Jun 29, 2012
July 2012: In order to assist oncologists in providingoptimal curative care to patientswho are overweight or obese, ASCOrecently released a clinical practiceguideline on “Appropriate Chemotherapy Dosing for Obese Adult Patients With Cancer,” which covers both intravenousand oral chemotherapy.
“This guideline will reduce the uncertaintyand variation of chemotherapydosing in clinical practice and result inmore consistent evidence-based treatmentand improved clinical outcomes,”said Gary H. Lyman, MD, MPH, FASCO,FRCP, of Duke University School of Medicineand Co-Chair of the Expert Panelthat developed the recommendations.
The guideline highlights the fact thatmany overweight and obese patientsreceive limited or reduced chemotherapydoses and discusses the evidencefor using actual body weight to determinethe appropriate cytotoxic chemotherapydosing essential for cure. Morethan 60% of U.S. adults have a bodymass index (BMI) over 25% and areconsidered overweight or obese.
Safety and importance
Based on the Expert Panel’s literaturereview, practice pattern studiesdemonstrate that up to 40% of obesepatients receive limited chemotherapydoses that are not based on actualbody weight. Concerns about toxicityor overdosing in obese patients withcancer, based on the use of actualbody weight, are unfounded. Studiesconfirm the safety and importance offull weight-based dosing. For example,even when chemotherapy doses arecalculated according to actual bodyweight, obese patients are less likely tohave bone marrow suppression.
“Many oncologists are not aware thatfull weight-based doses are used in patients on clinical trials. Disseminating the evidence against dose limits is one way to overcome the underdosing we have seen in up to 40% of patients. This is particularly important given the prevalence of obesity and the relationship between obesity and cancer incidence and outcome,” said Jennifer J. Griggs, MD, MPH, of the University of Michigan and an Expert Panel Co-Chair.
According to the guideline, clinicians should order and deliver chemotherapy doses based on a patient’s actual body weight. Toxicity is no greater for obese patients with appropriate dosing although comorbidities must always be considered. If dose is reduced as a result of toxicity, the clinician should consider returning to the appropriate weight-based dose when the toxicity is resolved and monitoring the patient’s reaction carefully. There are potential serious harms in underdosing patients who are obese in that efficacy may be compromised. The potential benefitsof weight-based dosing include maximizing the potential benefit ofchemotherapy.
Exceptions to this general recommendation, where fixed doses are acceptable, are noted within the full guideline.
Clinical resources, tools, and further reading are available, including:
“This guideline will reduce the uncertaintyand variation of chemotherapydosing in clinical practice and result inmore consistent evidence-based treatmentand improved clinical outcomes,”said Gary H. Lyman, MD, MPH, FASCO,FRCP, of Duke University School of Medicineand Co-Chair of the Expert Panelthat developed the recommendations.
The guideline highlights the fact thatmany overweight and obese patientsreceive limited or reduced chemotherapydoses and discusses the evidencefor using actual body weight to determinethe appropriate cytotoxic chemotherapydosing essential for cure. Morethan 60% of U.S. adults have a bodymass index (BMI) over 25% and areconsidered overweight or obese.
Safety and importance
Based on the Expert Panel’s literaturereview, practice pattern studiesdemonstrate that up to 40% of obesepatients receive limited chemotherapydoses that are not based on actualbody weight. Concerns about toxicityor overdosing in obese patients withcancer, based on the use of actualbody weight, are unfounded. Studiesconfirm the safety and importance offull weight-based dosing. For example,even when chemotherapy doses arecalculated according to actual bodyweight, obese patients are less likely tohave bone marrow suppression.
“Many oncologists are not aware thatfull weight-based doses are used in patients on clinical trials. Disseminating the evidence against dose limits is one way to overcome the underdosing we have seen in up to 40% of patients. This is particularly important given the prevalence of obesity and the relationship between obesity and cancer incidence and outcome,” said Jennifer J. Griggs, MD, MPH, of the University of Michigan and an Expert Panel Co-Chair.
According to the guideline, clinicians should order and deliver chemotherapy doses based on a patient’s actual body weight. Toxicity is no greater for obese patients with appropriate dosing although comorbidities must always be considered. If dose is reduced as a result of toxicity, the clinician should consider returning to the appropriate weight-based dose when the toxicity is resolved and monitoring the patient’s reaction carefully. There are potential serious harms in underdosing patients who are obese in that efficacy may be compromised. The potential benefitsof weight-based dosing include maximizing the potential benefit ofchemotherapy.
Exceptions to this general recommendation, where fixed doses are acceptable, are noted within the full guideline.
Clinical resources, tools, and further reading are available, including:
- The full guideline with evidence tables and data supplements
- A one-page summary
- FAQs with related case study
- A slide set to present the guideline to colleagues or trainees
- Podcasts on the guideline by Dr. Griggs and Dr. Lyman
- Oncologist-approved information for patients from Cancer.Net