Deliberation on Deferred Cytoreductive Nephrectomy and Postoperative Treatment for Advanced Renal Cell Carcinoma: A Case Report

In a rare case, free from systemic therapy, deferred cytoreductive nephrectomy was implemented in treating an advanced renal cell carcinoma with liver, lung, and splenic colon metastases. A 59-year-old man diagnosed with advanced renal cell carcinoma underwent deferred cytoreductive nephrectomy due to a partial response to systemic treatment after a period of 1 year. After the surgery, no additional treatment was implemented. Furthermore, after 10 months, the patient had no recurrence of renal cell carcinoma. Through a review of this case and deferred cases in the current literature, we could emphasize the importance of image evaluation and pathological findings as an indication for surgery and subsequent treatment options. However, there is room for debate with regards to the indications for deferred cytoreductive nephrectomy as well as a therapeutic strategy after the surgery. This report discusses the significance of deferred cytoreductive nephrectomy in terms of prognosis and quality-of-life improvement in advanced renal cancer

A Phenylfurocoumarin Derivative Reverses ABCG2-Mediated Multidrug Resistance In Vitro and In Vivo

The ATP-binding cassette subfamily G member 2 (ABCG2) transporter is involved in the development of multidrug resistance in cancer patients. Many inhibitors of ABCG2 have been reported to enhance the chemosensitivity of cancer cells. However, none of these inhibitors are being used clinically. The aim of this study was to identify novel ABCG2 inhibitors by high-throughput screening of a chemical library. Among the 5812 compounds in the library, 23 compounds were selected in the first screening, using a fluorescent plate reader-based pheophorbide a (PhA) efflux assay. Thereafter, to validate these compounds, a flow cytometry-based PhA efflux assay was performed and 16 compounds were identified as potential inhibitors. A cytotoxic assay was then performed to assess the effect these 16 compounds had on ABCG2-mediated chemosensitivity. We found that the phenylfurocoumarin derivative (R)-9-(3,4-dimethoxyphenyl)-4-((3,3-dimethyloxiran-2-yl)methoxy)-7H-furo [3,2-g]chromen-7-one (PFC) significantly decreased the IC50 of SN-38 in HCT-116/BCRP colon cancer cells. In addition, PFC stimulated ABCG2-mediated ATP hydrolysis, suggesting that this compound interacts with the substrate-binding site of ABCG2. Furthermore, PFC reversed the resistance to irinotecan without causing toxicity in the ABCG2-overexpressing HCT-116/BCRP cell xenograft mouse model. In conclusion, PFC is a novel inhibitor of ABCG2 and has promise as a therapeutic to overcome ABCG2-mediated MDR, to improve the efficiency of cancer chemotherapy