Cancer patients commonly receive what is known as maximum dose treatment. Doctors use the highest dose patients can tolerate to battle cancers like testicular cancer. As a result, however, many patients develop a resistance to treatment. Cancer comes back. Researchers at Moffitt Cancer center tested a new approach. Based on mathematical modeling and evolutionary principles, the team points to adaptive drug treatments as the way forward. Keep reading to learn more, or follow the original source here.
The Moffitt Center research team recently published their results online. The journal Cancer Research is scheduled to publish the study in print. The Moffitt team’s research indicates that for certain cancers, maximum dose treatments may not be most effective. Instead, the team proposes an adaptive program of treatment based on how cancer responds to previous treatment attempts.
Our current understanding of cancer treatment stems from a notion that effective treatment hinges on killing the greatest number of cancer cells in the smallest measure of time. This typically involves high drug doses. It’s a sort of all-in approach. Despite this knock-out blow, cancerous cells often manage to survive. They have a wide variety of survival abilities.
Jill Gallagher, Ph.D., and researcher at the Moffitt Department of Integrated Mathematical Oncology describes it this way: the maximum tolerated-dose strategy assumes that resistant cancers cannot exist prior to treatment. If the cancer cells have never seen the treatment, they cannot possibly fight it. Research reveals, however, that cancers cells may be resilient against treatments they’ve never encountered.
The evolutionary principle known as competitive release helps to explain this phenomenon. An example of competitive release is found in the use of pesticides. In cases where the highest concentration of pesticide is used – or the highest dose – large number of insects are destroyed, the selection pressure becomes very high. Some insects, however, due to preexisting conditions and special traits, survive the onslaught. With all competition eliminated, the surviving insects produce a resilient population as they reproduce. Tumor cells react in a similar fashion.
Through the use of mathematical modeling and the study of evolutionary principles, the Moffitt team evaluated the effectiveness of maximum dose treatments. They compared these results to adaptive treatment plans. Cell culture experiments helped to test both types of treatments.
The team’s research showed that there is no all purpose treatment. Generally, neither approach is superior. The composition of the tumor plays a major role in determining which types of treatments will be effective. Tumors that contain large numbers of similar cells, like testicular cancer, are highly susceptible to continuous, maximum-dose treatments. Other tumors, however, those made up of both sensitive and resistant cell types, such as melanoma, respond better to adaptive strategies.
“Our work illustrates clearly the importance of using treatment response as a key driver of treatment decisions, rather than fixed strategies” says Alexander RA Anderson, Ph.D., chair of the Department of Integrated Mathematical Oncology at Moffitt.
According to Anderson, the future of precision medicine does not lie solely in creating new drugs. Instead, it depends on the more intelligent and evolving use of preexisting treatments.
Researchers hope their study and work will convince others that patients may receive better treatment by thinking a little more outside the box. They believe existing drugs can be used to greater affect with a smarter approach.
