Although neutrophil extracellular traps (NETs) are present in various tumors, their roles in tumor biology have not been clarified yet. In this study, we examined how NETs affect the pharmacokinetics and effects of doxorubicin (DOX). NETs were generated by neutrophils stimulated with phorbol 12-myristate 13-acetate (PMA) or lipopolysaccharide (LPS). DOX was added to NETs and their distribution was observed under fluorescein microscopy, and the diffusion of DOX through 3 μM pores from lower to upper chambers was evaluated with a fluorescence-based assay. Ovarian cancer cells, KOC-2S and SKOV3, were embedded in collagen gel droplets and cultured in 3D way and their apoptosis was examined with flow cytometry. DOX was mostly co-localized with NETs. The transfer of DOX to upper chambers increased over time, which was significantly decreased by the presence of neutrophils stimulated with PMA or LPS in the lower chamber. DOX outside of the gel increased the rates of annexin V (+) apoptotic cells, which were significantly reduced by the addition of LPS-stimulated neutrophils in media both in KOC-2S and SKOV3. The reduced diffusion and apoptosis were mostly restored by the destruction of the NETs structure with 1000 u/ml DNAse I. NETs efficiently trap and inhibit the diffusion of DOX which may attenuate its ability to induce apoptosis of ovarian cancer cells. Degradation of NETs with DNAse I may augment the response of ovarian cancer to DOX.

Despite advances in systemic chemotherapy, patients with gastric cancer (GC) and peritoneal metastases (PMs) continue to have poor prognoses. Intraperitoneal (IP) administration of Paclitaxel (PTX) combined with systemic chemotherapy shows promise in treating PMs from GC. However, methods of drug administration need to be optimized to maximize efficacy. In this study, we utilized a mouse model with PMs derived from a human GC cell line, administering PTX either IP or intravenously (IV), and Carboplatin (CBDCA) IV 0, 1, and 4 days after PTX administration. The PMs were resected 30 min later, and concentrations of PTX and CBDCA in resected tumors were measured using liquid chromatography–tandem mass spectrometry (LC-MS/MS). Results indicated that PTX concentrations were higher with IP administration than with IV administration, with significant differences observed on days 0 and 1. CBDCA concentrations 4 days post-IP PTX administration were higher than with simultaneous IV PTX administration. These findings suggest that IP PTX administration enhances CBDCA concentration in peritoneal tumors. Therefore, sequential IV administration of anti-cancer drugs appears more effective than simultaneous administration with IP PTX, a strategy that may improve prognoses for patients with PMs.

Background/Objectives: Peritoneal metastases (PMs) remain difficult to treat because the peritoneum–plasma barrier limits drug penetration from the systemic circulation. Intraperitoneal chemotherapy (IPC), particularly repeated intraperitoneal (IP) administration via implantable ports, can achieve high local drug exposure with prolonged retention. This review summarizes the pharmacological rationale, clinical evidence, and future directions of catheter-based IPC, with emphasis on combined IP and systemic chemotherapy for ovarian, gastric, and pancreatic cancers. Methods: We narratively reviewed prospective clinical trials and key retrospective studies evaluating IPC and compared repeated catheter-based IPC with hyperthermic intraperitoneal chemotherapy (HIPEC) and pressurized intraperitoneal aerosol chemotherapy (PIPAC). Efficacy, safety, practice considerations, and opportunities for ascites-based monitoring were examined. Results: In ovarian cancer, several randomized trials demonstrated improved progression-free survival (PFS), and in selected trials, improved overall survival (OS) was demonstrated using IP plus intravenous (IV) therapy, although in the latter trials, toxicity and catheter-related complications limited treatment completion. A phase III Intraperitoneal Therapy for Ovarian Cancer with Carboplatin (iPocc) trial further showed significantly prolonged PFS with IP carboplatin and weekly paclitaxel, with non-catheter-related toxicity comparable to that of IV therapy. In gastric and pancreatic cancer, phase II studies reported symptomatic control, cytologic conversion, and higher rates of conversion surgery in selected patients, although confirmatory phase III data are limited. Device complications, including infection, obstruction, and leakage, occurred, but were manageable. Conclusions: Repeated catheter-based IPC is a feasible approach that enhances intraperitoneal drug delivery and complements IV chemotherapy. Future priorities include randomized trials, pharmacokinetic optimization, and biomarker-guided patient selection, supported by serial ascites assessment to refine indications and improve outcomes.

Tumor embolism to the coronary arteries is an extremely rare cause of acute myocardial infarction (AMI). It has been reported in lung and breast cancers but not in uterine leiomyosarcoma. Herein, we present a case of AMI caused by a coronary tumor embolism from uterine leiomyosarcoma, which was successfully treated with aspiration thrombectomy. A 51-year-old woman with metastatic uterine leiomyosarcoma underwent surgical resection followed by adjuvant chemotherapy. During her second trabectedin cycle, she developed acute chest pain and dyspnea. Electrocardiography revealed anterior AMI. Emergency coronary angiography demonstrated complete occlusion of the left anterior descending and circumflex arteries. Thrombus aspiration completely restored coronary flow. Histopathological examination of the aspirated material confirmed leiomyosarcoma. Following aspiration, her symptoms subsided and she was discharged and prescribed cardioprotective medications. No recurrent cardiac events occurred. While most AMI events result from thrombotic occlusion and respond to anticoagulation, tumor emboli require mechanical intervention. Aspiration thrombectomy proved effective in this case. Clinicians should recognize that tumor embolism can induce AMI even in previously unreported cancer types, as pulmonary metastases may invade the pulmonary veins enabling tumor fragments to enter systemic circulation. Early recognition and intervention are critical for survival in these patients. Tumor embolism should be considered in the differential diagnosis of patients with cancer presenting with unexplained chest pain or dyspnea.