Anyone faced with cancer is intimately familiar with the many tests and procedures involved in diagnosis and determining treatment. What is less clear is how your doctor knows what to do.
Progress in cancer requires research, and having a basic understanding of how research is conducted can help you understand your doctor's opinions.
When a morsel of a plant or toxin found in nature or in a lab is tested in a tissue culture or later in animals, the researcher gets a rudimentary idea as to which molecule might be active for a cancer and what beginning dose to try in humans. All cancer therapies start with this lab testing.
With this information, Phase I studies are designed. All human research is approved first by an investigational review board to protect study patients from undue harm. When the research is approved, a small group of patients is treated at progressively larger doses of a cancer agent to find a maximally tolerable dose.
Phase II studies are then conducted on a larger group of patients with advanced cancers. They receive the maximally tolerable dose to assess response to treatment and to collect information on toxicity.
If Phase II studies suggest the new agent is active against cancer, Phase III trials are performed on a larger group, and more data are collected.
If Phase III results are encouraging, the drug is released for general use outside of trials, a process that might take a decade. Phase IV data is collected by the company producing the new agent to document any additional toxicity or benefits. This lengthy process is necessary to safely discover new therapies.
It is essential for cancer research to be performed at the community level to have research results that apply to the typical patient. Patients who are healthy enough to travel long distances to participate in a study might produce overly optimistic results due to their vitality. If the same trial included patients treated in community cancer centers who were not healthy enough to travel long distances, results might be more accurate.