Posted by Keith Galloway on Tue, Dec 08, 2009 @ 04:05 PM
To maximize cancer treatment outcomes, oncologists administer what they believe to be the most effective chemotherapy dose tolerated by patients. Yet
research has shown that practitioners may be under-estimating the level of drug patients actually needs to achieve a positive response and improved survival rates.
New research reported in the October 2009 issue of Lung Cancer illustrates this point. Researchers at the S. Paolo Hospital in Milan, Italy studied more than 100 elderly patients diagnosed with advanced non-small cell lung cancer. Dr. A. Luciani and study co-authors compared the relative dose intensity (RDI) of chemotherapy agents administered to NSCLC patients. According to the study abstract, about one-third of patients received RDIs that were suboptimal, or less than 80 percent of the planned dose. The rest received RDIs above 80 percent. The response rate for patients receiving the higher doses was 55.2 percent compared to 33.3 percent for patients on the suboptimal doses.
Among the study authors' conclusions, it's noted that "an adequate dose intensity has a significant positive impact on both response rate and overall survival." With elderly patients oncologists may be too often erring on the side of suboptimal doses, and undertreatment, in order to avoid toxicity. But the research provides evidence that patients aged 70 and older can and should receive the optimal dose.
A second study published in the same journal compared the benefits of chemotherapy for elderly lung cancer patients versus younger patients. Mariano Provencio and associates examined treatment, toxicity, response rate, and survival in patients enrolled in six clinical trials. Their analysis found no significant differences in terms of treatment cycles or response rates. In their conclusions, study authors called for "more selective treatments, based on the genetic differences that older patients have."
Both studies support the principles of personalized medicine, and specifically personalized dose management. In the first study, individual characteristics such as body mass index, were more important than age in determining dose intensity. Even though the patients were older, the optimal dose brought about improvements both in terms of response and overall survival.
Given the fact that the number of elderly patients with cancer is on the rise, personalized chemotherapy management-with the goal of achieving optimal dosing and outcomes-merits further consideration. By incorporating optimal dose management into routine practice, oncologists can achieve greater efficacy with both elderly and young patients.
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.