Fass/Fasls Ratio: A Marker Of Chemoresistance In Advanced Colorectal Cancer (Crc).

3583 Background: Oxaliplatin (OXL) or Irinotecan (CPT11)-5-fluorouracil (FU) combinations have improved responses up to 40% in advanced CRC. Unfortunately, those patients who will respond are unknown and, initially sensitive patients become rapidly resistant to current therapies. Fas (CD95) has been implicated in DNA-damage sensitivity. Whereas the pro-apoptotic role of Fas and FasL are well characterized, the function of their soluble forms remains unknown. Methods: We designed a prospective study to evaluate the role of sFas, sFasL and their ratio in CCR chemoresistance. From July 2001 to September 2003, seventy-three patients with advanced CRC(median age= 61; PS 0=25,1=35, 2=13; 1 organ=46; >1=27) received either OXL 85mgr/m2, LV 200 mgr/m2 and FU 3gr/m2, c.i., bi-weekly (group A, n=51) or OXL-FU/CPT11-FU combinations (group B, n=22) in first-line therapy. CT scans were done every 3 months and responses were evaluated by RECIST. ELISA sFas and sFasL analysis were done before treatment and every 3 month...