Abstract: (1) Background: Surgery is the best curative option for Gastric Cancer (GC). However, morbimortality associated with surgery still a significant problem. Thus, it is essential to determine the preoperative surgical risk, to optimize outcomes in higher risk patients. (2) Methods: Patients who underwent curative gastrectomy between January 2010 and December 2013 were included, obtaining a sample of 131 patients, and the acuity of the scales understudy was evaluated. The predictive power of the scales was evaluated through calibration and discrimination. (3) Results and Conclusions: Regarding mortality, the scales demonstrated good calibration, with POSSUM and P-POSSUM obtaining the best O:E ratio. The scales presented good discrimination, with POSSUM showing the best result. Considering morbidity, the scales showed good calibration and discrimination. POSSUM and P-POSSUM seem to have potential in predicting morbidity and mortality when applied to the studied population, but there is a need for further studies in this area.

The potential to improve the effectiveness and efficiency of potential estrogen-based oral contraceptives (fertility control) for possums was investigated by comparing the inhibitory potential of hepatic CYP3A and UGT2B catalytic activity using a selected compound library (CYP450 inhibitor-based compounds) in possums to that of three other species (mouse, avian, and human). The results showed higher CYP3A protein levels in possum liver microsomes compared to other test species (up to a 4-fold difference). Also, possum liver microsomes had significantly higher basal p-nitrophenol glucuronidation activity than other test species (up to an 8-fold difference). However, no CYP450 inhibitor-based compounds significantly decreased the catalytic activity of possum CYP3A and UGT2B below the estimated IC₅₀ and 2-fold IC₅₀ values and were therefore not considered to be potent inhibitors of these enzymes. However, compounds such as isosilybin (65%), ketoconazole (72%) and fluconazole (74%) showed reduced UGT2B glucuronidation activity in possums, mainly at 2-fold IC₅₀ values compared to control (p<0.05). Given the structural features of these compounds, these results could provide opportunities for future compound screening. More importantly, however, this study provided preliminary evidence that the basal activity and protein content of two major drug metabolising enzymes differ in possums compared to other test species, suggesting that this could be further exploited to reach the ultimate goal, a potential target-specific fertility control for possums in New Zealand.