Search Results (420)

Background: Mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) colorectal tumors constitute 5% of metastatic colorectal cancer(mCRC). Immunotherapy is a new standard, but it is difficult to provide for all patients. 5-Flurouracil-based treatment with anti-EGFRs (cetuximab and panitumumab) in RAS/BRAF-wild or anti-VEGF (bevacizumab) is used in mCRC. Data is limited for the efficacy of anti-VEGF or anti-EGFRs in dMMR/MSI-H mCRC due to the small number of cases in the colorectal cancer population in trials. Aims: To evaluate prognostic factors in dMMR/MSI-H mCRC and compare progression-free survival time of patients receiving anti-VEGF and anti-EGFR combined with first-line 5FU-based therapy. Methods: Patients with metastatic dMMR/MSI-H colorectal cancer diagnosed between January 2015 and January 2023 were included in this cohort study. Progression-free survival times of patients treated with first-line therapy were compared. Prognostic factors associated with overall survival were investigated. Results: A total of 132 patients were included. Mutation rates were 35.6% (n:47) for RAS and 12.1% (n: 16) for BRAF (. Median progression-free survival (PFS) was 10.9 (95% CI: 9.2–12.6) months. Median overall survival (OS) was 44 months (95% CI: 26.23–63.03). 82 (62.1%) patients had primary tumor resection (PTR), 26 (19.7%) had PTR and metastasectomy. A total of 17 (12.8%) de novo mCRC patients had maximal cytoreductive surgery (MCS). A total of 14 (10.6%) patients had subsequent immunotherapy (IO). In multivariate analysis, RAS/BRAF mutation status, MCS, and subsequent IO are defined as prognostic factors for OS (p < 0.01, p: 0.022, and p: 0.005, respectively). No statistically significant difference (PFS, OS) was found in patients receiving first-line anti-VEGF or anti-EGFR therapy. Conclusions: dMMR/MSI-H mCRC is an entity with different tumor biology. We consider that dMMR/MSI-H mCRC patients with BRAF wild, MCS and subsequent IO have better outcomes with 1st line 5FU-based treatment with anti-VEGF/anti-EGFRs. Full article

Background: Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) can cure selected patients with colorectal peritoneal metastases (CPM). Real-world prognostic data, especially for the Peritoneal Cancer Index (PCI) and completeness of cytoreduction (CCR), are limited. Methods: We retrospectively analysed 75 consecutive patients treated with CRS + HIPEC at a tertiary centre (2014–2022), giving ≥36 months potential follow-up. Overall survival (OS) was assessed by Kaplan–Meier and Cox models. PCI was grouped 0–10, 11–20, >20; CCR was dichotomised (CCR-0 vs. CCR 1/2). Multivariable analysis included PCI, CCR, and resection extent; HIPEC drug was examined univariately. Results: The median follow-up was 41 months. Crude 3-year OS was 50.7% (38/75). Survival decreased with higher PCI: 69% for 0–10 (n = 42), 38% for 11–20 (n = 21), and 0% for > 20 (n = 4). Versus PCI 0–10, the adjusted hazard ratios (HR) were 3.02 (95% CI 1.52–6.03) for PCI 11–20 and 7.29 (1.72–30.81) for > 20. CCR-0 improved OS univariately (HR 0.43) but was non-significant after adjustment (HR 0.89). Resection limited to the peritoneum (HR 0.99) and choice of intraperitoneal drug showed no independent effect. Conclusions: In this real-world cohort, PCI was the only independent predictor of 3-year survival after CRS + HIPEC for CPM; neither CCR status, surgical extent, nor HIPEC agent altered prognosis once PCI was considered. PCI should therefore remain the principal selection criterion while molecular and biological markers are integrated into future risk models. Full article

Background/Objectives: For surgical candidates with metastatic renal cell carcinoma with a tumor thrombus (mRCC-TT), surgery is cytoreductive nephrectomy with tumor thrombectomy (CN-TT). This is carried out through an open (OCN-TT), laparoscopic (LCN-TT), or robotic (RCN-TT) approach. The purpose of this study was to compare survival outcomes to CN-TT by operative approach. Methods: This was a retrospective analysis of all patients with a diagnosis of mRCC-TT, who underwent CN-TT from a multi-institutional database from 1999–2024. Metastatic locations were qualified as either lung, bone, brain, liver, retroperitoneum, adrenal, paraaortic nodes, or other nodes. Progression was defined as radiographic evidence of recurrence or metastasis not seen on imaging prior to CN-TT. Progression locations were all metastatic locales previously noted plus the nephrectomy bed. Overall survival (OS), cancer-specific survival (CSS), and progression-free survival (PFS) were calculated. Comparisons were performed between OCN-TT, LCN-TT, and RCN-TT. Results: A total of 131 patients were included in the analysis (97 OCN-TT, 25 LCN-TT, and 9 RCN-TT). The TT level was not different (p-value > 0.05) by approach (p-value > 0.05). Preoperative tumor size, final pathologic tumor subtype, and postoperative tumor size were equivalent between the three surgical approaches (p-value > 0.05). Rates of progression were equivalent as were all locations of disease progression in the study (p-value > 0.05). Median OS was 1.6 years in OCN-TT, 1.5 years in LCN-TT, and 2.5 years in RCN-TT (p-value = 0.42). Median CSS was 2.1 years in OCN-TT, 3 years in LCN-TT, and 2.5 years in RCN-TT (p-value = 0.86). PFS was 0.8 years in OCN-TT, 1.2 years in LCN-TT, and 1.2 years in RNC-TT (p-value = 0.76). Conclusions: The operative approach does not affect survival outcomes for CN-TT. Surgeon comfort and patient preference should weigh heavily in operative decision making. Full article

Objective: The P-POSSUM scale is widely used in predicting perioperative morbidity and mortality. Evidence on the performance of P-POSSUM in predicting outcomes after cytoreductive surgery (CRS) for ovarian cancer (OC) is limited. In this study, we assess how well P-POSSUM predicts morbidity in OC CRS and explore whether incorporating additional clinical variables can enhance its predictive accuracy. We retrospectively collected data on consecutive patients undergoing OC CRS within a tertiary gynaecologic oncology network. The collected information included demographic characteristics, P-POSSUM morbidity and mortality scores, Edmonton Frail Scale (EFS) scores, preoperative serum albumin levels, and observed 30-day postoperative morbidity and mortality, classified using the Clavien–Dindo (CD) scale. The predictive performance of P-POSSUM was evaluated using receiver operating characteristic (ROC) curves to calculate sensitivity and specificity. A stepwise regression analysis was then applied to identify additional variables that could improve model performance, incorporating preoperative covariates. The final model incorporated parameters chosen through bootstrap investigation of the model variability (stepAIC). Predicted versus observed morbidity was calibrated and performance compared between P-POSSUM and the final model. Results: Of 161 sequential OC patients, 95 (59%) underwent primary, 45 (28%) interval, and 21 (13%) delayed CRS. The mean age was 66.4 (95%CI: 60–75) and duration of surgery was 223 mins (95%CI: 142–279). Sixty-five (40.3%) patients had ≥1 postoperative complication. Two deaths were reported. Among the observed complications, 4 patients (6.1%) experienced CD4, 10 patients (15.3%) CD3, 38 patients (58.5%) CD2, and 11 patients (16.9%) CD1 events. The mean P-POSSUM-predicted morbidity and mortality were 59.5% (95%CI: 56.7–62.3%) and 5.86% (95%CI: 5.02–6.70%), respectively. The area under the curve (AUC) for P-POSSUM in predicting morbidity and mortality was 0.539 (p = 0.401) and 0.569 (p = 0.137), respectively. Given the small number of deaths, no robust conclusions regarding mortality are possible. EFS and BMI emerged as significant predictors of observed morbidity using a stepwise-model selection process. The AIC of this final model was 211.44. Our final model of PPOSSUM + EFS + BMI had AUC = 0.6551 (Delong’s Z = 1.8845, p-value = 0.05949). Conclusions: The P-POSSUM scale shows poor performance for predicting morbidity in OC CRS. New validated and accurate model(s) are necessary for predicting surgical morbidity. Our proposed model incorporates additional variables to improve P-POSSUM’s performance. This requires further development and validation. Full article

Background: High-grade serous ovarian cancer (HGSC) is the most common and aggressive subtype of ovarian cancer. Despite initial response to platinum-based chemotherapy, most patients relapse. Cytoreductive surgery at relapse has been shown to improve survival in selected patients, but the biological mechanisms underlying recurrence and resistance remain unclear. This study aimed to investigate whether the mutational profile of HGSC changes from diagnosis to relapse, and to evaluate treatment patterns and survival outcomes in a cohort undergoing cytoreductive surgery. Methods: Sixteen patients with HGSC who underwent cytoreductive surgery at both diagnosis and relapse were included. Matched tumor tissue samples (n = 32) were collected and sequenced using a 501-gene cancer panel. Only pathogenic or likely pathogenic variants were registered. Clinical data, treatment history, and survival outcomes were obtained from medical records, with a median follow-up of 63 months. Results: All patients harbored pathogenic or likely pathogenic mutations, most frequently in TP53 (88%) and BRCA1/2 (38%). The mutational landscape was largely stable, with 15 of 16 patients (94%) showing no mutational changes between diagnosis and relapse. One patient acquired a NOTCH2 mutation at relapse. Complete resection was achieved in 88% of relapse surgeries. Median time to first relapse was 32 months, and overall survival was prolonged, with 87.5% of patients alive at last follow-up. BRCA mutated patients showed longer time to relapse, and overall follow-up compared to BRCA wild-type cases. Conclusions: The somatic mutational profile of HGSC remains remarkably stable from diagnosis to relapse. Clinically, this stability suggests that repeat mutational sequencing at relapse is unlikely to yield new actionable findings and may have limited value in guiding treatment decisions. Instead, resistance mechanisms likely arise from epigenetic or non-genetic changes, underscoring the need for future research in these areas and the continued importance of optimal surgical management in selected patients. Full article

Objective: While PARP inhibitors (PARPi) improve progression-free survival (PFS) in advanced ovarian cancer, their efficacy across different surgical outcomes is unclear. We aimed to determine if the efficacy of PARPi maintenance therapy, as measured by PFS, is modified by postoperative residual disease (R0 vs. R1/R2) in newly diagnosed advanced epithelial ovarian cancer. Methods: A systematic review and trial-level meta analysis of randomized controlled trials published through July 2025 was conducted. The primary endpoint was pooled hazard ratio (HR) for PFS, with subgroup analyses based on residual disease (R0 vs. R1/R2), clinical risk (higher risk vs. lower risk), and timing of surgery (primary cytoreductive surgery vs. interval cytoreductive surgery). Results: Six randomized controlled trials involving 3629 patients were included in this meta analysis. PARPi maintenance significantly improved PFS in both patients with no gross residual disease (R0) (HR 0.55, 95% CI 0.44–0.68, I² = 64.2%) and those with macroscopic residual disease (R1/R2) (HR 0.51, 95% CI 0.40–0.65, I² = 56.0%). The treatment effect did not differ significantly between these subgroups (p = 0.66). A numerically greater benefit was observed in lower-risk populations (HR 0.40, 95% CI 0.29–0.55, I² = 0.9%) compared to higher-risk populations (HR 0.51, 95% CI 0.36–0.73, I² = 78.5%, p = 0.30). The benefit was maintained irrespective of surgical timing, with similar pooled HRs for patients undergoing primary (HR 0.56, 95% CI 0.42–0.74, I² = 72.3%) versus interval (HR 0.54, 95% CI 0.45–0.66, I² = 44.2%) cytoreductive surgery. Conclusions: PARP inhibitor maintenance therapy provides a significant PFS benefit regardless of residual disease status, supporting its use in all eligible patients. Complete cytoreduction, however, remains crucial, as it provides the best foundation for achieving optimal long-term outcomes and maximizing the benefits of maintenance therapy. Full article

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. Full article

Background/Objectives: To compare oncologic outcomes of second-line chemotherapy regimens in relapsed high-grade serous ovarian cancer (HGSOC) by platinum sensitivity. Methods: We retrospectively reviewed HGSOC patients treated at two centers (June 2003–December 2020), classified by platinum-free interval (6- and 12-month cut-offs). Outcomes were progression-free survival (PFS, primary) and objective response and disease control rates (secondary). Regimens administered to ≥10% of patients or with favorable outcomes were compared using multivariable Cox analyses. Results: Among 468 patients (41.2% sensitive, 32.9% partially sensitive, 25.9% resistant), platinum-sensitive patients were younger (p = 0.024), diagnosed earlier, and more likely to undergo primary debulking surgery (both p < 0.001), achieving best outcomes after second-line chemotherapy (median PFS 14.8 vs. 10.5 and 5.2 months, p < 0.001). In both sensitive groups, the most common regimens were taxane + platinum ± bevacizumab, followed by pegylated liposomal doxorubicin + carboplatin, which was associated with shorter PFS in platinum-sensitive patients (hazard ratio (HR) 1.67, p = 0.016). Second-line maintenance with bevacizumab or poly(ADP-ribose) polymerase inhibitors was associated with improved PFS in both groups (p < 0.001). In platinum-resistant patients, the omission of bevacizumab (HR 2.01, p < 0.001) and a primary treatment history without cytoreduction (HR 4.43, p = 0.044) were associated with inferior outcomes. Conclusions: In platinum-sensitive patients with a favorable prognosis, taxane + platinum regimens were most commonly used and outperformed PLD + carboplatin. Maintenance therapy also conferred a meaningful benefit. In platinum-resistant disease, bevacizumab use and prior cytoreductive surgery may improve outcomes, underscoring the importance of treatment selection and surgical approach. Full article

Primary ovarian large cell neuroendocrine carcinoma is an extremely rare and aggressive gynecologic malignancy with poorly defined molecular characteristics and no standard treatment protocols. We present a case of pure ovarian LCNEC in a postmenopausal woman who underwent optimal cytoreductive surgery followed by platinum-based chemotherapy. Histopathologic and immunohistochemical analyses confirmed the diagnosis. Next-generation sequencing (NGS) revealed a pathogenic BRCA2 frameshift mutation (c.7177dupA), an ATM nonsense mutation, and Tier II mutations in TP53 and PTEN. The tumor exhibited homologous recombination deficiency (HRD), microsatellite instability-high (MSI-H), and an exceptionally high tumor mutational burden (TMB) of 277.49 mutations/Mb. These molecular alterations closely resemble those observed in high-grade neuroendocrine carcinomas of cervical and endometrial origin, suggesting a convergent genomic profile across gynecologic neuroendocrine carcinomas (NECs). Our findings underscore the potential of comprehensive genomic profiling in rare tumors such as ovarian LCNEC to refine diagnosis and identify candidates for biomarker-driven therapies, including PARP inhibitors and immune checkpoint inhibitors. This case supports the integration of molecular diagnostics into clinical practice and highlights the need for prospective studies incorporating molecular stratification to inform treatment strategies for rare and aggressive neuroendocrine tumors. Full article

Background: The optimal timing of cytoreductive nephrectomy (CN) in metastatic renal cell carcinoma (mRCC) remains a subject of debate, particularly in the immunotherapy era. This study compares survival outcomes between deferred CN (dCN) and upfront CN (uCN) in mRCC patients receiving modern immunotherapy regimens in the real-world setting. Methods: We retrospectively analyzed the SEER database for mRCC patients diagnosed between 2016 and 2021 who underwent dCN or uCN. The primary endpoint was overall survival (OS), while the secondary endpoints were disease-specific survival (DSS) and other-cause specific survival (OCSS). Statistical analyses included propensity score matching (PSM), Kaplan–Meier survival curves, Cox proportional hazards modeling, as well as sensitivity, subgroup, and landmark analyses. Results: A total of 1892 mRCC patients were included, with 346 patients (18.3%) undergoing dCN and 1546 patients (81.7%) receiving uCN. Patients in the uCN group were characterized with lower T stage (p < 0.001), while those in the dCN group exhibited a higher incidence of lymph node involvement (p = 0.02) and sarcomatoid dedifferentiation (p = 0.002). Following 1:2 PSM, dCN demonstrated significantly better OS and DSS, but comparable OCSS to uCN. The sensitivity and subgroup analyses suggested that dCN may substantially improve the prognosis of mRCC patients across conditions. The landmark analysis showed that the survival advantage of dCN diminished after two years of follow-up. Conclusions: dCN may be associated with improved survival outcomes compared to uCN in selected mRCC patients receiving immunotherapy, and careful patient selection for dCN or uCN is essential. Full article

Background: The outcomes of patients with peritoneal metastases from gastric cancer (GCPMs) remain dismal, with an overall survival (OS) of less than 1 year. Approaches reported from East Asia include normothermic intraperitoneal systemic chemotherapy, aimed at downstaging the disease, allowing an R0 resection. This is the first Western study evaluating a bidirectional regimen in a neoadjuvant setting of GCPMs. This phase II study evaluates the tolerability, efficacy and conversion surgery rate. Methods: Patients with PCI < 13 without ascites or HER2 overexpression and no extraperitoneal spread were enrolled starting in January 2018. After staging laparoscopy combined with PIPAC (cisplatin + doxorubicin), NIPS began following Yonemura’s schedule: cisplatin (30 mg/m²) + docetaxel (30 mg/m²), intraperitoneally (day 1); capecitabine 1000 mg/m², orally (days 2–15); and cisplatin (30 mg/m²) + docetaxel (30 mg/m²), intravenous (day 8). After three cycles, patients with no progressive disease and negative peritoneal cytology underwent cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC). Three additional NIPS cycles were reserved for patients who underwent surgery. Results: Among the 25 treated patients with 17.3-month (95%CI: 10.4; NA) OS, no adverse events (CTCAE) ≥ G3 arose. With a 52% conversion surgery rate, 13 patients underwent CRS combined with HIPEC (cisplatin 100 mg/m²), 10 with CC0 status 3 with CC experienced no operative mortality, and major complications rated Clavien–Dindo IIIB occurred in 2 patients (15.4%). The median OS for patients undergoing surgery was 26 (95%CI: 23.1; NA) months, with progression-free survival of 20 (95%CI: 16.7–NA) months. Conclusions: NIPS is safe and effective. The conversion rate in our Western patients is comparable to that reported in Eastern Asian countries. Full article

Background/Objectives: Cytoreductive surgery for women with advanced ovarian cancer is a demanding process with high morbidity. The present analysis aims to identify whether using the Ligasure^® Maryland jaw open sealer/divider (LMJsd) with a nanocoating (Covidien^®, Medtronic^®, 710 Medtronic Parkway, Minneapolis, MN, USA), could lead to better outcomes during cytoreduction surgery by reducing intraoperative bleeding and other hospitalization-related parameters. Methods: Patients with ovarian cancer (FIGO III/IV) who were subjected to primary or interval cytoreductive surgery at the Gynecologic-Oncology Unit, 1st Department of Obstetrics and Gynecology, Papageorgiou General Hospital, Thessaloniki, Greece, were included in the analysis. Patients were retrospectively allocated into two groups: women operated on with or without using the LMJsd. Differences between the two groups (intraoperative blood loss and blood transfusion, duration of surgery, postoperative blood transfusion, admission to intensive care unit (ICU), and overall hospital length of stay) were investigated. Results: From 2012 to 2020, 284 women with ovarian cancer were surgically treated; 208 were stage III/IV. In the LMJsd group of women (n = 34), the duration of surgery and blood loss during surgery were significantly decreased (p < 0.0005) compared to the non-LMJsd group (n = 174). The intraoperative blood transfusion rate and the number of packed red blood cell units transfused were significantly decreased in the first group (p = 0.0025); the postoperative blood transfusion rate was not different (p = 0.065). Moreover, ICU admission and overall hospital length of stay were significantly decreased in the LMJsd group (p < 0.0005 and p = 0.015). Conclusions: Using the LMJsd is associated with decreased intraoperative bleeding and transfusion rates, duration of surgery, admission to ICU, and overall hospital length of stay in women treated with surgical cytoreduction for advanced ovarian cancer. Some limitations of this study are as follows: its limited impact because it is an observational retrospective analysis and bias because the cumulative experience of the surgeons may have an impact on the surgical outcomes. Full article

Peritoneal carcinomatosis (PC) is a late-stage manifestation of abdominopelvic malignancies with poor prognosis and limited treatment options. Unique biochemical mechanisms within the peritoneal cavity play a key role in disease progression and resistance to therapy. Despite current therapies like systemic chemotherapy and cytoreductive surgery, patients frequently develop severe complications, including bowel obstruction, nutritional decline, and ascites, driving the need to address the pro-tumorigenic niche in the peritoneal cavity. The immune microenvironment in PC is marked by elevated proinflammatory mediators, such as IL-6 and IL-8, which skew the response toward innate rather than adaptive immune responses. IL-8 signaling, through its receptors CXCR1 and CXCR2, promotes neutrophil recruitment, chronic inflammation, angiogenesis, epithelial–mesenchymal transition, and immune evasion, making the IL-8/CXCR1/CXCR2 axis a potential therapeutic target in PC. Pre-clinical models provide evidence that IL-8 or CXCR1/CXCR2 blockade may be a valuable therapeutic strategy. IL-8 targeting agents such as monoclonal antibodies (BMS-986253) and small-molecule inhibitors (SX-682, AZD5069, navarixin) have shown efficacy in mitigating tumor growth and improving the efficacy of immune checkpoint inhibitors. Phase I and II trials have demonstrated encouraging safety profiles and preliminary efficacy when treating multiple abdominopelvic malignancies. In this review, we discuss the influence of the IL-8/CXCR1/CXCR2 axis within the peritoneal immune environment in PC and highlight recent work using IL-8 or CXCR1/CXCR2 blockade as a therapeutic strategy for PC. Continued research into the peritoneal immune microenvironment and the development of targeted therapies are essential for improving the management and prognosis of PC, potentially enhancing antitumor immunity and patient outcomes. Full article

Introduction: Cytoreductive surgery (CRS) with hyperthermic intraperitoneal early chemotherapy (HIPEC) has gained traction as a viable treatment option for patients with colorectal cancer peritoneal metastases (CRC-PM). Refinements have been made to patient selection and choice of HIPEC agent. We report outcomes with respect to peritoneal disease volume (peritoneal cancer index, PCI) and HIPEC agent for patients treated at the Western Australian Peritonectomy Service (WAPS) in the ten years from December 2013. Methods: A retrospective statistical analysis assessing the factors affecting survival outcomes of patients with CRC-PM who received CRS with HIPEC was performed, with particular focus on disease volume and HIPEC agent (Mitomycin C and Oxaliplatin). Results: 89 patients with CRC-PM were treated with CRS-HIPEC with a median overall survival (OS) of 58 months, 5-year OS of 48% and disease-free survival (DFS) of 20%. PCI <10 (n = 57) had OS and DFS of 60% and 29%, compared to 23% and 0% for PCI ≥ 10 (n = 32); HR = 2.9, p = 0.002. Three-year OS and DFS for treatment with Oxaliplatin HIPEC (n = 40) were 61% and 41%, which was not significantly different from 71% and 34% with Mitomycin C HIPEC (n = 49); HR = 1.5, p = 0.3. Conclusions: CRS/HIPEC should continue to evolve into the standard of care for carefully selected patients with CRC-PM as almost half of all selected patients survive to at least five years; in particular patients with low-volume disease (PCI < 10) can benefit greatly with a 60% five-year OS and 29% five-year DFS with low morbidity. The choice of HIPEC agent, Oxaliplatin or Mitomycin C, remains uncertain. Full article

Background/Objectives: In patients with peritoneal metastases from ovarian cancer, current clinical guidelines recommend “optimal cytoreductive surgery (CRS)”, defined as leaving no residual tumor nodules greater than 1 cm in diameter. Of note, the 1 cm threshold is somewhat arbitrary, as even a minimal residual tumor burden may adversely impact the patient’s outcomes. The aim of the current study is to identify the independent risk factors associated with overall survival (OS) and progression-free survival (PFS) after “optimal” CRS, with a special focus on the impact of completeness of cytoreduction (defined according to Sugarbaker’s scoring system). Methods: This retrospective cohort study included all the patients with peritoneal metastasis from ovarian cancer who underwent “optimal CRS” (residual nodules less than 1 cm), performed by a single team. Regarding the completeness of cytoreduction (CC), the patients were divided into two groups (without residual disease or with residual nodules less than 2.5 mm (CC0/CC1), and those with residual nodules larger than 2.5 mm and less than 1 cm (“optimal” CC2)). Risk factors associated with OS and PFS were identified by univariate and multivariate analysis. Results: Between September 2010 and February 2025, 52 patients with a median age of 62 [53.25–66.5] years underwent “optimal” CRS. For the entire group, the median OS was 70.83 months, and the median PFS was 25.8 months. In univariate analysis, the factors associated with significantly better OS were a peritoneal cancer index (PCI) lower or equal to 10 (vs. PCI > 10; p = 0.025) and CC0/CC1 status (vs. “optimal” CC2; p = 0.004), while in multivariate analysis, the only independent factor associated with higher OS was CC0/CC1 (HR = 0.253; 95% CI: 0.092–0.696, p = 0.008). Regarding PFS, the only factors independently associated with higher PFS were CC0/CC1 (HR = 0.155; 95% CI: 0.046–0.527, p = 0.003) and no preoperative chemotherapy (HR = 0.387; 95%CI: 0.155–0.963, p = 0.041). Conclusions: To the best of our knowledge, this is the first study to reveal that in patients with peritoneal metastases from ovarian carcinoma who underwent “optimal” CRS, the only independent factor associated with both better OS and PFS was the achievement of CC0/CC1 (no residual macroscopic nodules or residual nodules less than 2.5 mm). This observation supports the notion of redefining the threshold of “optimal” cytoreduction and potentially of implementing the Sugarbaker classification of cytoreduction even in ovarian cancer. Full article