The oncology community must acknowledge that the current practice of dosing chemotherapeutic drugs based on a patient’s height and weight, or body surface area (BSA), is highly inadequate. BSA-based dosing overlooks the fact that each patient metabolizes drugs differently. As a result, some patients may be overexposed to the drug, leading to severe toxicities, while others may receive insufficient exposure, reducing effectiveness and potentially causing treatment resistance.

There are, however, routine laboratory methods available that can measure the active drug levels in a patient’s bloodstream. While commonly used in other fields of medicine, this “Drug Management” approach is rarely applied in cancer treatment. By utilizing these tests, oncologists can assess an individual’s drug exposure and adjust dosages accordingly. This personalized approach allows physicians to tailor chemotherapy doses, ensuring optimal exposure to these highly toxic treatments. BSA dosing has become a deeply ingrained practice that has not evolved to incorporate innovative approaches. Several barriers hinder progress towards individualized dosing of these highly toxic oncology drugs, including misaligned incentives, challenges in gathering evidence, and the absence of clear regulatory pathways. While personalized dosing is already the standard of care in other fields—such as organ transplantation, infectious diseases, and antipsychotics—it remains largely unutilized in oncology, depriving cancer patients of the benefits of optimized therapies.

In the 21st century, “Precision Medicine” has primarily focused on gene sequencing and selecting the right drug for the right patient, but it has neglected to individualize dosage. To fully realize the potential of Precision Medicine and maximize patient survival, we must not only select the correct drug but also ensure the correct dose is administered to achieve optimal drug exposure.

We strongly encourage making Therapeutic Drug Management (TDM) a fundamental element in personalizing treatment. Without TDM, the full potential of Precision Medicine cannot be realized!