A Novel Assessment of Metabolic Pathways in Peritoneal Metastases from Low-Grade Appendiceal Mucinous Neoplasms.

BACKGROUND: There is a paucity of targeted therapies for patients with pseudomyxoma peritonei (PMP) secondary to low-grade appendiceal mucinous neoplasms (LAMNs). Dysregulated metabolism has emerged as a hallmark of cancer, and the relationship of metabolomics and cancer is an area of active scientific exploration. We sought to characterize phenotypic differences found in peritoneal metastases (PM) derived from LAMN versus adenocarcinoma. METHODS: Tumors were washed with phosphate-buffered saline (PBS), microdissected, then dissociated in ice-cold methanol dried and reconstituted in pyridine. Samples were derivatized in tert-butyldimethylsilyl (TBDMS) and subjected to gas chromatography-coupled mass spectrometry. Metabolites were assessed based on a standard library. RNA sequencing was performed, with pathway and network analyses on differentially expressed genes. RESULTS: Eight peritoneal tumor samples were obtained and analyzed: LAMNs (4), and moderate to poorly differentiated adenocarcinoma (colon [1], appendix [3]). Decreases in pyroglutamate, fumarate, and cysteine in PM from LAMNs were found compared with adenocarcinoma. Analyses showed the differential gene expression was dominated by the prevalence of metabolic pathways, particularly lipid metabolism. The gene retinol saturase (RETSAT), downregulated by LAMN, was involved in the multiple metabolic pathways that involve lipids. Using network mapping, we found IL1B signaling to be a potential top-level modulation candidate. CONCLUSIONS: Distinct metabolic signatures may exist for PM from LAMN versus adenocarcinoma. A multitude of genes are differentially regulated, many of which are involved in metabolic pathways. Additional research is needed to identify the significance and applicability of targeting metabolic pathways in the potential development of novel therapeutics for these challenging tumors.

Disparities in Care Access to Liver-Directed Therapy Among Medicare Beneficiaries with Colorectal Cancer Liver Metastasis.

BACKGROUND: Liver-directed therapies (LDT) are important components of the multidisciplinary care of patients with colorectal cancer liver metastases (CRCLM) that contribute to improved long-term outcomes. Factors associated with receipt of LDT are poorly understood. PATIENTS AND METHODS: Patients > 65 years old diagnosed with CRCLM were identified within the Medicare Standard Analytic File (2013-2017). Patients with extrahepatic metastatic disease were excluded. Mixed-effects analyses were used to assess patient factors associated with the primary outcome of LDT, defined as hepatectomy, ablation, and/or hepatic artery infusion chemotherapy (HAIC), as well as the secondary outcome of hepatectomy. RESULTS: Among 23,484 patients with isolated CRCLM, only 2004 (8.5%) received LDT, although resectability status could not be determined for the entire cohort. Among patients who received LDT, 61.7% underwent hepatectomy alone, 28.1% received ablation alone, 8.5% underwent hepatectomy and ablation, and 1.8% received HAIC either alone (0.8%) or in combination with hepatectomy and/or ablation (0.9%). Patient factors independently associated with lower odds of LDT included older age, female sex, Black race, greater comorbidity burden, higher social vulnerability index, primary rectal cancer, synchronous liver metastasis, and further distance from a high-volume liver surgery center (p < 0.05). Results were similar for receipt of hepatectomy. CONCLUSIONS: Despite the well-accepted role of LDT for CRCLM, only a small proportion of Medicare beneficiaries with CRCLM receive LDT. Increasing access to specialized centers with expertise in LDT, particularly for Black patients, female patients, and those with higher levels of social vulnerability or long travel distances, may improve outcomes for patients with CRCLM.

Genetic p53 deficiency partially rescues the adrenocortical dysplasia phenotype at the expense of increased tumorigenesis.

Telomere dysfunction and shortening induce chromosomal instability and tumorigenesis. In this study, we analyze the adrenocortical dysplasia (acd) mouse, harboring a mutation in Tpp1/Acd. Additional loss of p53 dramatically rescues the acd phenotype in an organ-specific manner, including skin hyperpigmentation and adrenal morphology, but not germ cell atrophy. Survival to weaning age is significantly increased in Acd(acd/acd) p53(-/-) mice. On the contrary, p53(-/-) and p53(+/-) mice with the Acd(acd/acd) genotype show a decreased tumor-free survival, compared with Acd(+/+) mice. Tumors from Acd(acd/acd) p53(+/-) mice show a striking switch from the classic spectrum of p53(-/-) mice toward carcinomas. The acd mouse model provides further support for an in vivo role of telomere deprotection in tumorigenesis.