Posted by Keith Galloway on Wed, Jan 27, 2010 @ 08:13 AM
One of the key benefits of personalized dose management is a reduction in chemotherapy side effects, which enhances patients' treatment and quality of life.
Dose management lessens the risk of severe toxicity and side effects in two ways. First, it enables the oncologist to more accurately prescribe the most appropriate dose to an individual patient rather than a standard dose. Second, it gives the doctor a tool to measure and adjust dosage over time to ensure that blood drug levels remain optimal but never get too high.
Research has demonstrated the impact of dose management on patient side effects. In a 2008 study, colorectal cancer patients whose treatment was based on the testing of blood drug levels had fewer severe side effects typically associated with the drug 5-fluorouracil (5-FU). Patients given adjusted rather than fixed doses were far less likely to suffer from Grade 3 / 4 (the most severe) diarrhea, one of the most common side effects of 5-FU and other chemotherapy agents. Researchers also noted a reduction in hematologic toxicity.
Dose management based on testing of blood drug levels also has the potential to lessen severe side effects of busulfan, a common chemotherapeutic agent. Busulfan is often used with patients undergoing hematopoietic stem cell transplantation for cancers of the blood and immune system. Because it is a high-dose regimen busulfan can cause veno-occlusive disease, among other serious side effects. But with timely testing and careful management of busulfan blood levels, oncologists can better manage dosing and minimize the risks of this critical treatment.
As the impact of blood drug level testing and dose management on chemotherapy side effects become more widely known and incorporated into clinical practice, oncologists can more successfully balance efficacy against those effects.
Posted by Keith Galloway on Thu, Oct 01, 2009 @ 10:52 AM
Personalized dose management for chemotherapy patients differs from standard dosing in important ways.
Oncologists typically administer doses of chemotherapy drugs based on body surface area (BSA), a standard determined by the height and weight of a patient. They rely on this standard to deliver cancer drugs in doses that are effective without causing severe side effects or toxicity.
Dose management is also influenced by the practice of delivering the maximum dose tolerated by patients. Oncologists engage in this practice in order to achieve and maintain positive response from a given drug. However, oncologists also aim to avoid toxic side effects. These competing goals often lead to either under-dosing or over-dosing of patients, undermining treatment, efficacy and cost effectiveness. That's one reason why oncology has one of the worst efficacy rates in medicine.
The problem with standard chemotherapy dose management based on current standards (BSA) is that it does not take into account key individual differences among cancer patients. These differences include age, health status, genetic makeup, diet, and other medications that might interfere with chemotherapy drugs. Standard dose management also does not reflect the fact that each patient absorbs, metabolizes and eliminates drugs differently. With this standard, blood drug level variations among patients can be greater than ten-fold. See relevant articles.
Personalized dose management, by contrast, is personal because it is customized to the characteristics of individual patients. It is based on simple blood tests that measure the concentration level of a cancer drug in the patient's body. The results of these blood tests allow oncologists to more accurately prescribe doses that are high enough to be therapeutic but low enough to minimize severe side effects and toxicity. Through blood testing, an oncologist can better determine the level of drug in a patient's bloodstream, and adjust drug doses accordingly.
The therapeutic benefits of blood testing are well established. In a published study, patients given doses of the widely used cancer drug 5-fluorouracil based on blood drug level testing (as opposed to standard BSA) received a range of dose adjustments. Compared to patients receiving fixed doses, the patients on adjusted doses achieved nearly double the positive response and greater survival rates. They also enjoyed lower rates of toxic side effects.
Personalized Chemotherapy Management Assays are an example of this more accurate, personalized approach to dose management. Because personalized dose management is based on multiple variables, it is more likely to deliver the appropriate dose to chemotherapy patients. The more effective treatments resulting from this powerful tool increase patient survival rates and quality of life.