iressa effective

My 84 y/o father has been taking Iressa for approx. 10 months. He was told his lung ca had spread to both lungs and adrenal glands and given 3-7 months to live last july, before starting the iressa. He is now cancer free the iressa not only shrunk the tumors within 8 weeks but has totally eradicated them as far as we know thru CT scans etc..His side effects include major loss of appetite, inability to put weight on and a feeling of weakness most of the time.