ESR1 and ESR2 polymorphisms in the BIG 1-98 trial comparing adjuvant letrozole versus tamoxifen or their sequence for early breast cancer.

Estrogen receptor 1 (ESR1) and ESR2 gene polymorphisms have been associated with endocrine-mediated physiological mechanisms, and inconsistently with breast cancer risk and outcomes, bone mineral density changes, and hot flushes/night sweats. DNA was isolated and genotyped for six ESR1 and two ESR2 single-nucleotide polymorphisms (SNPs) from tumor specimens from 3691 postmenopausal women with hormone receptor-positive breast cancer enrolled in the BIG 1-98 trial to receive tamoxifen and/or letrozole for 5 years. Associations with recurrence and adverse events (AEs) were assessed using Cox proportional hazards models. 3401 samples were successfully genotyped for five SNPs. ESR1 rs9340799(XbaI) (T>C) variants CC or TC were associated with reduced breast cancer risk (HR = 0.82,95% CI = 0.67-1.0), and ESR1 rs2077647 (T>C) variants CC or TC was associated with reduced distant recurrence risk (HR = 0.69, 95% CI = 0.53-0.90), both regardless of the treatments. No differential treatment effects (letrozole vs. tamoxifen) were observed for the association of outcome with any of the SNPs. Letrozole-treated patients with rs2077647 (T>C) variants CC and TC had a reduced risk of bone AE (HR = 0.75, 95% CI = 0.58-0.98, P interaction = 0.08), whereas patients with rs4986938 (G>A) genotype variants AA and AG had an increased risk of bone AE (HR = 1.37, 95% CI = 1.01-1.84, P interaction = 0.07). We observed that (1) rare ESR1 homozygous polymorphisms were associated with lower recurrence, and (2) ESR1 and ESR2 SNPs were associated with bone AEs in letrozole-treated patients. Genes that are involved in estrogen signaling and synthesis have the potential to affect both breast cancer recurrence and side effects, suggesting that individual treatment strategies can incorporate not only oncogenic drivers but also SNPs related to estrogen activity.

CYP19A1 polymorphisms and clinical outcomes in postmenopausal women with hormone receptor-positive breast cancer in the BIG 1-98 trial.

To determine whether CYP19A1 polymorphisms are associated with abnormal activity of aromatase and with musculoskeletal and bone side effects of aromatase inhibitors. DNA was isolated from tumor specimens of 4861 postmenopausal women with hormone receptor-positive breast cancer enrolled in the BIG 1-98 trial to receive tamoxifen and/or letrozole for 5 years. Tumors were genotyped for six CYP19A1 polymorphisms using PCR-based methods. Associations with breast cancer-free interval (BCFI), distant recurrence-free interval (DRFI), musculoskeletal and bone adverse events (AEs) were assessed using Cox proportional hazards models. All statistical tests were two-sided. No association between the CYP19A1 genotypes and BCFI or DRFI was observed overall. A reduced risk of a breast cancer event for tamoxifen-treated patients with rs700518 variants was observed (BCFI CC/TC vs. TT: HR 0.53, 95 % CI 0.34-0.82, interaction P = 0.08), but not observed for letrozole-treated patients. There was an increased risk of musculoskeletal AEs for patients with rs700518 variants CC/TC versus TT (HR 1.22, 95 % CI 1.03-1.45, P = 0.02), regardless of treatment. Tamoxifen-treated patients with rs4646 variants had a reduced risk of bone AEs (AA/CA vs. CC: HR 0.76, 95 % CI 0.59-0.98), whereas an increase of minor allele (C) of rs10046 was associated with an increased risk of bone AEs (HR 1.28, 95 % CI 1.07-1.52). rs936308 variants were associated with a reduced risk of bone AEs in letrozole-treated patients (GG/GC vs. CC: HR 0.73, 95 % CI 0.54-0.99), different from in tamoxifen-treated patients (GG/GC vs. CC: HR 1.32, 95 % CI 0.92-1.90, interaction P = 0.01). CYP19A1 rs700518 variants showed associations with BCFI, DRFI, in tamoxifen treated patients and musculoskeletal AEs regardless of treatment. SNPs rs4646, rs10046, and rs936308 were associated with bone AEs.

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.

Assessing the status of axillary sentinel lymph nodes of breast carcinoma patients by a real-time quantitative RT-PCR assay for mammaglobin 1 mRNA.

The aim of the study was to assess the accuracy of a real-time quantitative RT-PCR (qRT-PCR) assay for mammaglobin 1 mRNA in the detection of metastatic breast cancer in axillary sentinel lymph nodes (SLN), comparing the results with those of qualitative RT-PCR assays and of an extensive histopathological examination. A retrospective series of 81 SLN from 72 patients and a validation series of 61 SLN from 61 patients were evaluated. In the retrospective series, the qRT-PCR assay was positive for 23 (28.4%) of the 81 SLN. The overall concordance with histopathology was 93.8%, with a sensitivity of 90.9%, a specificity of 94.9%, a positive predictive value (PPV) of 87% and a negative predictive value (NPV) of 96.6%. In the same series, qualitative RT-PCR showed an overall concordance with histopathology of 86.4%, a sensitivity of 72.7%, a specificity of 91.5%, a PPV of 76.2% and a NPV of 90%. In the validation series, including 23 patients with pure in situ carcinoma, the real-time qRT-PCR assay showed an overall concordance with the histopathologic findings of 93.4%, with a sensitivity of 75.0%, a specificity of 94.7%, a PPV of 50.0% and a NPV of 98.2%. We conclude that real-time qRT-PCR assays for mammaglobin 1 are more sensitive and specific that qualitative RT-PCR assays for the detection of metastatic breast carcinoma in axillary SLN, but it should not be regarded as a possible substitute for an extensive histopathological scrutiny of the SLN in the clinical practice.

The transactivating isoforms of p63 are overexpressed in high-grade follicular lymphomas independent of the occurrence of p63 gene amplification.

p63 is a p53-related gene mapping to 3q28 that codes for multiple mRNA transcripts with (TA-p63) or without (DeltaN-p63) transactivating effects on genes that promote cell differentiation and apoptosis. We analysed p63 alterations by immunohistochemistry, quantitative real-time RT-PCR and FISH in a series of 45 follicular lymphomas (FL). None of the tumours showed immunoreactivity for the p40 antibody, which recognizes only the truncated isoforms of p63, or DeltaN-p63 mRNA expression. Immunoreactivity for the 4A4 antibody, which recognizes both the transactivating and the truncated p63 isoforms, was found in 5 +/- 5.5%, 6.85 +/- 4.88% and 33.2 +/- 22.31% of grade I, II and III FL cells, respectively (p < 0.0001). Quantitative RT-PCR analysis showed that all cases but one had TA-p63 mRNA levels higher than non-neoplastic lymphocytes, and that TA-p63 mRNA expression correlated significantly (r = 0.9194, p < 0.0001) with the prevalence of p63 immunoreactivity. FISH extra signals for the p63 gene were found in seven (23.3%) of the 30 cases analysed (0/6 grade I, 2/15 grade II and 5/9 grade III; p = 0.01937). Further hybridizations showed a pattern highly suggestive of chromosome 3 polysomy in six cases. One of these cases also bore extra copies of the p63 and bcl-6 genes. Co-localization of p63 and IgH signals was found in one case. No association between the prevalence of p63 immunoreactivity and extra p63 gene signals was detectable when the cases were dichotomized according to a p63 immunoreactivity threshold of 10%. Our data suggest that TA-p63 is overexpressed in high-grade FL, possibly independent of the occurrence of gene abnormalities, and that it may be involved in the highly complex mechanism of regulation of apoptosis of FL cells.