Medline ® Abstracts for References 42-45
of 'Adjuvant chemotherapy for HER2-negative breast cancer'
Effect of body mass index on recurrences in tamoxifen and anastrozole treated women: an exploratory analysis from the ATAC trial.
Sestak I, Distler W, Forbes JF, Dowsett M, Howell A, Cuzick J
J Clin Oncol. 2010;28(21):3411. Epub 2010 Jun 14.
PURPOSE: Third-generation aromatase inhibitors have been widely used in postmenopausal women for the adjuvant treatment of hormone receptor-positive breast cancer. As aromatase inhibitors work by inhibiting the conversion of androgens to estrogens in adipose tissue, we hypothesized that anastrozole may be more effective in women with a high body mass index (BMI).
PATIENTS AND METHODS: The Arimidex, Tamoxifen Alone or in Combination (ATAC) study was a double-blind randomized clinical trial in which postmenopausal women with early-stage breast cancer were randomly assigned to receive oral daily anastrozole (1 mg) alone, tamoxifen (20 mg) alone, or the combination in a double-blind fashion. Analyses were based on the 100-month median follow-up for women with hormone receptor-positive breast cancers (estrogen [ER]and/or progesterone [PgR]positive). Here, we investigate the impact of BMI on recurrence and the relative benefit of anastrozole versus tamoxifen according to baseline BMI. Results Overall, women with a high BMI (BMI>35 kg/m(2)) at baseline had more recurrences than those women with a low BMI (BMI<23 kg/m(2); adjusted hazard ratio [HR], 1.39; 95% CI, 1.06 to 1.82; P(heterogeneity) = .03) and significantly more distant recurrences (adjusted HR, 1.46; 95% CI, 1.07 to 1.61; P(heterogeneity) = .01). Overall, the relative benefit of anastrozole versus tamoxifen was nonsignificantly better in thin women compared to overweight women.
CONCLUSION: These results confirm the poorer prognosis of obese women with early-stage breast cancer. Recurrence rates were lower for anastrozole than tamoxifen for all BMI quintiles. Our results suggest that the relative efficacy of anastrozole compared to tamoxifen is greater in thin postmenopausal women and higher doses or more complete inhibitors might be more effective in overweight women, but this requires independent confirmation.
Cancer Research UK UK, Queen Mary University of London, London, United Kingdom. email@example.com
Impact of body mass index on the efficacy of endocrine therapy in premenopausal patients with breast cancer: an analysis of the prospective ABCSG-12 trial.
Pfeiler G, Königsberg R, Fesl C, Mlineritsch B, Stoeger H, Singer CF, Pöstlberger S, Steger GG, Seifert M, Dubsky P, Taucher S, Samonigg H, Bjelic-Radisic V, Greil R, Marth C, Gnant M
J Clin Oncol. 2011;29(19):2653. Epub 2011 May 9.
PURPOSE: Aromatase inhibitors are effective as endocrine treatment for patients with hormone receptor-positive breast cancer. According to the hypothesis that overweight patients have higher levels of aromatase enzyme availability, we investigated the influence of body mass index (BMI) on the efficacy of adjuvant endocrine therapy in premenopausal patients in a retrospective analysis of the Austrian Breast and Colorectal Cancer Study Group (ABCSG) 12 trial.
PATIENTS AND METHODS: ABCSG-12 examined the efficacy of ovarian suppression using goserelin (3.6 mg subcutaneously every 28 days) in combination with anastrozole or tamoxifen with or without zoledronic acid (4 mg intravenously every 6 months) in premenopausal women with endocrine-responsive breast cancer. BMI was calculated using the prospectively collected data on patients' height and weight at study entry. BMI categories have been differentiated according to the WHO definition.
RESULTS: Overweight patients treated with anastrozole had a 60% increase in the risk of disease recurrence (hazard ratio [HR], 1.60; 95% CI, 1.06 to 2.41; P = .02) and more than a doubling in the risk of death (HR, 2.14; 95% CI, 1.17 to 3.92; P = .01) compared with normal weight patients treated with anastrozole. In the overweight group, patients treated with anastrozole had a nearly 50% increase in the risk of disease recurrence (HR, 1.49; 95% CI, 0.93 to 2.38; P = .08) and a three-fold increase in the risk of death (HR, 3.03; 95% CI, 1.35 to 6.82; P = .004) compared with patients treated with tamoxifen.
CONCLUSION: BMI significantly impacts on the efficacy of anastrozole plus goserelin in premenopausal patients with breast cancer, probably through influencing aromatase availability and/or ovarian suppression by goserelin.
Department of Surgery, Comprehensive Cancer Center Vienna, Medical University of Vienna, Waehringer Guertel 18-20, A-1090, Vienna, Austria.
Obesity at diagnosis is associated with inferior outcomes in hormone receptor-positive operable breast cancer.
Sparano JA, Wang M, Zhao F, Stearns V, Martino S, Ligibel JA, Perez EA, Saphner T, Wolff AC, Sledge GW Jr, Wood WC, Fetting J, Davidson NE
Cancer. 2012;118(23):5937. Epub 2012 Aug 27.
BACKGROUND: Obesity has been associated with inferior outcomes in operable breast cancer, but the relation between body mass index (BMI) and outcomes by breast cancer subtype has not been previously evaluated.
METHODS: The authors evaluated the relation between BMI and outcomes in 3 adjuvant trials coordinated by the Eastern Cooperative Oncology Group that included chemotherapy regimens with doxorubicin and cyclophosphamide, including E1199, E5188, and E3189. Results are expressed as hazard ratios (HRs) from Cox proportional hazards models (HR>1 indicates a worse outcome). All P values are 2-sided.
RESULTS: When evaluated as a continuous variable in trial E1199, increasing BMI within the obese (BMI,≥30 kg/m(2)) and overweight (BMI, 25-29.9 kg/m(2)) ranges was associated with inferior outcomes in hormone receptor-positive, human epidermal growth receptor 2 (HER-2)/neu-negative disease for disease-free survival (DFS; P = .0006) and overall survival (OS; P = .0007), but not in HER-2/neu-overexpressing or triple-negative disease. When evaluated as a categorical variable, obesity was associated with inferior DFS (HR, 1.24; 95% confidence interval [CI], 1.06-1.46; P = .0008) and OS (HR, 1.37; 95% CI, 1.13-1.67; P = .002) in hormone receptor-positive disease, but not other subtypes. In a model including obesity, disease subtype, and their interaction, the interaction term was significant for OS (P = .02) and showed a strong trend for DFS (P = .07). Similar results were found in 2 other trials (E5188, E3189).
CONCLUSIONS: In a clinical trial population that excluded patients with significant comorbidities, obesity was associated with inferior outcomes specifically in patients with hormone receptor-positive operable breast cancer treated with standard chemohormonal therapy.
Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York, USA. firstname.lastname@example.org
Obesity, tamoxifen use, and outcomes in women with estrogen receptor-positive early-stage breast cancer.
Dignam JJ, Wieand K, Johnson KA, Fisher B, Xu L, Mamounas EP
J Natl Cancer Inst. 2003;95(19):1467.
BACKGROUND: Obesity is associated with both increased breast cancer risk and poorer prognosis after disease onset. However, little is known about the effect of obesity on treatment efficacy. We evaluated the association of obesity with outcomes and with tamoxifen efficacy in women with early-stage, hormone-responsive breast cancer participating in a multicenter cancer cooperative group clinical trial.
METHODS: The cohort consisted of 3385 women enrolled in National Surgical Adjuvant Breast and Bowel Project (NSABP) protocol B-14, a randomized, placebo-controlled trial evaluating tamoxifen for lymph node-negative, estrogen receptor (ER)-positive breast cancer. Hazards of breast cancer recurrence, contralateral breast tumors, other new primary cancers, and several mortality endpoints were evaluated in relation to body mass index (BMI), using statistical modeling to adjust for other prognostic factors. Median follow-up time was 166 months. All statistical tests were two-sided.
RESULTS: The hazard of breast cancer recurrence was the same among obese (BMI>or=30.0 kg/m2) women as compared with underweight and normal-weight women (BMI<25.0; hazard ratio [HR]= 0.98, 95% confidence interval [CI]= 0.80 to 1.18). Contralateral breast cancer hazard was higher in obese women than in underweight/normal-weight women (HR = 1.58, 95% CI = 1.10 to 2.25), as was the risk of other primary cancers (HR = 1.62, 95% CI = 1.16 to 2.24). Compared with normal-weight women, obese women had greater all-cause mortality (HR = 1.31, 95% CI = 1.12 to 1.54) and greater risk of deaths due to causes unrelated to breast cancer (HR = 1.49, 95% CI = 1.15 to 1.92). Breast cancer mortality was not statistically significantly increased for obese women (HR = 1.20, 95% CI = 0.97 to 1.49). Tamoxifen reduced breast cancer recurrence and mortality, regardless of BMI.
CONCLUSIONS: For women with lymph node-negative, ER-positive breast cancer, obesity was not associated with a material increase in recurrence risk or a change in tamoxifen efficacy. However, because obesity was associated with increased risks of contralateral breast cancer, of other primary cancers, and of overall mortality, it may influence long-term outcomes for breast cancer survivors.
Department of Health Studies and Cancer Research Center, The University of Chicago, Chicago, IL 60637, USA. email@example.com