Tumor promotion refers to an acceleration in growth of existing tumor cells. This is the second phase of development, followed by progression, where the cells start to become more aggressive, establishing a cancerous growth. From a research perspective, understanding tumor promotion is important, as this process can be reversed and presents a target for cancer treatment. Learning how and why cancers start to develop can also help researchers identify ways to prevent them.
Within the body, complex cellular processes regulate cell growth. Sometimes these go wrong, usually in the wake of cell injury and repeated inflammation. Instead of growing and dying within a normal lifespan, cells keep growing and dividing. Tumor promotion encourages this, rather than allowing the body to kill off the abnormal cells and break them down. In the wake of tissue injury, for instance, cells around the site can start producing chemicals that encourage tumors to grow.
Compounds involved in tumor promotion cannot cause tumors to form, but if cancerous cells are present and they are exposed to the compounds, they can grow more quickly. Once they start growing, they can transition to the final phase, where they change and become aggressive. These cells can start to infiltrate neighboring tissues and resist the body’s defenses to halt their progression, leading to cancer.
In addition to being mediated by compounds released from the body, tumor promotion can also be the result of chemical exposure. Some chemicals encourage cell growth and may interact with cancerous cells to facilitate more rapid development. These can be found in the natural environment as well as workplace settings. Research can help people identify which chemicals are involved in tumor promotion with the goal of more closely controlling them to prevent instances of cancerous cells from developing any further.
This is also a very valuable target for cancer treatment. During the tumor promotion phase of development, the cancer can be arrested and reversed, if it is identified and the patient gets treatment. Medications to target cells in this stage could be used to control the growth, including in people who are at high risk of specific cancers. Proactive approaches like this can reduce the risk of complications that may occur as tumor cells enter the progressive stage and become more apparent. Drug development focusing on this aspect of cancer requires careful research to identify the compounds involved and determine how to target them most effectively.