All cancer treatments aim to find a treatment that selectively targets cancer cells without affecting normal cells. Unfortunately, this is a difficult task because cancer cells are formed from normal cells. Drugs like antibiotics can exploit differences between 'self' and 'non-self' cells. But with cancer cells, there are no such clear distinctions. Instead, scientists must determine what makes a specific cancer cell different from a normal cell and then design agents that can selectively target those pathways.
As we have seen with the hallmarks of cancer, tumor cells have unique qualities that can be targeted. Every hallmark of cancer is being studied as a potential area for intervention with pharmaceutical agents. Once a suitable candidate drug is available, the patient’s physician must know if the patient has the appropriate biomarker. Only testing for this specific biomarker will reveal whether the patient will likely respond to the new therapy. The laboratory will determine the presence or absence of these biomarkers.
We are living in an age in which personalized medicine is now routinely used to treat cancer patients. Unfortunately, there are still many more biomarkers than targeted drugs for them. In these cases, where no targeted therapy is available, patients still receive less specific chemotherapy agents.
