Peritoneal Cancer Research Articles

A phase II study of anlotinib plus albumin-bound paclitaxel in patients with recurrent, platinum-resistant primary epithelial ovarian or peritoneal carcinomar (A-Plus trial): Updated efficacy and safety.

5557 Background: Initial results of the open-label, single-arm phase II clinical trial, we had demonstrated anlotinib plus albumin-bound paclitaxel treatment activity and favorable tolerance in patients with recurrent, platinum-resistant primary epithelial ovarian or peritoneal carcinoma (SGO 2023. Oral featured poster 549). Here we update the latest efficacy and safety data in enrolled patients. Methods: In this study, 44 patients diagnosed with platinum-resistant or platinum-refractory ovarian cancer were planned to be enrolled. Patients received ab-paclitaxel 260 mg/m2 given by intravenous infusion over 30 min every 3 weeks and anlotinib (10mg, po, qd, for 14 days, every 3 weeks) until disease progression or intolerable toxicity. For efficacy evaluation, the following were required: measurable disease defined by RECIST 1.1, or if there were no measurable lesions but an elevated CA125 with significant symptoms such as abdominal pain, bloating, or pleural effusion/ascites (Rustin criteria). The primary end point were investigator-confirmed objective response rate (ORR). Results: From January 2021 to March 2023, 44 patients were enrolled with a median age of 49 years(range, 40-66). 29 patients had measurable lesions and 15 patients had no measurable lesions but an elevated CA125 evaluated according to Rustin criteria. As of efficacy evaluation, 43 out of 44 patients can be analyzed and one without measurable lesions can not be included due to the absence of a post-treatment data. Among the 29 patients with measurable lesions, 16 (55.2%; 95% CI 0.359-0.730) achieved objective responses, including CR in two patients, PR in fourteen, stable disease in thirteen, and PD in zero. In the group of 14 patients without measurable lesions, 9 (60%; 95% CI 0.328-0.825) achieved responses, including CA 125 responses in nine patients, CA 125 no response in four, and CA125 disease progression in one. Overall responses were observed in 25 out of 44 patients (56.8%; 95% CI 0.411-0.713) in the intention-to-treat population, and in the per-protocol population, the response was seen in 25 out of 43 patients (58.1%; 95% CI 0.422-0.726). The grade 3/4 AEs encompassed leukopenia (31 patients, 70.5%), gum-pain (10 patients, 22.7%), hypertension (10 patients, 22.7%), Hand-foot syndrome (4 patients, 9.1%). Conclusions: Updated results reconfirm a favorable antitumor activity and manageable safety from anlotinib plus albumin-bound paclitaxel in the treatment of recurrent ovarian or peritoneal carcinoma. Further survival results are expected. Clinical trial information: ChiCTR2100054329.

A first-in-human, phase 1 study evaluating oral TACC3 inhibitor, AO-252, in advanced solid tumors.

TPS3176 Background: TACC3 is the most oncogenic member of the transforming acidic coiled-coil domain-containing protein (TACC) family, which have important roles in microtubule and centrosome-related processes. TACC3 is overexpressed in multiple cancers with centrosome amplification caused by genomic aberrations such as TP53 mutations, leading to chromosome instability and worse prognosis. AO-252 is a computationally designed, small molecule inhibitor of TACC3 protein-protein interactions. Binding assays and kinome screening suggested the specificity of AO-252 to TACC3. AO-252 targets the interactions of TACC3 with Clathrin/KIFC1, BRDA1 and MBD2/HAT complexes regulating mitosis, DNA damage response and epigenetic functions and was confirmed using co-immunoprecipitation (co-IP) assays. Gene expression analysis in multiple cell lines further confirmed the various TACC3 pathways affected by AO-252. In vitro, AO-252 showed low nanomolar potency in >200 cell line panel covering multiple different cancer indications and spared the normal cells. In vivo, AO-252 demonstrated strong tumor growth inhibition or regression in multiple xenograft models including triple-negative breast (TNBC), high-grade serous ovarian (HGSOC) and endometrial cancer with TP53 mutation/loss with a good therapeutic index. Methods: This first-in-human, multicenter, open-label phase I dose escalation and expansion study evaluates the safety, tolerability, maximum tolerated dose, and recommended phase 2 dose (RP2D) of AO-252 in solid tumors (NCT06136884). Patients with unresectable or metastatic TNBC, platinum-resistant HGSOC, primary peritoneal, fallopian-tube and serous endometrial cancers with documented TP53 mutation/loss, who have failed on at least 1 prior line of systemic therapy in advanced/metastatic setting (maximum 4 for TNBC and endometrial carcinoma) are eligible for enrollment. Part 1 follows an accelerated titration dose-escalation for cohort 1 and 2 and a traditional 3+3 study design from cohort 3. A maximum of 54 patients will be treated in the dose escalation, patients receiving AO-252 orally once or twice daily in a 28-day cycle. Part 2 consists of dose-expansion of a maximum of 30 patients into 2 RP2D levels of AO-252. Primary objectives are to evaluate the safety and tolerability as noted by dose-limiting toxicities, adverse events, serious adverse events, laboratory test results, electrocardiograms, vital signs, physical exams, and ECOG performance status. Secondary objectives are to determine the antitumor activity assessed by objective response rate per RECIST1.1, duration of response and disease control rate and to determine the pharmacokinetics of single and repeated doses of AO-252. Potential biomarkers relating to treatment outcome will be evaluated as exploratory endpoints. Enrollment in Cohort 1 is completed and enrollment to Cohort 2 will begin in February 2024. Clinical trial information: NCT06136884 .

A phase IV trial to confirm the efficacy of olaparib in combination with bevacizumab as maintenance frontline treatment of HRD-positive ovarian tumours (IOlanTHe).

TPS5628 Background: PAOLA-1/ENGOT-ov25 trial demonstrated that Olaparib (O) plus Bevacizumab (B) determined a significant survival benefit in patients (pts) with advanced, high-grade, epithelial ovarian, peritoneal and/or fallopian-tube cancer (HEOC) presenting defects of homologous recombination repair system (HRD+) in clinical response after first-line platinum-based chemotherapy (CT) plus B. Methods: IOLANTHE is a multicenter Italian phase IV trial (sponsored by the MaNGO group, Protocol Number IRFMN-OVA-8542) aiming to confirm in a setting close to clinical practice the efficacy of this combination in pts with HRD+HEOC. As the study includes a consistent translational component, all suspicious advanced cases will be considered for study enrollment. Pts with a confirmed pathological diagnosis of HEOC will be included in the step 1 of the trial which main inclusion criteria are the following: -availability of formalin-fixed, paraffin-embedded samples for the central testing of HRD status (performed by Myriad Mychoice CDx Plus assay) - suitability to receive CT + B. Only HRD+ pts responding to first line CT plus at least one cycle of B will be enrolled in the step 2 of the trial and will be treated with B 15 mg/kg every 3 weeks plus O 300 mg twice daily. Considering the PAOLA-1 median progression free survival (PFS) of 37.2 months (mo) in the B-O arm, with a sample size of 90 pts followed for 24 months and setting a one-side error of 5%, we will have a statistical power of 80% to demonstrate a PFS-24mo≥64% with an upper critical value of 61%. In order to have 90 patients eligible for the step 2 of the study, 190 pts are needed to be enrolled in the step 1 of the clinical study (as approximately 80% of pts with HEOC will respond to CT and out of these, 60% will be HRD+). The translational subproject 1 will consist of the analysis of circulating-tumor (ctDNA), using whole genome sequencing aiming - to correlate residual tumour after surgery and ctDNA levels - to anticipate the diagnosis of progression - to monitor the mutational status of HR-related genes and other genes such as Tp53BP1, POLQ, REV7 probably involved in PARPi resistance during the maintenance therapy. The translational subproject 2 will be developed to compare pts’ response to therapy with that of cancer cells, tested by organotypic model treated with the combination. These models will be generated using fresh tumor tissue and ascitic fluid for the isolation of the tumor cells and macroscopically healthy omentum for the isolation of the mesothelial cells and fibroblasts. Eight centers have been activated and other 6 are waiting for the activation with 19 patients registered and 3 screening failures. The enrollment is continuing, according to protocol timeline (12 months for enrollment, 6 months for surgery and CT and 24 months for maintenance treatment). Clinical trial information: NCT06121401 .

PIPAC in patients with peritoneal metastases from gastrointestinal tract (PIPOX): An open label, non-comparative phase 1/2 dose escalation and expansion trial.

e15561 Background: Withmodern systemic chemotherapy, survival remain poor for patient withadvanced isolated peritoneal metastases from gastrointestinal tract. We aimed to assess the safety and efficacy of PIPAC to oxaliplatin in combination or not with systemic chemotherapy. Methods: We did a phase 1/2, open label, non-comparative, dose escalation and expansion trial of PIPAC to oxaliplatin forpatients with peritoneal cancer index (PCI) more than 5, 13 and 15 for respectively a gastric, small bowell and colorectal cancer primary; who had received at least three months of systemic chemotherapy. PIPAC cycle lengths was 4 to 6 weeks with systemic chemotherapy allowed 15 days after each PIPAC. PCI and oxaliplatin concentration tumor was assessed every PIPAC cycles. Main endpoints were, tolerability, tumor response and survival. Results: Between2017 to 2020, 34 for patients were enrolled in three centers, in this phase 1/2 study of whom 25 were evaluable at recommanded dose of phase I of 90 mg/m2 plus systemic 5-FU. At this dose, safety profile showed acceptable tolerability. 8 patients (32%) had grade 3/4 treatment related adverse event. Minors (grade 1/2) adverse events were mainly abdominal pain (n = 19, 76%) and nausea (n = 16, 64%). Before inclusion patients received a median of 2 [1-4] chemotherapy lines and had a median PCI of 22.5 [7-29]. Median PFS was 6.1 months and median OS was 13 months. Conclusions: In patients with advanced and refractory peritoneal metastasis, PFS of 6.1 months is encouraging. A prospective randomized phase II study is required. Clinical trial information: NCT03294252 .

HIPEC application potential in the treatment of extensive carcinomatosis in ovarian cancer (retrospective study)

Background. The high prevalence of advanced forms of cancer currently requires new treatment approaches. Only modern high-tech surgical procedures can provide means for improving the results of treatment.The aim. To study the results of treatment of patients with ovarian cancer with symptoms of peritoneal carcinomatosis using the HIPEC (Hyperthermic IntraPEritoneal Chemotherapy) method.Materials and methods. The study was conducted in Irkutsk Regional Cancer Center and included 88 patients. They were divided into 2 groups: group 1 – primary cytoreductive surgery (CRS) with the HIPEC method (41 patients); group 2 – primary cytoreductive surgery (47 patients). The most important criterion was the peritoneal cancer index (PCI). If the PCI was ≤ 14, we chose cytoreductive surgery with or without HIPEC.Results. PCI analysis showed differences in its values between the study groups (CRS – 10.17 ± 0.952; CRS + HIPEC – 12.93 ± 0.744; p = 0.002). There was an increase in length of stay in patients who underwent major surgeries in combination with HIPEC (21.8 ± 0.9 days versus 14.5 ± 0.6 days in the CRS group; p = 0.001). The CRS + HIPEC group had a longer duration of surgery (394.88 ± 19.935 min vs. 172.98 ± 11.514 min in the CRS group; p = 0.001). There was an increase in the overall percentage of postoperative complications in the CRS + HIPEC group – up to 26.8 % without statistically significant differences with the CRS group – 8.5 % (p = 0.082). The median time of relapse onset in the CRS + HIPEC group was 26 ± 4.3 months, while in the CRS group it was 18 ± 2.6 months.Conclusion. Using HIPEC method has proven its significance in increasing diseasefree survival.

Long-term survival outcomes following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for peritoneal metastasis of hepatocellular carcinoma patients

BackgroundHepatocellular carcinoma with peritoneal metastasis (HCC-PM) has a poor outlook. Traditional treatments have limited effect on survival. The safety and efficacy of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) have been shown in other peritoneal cancers. This study evaluates the role of CRS + HIPEC in HCC-PM.MethodsA retrospective analysis of HCC-PM patients treated with CRS + HIPEC at Beijing Shijitan Hospital from March 2017 to December 2023 was conducted, assessing clinical features, severe adverse events (SAEs), and overall survival (OS) rates.ResultsThe study population comprised 10 HCC-PM patients who underwent CRS + HIPEC. The median peritoneal cancer index (PCI) was 25, and complete cytoreduction (CC0 ~ 1) was achieved in half of the patients. Three patients experienced SAEs within 30 days postoperatively. The 1-year, 3-year, and 5-year OS rates were recorded as 89.0%, 89.0%, and 21.0% respectively, with a median OS1 of 107.8 months and OS2 of 49.9 months. The median progression-free survival (PFS) was 5.0 months.ConclusionThe application of CRS + HIPEC offers significant benefits to patients with HCC-PM. A selected group of patients may achieve prolonged PFS. Incorporating CRS + HIPEC into the treatment paradigm can thus be considered a strategic therapeutic option for patients with HCC-PM.

Secondary cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for recurrent colorectal peritoneal metastases

BackgroundSecondary treatment of recurrent colorectal peritoneal metastases after previous cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is poorly investigated. ObjectivesTo evaluate the overall survival outcome of secondary (repeat) CRS + HIPEC compared to palliative treatment in recurrent peritoneal disease. MethodsPatients with colorectal peritoneal metastases treated with an index CRS + HIPEC and subsequently having recurrent peritoneal disease were identified from the prospective Swedish national HIPEC registry. Patients were divided into interventional group (secondary CRS + HIPEC) or palliative group. Multivariable logistic regression, propensity-score matching, and survival outcomes were calculated. ResultsAmong 575 patients who underwent complete CRS between 2010 and 2021, 208 (36 %) were diagnosed with a subsequent recurrent peritoneal disease. Forty-two patients (20 %) were offered secondary CRS + HIPEC. Propensity-score matching of secondary interventional cases with palliative cases succeeded in 88 % (n = 37) in which female sex, lower peritoneal cancer index at index surgery, longer disease-free interval, and absence of extra-peritoneal metastases were identified as the most relevant matching covariates. Median OS from date of recurrence was 38 months (95%CI 30–58) in the interventional group and 19 months (95%CI: 15–24) in the palliative group (HR 0.35 95%CI: 0.20–0.63, p = 0.0004). Sensitivity analyses confirmed the results. As reference, the median OS from index CRS + HIPEC in the whole colorectal registry (n = 575) was 41 months (95%CI: 38–45). ConclusionAfter matching for relevant factors, the hazard ratio for death was significantly reduced in patients who were offered a secondary CRS + HIPEC procedure for recurrent peritoneal disease. Selection bias is inherent, but survival outcomes were comparable to those achieved after the initial procedure.

Inflammatory Bowel Disease in Cytoreductive Surgery and Heated Intraperitoneal Chemotherapy.

Inflammatory bowel diseases (IBDs) pose an increased risk of gastrointestinal cancer with especially worse prognosis. Cytoreductive surgery and heated intraperitoneal chemotherapy (CRS/HIPEC) improves outcomes in selected patients with colorectal peritoneal metastases. Little published data describes the outcomes of CRS/HIPEC in IBD patients. We performed a retrospective review of a prospectively maintained CRS/HIPEC database. Outcomes in patients with and without IBD were compared for short-term outcomes such as hospital/intensive care unit stay, blood loss/transfusions, complications, and reoperations. We also examined oncological outcomes including recurrence, overall (OS), and disease-free survival (DFS). We identified 232 patients that underwent CRS/HIPEC for colorectal or small bowel adenocarcinoma, of which 10 were with IBD. Patients with IBD had lower ASA (p=0.005), less hypertension (p=0.033), and 30% small bowel primary compared to none in the non-IBD cohort (p<0.001). Otherwise, demographic and perioperative characteristics were similar between the groups. The median peritoneal cancer index (PCI) was 7 and similar between the cohorts (p=0.422). Extent of organ resections and peritonectomies performed were similar. Complications occurred in 60.3% of patients (21.2% major), similar between the groups (p=0.744 and p=0.444, respectively). Reoperation rate of 27% was similar between groups (p=0.097). The median OS in the IBD cohort was 19.6 vs 53.2 months in the non-IBD cohort (p = 0.056). The median DFS in the IBD cohort was 4.9 vs 9.4 months in the non-IBD cohort (p=0.174). Cytoreductive surgery and heated intraperitoneal chemotherapy in patients with IBD has similar complication profile and trended towards poorer oncological outcomes as CRS/HIPEC in non-IBD patients.

Important Predictive Factors for the Prognosis of Patients With Peritoneal Metastasis of Gastric Cancer.

This study investigated predictive factors for patients with peritoneal metastases of gastric cancer (PMGC) who underwent conversion cytoreductive surgery (C-CRS) and hyperthermic intraperitoneal intraoperative chemotherapy (HIPEC) after responding to induction chemotherapy (laparoscopic HIPEC [LHIPEC]) followed by concomitant systemic and intraperitoneal chemotherapy (bidirectional intraperitoneal and systemic chemotherapy [BIC]). Diagnostic laparoscopy was performed for 62 patients with PMGC between January 2017 and December 2022. The patients underwent LHIPEC and BIC induction chemotherapy using intraperitoneal docetaxel (30mg/m2) and cisplatin (30mg/m2), and intravenous chemotherapy for three cycles. The predictive parameters for progression-free and overall survival were analyzed using Kaplan-Meier and Cox regression analyses. The optimal cutoff values for Ki-67 parameters were assessed using receiver operating characteristic curve analysis. The study retrospectively examined 36 (58 %) of 62 patients who responded to induction therapy and underwent C-CRS or HIPEC. A Ki-67 index lower than 10 (p = 0.000), lymph node involvement (LNI) less than 2 (p = 0.039), and an omental lesion size score lower than 0.5 cm (p = 0.002) were predictive of recurrence-free and overall survival in addition to completeness of cytoreduction and the peritoneal cancer index. Cox regression analysis showed that the independent factors associated with recurrence-free survival were decreased Ki-67 expression (≥10 % vs <10 %) (hazard ratio [HR] 4.7; 95 % confidence interval [CI] 1.6-5.210; p = 0.020) and LNI higher than 2 (HR 1.92; 95% CIS 0.923-4.0; p = 0.023). Lymph node involvement and decreased Ki-67 expression are independent predictive factors of recurrence-free survival for patients with PMGC after induction chemotherapy.

Analysis of sequential chemotherapy efficacy in ovarian epithelial carcinoma, fallopian tube carcinoma and primary peritoneal carcinoma

Objective: To explore the sequential chemotherapy efficacy of different chemotherapeutic regimens in ovarian epithelial carcinoma, fallopian tube carcinoma, and primary peritoneal carcinoma. Methods: A retrospective analysis was conducted on clinical and pathological data of 100 patients with platinum-sensitive ovarian epithelial carcinoma, fallopian tube carcinoma, and primary peritoneal carcinoma treated at Peking University Peopel's Hospital from January 1992 to January 2019. All patients underwent staging surgery or cytoreductive surgery followed by adjuvant chemotherapy. Based on different postoperative adjuvant chemotherapy regimens, patients were divided into the sequential chemotherapy group (70 cases) and the conventional chemotherapy group (30 cases). Clinical and pathological characteristics, chemotherapy efficacy, adverse reactions, and prognosis were compared between the two groups. Results: (1) Clinical and pathological characteristics: the age, tumor types (including ovarian epithelial carcinoma, fallopian tube carcinoma, and primary peritoneal carcinoma), pathological types, International Federation of Gynecology and Obstetrics (FIGO) stage, postoperative residual disease size, presence of neoadjuvant chemotherapy, and total number of chemotherapy cycles were compared between the sequential chemotherapy group and the conventional chemotherapy group. There were no statistically significant differences observed in these characteristics between the two groups (all P>0.05). (2) Chemotherapy efficacy: the median sum of complete response (CR)+partial response (PR) duration in the sequential chemotherapy group was 80.0 months (range: 39 to 369 months), whereas in the conventional chemotherapy group, it was 28.0 months (range: 13 to 52 months). A statistically significant difference was observed between the two groups (Z=-7.82, P<0.001). (3) Chemotherapy adverse reactions: in the sequential chemotherapy group, 55 cases (79%, 55/70) experienced bone marrow suppression and 20 cases (29%, 20/70) had neurological symptoms. In the conventional chemotherapy group, these adverse reactions occurred in 11 cases (37%, 11/30) and 2 cases (7%, 2/30), respectively. Statistically significant differences were observed between the two groups for both bone marrow suppression and neurological symptoms (all P<0.05). For the other chemotherapy adverse reactions compared between the two groups, no statistically significant differences were observed (all P>0.05). (4) Prognosis: during the follow-up period, the recurrence rate in the sequential chemotherapy group was 73% (51/70) and in the conventional chemotherapy group was 100% (30/30). The median sum of recurrence-free interval was 70.5 months (range: 19 to 330 months) in the sequential chemotherapy group and 15.0 months (range: 6 to 40 months) in the conventional chemotherapy group. Statistically significant differences were observed between the two groups for both recurrence rate and median recurrence-free interval (all P<0.01).In the sequential chemotherapy group, the median progression-free survival (PFS) time was 84.0 months (range: 34 to 373 months), and the median overall survival (OS) time was 87.0 months (range: 45 to 377 months). In contrast, in the conventional chemotherapy group, the median PFS time was 30.5 months (range: 14 to 60 months), and the median OS time was 37.5 months (range: 18 to 67 months). Statistically significant differences were observed between the two groups for both PFS and OS (all P<0.001). In the sequential chemotherapy group, the 3-year, 5-year, and 10-year OS rates were 100% (70/70), 93% (65/70), and 21% (15/70), respectively. In contrast, in the conventional chemotherapy group, the OS rates were 50% (15/30) at 3 years, 3% (1/30) at 5 years, and 0 at 10 years, respectively. The two groups were compared respectively, and the differences were statistically significant (all P<0.05). Conclusions: Sequential chemotherapy significantly prolongs PFS and OS in patients with ovarian epithelial carcinoma, fallopian tube carcinoma, and primary peritoneal carcinoma. The efficacy is superior to that of the conventional chemotherapy, with manageable adverse reactions. The use of sequential chemotherapy as first-line treatment for patients with ovarian epithelial carcinoma, fallopian tube carcinoma, and primary peritoneal carcinoma is recommended.

Malignant peritoneal mesothelioma interactome with 417 novel protein–protein interactions

BackgroundMalignant peritoneal mesothelioma (MPeM) is an aggressive cancer affecting the abdominal peritoneal lining and intra-abdominal organs, with a median survival of ~2.5 years.MethodsWe constructed the protein interactome of 59 MPeM-associated genes with previously known protein-protein interactions (PPIs) as well as novel PPIs predicted using our previously developed HiPPIP computational model and analysed it for transcriptomic and functional associations and for repurposable drugs.ResultsThe MPeM interactome had over 400 computationally predicted PPIs and 4700 known PPIs. Transcriptomic evidence validated 75.6% of the genes in the interactome and 65% of the novel interactors. Some genes had tissue-specific expression in extramedullary hematopoietic sites and the expression of some genes could be correlated with unfavourable prognoses in various cancers. 39 out of 152 drugs that target the proteins in the interactome were identified as potentially repurposable for MPeM, with 29 having evidence from prior clinical trials, animal models or cell lines for effectiveness against peritoneal and pleural mesothelioma and primary peritoneal cancer. Functional modules related to chromosomal segregation, transcriptional dysregulation, IL-6 production and hematopoiesis were identified from the interactome. The MPeM interactome overlapped significantly with the malignant pleural mesothelioma interactome, revealing shared molecular pathways.ConclusionsOur findings demonstrate the utility of the interactome in uncovering biological associations and in generating clinically translatable results.

Transcriptome profiling and characterization of peritoneal metastasis ovarian cancer xenografts in humanized mice

Although immunotherapy has not yet been as successful in ovarian cancer (OC), it remains a potential therapeutic strategy. Preclinical models of OC are necessary to evaluate the efficacy of immuno-oncology (IO) drugs targeting human immune components but have been underutilized. Developing mouse models with a humanized (Hu) immune system can help understand the human immune response to IO drugs which have demonstrated limited effectiveness in OC patients. We established OC xenograft Hu-mouse models by intraperitoneally injecting luciferase-expressing SKOV-3 Luc and OVCAR-3 Luc OC cells into CD34+ Hu-mice. Tumor growth was monitored through bioluminescence imaging (BLI). In the SKOV-3 Luc Hu-mouse model, we assessed the efficacy of PD-1 blockade with pembrolizumab. We observed the presence of human lymphocyte and myeloid cell subsets within the tumors, lymph nodes, blood, and spleens in these models. Notably, these tumors exhibited a high prevalence of tumor-infiltrating macrophages. Furthermore, we identified HDAC class I target genes, and genes associated with epithelial-mesenchymal transition (EMT) and fibroblasts in the tumors of Hu-mice treated with pembrolizumab. Our xenograft Hu-mouse model of OC provides a valuable tool for investigating the efficacy of IO drugs. The insights gained from this model offer useful information to explore potential mechanisms associated with unresponsive anti-PD-1 treatment in OC.

Critical reappraisal of prognostic indicators for 949 mucinous appendiceal neoplasm patients.

The standard of care for treatment of an appendiceal mucinous neoplasm with peritoneal dissemination is cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC). These two treatments are combined in the operating room. A crucial requirement for benefit long-term is proper patient selection. Clinical and histopathologic prognostic indicators are used, along with the patient's fitness for surgery, to select patients to receive CRS and HIPEC. This study seeks to identify the reliable prognostic indicators for four different groups of patients. They are (1) the low-grade appendiceal mucinous neoplasms (LAMN) with a complete CRS, (2) the mucinous appendiceal adenocarcinomas (MACA) with complete CRS, (3) MACA with lymph node metastases (MACA-LN) with complete CRS, and (4) all histologic subtypes with incomplete cytoreduction. The prognostic indicators were evaluated for their impact on overall survival in these four groups of patients. The completeness of cytoreduction (CC) score statistically significantly showed survival differences in all three histologic subtypes. The peritoneal cancer index (PCI) showed significance with LAMN and MACA-LN but not with MACA and not with incomplete CRS. The prior surgical score (PSS) was a prognostic indicator that predicted the outcome with LAMN, MACA-LN, and incomplete CRS patients but not with the MACA group. Patients who were symptomatic or who had extensive systemic chemotherapy before CRS had a significantly reduced survival. The utility of prognostic indicators varied greatly within our four different groups of appendiceal mucinous neoplasms. CC score was always a reliable prognosticator. Surprisingly, PCI was not.

Olaparib maintenance therapy for platinum-sensitive relapsed ovarian cancer at a single institution: A retrospective study.

In this study, we aimed to investigate patient characteristics, efficacy, prognostic factors, and safety of olaparib maintenance therapy for platinum-sensitive recurrent ovarian cancer at our institution. Patients responding to platinum-based therapy and starting olaparib maintenance therapy for recurrent epithelial ovarian, fallopian tube, or peritoneal cancer at Kurume University Hospital between January 2018 and November 2021 were enrolled in the study. Their data were extracted retrospectively from medical records. In all, 50 patients were included. The median (range) age of the patients, follow-up time, and duration of olaparib maintenance therapy were 62 (39-87) years, 21.6 (2.2-45.9) months, and 7.2 (2-45.9) months, respectively. Among the 29 patients tested for homologous recombination (HR) status, 22 (75.9%) were positive for HR deficiency (HRD), 12 (54.5%) of whom had BRCA-positive tumors. The median progression-free survival was 8.9 months (95% confidence interval: 6.2-12.6), and the median overall survival was 27.1 months (95% confidence interval: 22.5-40.3). Multivariate analysis of prognostic factors revealed that HRD was an independent prognostic factor for both progression-free survival and overall survival. The most common adverse event was nausea (any grade, n = 30, 60%), resulting in drug interruption (n = 23, 46%), dose reduction (n = 17, 34%), and discontinuation of treatment (n = 1, 2%). Olaparib maintenance therapy for recurrent platinum-sensitive ovarian cancer at our institution was effective, with acceptable adverse events. HRD was the most significant prognostic factor for patients with recurrent platinum-sensitive ovarian cancer.

Modified scoring system for the quantitative assessment of histological regression in peritoneal carcinomatosis after pressurized intraperitoneal aerosol chemotherapy: A pilot study.

Peritoneal carcinomatosis is one of the leading causes of death in patients with gastrointestinal cancer. Newer locoregional treatment concepts include pressurized intraperitoneal aerosol chemotherapy (PIPAC), the regional application of pressurized chemotherapeutic agents to the abdominal cavity, which is usually performed every 4 to 8 weeks. One of the main challenges of PIPAC therapy remains the objective assessment of treatment response. The present study describes a new scoring system to histologically assess the regression of peritoneal cancer following PIPAC therapy, quantitative assessment of histological regression in peritoneal carcinomatosis (QARP). Peritoneal biopsies from 27 patients with peritoneal metastases undergoing PIPAC were obtained and processed in a standardized fashion. Biopsies were scored according to the QARP grading system. The five-tiered system was graded as follows, Grade 0, no residual tumor cells with regressive changes present; grade 1, 1-25% viable tumor cells per tumor focus with regressive changes present; grade 2, 26-50% viable tumor cells per tumor focus with regressive changes present; grade 3, 51-75% viable tumor cells per tumor focus with few regressive changes; grade 4, >75% viable tumor cells per tumor focus with minimal or no regressive changes. Based on the new grading system, the study cohort was divided into QARP responders and QARP non-responders following PIPAC treatment. Higher QARP scores were significantly correlated with higher PCI scores (r=0.32; P=0.007). However, no difference in overall survival was detected between QARP responders and QARP non-responders. Further studies are required to ascertain the reproducibility and prognostic significance of QARP.

Niraparib maintenance therapy using an individualised starting dose in patients with platinum-sensitive recurrent ovarian cancer (NORA): final overall survival analysis of a phase 3 randomised, placebo-controlled trial

Niraparib significantly prolonged progression-free survival versus placebo in patients with platinum-sensitive, recurrent ovarian cancer (PSROC), regardless of germline BRCA mutation (gBRCAm) status, in NORA. This analysis reports final data on overall survival (OS). This randomised, double-blind, placebo-controlled, phase 3 trial enrolled patients across 30 centres in China between 26 September 2017 and 2 February 2019 (clinicaltrials.gov, NCT03705156). Eligible patients had histologically confirmed, recurrent, (predominantly) high-grade serous epithelial ovarian cancer, fallopian tube carcinoma, or primary peritoneal carcinoma (no histological restrictions for those with gBRCAm) and had received ≥2 prior lines of platinum-based chemotherapy. Patients were randomised (2:1) to receive niraparib or placebo, with stratification by gBRCAm status, time to recurrence following penultimate platinum-based chemotherapy, and response to last platinum-based chemotherapy. Following a protocol amendment, the starting dose was individualised: 200mg/day for patients with bodyweight <77kg and/or platelet count <150×103/μL at baseline and 300mg/day otherwise. OS was a secondary endpoint. Totally, 265 patients were randomised to receive niraparib (n=177) or placebo (n=88), and 249 (94.0%) received an individualised starting dose. As of 14 August 2023, median follow-up for OS was 57.9 months (IQR, 54.8-61.6). Median OS (95% CI) with niraparib versus placebo was 51.5 (41.4-58.9) versus 47.6 (33.3-not evaluable [NE]) months, with hazard ratio [HR] of 0.86 (95% CI, 0.60-1.23), in the overall population; 56.0 (36.1-NE) versus 47.6 (31.6-NE) months, with HR of 0.86 (95% CI, 0.46-1.58), in patients with gBRCAm; and 46.5 (41.0-NE) versus 46.9 (31.8-NE) months, with HR of 0.87 (95% CI, 0.56-1.35), in those without. No new safety signals were identified, and myelodysplastic syndromes/acute myeloid leukaemia occurred in three (1.7%) niraparib-treated patients. Niraparib maintenance therapy with an individualised starting dose demonstrated a favourable OS trend versus placebo in PSROC patients, regardless of gBRCAm status. Zai Lab (Shanghai) Co., Ltd; National Major Scientific and Technological Special Project for "Significant New Drugs Development" in 2018, China [grant number 2018ZX09736019].

Superiority of 18F-FAPI-42 PET/CT in the detection of primary tumor and management of appendiceal neoplasm to 18F-FDG PET/CT and CE-CT

BackgroundIn the present study, we investigated the value of 18F-fibroblast-activation protein inhibitor (FAPI) positron emission tomography/computed tomography (18F-FAPI-42 PET/CT) to preoperative evaluations of appendiceal neoplasms and management for patients.MethodsThis single-center retrospective clinical study, including 16 untreated and 6 treated patients, was performed from January 2022 to May 2023 at Southern Medical University Nanfang Hospital. Histopathologic examination and imaging follow-up served as the reference standard. 18F-FAPI-42 PET/CT was compared to 18F-fluorodeoxyglucose (18F-FDG) PET/CT and contrast-enhanced CT (CE-CT) in terms of maximal standardized uptake value (SUVmax), diagnostic efficacy and impact on treatment decisions.ResultsThe accurate detection of primary tumors and peritoneal metastases were improved from 28.6% (4/14) and 50% (8/16) for CE-CT, and 43.8% (7/16) and 85.0% (17/20) for 18F-FDG PET/CT, to 87.5% (14/16) and 100% (20/20) for 18F-FAPI-42 PET/CT. Compared to 18F-FDG PET/CT, 18F-FAPI-42 PET/CT detected more regions infiltrated by peritoneal metastases (108 vs. 43), thus produced a higher peritoneal cancer index (PCI) score (median PCI: 12 vs. 5, P < 0.01). 18F-FAPI-42 PET/CT changed the intended treatment plans in 35.7% (5/14) of patients compared to CE-CT and 25% (4/16) of patients compared to 18F-FDG PET/CT but did not improve the management of patients with recurrent tumors.ConclusionsThe present study revealed that 18F-FAPI-42 PET/CT can supplement CE-CT and 18F-FDG PET/CT to provide a more accurate detection of appendiceal neoplasms and improved treatment decision making for patients.

Perioperative intraperitoneal plus systemic chemotherapy and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for gastric cancer: phase Ib/II single-arm prospective study

BackgroundIn gastric cancer, peritoneal metastasis is the most common form of metastasis and leads to dismal prognosis. We aimed to evaluate the safety and efficacy of combining perioperative intraperitoneal (IP) plus systemic chemotherapy, cytoreductive surgery (CRS), and hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with gastric cancer with limited peritoneal metastasis or even after reducing peritoneal tumor burden by upfront IP chemotherapy. MethodPatients were enrolled in phase Ib in a 3 + 3 dose escalation of IP paclitaxel plus a fixed dose of IP cisplatin and oral S-1. In phase II, patients were managed according to the peritoneal cancer index (PCI) by diagnostic laparoscopy. For patients with a PCI of >12, upfront IP and systemic chemotherapy were given. Patients with a PCI of ≤12 or reduced to ≤12 after upfront chemotherapy underwent CRS with HIPEC. The primary endpoints were safety and the recommended phase II dose (RP2D) confirmation for phase Ib and the 1-year overall survival rate for phase II. ResultsThe RP2D was defined as IP 175 mg/m2 paclitaxel and 60 mg/m2 cisplatin and oral 70 mg/m2/day S-1 for 14 days. A total of 22 patients were included. After CRS with HIPEC, there were no grade 3 or higher complications. The median hospital stay was 7 days (range, 6–11). The median overall and progression-free survival were 27.3 months (95% CI, 14.4 to not estimable) and 12.6 months (95% CI, 7.7–14.5), respectively. One-year overall and progression-free survival rates were 81.0% (95% CI, 65.8–99.6) and 54.5% (95% CI, 37.2–79.9), respectively. ConclusionA combination of IP plus systemic chemotherapy, CRS, and HIPEC was safe and resulted in good survival outcomes.

Abstract PO5-08-08: Tumor Registry Guided Genetic Testing: Opportunities Unlocked

Abstract Introduction With the expansion of guidelines for germline genetic testing, more patients are eligible for testing. Unfortunately, many remain untested. Testing is critical, as patients with pathogenic variants (and their families) can benefit from more aggressive screening and preventative strategies, as well as targeted therapies (e.g., poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitors) if cancer does occur. Objectives To study the prevalence of Hereditary Breast Ovarian Cancer (HBOC) genetic testing eligibility and uptake among cancer patients from the tumor registry at the Medical University of South Carolina (MUSC) in order to identify a group of living patients who require testing now. Methods This Quality Improvement study included patients 18 years of age or older diagnosed with breast, ovarian/fallopian/primary peritoneal, pancreas and prostate cancers between 1991 and 2021 as reported to the MUSC Tumor Registry. Each patient was evaluated using the latest National Comprehensive Cancer Network (NCCN) criteria for breast-ovarian genetic testing (Excluding family history criteria, which were not available in the tumor registry). Using our genetic testing database, we also determined which had had testing. We describe the prevalence of genetic testing performed vs the number of patients that would benefit from testing under the newest guidelines. Results Patients identified as eligible for testing included 399 breast cancer patients, all 544 ovarian/fallopian/primary peritoneal cancer patients, all 1534 pancreas cancer patients and 872 prostate cancer patients. Reported testing of eligible patients was low (breast: 35%, Ovarian: 33%, pancreas: 4%, and prostate cancer: 6%). Of eligible patients not tested, 310 patients with breast cancer, 343 patients with ovarian/fallopian/primary peritoneal cancer, 717 patients with pancreas cancer and 763 patients with prostate cancer, are alive and eligible for testing (2133 patients) Discussion Using Tumor Registry data plus genetic testing data allowed us to detect a large number of living patients with cancer that would be eligible for HBOC genetic testing. This is despite the fact that this approach underestimates the number of patients that would benefit from further testing as it does not include family history and other factors. A similar approach for colorectal or other cancers will yield additional patients. Conclusion Most cancer patients eligible for breast ovarian genetic testing have not been tested. There is an opportunity to use Tumor Registry and genetic testing data to identify a large number of living patients who can be approached for testing. As we showed in our study, by adopting updated cancer genetic testing guidelines, there is increased opportunity to detect more patients that would benefit from such testing. In our study this benefit is shown especially in the prostate and pancreas cancer groups. Next steps will be to determine how best to notify and make testing available to these patients. Table 1. Testing Status Comparison Assessing Genetic Testing Rates Using Tumor Registry Among Eligible Patients with Breast, Ovarian/Fallopian/Primary Peritoneum, Pancreas and Prostate cancer as per the New Testing Guidelines Citation Format: Kevin Hughes, Antoine Finianos, Kiersten Meeder. Tumor Registry Guided Genetic Testing: Opportunities Unlocked [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-08-08.

Correlation between peritoneal cancer index and survival in advanced epithelial ovarian cancer with complete resection

ObjectiveThe aim of this study was to investigate the relation between the peritoneal cancer index, overall survival, and recurrence free survival, in patients with epithelial ovarian cancer.MethodsPatients treated at the...