What is Chemotherapy?
Francisco Garcia-Moreno, M.D.
Chemotherapy. Few words strike as much fear and hope at the same time. The fear stems from the unknown, from images and experiences that we have each encountered over the years. The hope arises from its promising effects. Due to new developments, there is now much hope for cancer patients who need to undergo chemotherapy.
The origins of chemotherapy go back to the battlefields of France during World War I. During that time, the use of Mustard Gas was clearly devastating, but American scientists made an interesting observation in soldiers who had been exposed to this agent. They found that the number of lymphocytes (a type of cell that is a component of our white blood cell count) had decreased. It didn’t take much for physicians to realize that this substance could be useful in the treatment of lymphomas. This was the first practical medical use of chemotherapy. A weapon once feared was found to have a positive use. Fear and hope.
Since then, advances in chemotherapy had been painstakingly slow. The benefits of all new substances have to be clearly proven, defining their side effects and establishing appropriate delivery schedules. The period between discovery of a new agent and availability to the public was measured in years. Amazingly, until very recently, all chemotherapy agents were discovered in nature. Seaweed1, fungus2 Pacific Yew Tree3 and my favorite, the Periwinkle plant4 yielded useful chemotherapeutic agents. Claims that physicians were utilizing synthetic, “unnatural” substances were unfounded.
As our understanding of the human genetic structure progressed, our understanding of the mechanisms by which malignancies arise progressed rapidly. This understanding has made it possible to develop therapies specifically designed for certain cancers. Synthetic agents developed for specific malignancies are no longer science fiction. In a sense, we’re no longer treating cancers with our eyes closed. We’re now able to focus your therapy with a treatment that is designed specifically for your cancer. No longer guessing in the dark, the development of new agents has sped up dramatically. Things are looking up!
The first time you receive chemotherapy is like the first time you travel someplace you have never been before…it seems to take FOREVER. It is hard to understand the journey and you will never quite grasp it until you walk down that road for the first time. The vast majority of treatments are given safely and comfortably in an outpatient setting and most agents are administered intravenously. Sometimes an indwelling catheter will be necessary and often used because the patient has poor venous access or the agents that are going to be used have the ability to cause injury to the local tissue if they should leak out of the smaller veins.
Importantly, we also focus on both the effectiveness of these agents, as well as curtailing their unwanted side effects.
Side effects can be variable depending on which agents are being used. Since chemotherapy destroys the most rapidly dividing cells in the body, hopefully the cancer cells. Tissues that reproduce quickly are the tissues that are most often affected. These include hair cells, bone marrow and cells of the GI system. Therefore hair loss, nausea, vomiting and decreased blood counts are an expected side effect of chemotherapy. The truth is that there have been major advances in therapies that guard against or correct these issues. Most current agents do NOT cause these effects but if they do, there are treatments that minimize these side effects and therefore have revolutionized the administration of chemotherapy by allowing the Oncologist to increase the strength of the chemotherapy delivered while still protecting the patient. As the treatments improve and the success rates rise, we can direct our attention to decreasing these side effects and improving quality of life.
With the advent of targeted therapy, it is clear that the tide is turning and success is within our grasp. As our understanding increases, fears dissipate and hope triumphs.