 5,0 L (rango 0,7-10,0). La mediana de concentración intraperitoneal del agente quimioterápico fue de 13,3 mg/L (rango 7,0-76,0) para MMC y 156,0 mg/L (rango 91,9 - 377,6) en pacientes tratados con OXA. Las complicaciones de grado 3 o mayores ocurrieron en 23,4% (n = 75). La mediana de supervivencia global fue de 36,9 meses (rango intercuartílico 19,5-62,9). Las concentraciones de quimioterapia intraperitoneal no se asociaron con las complicaciones postoperatorias ni con la supervivencia. CONCLUSIÓN: La CRS-HIPEC se realizó con una amplia variación en las concentraciones de quimioterapia intraperitoneal que no se asociaron con las complicaciones ni con la supervivencia.

Factors influencing long-term survival after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei originating from appendiceal neoplasms.

Background: Pseudomyxoma peritonei (PMP) is a rare disease, most commonly of appendiceal origin. Treatment consists of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). The aim of this study was to identify prognostic factors for recurrence and survival. Methods: This was an observational study using a prospectively designed database containing consecutive patients with PMP originating from the appendix, undergoing CRS-HIPEC at a tertiary referral centre between 1996 and 2015. Histopathological slides were reassessed. Cox regression was used for multivariable analyses. Results: Of 225 patients identified, 36 (16·0 per cent) were diagnosed with acellular mucin, 149 (66·2 per cent) had disseminated peritoneal adenomucinosis (DPAM) and 40 (17·8 per cent) had peritoneal mucinous carcinomatosis (PMCA). The 5-year overall survival (OS) rates were 93, 69·8 and 55 per cent respectively. Recurrence was observed in 120 patients (53·3 per cent), 39 of whom (17·3 per cent) were treated with a second CRS-HIPEC procedure. Factors independently associated with poor disease-free survival were six or seven affected regions (hazard ratio (HR) 6·01, 95 per cent c.i. 2·04 to 17·73), incomplete cytoreduction (R2a resection: HR 1·67, 1·05 to 2·65; R2b resection: HR 2·00, 1·07 to 3·73), and more than threefold raised carcinoembryonic antigen (CEA) and/or carbohydrate antigen (CA) 19-9 level (HR 2·31, 1·30 to 4·11). Factors independently associated with poorer OS were male sex (HR 1·74, 1·09 to 2·77), incomplete cytoreduction (R2a resection: HR 1·87, 1·14 to 3·08; R2b resection: HR 2·28, 1·19 to 4·34), and more than threefold raised CEA and/or CA19-9 level (HR 2·89, 1·36 to 6·16). Conclusion: CEA and CA19-9 levels raised more than threefold above the upper limit identify patients with PMP of appendiceal origin and poorer survival.

Diffusion-weighted MRI assessment of the peritoneal cancer index before cytoreductive surgery.

BACKGROUND: Patients with limited peritoneal metastases from colorectal cancer may be candidates for an aggressive surgical approach including cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). Selection is based on surgical inspection during laparoscopy or laparotomy. The aim of this study was to investigate whether diffusion-weighted MRI (DW-MRI) can be used to select patients for CRS-HIPEC. METHODS: This was a prospective study at a tertiary referral centre. Patients with confirmed or suspected colorectal peritoneal metastases scheduled for exploratory laparotomy or laparoscopy were eligible. Two radiologists assessed the peritoneal cancer index (PCI) on CT (CT-PCI) and DW-MRI (MRI-PCI). The reference standard was PCI at surgery. Radiologists were blinded to the surgical PCI and to each other's findings. The main outcome was the accuracy of DW-MRI in predicting whether patients had resectable disease (PCI less than 21) or not. RESULTS: Fifty-six patients were included in the study, of whom 49 could be evaluated. The mean(s.d.) PCI at surgery was 11·27(7·53). The mean MRI-PCI was 10·18(7·07) for reader 1 and 8·59(7·08) for reader 2. Readers 1 and 2 correctly staged 47 of 49 and 44 of 49 patients respectively (accuracy 96 and 90 per cent). Both readers detected all patients with resectable disease with a PCI below 21 at surgery (sensitivity 100 per cent). No patient was overstaged. The intraclass correlation (ICC) between readers was excellent (ICC 0·91, 95 per cent c.i. 0·77 to 0·96). MRI-PCI had a stronger correlation with surgical PCI (ICC 0·83-0·88) than did CT-PCI (ICC 0·39-0·44). CONCLUSION: DW-MRI is a promising non-invasive tool to guide treatment selection in patients with peritoneal metastases from colorectal cancer.

Histopathological and molecular classification of colorectal cancer and corresponding peritoneal metastases.

BACKGROUND: Patients with colorectal peritoneal carcinomatosis have a very poor prognosis. The recently developed consensus molecular subtype (CMS) classification of primary colorectal cancer categorizes tumours into four robust subtypes, which could guide subtype-targeted therapy. CMS4, also known as the mesenchymal subtype, has the greatest propensity to form distant metastases. CMS4 status and histopathological features of colorectal peritoneal carcinomatosis were investigated in this study. METHODS: Fresh-frozen tissue samples from primary colorectal cancer and paired peritoneal metastases from patients who underwent cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy were collected. Histopathological features were analysed, and a reverse transcriptase-quantitative PCR test was used to assess CMS4 status of all collected lesions. RESULTS: Colorectal peritoneal carcinomatosis was associated with adverse histopathological characteristics, including a high percentage of stroma in both primary tumours and metastases, and poor differentiation grade and high-grade tumour budding in primary tumours. Furthermore, CMS4 was significantly enriched in primary tumours with peritoneal metastases, compared with unselected stage I-IV tumours (60 per cent (12 of 20) versus 23 per cent; P = 0.002). The majority of peritoneal metastases (75 per cent, 21 of 28) were also classified as CMS4. Considerable intrapatient subtype heterogeneity was observed. Notably, 15 of 16 patients with paired tumours had at least one CMS4-positive tumour location. CONCLUSION: Significant enrichment for CMS4 was observed in colorectal peritoneal carcinomatosis. Surgical relevance Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) improves survival of selected patients with colorectal peritoneal carcinomatosis, but recurrence is common. Histopathological and molecular analysis of colorectal peritoneal carcinomatosis could provide clues for development of novel therapies. In this study, colorectal peritoneal carcinomatosis was found to be enriched for tumours with high stromal content and CMS4-positive status. To further improve prognosis for patients with colorectal peritoneal carcinomatosis, therapies that target tumour-stroma interaction could be added to CRS-HIPEC.

Safety of intraperitoneal Mitomycin C versus intraperitoneal oxaliplatin in patients with peritoneal carcinomatosis of colorectal cancer undergoing cytoreductive surgery and HIPEC.

BACKGROUND: Colorectal peritoneal carcinomatosis (PC) is commonly treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). There is an ongoing international debate about which intraperitoneal chemotherapeutic agent is preferred, Mitomycin C (MMC) or oxaliplatin. We questioned whether the type of chemotherapeutic agent influenced postoperative complication rates or short-term survival. METHODS: In this retrospective cohort study patients with colorectal PC who underwent CRS-HIPEC between January 2010 and December 2016 were included. Until March 2014 patients had preferentially been treated with MMC and thereafter with oxaliplatin in an iso-osmotic glucose/electrolyte dialysis (Dianeal®) carrier solution. Main outcomes were postoperative complications, disease free survival (DFS) and overall survival (OS). Survival analyses and multivariable analyses were performed. RESULTS: One hundred four patients received MMC and 73 patients oxaliplatin. Postoperative complications did not differ between groups (44.2% (MMC) versus 43.8% (oxaliplatin); P = 0.958). Median DFS was 12.5 months (IQR 6.4-32.4) in the MMC-group and 13.1 months (IQR 6.1-NA) in the oxaliplatin-group (P = 0.669). Median OS was 37.2 months (IQR 17.2-NA) in the MMC-group and 29.4 months (IQR 17.0-NA) in the oxaliplatin-group (P = 0.764). The type of chemotherapeutic agent did not influence OS in multivariable analysis (oxaliplatin versus MMC HR 1.09 (95%CI 0.58-2.06)). The HIPEC-phase was shorter for oxaliplatin (median 32 (IQR 31-34) versus 91 min (IQR 90-92) for MMC (P < 0.001)). CONCLUSION: Intraperitoneal oxaliplatin reduced the chemoperfusion time when compared to intraperitoneal MMC without adversely influencing complication rates or short-term survival. It may therefore be the preferential drug in CRS-HIPEC procedures for colorectal PC.