Exosomal miR-493 suppresses MAD2L1 and induces chemoresistance to intraperitoneal paclitaxel therapy in gastric cancer patients with peritoneal metastasis.

Intraperitoneal (IP) chemotherapy with paclitaxel (PTX) for gastric cancer (GC) with peritoneal metastasis (PM) is considered a promising treatment approach, however, there are no useful biomarkers to predict the efficacy of IP therapy. We examined the association between intra-peritoneal exosomes, particularly exosomal micro-RNAs (exo-miRNAs), and IP-chemo sensitivity. MKN45 cells that were cultured with intra-peritoneal exosomes from patients who did not respond to IP therapy with PTX (IPnon-respond group) exhibited resistance to PTX compared with exosomes from responding patients (IPrespond group) (p = 0.002). A comprehensive search for exo-miRNAs indicated that miR-493 was significantly up-regulated in exosomes from the IPnon-respond group compared with those collected from the IPrespond group. The expression of miR-493 in PTX-resistant MKN45 cells (MKN45PTX-res) was higher compared with that in MKN45. In addition, MKN45PTX-res cells exhibited lower MAD2L1 gene and protein expression compared with MKN45. Finally, miR-493 enhancement by transfection of miR-493 mimics significantly down-regulated MAD2L1 expression in MKN45 cells and reduced PTX sensitivity. Our results suggest that intra-peritoneal exo-miR-493 is involved in chemoresistance to PTX by downregulating MAD2L1 in GC with PM. Exo-miR-493 may be a biomarker for chemoresistance and prognosis of GC patients with PM and may also be a promising therapeutic target.

Colorectal carcinoma peritoneal metastases-derived organoids: results and perspective of a model for tailoring hyperthermic intraperitoneal chemotherapy from bench-to-bedside.

BACKGROUND: Peritoneal metastases from colorectal cancer (CRCPM) are related to poor prognosis. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been reported to improve survival, but peritoneal recurrence rates are still high and there is no consensus on the drug of choice for HIPEC. The aim of this study was to use patient derived organoids (PDO) to build a relevant CRCPM model to improve HIPEC efficacy in a comprehensive bench-to-bedside strategy. METHODS: Oxaliplatin (L-OHP), cisplatin (CDDP), mitomycin-c (MMC) and doxorubicin (DOX) were used to mimic HIPEC on twelve PDO lines derived from twelve CRCPM patients, using clinically relevant concentrations. After chemotherapeutic interventions, cell viability was assessed with a luminescent assay, and the obtained dose-response curves were used to determine the half-maximal inhibitory concentrations. Also, induction of apoptosis by different HIPEC interventions on PDOs was studied by evaluating CASPASE3 cleavage. RESULTS: Response to drug treatments varied considerably among PDOs. The two schemes with better response at clinically relevant concentrations included MMC alone or combined with CDDP. L-OHP showed relative efficacy only when administered at low concentrations over a long perfusion period. PDOs showed that the short course/high dose L-OHP scheme did not appear to be an effective choice for HIPEC in CRCPM. HIPEC administered under hyperthermia conditions enhanced the effect of chemotherapy drugs against cancer cells, affecting PDO viability and apoptosis. Finally, PDO co-cultured with cancer-associated fibroblast impacted HIPEC treatments by increasing PDO viability and reducing CASPASES activity. CONCLUSIONS: Our study suggests that PDOs could be a reliable in vitro model to evaluate HIPEC schemes at individual-patient level and to develop more effective treatment strategies for CRCPM.

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.

Hydroxygenkwanin suppresses peritoneal metastasis in colorectal cancer by modulating tumor-associated macrophages polarization.

Peritoneal metastasis is an important cause of high mortality and poor prognosis in colorectal cancer (CRC) patients. Therefore, the development of compounds with unique anti-CRC Peritoneal metastasis activities is urgently needed to improve the survival of CRC patients. Hydroxygenkwanin (HGK),a natural flavonoid compound, have been shown to display anti-inflammatory, antioxidant, antitumor, and immunoregulatory effects. Here, we employed CRC peritoneal metastasis mouse model with MC38 cells to examine the antitumor activity of HGK. The result showed that HGK not only inhibited peritoneal metastasis, but also significantly increased the proportion of M1-like macrophages while decreasing the proportion of M2-like macrophages within the tumor microenvironment (TME). Furthermore, we demonstrated that the inhibitory effect of HGK on peritoneal metastasis of CRC depended on macrophages in vitro and in vivo. Moreover, we revealed that HGK promoted the polarization of TAMs into M1-like macrophages and inhibited their polarization into M2-like macrophages in a LPS- or IL-4-induced bone marrow-derived macrophages (BMDMs) model and co-culture system. Finally, we also investigated the regulatory mechanism of HGK on TAMs polarization that HGK may active p-STAT5, p-NF-κB signaling in M1-like macrophages and inhibit p-STAT6, JMJD3, PPARγ expression in M2-like macrophages. Taken together, our findings suggest that HGK is a natural candidate for effective prevention of peritoneal metastasis in colorectal cancer, which provides a potential strategy for clinical treatment of colorectal cancer.

Intraperitoneal chemotherapy for peritoneal metastases of gastric origin: a systematic review and meta-analysis.

BACKGROUND: Gastric cancer with peritoneal metastases is associated with a dismal prognosis. Normothermic catheter-based intraperitoneal chemotherapy and normothermic pressurized intraperitoneal aerosol chemotherapy (PIPAC) are methods to deliver chemotherapy intraperitoneally leading to higher intraperitoneal concentrations of cytotoxic drugs compared to intravenous administration. We reviewed the effectiveness and safety of different methods of palliative intraperitoneal chemotherapy. METHODS: Embase, MEDLINE, Web of Science and Cochrane were searched for articles studying the use of repeated administration of palliative intraperitoneal chemotherapy in patients with gastric cancer and peritoneal metastases, published up to January 2024. The primary outcome was overall survival. RESULTS: Twenty-three studies were included, representing a total of 999 patients. The pooled median overall survival was 14.5 months. The pooled hazard ratio of the two RCTs using intraperitoneal paclitaxel and docetaxel favoured the intraperitoneal chemotherapy arm. The median overall survival of intraperitoneal paclitaxel, intraperitoneal docetaxel and PIPAC with cisplatin and doxorubicin were respectively 18.4 months, 13.2 months and 9.0 months. All treatment methods had a relatively safe toxicity profile. Conversion surgery after completion of intraperitoneal therapy was performed in 16% of the patients. CONCLUSIONS: Repeated intraperitoneal chemotherapy, regardless of method of administration, is safe for patients with gastric cancer and peritoneal metastases. Conversion surgery after completion of the intraperitoneal chemotherapy is possible in a subset of patients.

[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.

Genomic characterization and detection of potential therapeutic targets for peritoneal mesothelioma in current practice.

Peritoneal mesothelioma (PeM) is an aggressive tumor with limited treatment options. The current study aimed to evaluate the value of next generation sequencing (NGS) of PeM samples in current practice. Foundation Medicine F1CDx NGS was performed on 20 tumor samples. This platform assesses 360 commonly somatically mutated genes in solid tumors and provides a genomic signature. Based on the detected mutations, potentially effective targeted therapies were identified. NGS was successful in 19 cases. Tumor mutational burden (TMB) was low in 10 cases, and 11 cases were microsatellite stable. In the other cases, TMB and microsatellite status could not be determined. BRCA1 associated protein 1 (BAP1) mutations were found in 32% of cases, cyclin dependent kinase inhibitor 2A/B (CDKN2A/B) and neurofibromin 2 (NF2) mutations in 16%, and ataxia-telangiectasia mutated serine/threonine kinase (ATM) in 11%. Based on mutations in the latter two genes, potential targeted therapies are available for approximately a quarter of cases (i.e., protein kinase inhibitors for three NF2 mutated tumors, and polyADP-ribose polymerase inhibitors for two ATM mutated tumors). Extensive NGS analysis of PeM samples resulted in the identification of potentially effective targeted therapies for about one in four patients. Although these therapies are currently not available for patients with PeM, ongoing developments might result in new treatment options in the future.

Transhepatic Bromelain and Acetylcysteine for Treatment of Posterior Gastric Pseudomyxoma Peritonei: A Case Report.

BACKGROUND/AIM: Pseudomyxoma peritonei (PMP) is a rare condition characterized by diffuse spread of mucinous tumors within the peritoneal cavity. Traditional treatment modalities, such as cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are challenging in cases of recurrent disease, owing to anatomical complexities and increasing morbidity and mortality risk. BromAc® has emerged as a novel, targeted therapy for PMP with evidence for intra-tumoral administration to break down mucin deposits. CASE REPORT: We present a 70-year-old female with confirmed diagnosis of symptomatic appendiceal PMP situated behind the stomach, refractory to prior CRS and HIPEC. Transhepatic intra-tumor injection of BromAc® was performed, guided by imaging, with catheter placement into the posterior gastric mucinous tumor. The procedure was well-tolerated, and post-treatment imaging revealed a significant 40% reduction in tumor burden. The patient had fever on cycle days two and three, which self-resolved and septic screen performed was negative. Following BromAc® administration, the patient demonstrated improvement in symptoms and quality of life. CONCLUSION: This case highlights the potential efficacy and safety of transhepatic administration of BromAc® for the treatment of recurrent PMP behind the stomach. The targeted delivery of BromAc® directly into a mucinous tumor via the transhepatic route offers a minimally invasive alternative for cases where traditional surgical interventions pose challenges. However, further research and clinical trials are warranted to validate the broader applicability of this novel approach, assess long-term outcomes, and optimize procedural parameters for enhanced therapeutic outcomes in PMP treatment.

Targeting interleukin-6 as a treatment approach for peritoneal carcinomatosis.

Peritoneal carcinomatosis (PC) is a complex manifestation of abdominal cancers, with a poor prognosis and limited treatment options. Recent work identifying high concentrations of the cytokine interleukin-6 (IL-6) and its soluble receptor (sIL-6-Rα) in the peritoneal cavity of patients with PC has highlighted this pathway as an emerging potential therapeutic target. This review article provides a comprehensive overview of the current understanding of the potential role of IL-6 in the development and progression of PC. We discuss mechansims by which the IL-6 pathway may contribute to peritoneal tumor dissemination, mesothelial adhesion and invasion, stromal invasion and proliferation, and immune response modulation. Finally, we review the prospects for targeting the IL-6 pathway in the treatment of PC, focusing on common sites of origin, including ovarian, gastric, pancreatic, colorectal and appendiceal cancer, and mesothelioma.

Standardizing eligibility and patient selection for Pressurized Intraperitoneal Aerosol Chemotherapy: A Delphi consensus statement.

INTRODUCTION: Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) is a procedure for minimally invasive drug administration in patients with peritoneal metastasis. Previous studies have emphasized the importance of uniformity in treatment protocols and standardization of this practice. This study aimed to reach a consensus on eligibility, patient selection, and choice of chemotherapy for PIPAC. METHODS: A three-round modified Delphi study was conducted. A steering group formulated a list of baseline statements, addressing the objectives. The steering group consisted of seven expert surgical and medical oncologists. Available evidence and published key opinions were critically reviewed. An international expert panel scored those statements on a 4-point Likert scale. The statements were submitted electronically and anonymously. Consensus was reached if the agreement rate was ≥75%. A minimum Cronbach's alpha of >0.8 was set. RESULTS: Forty-five (45/58; 77.6%) experts participated and completed all rounds. Experts were digestive surgeons (n = 28), surgical oncologists (n = 7), gynecologists (n = 5), medical oncologists (n = 4), and one clinical researcher. Their assessment of 81 preliminary statements in the first round resulted in 41 consolidated statements. In round two, consensus was reached on 40 statements (40/41; 97.6%) with a consensus of ≥80% for each individual statement. In the third round, 40 statements were unanimously approved as definitive. The choice of first- and second-line chemotherapy remained controversial and could not reach consensus. CONCLUSIONS: This International Delphi study provides practical guidance on eligibility and patient selection for PIPAC. Ongoing trial data and long-term results that could contribute to the further standardization of PIPAC are eagerly awaited.

Thermosensitive methyl-cellulose-based injectable hydrogel carrying oxaliplatin for the treatment of peritoneal metastasis in colorectal cancer.

Advanced colorectal cancer (CRC) with peritoneal metastasis (PM) is a highly aggressive malignancy with poor prognosis. Systematic chemotherapy and local treatments are the primary therapeutic approaches. However, systemic chemotherapy is limited by low accumulation of drugs at the tumor site and systemic toxicity. Local treatments include cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). However, CRS faces challenges related to incomplete tumor resection, while HIPEC is restricted by the uneven distribution of drugs and potential complications. Herein, a thermosensitive methyl-cellulose-based injectable hydrogel carrying oxaliplatin (OXA) was synthesized to improve this situation. Specifically, methyl cellulose (MC) coagulated into a hydrogel, and OXA was loaded into the MC hydrogel to construct the OXA-MC hydrogel. We explored the OXA-MC hydrogel for the treatment of PM in CRC. The results demonstrated that the OXA-MC hydrogel had favorable biocompatibility and thermo-sensitivity and could act as a local slow-release drug carrier. Moreover, in a CT-26 tumor-bearing model, it showed a remarkable anti-tumor effect by inhibiting proliferation and promoting apoptosis. Additionally, transcriptome analysis indicated that the OXA-MC hydrogel might be involved in the regulation of the PI3K-AKT signaling pathway. In summary, we successfully prepared the OXA-MC hydrogel and provided a valid approach in the treatment of PM in CRC, which lays a foundation for other PM treatments.

Dynamic change in the peritoneal cancer index based on CT after chemotherapy in the overall survival prediction of gastric cancer patients with peritoneal metastasis.

PURPOSE: The purpose of this research was to investigate the efficacy of the CT-based peritoneal cancer index (PCI) to predict the overall survival of patients with peritoneal metastasis in gastric cancer (GCPM) after two cycles of chemotherapy. METHODS: This retrospective study registered 112 individuals with peritoneal metastasis in gastric cancer in our hospital. Abdominal and pelvic enhanced CT before and after chemotherapy was independently analyzed by two radiologists. The PCI of peritoneal metastasis in gastric cancer was evaluated according to the Sugarbaker classification, considering the size and distribution of the lesions using CT. Then we evaluated the prognostic performance of PCI based on CT, clinical characteristics, and imaging findings for survival analysis using multivariate Cox proportional hazard regression. RESULTS: The PCI change ratio based on CT after treatment (ΔPCI), therapy lines, and change in grade of ascites were independent factors that were associated with overall survival (OS). The area under the curve (AUC) value of ΔPCI for predicting OS with 0.773 was higher than that of RECIST 1.1 with 0.661 (P < 0.05). Patients with ΔPCI less than -15% had significantly longer OS. CONCLUSION: CT analysis after chemotherapy could predict OS in patients with GCPM. The CT-PCI change ratio could contribute to the determination of an appropriate strategy for gastric cancer patients with peritoneal metastasis.

Real World Analysis of Peritoneal Metastasis From Renal Cell Carcinoma. Meet-Uro27.

BACKGROUND: Peritoneal metastases (PM) have been reported in approximately 1% of patients with metastatic Renal Cell Carcinoma (mRCC). Outcome data are limited due to the rarity of this metastatic site. Therefore, the aim of our study is to describe renal cell carcinoma (RCC) patients with PM treated as per clinical practice. MATERIALS AND METHODS: Baseline characteristics and outcome data of patients with PM from RCC were retrospectively collected from 18 Italian oncological referral centers adhering to the Meet-Uro group, from January 2016 to January 2023. RESULTS: We collect 81 RCC patients with PM. 78/81 received systemic treatment, 3/81 only best supportive care. First line treatment included tyrosine-kinase inhibitors (TKI) (46/78), ImmuneOncology (IO)-TKI (26/78) and IO-IO (6/78), with different Objective Response Rate (ORR) (43.4% in TKI monotherapy group vs 50% in IO-TKI group, respectively) and Disease Control Rate (DCR) (60.8% in TKI treated patients vs. 76.9% in IO-TKI treated patients). Median PFS was 6.4 months (95%CI 4.18-14.8) in patients treated with TKI monotherapy vs 23.7 months (95%CI 11.1-NR) in patients treated with IO-TKI (p < 0.015). The median OS (mOS) was 22.7 months (95%CI 13.32 - 64.7) in the TKI monotherapy group vs 34.5 mo (95%CI NR-NR) in the IO-TKI group with 53.8% of patients alive at 1 years in the latter group, (p < 0.16). Primary refractory patients were 36.9% for TKI and 15.3% for IO-TKI. According to International Metastatic renal cell carcinoma Database Consortium (IMDC) score, mPFS and mOS were consistent among risk categories. Median PFS was 36.6 months (95%CI 10.9-NR) for good risk patients compared to 10 months (95%CI 7.5-29.8) for intermediate risk and 2.96 months (95%CI 2.43-11.28) for poor risk population (p < 0.0005) whereas mOS was NR (95%CI 28.65-NR) for good risk patients compared to 35.3 months (95%CI 24.6-NA) and 12.4 months (95%CI 3.52-NR) for intermediate and poor risk population, respectively, (p < 0.0002). Only 34/78 (43.5%) received a second line treatment that was TKI (ORR 8.3% and DCR 41.6%) or IO (ORR 18.1% and DCR 40.9%). CONCLUSION: We report one of the largest case series regarding PM from RCC. Characteristics of patients suggest a more aggressive behavior of PM from mRCC. Outcome data suggest that TKI-IO as first line treatment, and TKI as second line, confirm their activity for these patients with dismal prognosis.

Exploiting a subtype-specific mitochondrial vulnerability for successful treatment of colorectal peritoneal metastases.

Peritoneal metastases (PMs) from colorectal cancer (CRC) respond poorly to treatment and are associated with unfavorable prognosis. For example, the addition of hyperthermic intraperitoneal chemotherapy (HIPEC) to cytoreductive surgery in resectable patients shows limited benefit, and novel treatments are urgently needed. The majority of CRC-PMs represent the CMS4 molecular subtype of CRC, and here we queried the vulnerabilities of this subtype in pharmacogenomic databases to identify novel therapies. This reveals the copper ionophore elesclomol (ES) as highly effective against CRC-PMs. ES exhibits rapid cytotoxicity against CMS4 cells by targeting mitochondria. We find that a markedly reduced mitochondrial content in CMS4 cells explains their vulnerability to ES. ES demonstrates efficacy in preclinical models of PMs, including CRC-PMs and ovarian cancer organoids, mouse models, and a HIPEC rat model of PMs. The above proposes ES as a promising candidate for the local treatment of CRC-PMs, with broader implications for other PM-prone cancers.

[Long-Term Suppression with First-Line Chemotherapy(FOLFIRI plus BV)for Peritoneal Metastasis].

A 72-year-old man underwent right hemicolectomy for transverse colon cancer(pT4aN1aM0, Stage ⅢB), after which he received adjuvant chemotherapy(capecitabine plus oxaliplatin[CAPOX])for 6 months. Three years after the first surgery, FDG-PET/CT revealed a tumor in the abdomen. He underwent a tumorectomy and adjuvant chemotherapy(CAPOX plus bevacizumab[BV])performed for 6 months. Two years after a tumorectomy, the CEA level rose again. He was diagnosed peritoneal metastasis again. A central venous(CV)port was implanted for access to the right internal jugular vein, and he received systemic chemotherapy(fluorouracil, Leucovorin, and irinotecan[FOLFIRI]plus BV)as an outpatient. One year after this recurrence, no peritoneal dissemination was detected by CT. Thereafter, total 49 courses of FOLFIRI plus BV were introduced, but chemotherapy was discontinued due to CV port-related infection. Three months later, low back pain appeared and became a diagnosis of spondylodiscitis. He had surgery, but follow-up CT performed 8 years after the first surgery detected multiple liver metastasis. It was considered necessary to take infection control measures during long-term chemotherapy.

[A Case Report of Metastatic Breast Cancer with Peritoneal Metastasis and Massive Ascites Responding to CDK4/6 Inhibitor(Palbociclib)].

A 52-year-old woman was presented with abdominal distension. Chest-abdominal CT showed some tumors in the left breast, enlarged axillary lymph nodes, ovary metastasis peritoneal thickening, a large amount of ascites. The diagnosis of needle biopsy in the breast mass was invasive ductal carcinoma, Luminal A type. The large amount of ascites decreased after the start of administration of fulvestrant and CDK4/6 inhibitor(PAL). Also chest and abdominal CT showed reduction of all lesions. We found the high expression of cyclin D1 protein and the negative of p16 protein in tissues of the needle biopsy. Fifty months later, she continues to do good ADL and PR status. We experienced a case of metastatic breast cancer with massive ascites and peritoneal metastasis that was successfully treated with a CDK4/6 inhibitor(PAL)and achieved long- term survival.

Peritoneal carcinomatosis in mouse models.

Peritoneal carcinomatosis (PCa) represents a metastatic stage of a disease with unmet therapeutic options. Malignant cells from primary tumors (gastrointestinal or gynecologic malignancies) invade the peritoneal cavity and eventually seed onto peritoneal surfaces, with the omentum being the most common nest area. With a median survival of less than 6 months, PCa has a dismal prognosis that can be improved with treatments only available to a select few individuals with low tumor burden. Thus, the discovery of novel and effective therapies for this disease depends on reliable animal models. Here, we describe a method to generate syngeneic PCa mouse models based on intraperitoneal (i.p.) administration of tumor cells. This model allows to follow-up cancer progression in PCa models from ovarian and colorectal origins monitoring mice bodyweight changes, ascites development and overall survival. Moreover, luciferase-expressing tumor cells can also be used to assess tumor growth after i.p. injection through in vivo bioluminescence quantification. The establishment of reliable, easy-to-monitor and reproducible intraperitoneal syngeneic tumors models, as described here, is the first step to develop cutting-edge therapies against PCa.

Imaging-guided prognostic score-based approach to assess the benefits of combotherapy versus monotherapy with immune checkpoint inhibitors in metastatic MSI-H colorectal cancer patients.

BACKGROUND: This retrospective study determined survival responses to immune checkpoint inhibitors (ICIs), comparing mono- (mono) and combo-immunotherapy (combo) in patients with microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC) by analyzing quantitative imaging data and clinical factors. METHODS: One hundred fifty patients were included from two centers and divided into training (n = 105) and validation (n = 45) cohorts. Radiologists manually annotated chest-abdomen-pelvis computed tomography and calculated tumor burden. Progression-free survival (PFS) was assessed, and variables were selected through Recursive Feature Elimination. Cutoff values were determined using maximally selected rank statistics to binarize features, forming a risk score with hazard ratio-derived weights. RESULTS: In total, 2258 lesions were annotated with excellent reproducibility. Key variables in the training cohort included: total tumor volume (cutoff: 73 cm3), lesion count (cutoff: 20), age (cutoff: 60) and the presence of peritoneal carcinomatosis. Their respective weights were 1.13, 0.96, 0.91, and 0.38, resulting in a risk score cutoff of 1.36. Low-score patients showed similar overall survival and PFS regardless of treatment, while those with a high-score had significantly worse survivals with mono vs combo (P = 0.004 and P = 0.0001). In the validation set, low-score patients exhibited no significant difference in overall survival and PFS with mono or combo. However, patients with a high-score had worse PFS with mono (P = 0.046). CONCLUSIONS: A score based on total tumor volume, lesion count, the presence of peritoneal carcinomatosis, and age can guide MSI-H mCRC treatment decisions, allowing oncologists to identify suitable candidates for mono and combo ICI therapies.