CANCER AND SYMPTOM-CONTROL DRUGS
Although not directly treating the cancer, a range of supportive care drugs have contributed to big improvements in cancer treatments over the last 10 to 15 years. The improved anti-sickness drugs have already been mentioned. Also related to chemotherapy safety and delivery are the growth factors, in particular granulocyte colony stimulating factor (G-CSF) which boosts white blood cell counts, reducing infection risks. A second related product called GM-CSF (granulocyte-macrophage colony stimulating factor), initially developed for the same purpose, has turned out to have a valuable role in releasing blood cell precursors called stem cells into the circulation. This somewhat esoteric observation has allowed the harvesting of stem cells prior to high-dose chemotherapy intended to destroy the normal bone marrow. Previously patients needed a bone marrow transplant to ‘rescue’ them from such treatment, but it turns out that harvested stem cells do the same job but more quickly and with a much easier pre-treatment harvesting procedure, extending the range of patients suitable for these high-dose therapies.
Another area of recent research has been bone-protecting agents. Many cancers spread into bone with devastating consequences, including pain, fracture, and paralysis due to spinal column damage. Research demonstrated that the body ‘over-reacting’ to the cancer led, paradoxically, to increased damage. Drugs initially developed for osteoporosis (bone thinning) turned out to reduce this collateral, self-inflicted damage. The initial drugs available, such as clodronate, were relatively low in potency but later drugs, such as zoledronate and ibandronate, are many times more effective and can substantially reduce bone damage in patients with advanced cancer. Even more intriguingly, in adjuvant trials in high-risk breast cancer, zoledronate also appeared to reduce soft tissue disease, suggesting these agents may in addition have direct anticancer properties.
The improvements in cancer treatment seen in the last 100 years have been dramatic and have transformed the outcomes for millions of people across the world. Cancer treatment in the early 21st century is safer, more effective, and less toxic than it was 50 or 100 years ago. Surgery and radiotherapy continue to be refined and improved, with better targeting and minimal access technologies increasingly available. The ancillary imaging and pathology services will also continue to improve and allow better selection of treatment options in the future. The range of drugs and the effectiveness of those drugs are increasing rapidly, and this will generate further improvements in the coming years. The main problem with all this is the escalating cost, but grappling with this issue is better than not having the options available.