Peritoneal metastasis (PM) is one of the most frequent metastasis patterns of gastric cancer (GC), and the prognosis of patients with PM is very dismal. According to Paget’s theory, disseminated free cancer cells are seeded and survive in the abdominal cavity, adhere to the peritoneum, invade the subperitoneal tissue, and proliferate through angiogenesis. In these sequential processes, several key molecules are involved. From a therapeutic point of view, immunotherapy with chemotherapy combination has become the standard of care for advanced GC. Several clinical trials of newer immunotherapy agents are ongoing. Understanding of the molecular process of PM and the potential rationale of immunotherapy for PM treatment is necessary. Beyond understanding of the molecular aspect of PM, many studies have been conducted on the modality of treatment of PM. Notably, intraperitoneal approaches, including chemotherapy or immunotherapy, have been conducted, because systemic treatment of PM has limitations. In this study, we reviewed the molecular mechanisms and immunologic aspects of PM, and intraperitoneal approaches under investigation for treating PM.

Approximately 400,000 patients are diagnosed with kidney cancer annually worldwide, leading to approximately 170,000 deaths. Renal cell carcinoma (RCC) accounts for more than 90% of kidney cancers. The most common histological subtype is clear cell RCC, which is found in approximately 85% of metastatic RCC cases. The VHL-HIF-VEGF axis is well known; therefore, targeting VEGF has been the mainstay for managing advanced clear cell RCC. Recently, the treatment landscape for advanced clear cell RCC has changed extensively. In particular, immune checkpoint inhibitor-based treatment showed promising results in front-line treatment and became the standard of care. Herein, we review the current evidence on front-line treatment options and discuss the clinical and future perspective.

KRAS mutations occur in over 90% of pancreatic ductal adenocarcinomas (PDACs), most commonly at codon 12, but the clinical implications of codon-specific subtypes in advanced disease remain unclear. We retrospectively analyzed 269 patients with advanced PDAC who underwent next-generation sequencing between 2020 and 2024 at a single tertiary cancer center. Clinical features, co-mutations, treatment outcomes, and survival were evaluated. KRAS mutations were detected in 92% of patients, most frequently G12V (36%) and G12D (34%), followed by G12R (10%) and non-G12 variants (9%). TP53 was the most frequent co-mutation (67%) and was significantly enriched in G12D tumors compared with wild type (74.2% vs. 31.8%). Mutations in homologous recombination and DNA damage response genes were more common in non-G12 and wild-type tumors, although not statistically significant. Serum CA 19-9 was elevated in most G12-mutant tumors, whereas approximately 40% of non-G12 and wild-type patients showed normal levels despite advanced disease. No significant survival differences were observed among KRAS subtypes in the overall or treated cohorts. However, patients with G12V mutations achieved significantly longer survival with fluorouracil-based than gemcitabine-based chemotherapy. These findings suggest that, while KRAS subtyping alone lacks prognostic value, the G12V subtype may inform chemotherapy selection and warrants further prospective validation.

Purpose: This dosimetry study aimed to evaluate the organ-absorbed doses and safety profile of multiple doses of [¹⁷⁷Lu]Ludotadipep, a novel PSMA-targeted radiopharmaceutical with an albumin-binding motif, in patients with metastatic androgen pathway modulator-resistant (mAPMR) prostate cancer. Methods: Twenty patients received a total of 68 cycles of [¹⁷⁷Lu]Ludotadipep (3.70 GBq/cycle, up to six cycles, 8-week intervals), and dosimetry analysis was done for 67 cycles. Organ-absorbed doses were estimated using planar and SPECT/CT imaging and blood-based methods. Red marrow dose was calculated using a red marrow-to-blood activity concentration ratio (RMBLR) derived from a hematocrit-adjusted model for large molecules and cross-checked by comparison with data derived from quantitative SPECT/CT images and blood samples. Results: The hematocrit-adjusted RMBLR of 0.28 was consistent with physiologic expectations for albumin-bound agents for marrow dosimetry. The highest absorbed dose coefficients in the first cycle were in the salivary glands and kidneys (1.22 ± 0.530 and 0.674 ± 0.330 Gy/GBq, respectively), while the red marrow dose (0.0533 ± 0.0115 Gy/GBq) was lower. Summing the cycle-specific mean absorbed dose coefficients and multiplying by 3.70 GBq per cycle yielded projected six-cycle absorbed doses of 18.1 Gy for kidneys, 15.3 Gy for salivary glands, and 1.28 Gy for red marrow, all of which were below the reference dose constraints. Salivary gland dose coefficients declined significantly over repeated cycles (p < 0.001), possibly from radiation-induced tissue damage. Conclusion: [¹⁷⁷Lu]Ludotadipep demonstrates a favorable dosimetric safety profile across multiple cycles, up to six cycles. Application of an appropriately adjusted RMBLR for albumin-binding behavior allowed for reproducible red marrow dose estimation.