Page 68 - Demo

Chapter 466acid and vitamin B12 could increase the efficacy of gemcitabine and cisplatin in advanced esophagogastric cancer. Patients and methodsEffect of folic acid supplementation on intratumoral accumulation of cisplatin and tumor cell sensitivity to cisplatin In order to determine whether and how folic acid supplementation would affect sensitivity to cisplatin we tested the cisplatin sensitivity of two pairs of adenocarcinoma cell lines WiDr and CaCo2 and their sublines (WiDr/LF, CaCo2/LF/LV and CaCo2/LF/FA) adapted to grow under low folate conditions [13,14]. Due to the unavailability of modified esophageal adenocarcinoma cell lines, adenocarcinoma cell lines of colorectal origin were used for this purpose. Standard mycoplasma testing was performed. Wild type WiDr and CaCo2 are cultured in standard DMEM medium containing 8 %u03bcM folic acid, WiDr/LF and CaCo2/LF/LV have been selected to grow in folate-free RPMI medium supplemented with 2.5 and 1 nM leucovorin, respectively, while CaCo2/LF/FA is adapted to grow in RPMI medium supplemented with 1 nM folic acid. Sensitivity of these cells to cisplatin was determined by a 72 hr exposure to cisplatin alone or in combination with gemcitabine using the sulforodamide B (SRB) assay[15]. We also determined whether folate supplementation would affect the accumulation of cisplatin into these cells. Intracellular platinum concentrations were determined as described earlier[16].Clinical study design and study populationThe clinical study was a multicenter randomized open label phase 2 study comparing therapy with gemcitabine and cisplatin with or without vitamin B12 and folic acid supplementation. From October 2004 to August 2013, 82 patients were included in the study. The study recruited patients in the VU University medical center (VUmc) in Amsterdam, The Netherlands and the Noordwest Ziekenhuisgroep in Alkmaar, The Netherlands. Main inclusion criteria included histologically or cytologically confirmed metastatic or locally advanced unresectable advanced esophagogastric carcinoma (AEGC), squamous cell or adenocarcinoma, not amenable to curative treatment, measurable disease according to RECIST[17], age of at least 18 years, ECOG performance score of 0-2,