Peritoneal Cancer Index Research Articles (Page 1)

Introduction and Importance: Low-grade appendiceal mucinous neoplasm (LAMN) is a rare epithelial tumor characterized by mucin production and potential dissemination into the peritoneal cavity, resulting in pseudomyxoma peritonei (PMP). The coexistence of LAMN with a mucinous borderline ovarian tumor (MBOT) represents a complex and exceedingly rare clinical scenario. Unlike the main introduction, this abstract focuses on the clinical and therapeutic significance rather than epidemiology. There are no standardized treatment protocols for synchronous LAMN with MBOT; hence, individualized management is essential. This report highlights an uncommon multimodal strategy combining cytoreductive surgery (CRS), modified FOLFIRINOX chemotherapy incorporating irinotecan, and planned second-look surgery with hyperthermic intraperitoneal chemotherapy (HIPEC). Case Presentation: A 44-year-old woman presented with abdominal distension. Imaging revealed diffuse mucinous peritoneal deposits, thickened appendix, and multilocular ovarian cyst. Preoperative CA-125 was 142 U/mL and CA 19-9 was 280 U/mL. CRS including appendectomy, right hemicolectomy, omentectomy, and bilateral salpingo-oophorectomy was performed. Histopathology confirmed LAMN with PMP and MBOT. The Peritoneal Cancer Index (PCI) at primary surgery was 18. A multidisciplinary team recommended systemic chemotherapy with modified FOLFIRINOX including irinotecan before second-look HIPEC. The patient tolerated the regimen well. Clinical Discussion: This case underscores an emerging role of irinotecan-based chemotherapy as part of a tailored multimodal treatment for low-grade mucinous neoplasms, especially in resource-constrained environments. Conclusion: The patient remained disease-free at one-year follow-up, highlighting the potential effectiveness and practicality of irinotecan-based regimens as part of an individualized management strategy for low-grade mucinous neoplasms.

BackgroundMalignant peritoneal mesothelioma (MPM) is a highly aggressive peritoneal malignancy with a significant recurrence rate following cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC). There is an urgent need to investigate novel therapeutic strategies for MPM. Natural killer (NK) cells exhibit rapid responsiveness in anti-tumor immunity; however, NK cells’ dynamic evolution and clinical significance in MPM remain unclear.MethodsThis study retrospectively enrolled 80 newly diagnosed MPM patients (preoperative group) and 64 patients who underwent CRS + HIPEC (postoperative group). The level of NK cells (CD3−CD56dimCD16+) in peripheral blood was quantified using flow cytometry. Univariate and multivariate regression analyses were performed to evaluate the association between NK cell counts and clinicopathological characteristics, intraoperative events, and prognosis. A multivariate prediction model for NK cell recovery was established.Results41 patients (51.3%) exhibited decreased NK cell levels preoperatively, which were significantly associated with an increased risk of thrombosis (P = 0.023), intraoperative plasma transfusion (P = 0.004), and prolonged hospitalization duration (P = 0.023). Postoperative dynamic changes in NK cell levels were found to correlate with Karnofsky performance scale (KPS) scores (P = 0.048) and elevated levels of IL-4, IL-5, IL-6, and IL-8 (P < 0.05). Multivariate analysis revealed that the volume of intraoperative plasma transfusion was an independent correlated factor for preoperative NK cell reduction (P = 0.013), while a low KPS score was an independent predictor of postoperative NK cell decline (P = 0.048). Survival analysis indicated that a high perioperative stress score (PSS) (P = 0.015), lymph node metastasis (P = 0.015), significant intraoperative blood loss (P = 0.013), low preoperative CD8⁺ T cell levels (P = 0.001), and reduced postoperative IL-17 expression (P = 0.013) were independent adverse prognostic factors for overall survival (OS). Furthermore, the dynamic NK cell recovery model demonstrated that baseline NK cell levels, peritoneal cancer index (PCI), CD8⁺ T cell status, and postoperative recovery time all significantly influenced the immune remodeling process (all P < 0.001).ConclusionsPreoperative NK depletion correlated with thrombosis and surgical risks, while postoperative NK recovery was influenced by KPS, specific cytokines (IL-4/5/6/8), and was significantly enhanced after CRS + HIPEC.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12957-025-04019-2.

Exploring PIPAC for managing platinum resistant and refractory ovarian cancer with peritoneal spread: A collaborative multi-institutional study.

Prognosis and clinical characteristics of signet ring cell colorectal peritoneal metastases - a Swedish population-based study.

Colorectal peritoneal metastases are associated with poor prognosis. Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy may improve survival in selected patients. To evaluate survival outcomes and identify prognostic factors affecting overall survival and disease-free survival in patients with colorectal peritoneal metastases undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Retrospective cohort study. This study was conducted at a single tertiary referral center between January 2013 and March 2024. Ninety-two patients with colorectal peritoneal metastases treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy were included. The cohort comprised 52 males and 40 females, with a mean age of 46 years. Synchronous metastases were present in 75 percent of cases. All patients underwent cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy. Overall survival, disease-free survival, and prognostic factors influencing outcomes. Complete cytoreduction was achieved in 92.3% of patients. Median overall survival was 24 months, and median disease-free survival was 11 months. The 3-year and 5-year overall survival rates were 43.6% and 32.2%, respectively. An increasing Peritoneal Cancer Index was independently associated with decreased overall survival, with poorer outcomes observed for a Peritoneal Cancer Index greater than 16 (hazard ratio 1.06, p = 0.016). The presence of perineural invasion (hazard ratio 2.06, p = 0.030) and intraoperative blood loss exceeding 1,500 milliliters (hazard ratio 1.96, p = 0.018) were also associated with reduced survival. These factors may help stratify patients for optimal surgical outcomes. Retrospective design, single-center experience, and limited molecular data may affect generalizability. Longer follow-up is needed to evaluate late recurrences and longterm survival. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy improves survival in selected patients with colorectal peritoneal metastases. High Peritoneal Cancer Index, perineural invasion, and excessive blood loss predict poorer outcomes and should guide patient selection. See Video Abstract.

Artificial Intelligence and radiomics models for the diagnosis and prognosis of peritoneal metastases on imaging: a systematic review and meta-analysis.

IntroductionSurgical management of patients with peritoneal surface malignancies (PSM) via multivisceral resection is associated with increased morbidity and mortality in the immediate postoperative period, rendering intensive care therapy critically important. We aimed to determine whether intensive care unit (ICU) course and scoring systems predict not only short-term but also long-term outcomes.MethodsWe retrospectively analyzed the medical records of all patients who underwent cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal surface malignancies (PSM) between 2008 and 2015 at a university cancer center. Upon postoperative ICU admission, Simplified Acute Physiology Score (SAPS II) and Sequential Organ Failure Assessment (SOFA) scores were recorded. Complications during the ICU stay and overall hospitalization were documented, and patients were followed according to a standardized protocol after discharge.ResultsA total of 251 patients were included. The mean Peritoneal Cancer Index (PCI) was 14 ± 9.1 and correlated significantly with both ICU stay duration (p = 0.002) and total hospital stay (p = 0.001). In-hospital mortality was 2%, and the reoperation rate was 16.7%. SOFA scores on the day of surgery, postoperative days 1, 2, and 7 demonstrated strong correlations with ICU length of stay (all p ≤ 0.001) and with overall hospital stay (p = 0.001 for the day of surgery and day 7; p ≤ 0.001 for days 1 and 2). In multivariate analysis, SOFA score on postoperative day 7 [hazard ratio (HR) 1.261; 95% confidence interval (CI) 1.120–1.421; p ≤ 0.001] and SAPS II on the day of surgery (HR 1.042; 95% CI 1.017–1.068; p ≤ 0.001) emerged as independent predictors of overall survival.DiscussionIn conclusion, SAPS II and SOFA scores not only predict ICU and hospital lengths of stay but also independently forecast overall survival in patients undergoing CRS and HIPEC for PSM.

Deep epigastric lymph node involvement in patients with ovarian and colorectal peritoneal metastasis: A prospective pilot study.

Background: Ovarian cancer remains a major contributor to cancer-related morbidity and mortality worldwide. Primary cytoreductive surgery is the cornerstone of treatment, and accurate preoperative assessment of tumor resectability is critical to guiding optimal therapeutic strategies in patients with advanced tubo-ovarian cancer. Methods: A narrative review about the role of ultrasound for assessing tumor spread and prediction of tumor resectability was performed. Results: The ISAAC study represents the largest prospective multicenter trial to date comparing the diagnostic performance of ultrasound (US), computed tomography (CT), and whole-body diffusion-weighted magnetic resonance imaging (WB-DWI/MRI) in predicting non-resectability, using surgical and histopathological findings as the reference standard. Key strengths of the study include the use of standardized imaging and intraoperative reporting protocols across ESGO-accredited high-volume oncologic centers. All three imaging modalities were performed within four weeks prior to surgery by independent, blinded expert operators. US demonstrated diagnostic accuracy comparable to that of CT and WB-DWI/MRI. The study also defined modality-specific thresholds for the Peritoneal Cancer Index (PCI) and Predictive Index Value (PIV), offering quantitative tools to support surgical decision-making. A noteworthy secondary finding was patient preference: in a cohort of 144 participants who underwent all three imaging modalities, nearly half preferred US, while WB-DWI/MRI was the least favored due to discomfort and examination duration. Conclusions: The ISAAC study represents a significant advancement in imaging-based prediction of surgical non-resectability in tubo-ovarian cancer. Its findings suggest that, in expert hands, ultrasound can match or even surpass cross-sectional imaging for preoperative staging, supporting its integration into routine clinical practice, particularly in resource-constrained settings.

Recurrence patterns following CRS-HIPEC in patients with colorectal peritoneal metastases: Insights from the Dutch CRS-HIPEC registry.

Abstract Background Computed tomography (CT) is widely used to diagnose peritoneal metastases (PM), with debated accuracy. Dual-energy CT (DECT) may improve accuracy, yet its diagnostic performance is still unknown. We explored the potential of DECT for PM detection and quantification. Materials and methods We retrospectively included patients undergoing staging DECT for cancers with a high risk of peritoneal involvement, followed by staging laparoscopy/laparotomy, which served as the reference standard. Nine readers with varying experience levels (three expert, three intermediate, and three inexpert) reviewed two sets of images, separated by ≥ 60 days, considering the presence/absence of PM, abdominal region(s) involved, and calculated the radiological peritoneal cancer index (PCI). The first set included contrast-enhanced delayed-DECT scans reconstructed as virtual 120-kVp images; the second set also included virtual monoenergetic, 40-keV images and iodine maps. Performance metrics, receiver operating characteristic (ROC) analysis, McNemar, DeLong, and Wilcoxon tests were applied. Results Twenty patients (mean age 64.2 years; 12 females) were included, 10 with PM. At per-patient analysis, the addition of monoenergetic 40-keV images and iodine maps slightly increased the performance and improved inter-reader agreement, with significant benefit for inexperienced readers only (p = 0.010). Per-region analysis demonstrated a significant advantage with an area under the ROC curve ranging from 0.709 to 0.766 (p &lt; 0.001), confirmed for each reader group; in addition, the inter-reader agreement significantly improved. Quantitative analysis showed a reduction in the differences between CT results and surgical PCI by DECT (4 ± 12 versus 2 ± 9, p &lt; 0.001). Conclusion DECT-derived reconstructions in the delayed-phase enhanced PM detection and quantification. Relevance statement Delayed-phase DECT reconstruction showed superior accuracy over conventional CT in detecting and quantifying peritoneal metastases. These findings could help establish a new standard CT protocol for malignancies with peritoneal tropism. Key Points CT is the most widely used technique for assessing peritoneal metastases. The accuracy of CT for peritoneal metastases is debated; dual-energy CT shows promise. In our study, delayed-phase dual-energy CT provided significant advantages for all readers. Graphical Abstract

Usefulness of [18F]FAPI-04 and [18F]FDG PET/CT for the Detection of Peritoneal Carcinomatosis: AComparative Study.

AimCytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is the standard treatment for peritoneal metastases (PM) of colorectal or appendiceal origin. Rectal anastomotic leakage (RAL) or rectal stump blow‐out is a serious complication following rectal resection after CRS‐HIPEC. This study aimed to compare outcomes between ileo‐/colorectal anastomosis and rectal stump procedure and to identify risk factors for RAL and blow‐out.MethodData were retrospectively collected between 2012 and 2024 from a prospectively maintained HIPEC Registry and supplemented with the review of medical records. Postoperative complications and the prevalence of RAL or blow‐out were registered. Pearson's chi‐squared test was used to compare differences in categorical variables. Logistic regression was used to identify risk factors for RAL and blow‐out.ResultsAmong 1271 CRS‐HIPEC procedures, 332 involved rectal resections. Patients received either an ileo‐/colorectal anastomosis (n = 158) or had a rectal stump procedure (n = 174). RAL occurred in 5.7% and blow‐out in 2.9% (p = 0.201). In the rectal stump group, patients were older (65 vs. 59 years; p = <0.001), had higher PCI scores (p = 0.031) and more often had received neoadjuvant treatment (p = 0.025). Logistic regression showed no independent association between RAL and type of rectal reconstruction (OR 1.99; 95% CI: 0.61–6.51), low anastomotic level (OR 2.17; 95% CI: 0.50–9.42) or peritoneal cancer index >21 (OR 6.47; 95% CI: 0.84–50.1).ConclusionBoth reconstruction strategies following rectal resection in CRS‐HIPEC were associated with low rates of RAL or blow‐out. No independent risk factors were identified, indicating that the choice of surgical approach should be individualized based on clinical context rather than presumed leakage risk.

Textbook outcomes among patients undergoing cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy for peritoneal surface malignancies in an Eastern European population.

Background: Pseudomyxoma peritonei (PMP) is a rare clinical syndrome characterised by progressive intraperitoneal accumulation of mucinous ascites, most commonly arising from appendiceal mucinous neoplasms. Once uniformly fatal, the prognosis has been transformed by cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC). Nevertheless, controversies persist regarding diagnostic strategies, surgical thresholds and the true incremental value of HIPEC. Objective: This review synthesises contemporary evidence on the pathogenesis, diagnostic pearls, surgical decision-making and HIPEC controversies in PMP, while exploring emerging systemic and targeted therapies and future directions in biomarker-driven and AI-assisted management. Methods: A comprehensive literature review of PubMed-indexed studies from 2000 to 2025 was performed, with emphasis on systematic reviews, meta-analyses, randomised controlled trials and multicentre registries. Key themes were integrated under diagnostic evaluation, surgical selection, HIPEC pharmacology, systemic therapy limitations and translational innovations. Seminal historical references were retained selectively for context. Conclusion: PMP exemplifies the convergence of rare disease biology and surgical audacity. CRS remains the cornerstone, with peritoneal cancer index (PCI) and completeness of cytoreduction (CC score) guiding operative decision-making. While HIPEC is widely practised, the absence of randomised data in PMP sustains debate over its necessity, optimal regimens and feasibility in low-resource settings. Systemic therapies remain limited, but novel mucinase strategies, immunotherapy and AI-driven imaging prediction herald a future of personalised care. Global collaboration through registries and consensus frameworks will be critical to resolving controversies and ensuring equitable access to curative strategies worldwide.

Preoperative clinical scores compared with dual-energy computed tomography parameters in predicting complete resection of ovarian advanced high-grade serous carcinoma.

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is a treatment option for selected patients with peritoneal carcinomatosis. This study investigates preoperative factors influencing incomplete CRS. We retrospectively reviewed 188 patients scheduled for curative-intent CRS/HIPEC between April 2015 and May 2023. Preoperative peritoneal cancer index (PCI) scores were determined using computed tomography (CT) (n = 155) and/or magnetic resonance imaging (MRI) (n = 82). Complete CRS was achieved in 126 patients (67.0%) and incomplete CRS in 62 (32.9%). Colorectal cancer was the predominant primary tumor (complete CRS: 42.9%; incomplete CRS: 50.0%), followed by ovarian cancer (34.1% vs. 17.7%). Multivariate analysis revealed imaging-specific risk factors: the CT model identified ascites (OR = 4.57) and higher PCI scores in regions 0 and 11, while the MRI model identified prior chemotherapy (OR = 101.06) and higher PCI scores in regions 2, 3, and 11. Decision tree analysis showed ascites altered PCI thresholds for patients with ascites (CT: 18.5, MRI: 6.5) versus without (CT: 8.5, MRI: 12.5). Both imaging modalities demonstrated moderate agreement with surgical findings for total PCI scores (ICC = 0.656 and 0.678), with stronger correlations in regions 0-8 than regions 9-12. Small bowel regions showed poor accuracy, with lowest sensitivity in region 11. Ascites and higher PCI scores in specific regions identified on preoperative imaging were associated with increased risk of incomplete CRS. These findings can improve patient selection and preoperative planning for CRS/HIPEC in peritoneal carcinomatosis.

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) is a cornerstone treatment for resectable peritoneal carcinomatosis. Urologic reconstructive surgery is required in 7-20% of cytoreductive surgeries due to urinary tract involvement or injury, yet current literature on outcomes remains limited. This study presents one of the largest single-institution cohorts examining outcomes of urologic reconstruction in CRS/HIPEC cases, and is the first to investigate the impact of preoperative planning and intraoperative timing of urologic reconstruction on postoperative outcomes. A retrospective analysis of 314 cases was performed from June 2010 to August 2023. Data from cases involving urologic reconstruction were analyzed, including demographics, surgical details, and outcomes. Statistical analyses evaluated associations between surgical variables and short and long-term urologic complications. Urologic reconstruction was performed in 35 cases (11.1%), with the majority occurring after HIPEC administration. Postoperative urologic complications occurred in 57% of cases. 40% of the urologic reconstruction cases resulted in low-grade, short-term urologic complications (AKI, UTI) while 20% were deemed high-grade (sepsis, urine leak). 29% developed long-term sequelae such as ureteral stricture or urinary retention. Longer operative times were significantly associated with long-term complications. No significant differences were found in long-term complication rates based on the timing of urologic repair (pre-HIPEC or post-HIPEC) or whether urologic intervention was planned prior to surgery. Interestingly, there was a significant association between fewer prior abdominal surgeries and higher complication rates. Surgical complexity and prior surgical history are key determinants of postoperative outcomes following urologic reconstruction at the time of cytoreductive surgery. Timing of urologic intervention and specific preoperative variables, such as age and peritoneal cancer index score, did not significantly impact long-term outcomes. Higher complication rates were also seen among patients with fewer prior abdominal surgeries, which may in part be due to selection bias or other unaccounted variables present in the patients with fewer abdominal surgeries. These findings highlight the importance of individualized surgical planning and inform preoperative discussions about the risks and benefits of CRS with HIPEC.

The optimal surveillance for mucinous appendix cancer (MAC) after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) remains unclear. We identified postoperative periods reflecting significant changes in recurrence probability. A prospective database (1998-2024) of patients with stage IV MAC with low-grade (LGMCP), high-grade (HGMCP), and signet-ring cell (SRC) histology treated with initial complete (CC-0/1) CRS/HIPEC was analyzed. A piecewise exponential recurrence-free survival model was employed. Excluding the first 6 months, postoperative follow-up was divided into periods by forwardly selected knots using minimal Bayesian Information Criterion (BIC) in an adjusted Cox regression. Per-period cumulative recurrence risk (CRR) was calculated by histology. Optimal surveillance was modeled based on 5% CRR changes. Of 385 patients, 60.3% had LGMCP, 20.8% HGMCP, and 19.0% SRC. Median age was 54 years, 64.9% were female, and median peritoneal cancer index was 26. Median follow-up was 92 months. Knots at 16 and 48 months (BIC = 484.4) defined three periods: I (6-16 months), II (16-48 months), and III (48-120 months). The CRR was highest in period I: 1.0, 2.6, and 3.8 per 10 person-years for LGMCP, HGMCP, and SRC, respectively. The CRR in period II was 0.5, 2.9, and 3.5 and in period III was 0.4, 0.5, and 1.8, respectively. Optimal surveillance occurs every 5.5, 8, and 18 months for LGMCP and every 2-2.5, 4, and 24 months for HGMCP in periods I-III, respectively. Mucinous appendix cancer exhibits a distinct recurrence probability by histology and key post-CRS/HIPEC periods, which can be addressed by a tailored surveillance schedule.

Association of cul-de-sac seeding with intraperitoneal tumor burden in advanced ovarian cancer (CIEL, KGOG 4003).