Abstract
Objective:To determine the effects on menopausal symptoms and quality of life of switching from tamoxifen to anastrozole as adjuvant endocrine treatment for early breast cancer patients.
Patients and methods:Forty-four women who had completed primary breast cancer treatment (surgery ± radiotherapy ± chemotherapy), were postmenopausal, and had switched from tamoxifen to anastrozole as adjuvant hormonal treatment because of tolerability issues were enrolled. Endocrine symptoms and health-related quality of life were assessed by the series of Functional Assessment of Cancer Therapy-Breast (FACT-B) and endocrine subscale (ES) questionnaires at the time of the switch and 12 months later, and by the ES alone at 3, 6, and 9 months after switching. Sample size was decided by the effect size method, with a standard deviation fixed at 0.5, the conventionally accepted value representative of an effect of medium value. To evaluate score modifications, one-way ANOVAs were applied.
Results:Endocrine symptoms improved between baseline and 3 months and stabilized thereafter. Improvements in mean ES scores from baseline were +3 (95% CI 1, 5), +4 (95% CI 3, 6), +5 (95% CI 3, 7), and +4 (95% CI 3, 6) at 3, 6, 9, and 12 months, respectively. The FACT-ES global score showed a mean improvement over 12 months of 9 points (95% CI 6, 13; p < 0.0005). A statistically significant improvement in Trial Outcome Index scores from baseline to 12 months (+4 points [95% CI 2, 6; p < 0.0005]) and in the physical and breast cancer subscales (+2 [95% CI 1, 2; p < 0.001] and +1 [95% CI 1, 2; p < 0.001]) was also observed. Compared with tamoxifen treatment, patients receiving anastrozole reported significantly higher rates of mild arthritic and bone pain (27%vs 7%; p = 0.021)
Conclusion:This study evaluated a small population of 44 patients who had switched from tamoxifen to enastrozole mainly because of gynecologic adverse effects with tamoxifen. However, the results of this study suggest that a change to anastrozole as adjuvant therapy should be considered for patients who develop endocrine symptoms while receiving tamoxifen to minimize those symptoms and improve quality of life.
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References
Goldhirsch A, Wood WC, Gelber RD, et al. Meeting highlights: updated international expert consensus on the primary therapy of early breast cancer. J Clin Oncol 2003; 21(17): 3357–65
Early Breast Cancer Trialists’ Collaborative Group. Tamoxifen for early breast cancer: an overview of the randomised trials. Lancet 1998; 351(9114): 1451–67
Koberle D, Thurlimann B. Adjuvant endocrine therapy in postmenopausal breast cancer patients. Breast 2005; 14(6): 446–51
Ring A, Dowsett M. Mechanisms of tamoxifen resistance. Endocr Relat Cancer 2004; 11(4): 643–58
Baum M, Budzar AU, Cuzick J, et al. Anastrozole alone or in combination with tamoxifen versus tamoxifen alone for adjuvant treatment of postmenopausal women with early breast cancer: first results of the ATAC randomised trial. Lancet 2002; 359(9324): 2131–9
Baum M, Buzdar A, Cuzick J, et al. Anastrozole alone or in combination with tamoxifen versus tamoxifen alone for adjuvant treatment of postmenopausal women with early-stage breast cancer: results of the ATAC (Arimidex, Tamoxifen Alone or in Combination) trial efficacy and safety update analyses. Cancer 2003; 98(9): 1802–10
Goss PE, Ingle JN, Martino S, et al. A randomized trial of letrozole in postmenopausal women after five years of tamoxifen therapy for early-stage breast cancer. N Engl J Med 2003; 349(19): 1793–802
Howell A, Cuzick J, Baum M, et al. Results of the ATAC (Arimidex, Tamoxifen, Alone or in Combination) trial after completion of 5 years’ adjuvant treatment for breast cancer. Lancet 2005; 365(9453): 60–2
Thurlimann B, Keshaviah A, Coates AS, et al. A comparison of letrozole and tamoxifen in postmenopausal women with early breast cancer. N Engl J Med 2005; 353(26): 2747–57
Boccardo F, Rubagotti A, Puntoni M, et al. Switching to anastrozole versus continued tamoxifen treatment of early breast cancer: preliminary results of the Italian Tamoxifen Anastrozole Trial. J Clin Oncol 2005; 23(22): 5138–47
Coombes RC, Hall E, Gibson LJ, et al. A randomized trial of exemestane after two to three years of tamoxifen therapy in postmenopausal women with primary breast cancer. N Engl J Med 2004; 350(11): 1081–92
Fallowfield L. Acceptance of adjuvant therapy and quality of life issues. Breast 2005; 14(6): 612–6
Fallowfield L, Cella D, Cuzick J, et al. Quality of life of postmenopausal women in the Arimidex, Tamoxifen, Alone or in Combination (ATAC) adjuvant breast cancer trial. J Clin Oncol 2004; 22(21): 4261–71
National Cancer Institute [online]. Available from URL: http://ctep.cancer.gov [Accessed 2006 Nov 6]
Functional Assessment of Chronic Illness Therapy [online]. Available from URL: http://www.facit.org [Accessed 2006 Nov 6]
Bonomi AE, Cella DF, Hahn EA, et al. Multilingual translation of the Functional Assessment of Cancer Therapy (FACT) quality of life measurement system. Qual Life Res 1996; 5(3): 309–20
Cella DF, Tulsky DS, Gray G, et al. The functional assessment of cancer therapy scale: development and validation of the general measure. J Clin Oncol 1993; 11(3): 570–9
Brady MJ, Cella DF, Mo F, et al. Reliability and validity of the Functional Assessment of Cancer Therapy-Breast quality-of-life instrument. J Clin Oncol 1997; 15(3): 974–86
Fallowfield LJ, Leaity SK, Howell A, et al. Assessment of quality of life in women undergoing hormonal therapy for breast cancer: validation of an endocrine symptom subscale for the FACT-B. Breast Cancer Res Treat 1999; 55(2): 189–99
Osoba D, Rodrigues G, Myles J, et al. Interpreting the significance of changes in health-related quality-of-life scores. J Clin Oncol 1998; 16(1): 139–44
Fallowfield LJ, Price MH, Hall E, et al. Intergroup exemestane study: results of the quality of life sub-protocol [abstract no. 4]. Breast Cancer Res Treat 2004; 88 Suppl. 1: S8
Fallowfield LJ, Bliss JM, Porter LS, et al. Quality of life in the intergroup exemestane study: a randomized trial of exemestane versus continued tamoxifen after 2 to 3 years of tamoxifen in postmenopausal women with primary breast cancer. J Clin Oncol 2006; 24(6): 910–7
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Massacesi, C., Sabbatini, E., Zepponi, L. et al. Effects of Switching from Tamoxifen to Anastrozole on Tamoxifen-Related Endocrine Symptoms and Quality of Life. Am J Cancer 5, 433–440 (2006). https://doi.org/10.2165/00024669-200605060-00009
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DOI: https://doi.org/10.2165/00024669-200605060-00009