Posted by Keith Galloway on Fri, Nov 06, 2009 @ 10:04 AM
The goal of every oncologist is to deliver chemotherapy to patients at doses that are the most efficacious without causing severe toxic effects. The optimal dose lies between doses that are too low to produce a positive response and those that are too high to avoid toxicity.
Compared to other fields of medicine, however, oncology tends to have among the lowest efficacy rates. One reason for this may be that oncologists often err on the side of under-dosing to minimize debilitating side effects. But if a patient receives levels of chemotherapy that are too low, the results are little to no therapeutic response, continued growth of tumors, developing resistance to the drugs, and a higher risk of disease recurrence.
Oncologists have been trained to administer and believe they are administering the maximum tolerated dose (MTD) in order to achieve and maintain the optimal level of a given cancer drug in patients' bloodstream. However, to date, doctors have not had the appropriate tools to verify whether the dose they give is actually the MTD for their individual patient. If the drug dose is too high, the patient suffers from excessive toxicity which can lead to severe adverse reactions and compromised immunity in patients, resulting in termination or interruption of treatment.
Dose optimization offers a solution to these ongoing challenges facing oncologists and patients. With personalized dose management, based on the testing of chemotherapy blood levels, oncologists can more reliably attain the optimal dose for each patient and maintain dose optimization throughout the course of treatment.
How is dose optimization achieved? Through blood testing of individual patients, oncologists can more accurately determine the most effective dose for the individual patient considering age, gender, weight, health status, genetics and other key factors. Repeat testing allows the oncologist to not only account for the fact that each patient absorbs, metabolizes, and eliminates drugs differently but also at a rate that varies over time. Adjustments in dosing can be made accordingly.
The benefits of dose optimization are multiple: more effective dosing, greater therapeutic response, and higher survival rates. Reduced toxicity also translates into better quality of life for patients.
With a tool like Personalized Chemotherapy Management Assays, dose optimization can become standard practice, raising the efficacy of treatment and improving outcomes for cancer patients.
Posted by Keith Galloway on Fri, Oct 09, 2009 @ 07:48 AM
A personalized approach to dose management has multiple benefits for chemotherapy patients and the oncologists who treat them. These benefits include:
More accurate dosing. Personalized dose management begins with testing of actual drug blood levels in patients. Blood tests offer oncologists a more precise tool than body surface area (BSA) for determining the most appropriate drug dosage for a given patient. With the test results, oncologists can better determine whether an individual cancer patient is receiving a dose within the optimal range - high enough to incur a response but low enough to prevent severe side effects or toxicity. With this approach, oncologists can assess treatment and make the critical adjustments to dosage should a patient require them.
In a recently published study in the Journal of Clinical Oncology, 85% of colorectal patients treated with 5-fluorouracil (5-FU) were found to be outside the optimal range when dosed by the standard dosing method - Body Surface Area (BSA). Surprisingly, 68% of patients were underdosed, resulting in sub-optimal therapeutic response with a higher chance of developing drug resistance and disease progression. The other 17% were overdosed, leading to debilitating toxic side effects that can result in treatment delay or termination. Only 15% of patients received the optimal dose of 5-FU to combat their disease.
Better clinical response. With more precise dosing and better dose management over time, oncologists and patients can expect a more positive response to chemotherapy treatment. In the study cited above, , patients receiving pharmacokinetic dose management of 5-FU for colon cancer had nearly double the positive response compared to patients treated by BSA dosing. The patients who underwent blood testing and dose adjustments based on those tests had a reduction in tumor size of at least 50 percent.
Fewer toxic side effects. Personalized dose management reduces the likelihood of both unintentional over-dosing and under-dosing of chemotherapy drugs-common challenges to oncologists. Even patients whose oncologists prescribe dose increases based on blood testing may be less likely to experience toxic effects. In the same study of colon cancer patients described above, recipients of personalized treatment had lower incidences of common chemotherapy toxicities such as diarrhea, mucositis, and blood disease.
Greater survival rates. Higher rates of positive response to chemotherapy treatment translate into greater efficacy and better outcomes. These outcomes may include reduced tumor size, longer periods of progression-free disease, and lower rates of recurrence. The evidence suggests that personalized dose management can boost survival rates, adding months, if not years, to patients' lives.
Better quality of life. In addition to improved survival rates, personalized dose management can enhance patient life quality in several ways. The more accurate dose management achieved through pharmacokinetics may reduce the incidence and severity of toxic side-effects, improving well-being during and after treatment, and reduce the need for medical interventions , supportive medications, and frequent or long hospital stays.
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.