ABSTRACT
INTRODUCTION: Resection of colorectal liver metastases provides the best chance for survival in patients with Stage IV colorectal cancer; however, hepatic recurrence is frequent and the main cause of death. Multiple epidemiological studies have documented an association between metformin and anti-neoplastic effects in a variety of cancers. Given the vast literature, we evaluated the incidence on recurrence and survival of patients on metformin who undergo surgery for colorectal liver metastasis (CRLM). METHODS: We selected 270 consecutive patients with known CRLM who underwent hepatic metastases resection at our institution between January 1st 2012 and December 31st 2019. Patients were divided based on their use of metformin (n = 62) or no metformin (n = 208). Adjusted analysis of recurrence-free (RFS) and overall survival (OS) was performed. RESULTS: Patients on metformin had significantly longer RFS (HR: .44, 95% CI: .26-.75, P < .002; Median RFS: 49 months vs 33 months) and OS (HR .60, 95% CI .31-.97, P < .048, Median OS: 72 months vs 60 months). Additional factors associated with shorter RFS on univariate analysis included the following: CEA > 200 ng/ml (HR: 2.23, 95% CI 1.21-4.03, P < .010), positive liver margin (HR: 3.70, 95% CI 2.27-6.03, P < .001), and >1 tumor (HR: 1.98, 95% CI 1.26-3.09, P < .003). Liver margin remained a significant factor for predicting shorter OS (HR: 4.99, 95% CI 2.49-10.0, P < .001). CONCLUSION: In this study, we found that patients with CRLM on metformin have prolonged RFS and OS postliver resection. Further prospective randomized trials need to be carried out to evaluate the anti-neoplastic effect of metformin in diabetic and non-diabetic cancer patients.
Subject(s)
Colorectal Neoplasms/surgery , Hepatectomy/mortality , Hypoglycemic Agents/adverse effects , Liver Neoplasms/secondary , Metformin/adverse effects , Neoplasm Recurrence, Local/epidemiology , Aged , Case-Control Studies , Colorectal Neoplasms/mortality , Colorectal Neoplasms/pathology , Disease-Free Survival , Female , Humans , Kaplan-Meier Estimate , Liver Neoplasms/mortality , Liver Neoplasms/surgery , Male , Middle Aged , Neoplasm Recurrence, Local/mortality , Risk Factors , Survival AnalysisABSTRACT
The impacts of land use and land cover (LULC) change in buffer zones surrounding protected ecological reserves have important implications for the management and conservation of these protected areas. This study examines the spatial and temporal patterns of LULC change along the boundary of Rio Abiseo National Park in the Northern Peruvian Andes. Landscape change within four ecological zones was evaluated based on trends expected to occur between 1987 and 2001. Landsat TM and ETM imagery were used to produce LULC classification maps for both years using a hybrid supervised/unsupervised approach. LULC changes were measured using landscape metrics and from-to change maps created by post-classification change detection. Contrary to expectations, tropical upper wet montane forest increased despite being threatened by human-induced fires and cattle grazing of the highland grasslands inside the park. Within the park's buffer zone, tropical moist forest remnants were fragmented into more numerous and smaller patches between 1987 and 2001; this was in part due to conversion into agricultural land. The methods used in this study provide an effective way to monitor LULC change detection and support the management of protected areas and their surrounding environments.
