Appropriate chemotherapy dosing for obese adult patients with cancer: American Society of Clinical Oncology clinical practice guideline.

PURPOSE: To provide recommendations for appropriate cytotoxic chemotherapy dosing for obese adult patients with cancer. METHODS: The American Society of Clinical Oncology convened a Panel of experts in medical and gynecologic oncology, clinical pharmacology, pharmacokinetics and pharmacogenetics, and biostatistics and a patient representative. MEDLINE searches identified studies published in English between 1996 and 2010, and a systematic review of the literature was conducted. A majority of studies involved breast, ovarian, colon, and lung cancers. This guideline does not address dosing for novel targeted agents. RESULTS: Practice pattern studies demonstrate that up to 40% of obese patients receive limited chemotherapy doses that are not based on actual body weight. Concerns about toxicity or overdosing in obese patients with cancer, based on the use of actual body weight, are unfounded. RECOMMENDATIONS: The Panel recommends that full weight-based cytotoxic chemotherapy doses be used to treat obese patients with cancer, particularly when the goal of treatment is cure. There is no evidence that short- or long-term toxicity is increased among obese patients receiving full weight-based doses. Most data indicate that myelosuppression is the same or less pronounced among the obese than the non-obese who are administered full weight-based doses. Clinicians should respond to all treatment-related toxicities in obese patients in the same ways they do for non-obese patients. The use of fixed-dose chemotherapy is rarely justified, but the Panel does recommend fixed dosing for a few select agents. The Panel recommends further research into the role of pharmacokinetics and pharmacogenetics to guide appropriate dosing of obese patients with cancer.

Quality of life as a predictor of weight loss in obese, early-stage breast cancer survivors.

PURPOSE/OBJECTIVES: To investigate whether quality of life (QOL) assessed before weight loss intervention predicts weight loss and, in turn, what the effect of weight loss is on QOL measures after 12 months in early-stage breast cancer survivors. DESIGN: A clinical trial of a weight loss intervention in breast cancer survivors. SETTING: Community-wide recruitment in Detroit, MI. SAMPLE: 39 breast cancer survivors (body mass index = 30-44 kg/m2), within three years of initial diagnosis and at least three months after chemotherapy or radiation therapy. METHODS: Participants were randomized to one of three weight loss methods or a control group. The Functional Assessment of Cancer Therapy-Anemia (FACT-An) QOL questionnaire was administered at baseline and after the intervention. MAIN RESEARCH VARIABLES: Six subscales of the FACT-An and weight change. FINDINGS: Modest but statistically significant associations were found for the physical and functional subscales of the FACT-An with weight loss for 39 subjects who completed 12 months of the study. Those reporting relatively impaired physical or functional QOL at baseline lost more weight, which accounted for 8%-9% of the weight loss variance beyond that resulting from the diet arm assignment. At 12 months, greater weight loss was associated with significant improvements in overall FACT-An score and in the physical, functional, fatigue, and anemia subscales (p < 0.05). CONCLUSIONS: Relatively low physical function at baseline was not a barrier to weight loss; indeed, it may have been a motivating factor in adherence to the weight loss intervention. Weight loss was associated with improvement in several QOL subscale measures in breast cancer survivors, but the emotional and social subscales were not affected. IMPLICATIONS FOR NURSING: Counseling for weight loss that includes recommendations for exercise should not be withheld for patients with relatively low physical functioning.

Random control clinical trial on the effects of aerobic exercise training on erythrocyte levels during radiation treatment for breast cancer.

BACKGROUND: Erythrocyte changes from aerobic exercise training were examined during radiation treatment of breast cancer. METHODS: Twenty sedentary females with breast carcinoma who were ages 35 to 65 years were randomized to aerobic exercise (AE) of walking for 20 to 45 minutes, 3 to 5 times per week, at 50% to 70% of measured maximum heart rates or to placebo stretching (PS) activities 3 to 5 days per week during 7 weeks of radiation treatment. Measures were obtained 1 week before and after the radiation regimen. Serum blood analyses, through complete blood counts, measured red blood cell counts (RBC), hematocrit (HCT), and hemoglobin (HB). Peak aerobic capacity (peak VO(2)) was measured by exercise testing with oxygen uptake analysis to assess training. A Wilcoxon Mann-Whitney U test examined changes between groups (P < or = .05 for significance). RESULTS: AE peak VO(2) increased by 6.3% (P = .001) and PS decreased by 4.6% (P = .083). RBC increased in AE from 4.10 to 4.21 million cells/microL and declined in PS from 4.30 to 4.19 million cells/microL; the between-group differences were significant (P = .014). HCT increased in AE from 38.0% to 38.8% and declined in PS from 37.40% to 36.50%; the between-group differences were significant (P = .046). HB increased in AE from 12.3 to 12.4 g/dL and declined in PS from 12.25 to 11.77 g/dL; the between-group differences were significant (P = .009). CONCLUSIONS: The results of the current study suggest that moderate intensity aerobic exercise appears to maintain erythrocyte levels during radiation treatment of breast cancer compared with the declines observed in nontraining individuals. These findings suggest a safe, economical method to improve fitness and maintain erythrocytes in women during radiation treatment of breast cancer.

Improvement of metabolism among obese breast cancer survivors in differing weight loss regimens.

OBJECTIVE: To compare the efficacy of different weight loss regimens on body weight loss and metabolic improvement in breast cancer survivors. RESEARCH METHODS AND PROCEDURES: Forty-eight obese breast cancer survivors were randomly divided into four groups and were followed for 1 year: 1) the Control group (subjects did not receive specific nutrition counseling); 2) the Weight Watchers group (subjects were given free coupons to attend weekly Weight Watchers meetings); 3) the Individualized group (a registered dietitian provided one-on-one nutritional counseling); and 4) the Comprehensive group (subjects received individualized dietary counseling and free coupons for the weekly Weight Watchers meetings). At baseline and 3-, 6-, and 12-month data collection visits, a fasting blood sample was obtained for assays. A three-day dietary record was kept during the week before these visits and dietary intake was analyzed. RESULTS: Subjects in the three intervention groups lost weight (Control: 1.1 +/- 1.7 kg; Weight Watchers: -2.7 +/- 2.1 kg; Individualized: -8.0 +/- 1.9 kg; Comprehensive: -9.5 +/- 2.7 kg) and percentage body fat, but only the Individualized and Comprehensive groups had significant losses. Subjects in the Comprehensive group showed the most improvement in cholesterol levels and had reductions in blood leptin levels. DISCUSSION: Because insulin resistance and high blood leptin levels are associated with breast cancer, losing weight to improve these parameters may reduce the risk of recurrence. Only subjects in the Comprehensive group showed significant reductions in body weight and fat, energy intake, and leptin levels. For breast cancer survivors, different weight loss strategies should be considered to assist them in losing weight.

Relationship of psychiatric diagnosis and weight loss maintenance in obese breast cancer survivors.

OBJECTIVE: Obese breast cancer survivors are a unique population for weight loss counseling because both obesity and a diagnosis of breast cancer can increase the risk of depression. In this pilot study, weight loss maintenance was examined in obese breast cancer survivors with relationship to psychiatric diagnosis. RESEARCH METHODS AND PROCEDURES: Forty-eight subjects were enrolled. The intervention, which used individualized counseling for diet and exercise, lasted 24 months. After a 6-month period of no contact with study subjects, a follow-up body weight was obtained at 30 months. RESULTS: The nine subjects who dropped out of the study before 12 months all failed to complete a structured psychiatric interview. Of the remaining 39 subjects, 9 had major depressive disorder, and 10 had a definable psychiatric disorder of lesser severity such as adjustment disorder. Subjects with any type of psychiatric diagnosis displayed significantly less weight loss at the 12-month time-point than those with no diagnosis (6.3% vs. 12.6% loss of baseline weight, respectively). At the 30-month follow-up visit, subjects with any psychiatric disorder had a mean weight loss of 1.2% of baseline weight compared with 7.8% weight loss in subjects with no diagnosis. DISCUSSION: These results suggest that the presence of psychiatric disorders can interfere with weight loss. Therefore, recognition and treatment of psychiatric disorders may be important in attempts at weight reduction, and this will be especially important in populations such as cancer survivors, who seem to have higher rates of depression and other disorders than the general population.

Combining weight-loss counseling with the weight watchers plan for obese breast cancer survivors.

OBJECTIVE: The objective was to develop effective weight-loss methods for women who have had breast cancer, because obesity may result in an adverse prognosis. RESEARCH METHODS AND PROCEDURES: This randomized pilot study tested an individualized approach toward weight loss in obese women who have had a diagnosis of breast cancer. An individualized approach was applied either alone or combined with the commercial Weight Watchers program. Forty-eight women (body mass index of 30 to 44 kg/m(2)) were enrolled. RESULTS: Weight change after 12 months of intervention was as follows (mean +/- SD): 0.85 +/- 6.0 kg in the control group, -2.6 +/- 5.9 kg in the Weight Watchers group, -8.0 +/- 5.5 kg in the individualized group, and -9.4 +/- 8.6 kg in the comprehensive group that used both individualized counseling and Weight Watchers. Weight loss relative to control was statistically significant in the comprehensive group 3, 6, and 12 months after randomization, whereas weight loss in the individualized group was significant only at 12 months. Weight loss of 10% or more of initial body weight was observed in 6 of 10 women in the comprehensive group at 12 months. In the comprehensive and Weight Watchers-only groups, weight loss was significantly related to frequency of attendance at Weight Watchers meetings, and attendance was more frequent in the comprehensive group. DISCUSSION: These data indicate that the most weight loss was achieved when the counseling approach combined both Weight Watchers and individualized contacts. This was effective even though most of the individualized contacts were by telephone.