[A Study on the Status of End-of-Life Chemotherapy for Solid Cancer after the Introduction of New Anti-Cancer Drugs].

BACKGROUND: In recent years, the decision to discontinue chemotherapy has become more difficult, and there is a tendency for chemotherapy to continue until just before death. We investigated the current state of end-of-life(EOL)chemotherapy for solid cancer patients. METHODS: Patients who died of cancer during hospitalization between January and November 2018 were included. Patients were divided into 2 groups, those who received EOL chemotherapy within 30 days of death(Near group: NG)and those who did not receive it(Far group: FG). The contents of each treatment were compared retrospectively. RESULTS: The number of patients were 46(32%)in the NG and 96(68%)in the FG. As EOL chemotherapy, the number of patients received cytotoxic drugs were 27(59%)and 68(71%), molecular targeted drugs were 6(13%)and 16(16%), immune-checkpoint inhibitors were 8(18%)and 12(12%), and hormone drugs were 0(0%)and 5(5%)in patients with NG and FG respectively(p<0.05). DISCUSSION: Minimally invasive drugs were often selected for EOL chemotherapy. It was suggested that the advent of new drugs has expanded the options for EOL chemotherapy.

Expression and activities of sulfotransferase in rat brain.

Sulfotransferase (SULT) has been found in the brain; however, the details of its function remain unclear. The present study aimed to elucidate the regional differences in the expression of SULT1 and SULT2 mRNA and SULT activities in the eight functional regions of the rat brain (cerebellum, cortex, hippocampus, medulla oblongata, midbrain, olfactory bulb, striatum, and thalamus). All SULT1 isoforms were detected in the medulla oblongata and thalamus. SULT2A1 mRNA was not observed in any of the eight regions, whereas SULT2B1a and SULT2B1b were found in all regions. The SULT2B1b mRNA expression level in the medulla oblongata was 1.7-fold higher than that in the liver. The sulfonation of p-nitrophenol and pregnenolone was detected in all regions. The kinetics of p-nitrophenol sulfonation in the cerebellum fitted to the substrate inhibition model (Km = 37.6 nM, Vmax = 2.72 pmol/min/mg, Vinh = 1.60 pmol/min/mg, and Ki = 0.87 µM). The pregnenolone sulfonation also exhibited substrate inhibition kinetics (Km = 0.99 µM, Vmax = 1.53 pmol/min/mg, and Ki = 54.67 µM). We clarified that SULT1 and SULT2 were expressed and had metabolizing capacities in the rat brain, suggesting that brain SULTs may be involved in metabolism of endogenous compounds and drugs.

Species and Tissue Differences in ß-Estradiol 17-Glucuronidation.

Uridine 5'-diphosphate-glucuronosyltransferase (UGT) is expressed in the liver and extrahepatic tissues. One of the major metabolic pathways of ß-estradiol (E2) is glucuronidation at the 17-hydroxy position by UGTs. This study was performed to determine E2 17-glucuronidation kinetics in human and rodent liver, small intestine, and kidney microsomes and to clarify the species and tissue differences. In the human liver and small intestine, Eadie-Hofstee plots exhibited biphasic kinetics, suggesting that E2 17-glucuronide (E17G) formation was catalyzed by more than two UGT isoforms in both tissues. The Km values for E17G formation by the high-affinity enzymes in the human liver and small intestine were 1.79 and 1.12 µM, respectively, and corresponding values for the low-affinity enzymes were 3.72 and 11.36 µM, respectively. Meanwhile, E17G formation in the human kidney was fitted to the Hill equation (S50=1.73 µM, n=1.63), implying that the UGT isoform catalyzing E17G formation in the kidney differed from that in the liver and small intestine. The maximum clearance for E17G formation in the human kidney was higher than the intrinsic clearance in the liver. E17G formation in the rat liver and kidney exhibited biphasic kinetics, whereas that in the small intestine was fitted to the Hill equation. In mice, all 3 tissues exhibited biphasic kinetics. In conclusion, we reported species and tissue differences in E2 17-glucuronidation, which occurred not only in the human liver but also in the extrahepatic tissues particularly the kidney.