A gene called cyclin G1 has been shown to play a very important part in cancer growth. In animal experiments, when this cyclin G1 gene is blocked, the cancer cells grow much slower or even die. This study will test the drug, Rexin-G, which contains a gene that works by getting rid of the cyclin G1 gene. The new gene will get into the tumor cells using a "vehicle" to carry it into the cells. The "vehicle" that will be used is a virus that has been changed so that it is not likely to cause disease. This "vehicle" is called a vector. When injected into a vein, the Rexin-G vector is designed to seek out and accumulate in cancerous tumors, therefore, increasing the concentration of the drug in the area of the cancer and not in normal neighbouring organs. When the killer gene gets into the cancer cell, it becomes part of the cell's genes and tells the cancer cell to begin using the new gene instead of the cyclin G1 gene. It is hoped that the Rexin-G will arrest the growth of the cancer or eradicate the tumor.