20-Year Risks of Breast-Cancer Recurrence after Stopping Endocrine Therapy at 5 Years

The administration of endocrine therapy for 5 years substantially reduces recurrence rates during and after treatment in women with early-stage, estrogen-receptor (ER)-positive breast cancer. Extending such therapy beyond 5 years offers further protection but has additional side effects. Obtaining data on the absolute risk of subsequent distant recurrence if therapy stops at 5 years could help determine whether to extend treatment

Distinct clinical and prognostic features of infiltrating lobular carcinoma of the breast: Combined results of 15 International Breast Cancer Study Group clinical trials

Purpose To determine how patients with infiltrating lobular carcinoma (ILC) differ from patients with the more common infiltrating ductal carcinoma (IDC) with regard to patient and tumor factors, local treatment, and patterns of recurrence. Patients and Methods Twelve thousand two hundred six breast cancer patients entered onto 15 International Breast Cancer Study Group trials between 1978 and 2002 were categorized as having ILC, IDC, or other/ mixed types. Results Seven hundred sixty-seven tumors (6.2%) were classified as ILC, 8,607 (70.5%) were classified as IDC, and 2,832 (23.2%) were classified as other. The analysis is limited to the 9,374 patients categorized as either pure IDC or ILC. The median follow-up time was 13 years. Compared with IDC, ILC was associated with older age; larger, better differentiated, and estrogen receptor (ER) -positive tumors; and less vessel invasion. Mastectomy was used more frequently for ILC (P < .01). There was a significant (P < .01) early advantage in disease-free survival and overall survival for the ILC cohort followed by a significant (P < .01) late advantage for the IDC cohort after 6 and 10 years, respectively. Similar patterns were observed in cohorts defined by ER status. ILC was associated with an increased incidence of bone events but a decrease in regional and lung events (all P < .01). Conclusion ILC is more than a histologic variant of breast cancer. The diagnosis of ILC carries distinct prognostic and biologic implications

Premenopausal endocrine-responsive early breast cancer : who receives chemotherapy?

BACKGROUND: The role of chemotherapy in addition to combined endocrine therapy for premenopausal women with endocrine-responsive early breast cancer remains an open question, yet trials designed to answer it have repeatedly failed to adequately accrue. The International Breast Cancer Study Group initiated two concurrent trials in this population: in Premenopausal Endocrine Responsive Chemotherapy (PERCHE), chemotherapy use is determined by randomization and in Tamoxifen and Exemestane Trial (TEXT) by physician choice. PERCHE closed with inadequate accrual; TEXT accrued rapidly. METHODS: From 2003 to 2006, 1317 patients (890 with baseline data) were randomly assigned to receive ovarian function suppression (OFS) plus tamoxifen or OFS plus exemestane for 5 years in TEXT. We explore patient-related factors according to whether or not chemotherapy was given using descriptive statistics and classification and regression trees. RESULTS: Adjuvant chemotherapy was chosen for 64% of patients. Lymph node status was the predominant determinant of chemotherapy use (88% of node positive treated versus 46% of node negative). Geography, patient age, tumor size and grade were also determinants, but degree of receptor positivity and human epidermal growth factor receptor 2 status were not. CONCLUSIONS: The perceived estimation of increased risk of relapse is the primary determinant for using chemotherapy despite uncertainties regarding the degree of benefit it offers when added to combined endocrine therapy in this population

Extracapsular tumor spread and the risk of local, axillary and supraclavicular recurrence in node-positive, premenopausal patients with breast cancer

Background: Extracapsular tumor spread (ECS) has been identified as a possible risk factor for breast cancer recurrence, but controversy exists regarding its role in decision making for regional radiotherapy. This study evaluates ECS as a predictor of local, axillary, and supraclavicular recurrence

CYP2D6 genotype and tamoxifen response in postmenopausal women with endocrine-responsive breast cancer : the Breast International Group 1-98 Trial

BACKGROUND: Adjuvant tamoxifen therapy is effective for postmenopausal women with endocrine-responsive breast cancer. Cytochrome P450 2D6 (CYP2D6) enzyme metabolizes tamoxifen to clinically active metabolites, and CYP2D6 polymorphisms may adversely affect tamoxifen efficacy. In this study, we investigated the clinical relevance of CYP2D6 polymorphisms. METHODS: We obtained tumor tissues and isolated DNA from 4861 of 8010 postmenopausal women with hormone receptor-positive breast cancer who enrolled in the randomized, phase III double-blind Breast International Group (BIG) 1-98 trial between March 1998 and May 2003 and received tamoxifen and/or letrozole treatment. Extracted DNA was used for genotyping nine CYP2D6 single-nucleotide polymorphisms using polymerase chain reaction-based methods. Genotype combinations were used to categorize CYP2D6 metabolism phenotypes as poor, intermediate, and extensive metabolizers (PM, IM, and EM, respectively; n = 4393 patients). Associations of CYP2D6 metabolism phenotypes with breast cancer-free interval (referred to as recurrence) and treatment-induced hot flushes according to randomized endocrine treatment and previous chemotherapy were assessed. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). All statistical tests were two-sided. RESULTS: No association between CYP2D6 metabolism phenotypes and breast cancer-free interval was observed among patients who received tamoxifen monotherapy without previous chemotherapy (P = .35). PM or IM phenotype had a non-statistically significantly reduced risk of breast cancer recurrence compared with EM phenotype (PM or IM vs EM, HR of recurrence = 0.86, 95% CI = 0.60 to 1.24). CYP2D6 metabolism phenotype was associated with tamoxifen-induced hot flushes (P = .020). Both PM and IM phenotypes had an increased risk of tamoxifen-induced hot flushes compared with EM phenotype (PM vs EM, HR of hot flushes = 1.24, 95% CI = 0.96 to 1.59; IM vs EM, HR of hot flushes = 1.23, 95% CI = 1.05 to 1.43). CONCLUSIONS: CYP2D6 phenotypes of reduced enzyme activity were not associated with worse disease control but were associated with increased hot flushes, contrary to the hypothesis. The results of this study do not support using the presence or absence of hot flushes or the pharmacogenetic testing of CYP2D6 to determine whether to treat postmenopausal breast cancer patients with tamoxifen

CYP2D6 genotype and tamoxifen response in postmenopausal women with endocrine-responsive breast cancer:the breast international group 1-98 trial

BACKGROUND: Adjuvant tamoxifen therapy is effective for postmenopausal women with endocrine-responsive breast cancer. Cytochrome P450 2D6 (CYP2D6) enzyme metabolizes tamoxifen to clinically active metabolites, and CYP2D6 polymorphisms may adversely affect tamoxifen efficacy. In this study, we investigated the clinical relevance of CYP2D6 polymorphisms. METHODS: We obtained tumor tissues and isolated DNA from 4861 of 8010 postmenopausal women with hormone receptor–positive breast cancer who enrolled in the randomized, phase III double-blind Breast International Group (BIG) 1-98 trial between March 1998 and May 2003 and received tamoxifen and/or letrozole treatment. Extracted DNA was used for genotyping nine CYP2D6 single-nucleotide polymorphisms using polymerase chain reaction–based methods. Genotype combinations were used to categorize CYP2D6 metabolism phenotypes as poor, intermediate, and extensive metabolizers (PM, IM, and EM, respectively; n = 4393 patients). Associations of CYP2D6 metabolism phenotypes with breast cancer-free interval (referred to as recurrence) and treatment-induced hot flushes according to randomized endocrine treatment and previous chemotherapy were assessed. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). All statistical tests were two-sided. RESULTS: No association between CYP2D6 metabolism phenotypes and breast cancer-free interval was observed among patients who received tamoxifen monotherapy without previous chemotherapy (P = .35). PM or IM phenotype had a non-statistically significantly reduced risk of breast cancer recurrence compared with EM phenotype (PM or IM vs EM, HR of recurrence = 0.86, 95% CI = 0.60 to 1.24). CYP2D6 metabolism phenotype was associated with tamoxifen-induced hot flushes (P = .020). Both PM and IM phenotypes had an increased risk of tamoxifen-induced hot flushes compared with EM phenotype (PM vs EM, HR of hot flushes = 1.24, 95% CI = 0.96 to 1.59; IM vs EM, HR of hot flushes = 1.23, 95% CI = 1.05 to 1.43). CONCLUSIONS: CYP2D6 phenotypes of reduced enzyme activity were not associated with worse disease control but were associated with increased hot flushes, contrary to the hypothesis. The results of this study do not support using the presence or absence of hot flushes or the pharmacogenetic testing of CYP2D6 to determine whether to treat postmenopausal breast cancer patients with tamoxifen

Overview of the randomized trials of radiotherapy in ductal carcinoma in situ of the breast.

Individual patient data were available for all four of the randomized trials that began before 1995, and that compared adjuvant radiotherapy vs no radiotherapy following breast-conserving surgery for ductal carcinoma in situ (DCIS). A total of 3729 women were eligible for analysis. Radiotherapy reduced the absolute 10-year risk of any ipsilateral breast event (ie, either recurrent DCIS or invasive cancer) by 15.2% (SE 1.6%, 12.9% vs 28.1% 2 P <.00001), and it was effective regardless of the age at diagnosis, extent of breast-conserving surgery, use of tamoxifen, method of DCIS detection, margin status, focality, grade, comedonecrosis, architecture, or tumor size. The proportional reduction in ipsilateral breast events was greater in older than in younger women (2P < .0004 for difference between proportional reductions; 10-year absolute risks: 18.5% vs 29.1% at ages <50 years, 10.8% vs 27.8% at ages ≥ 50 years) but did not differ significantly according to any other available factor. Even for women with negative margins and small low-grade tumors, the absolute reduction in the 10-year risk of ipsilateral breast events was 18.0% (SE 5.5, 12.1% vs 30.1%, 2P = .002). After 10 years of follow-up, there was, however, no significant effect on breast cancer mortality, mortality from causes other than breast cancer, or all-cause mortality.Journal ArticleResearch Support, Non-U.S. Gov'tReviewinfo:eu-repo/semantics/publishe

Effect of radiotherapy after breast-conserving surgery on 10-year recurrence and 15-year breast cancer death: meta-analysis of individual patient data for 10,801 women in 17 randomised trials.

After breast-conserving surgery, radiotherapy reduces recurrence and breast cancer death, but it may do so more for some groups of women than for others. We describe the absolute magnitude of these reductions according to various prognostic and other patient characteristics, and relate the absolute reduction in 15-year risk of breast cancer death to the absolute reduction in 10-year recurrence risk.Journal ArticleMeta-AnalysisResearch Support, Non-U.S. Gov'tReviewinfo:eu-repo/semantics/publishe