Chemotherapy sessions have traditionally relied on an individual's weight and height to determine the maximum tolerable doses (MTD) for cancer treatment. The MTD targets any rapidly growing cells. However, research on the effective low doses has been minimal, as all focus has been on controlling the cancer spread, as fast as possible. Recent focus has been to study an effective low dosage, at 20 to 30 percent of a standard full dosage. This is primarily to avoid the side effects of a typical high dosage.
Conventional MTD has more drastic and undesirable side effects on frail adults, children, and elderly who are living with cancer. These three groups often suffer immensely from residue toxicity of previous high-dose sessions. The low-dose chemotherapy enables continual drug provision without the risk of toxicity.
In standard chemotherapy with MTDs, due to the high dosage, there is a window between sessions that is typically between one and three weeks. The window depends on the cancer stage, type, and the chemo agents used. During this period, any surviving cancer cells may develop resistance to the drug besides the growth of new drug-resistant cancer cells. By contrast, low-dose chemotherapy that is administered more often maintains a continuous assault on cancer cells, thus lowering the chances of developing resistance. The frequent low dosage has an anti-angiogenic effect, meaning that it reduces blood supply to the cancer. The reduced blood supply decreases the nutrients required for cancer cell growth.
