S-phase fraction assessed by a variant of the rectangular model adapted to the flow-cytometric DNA histogram profile

Measurement of S-phase fraction by DNA flow cytometry is widely used in the analysis of human tumors. The calculation of fraction of S-phase cells is performed either by means of curve-fitting techniques or by more simple planimetric methods. Estimates by the latter often suffer from subjectivity or poor adaptation to complex DNA histograms. We describe a variant which is based on the rectangular model. The height of the rectangle is automatically determined from the lowest density value in the S-phase interval. The variant was tested on 141 DNA histograms, and the results were compared with those obtained with other variants based on the rectangular model. The new variant is thought to circumvent some of the problems concerning subjectivity and disturbances caused by aggregate peaks

Loss of TGFβ Receptor Type 2 Expression Impairs Estrogen Response and Confers Tamoxifen Resistance.

One third of the patients with estrogen receptor alpha (ER alpha)-positive breast cancer who are treated with the antiestrogen tamoxifen will either not respond to initial therapy or will develop drug resistance. Endocrine response involves crosstalk between ER alpha and TGF beta signaling, such that tamoxifen non-responsiveness or resistance in breast cancer might involve aberrant TGF beta signaling. In this study, we analyzed TGF beta receptor type 2 (TGFBR2) expression and correlated it with ER alpha status and phosphorylation in a cohort of 564 patients who had been randomized to tamoxifen or no-adjuvant treatment for invasive breast carcinoma. We also evaluated an additional four independent genetic datasets in invasive breast cancer. In all the cohorts we analyzed, we documented an association of low TGFBR2 protein and mRNA expression with tamoxifen resistance. Functional investigations confirmed that cell cycle or apoptosis responses to estrogen or tamoxifen in ER alpha-positive breast cancer cells were impaired by TGFBR2 silencing, as was ER alpha phosphorylation, tamoxifen-induced transcriptional activation of TGF beta, and upregulation of the multidrug resistance protein ABCG2. Acquisition of low TGFBR2 expression as a contributing factor to endocrine resistance was validated prospectively in a tamoxifen-resistant cell line generated by long-term drug treatment. Collectively, our results established a central contribution of TGF beta signaling in endocrine resistance in breast cancer and offered evidence that TGFBR2 can serve as an independent biomarker to predict treatment outcomes in ER alpha-positive forms of this disease. (C)2015 AACR

17 beta-Hydroxysteroid dehydrogenase type 1 as predictor of tamoxifen response in premenopausal breast cancer

17 beta-Hydroxysteroid dehydrogenases (17HSDs) are involved in the local regulation of sex steroids. 17HSD1 converts oestrone (El) to the more potent oestradiol (E2) and 17HSD2 catalyses the reverse reaction. The aim of this study was to investigate the expression of these enzymes in premenopausal breast cancers and to analyse if they have any prognostic or tamoxifen predictive value. Premenopausal patients with invasive breast cancer, stage II (UICC), were randomised to either 2 years of adjuvant tamoxifen (n = 276) or no tamoxifen (n = 288). The median follow-up was 13.9 years (range 10.5-17.5). The expression of 17HSD1 and 17HSD2 was analysed with immunohistochemistry using tissue microarrays. The enzyme expression level (-/+/++/+++) was successfully determined in 396 and 373 tumours, respectively. Women with hormone-receptor positive tumours, with low levels (-/+/++) of 17HSD1, had a 43% reduced risk of recurrence, when treated with tamoxifen (Hazard Ratio (HR) = 0.57; 95% confidence interval (CI), 0.37-0.86; p = 0.0086). On the other hand high expression (+++) of 17HSD1 was associated with no significant difference between the two treatment arms (HR = 0.91; 95% CI, 0.43-1.95; p = 0.82). The interaction between 17HSD1 and tamoxifen was significant during the first 5 years of follow-up (p = 0.023). In the cohort of systemically untreated patients no prognostic importance was observed for 17HSD1. We found no predictive or prognostic value for 17HSD2. This is the first report of 17HSD1 in a cohort of premenopausal women with breast cancer randomised to tamoxifen. Our data suggest that 17HSD1 might be a predictive factor in this group of patients. (C) 2009 Elsevier Ltd. All rights reserved

P27Kip1 is a predictive factor for tamoxifen treatment response but not a prognostic marker in premenopausal breast cancer patients

The cell cycle regulating protein p27(Kip1) (p27) has dual roles by acting as both a cdk-inhibitor and as an assembly factor for different cdk-complexes. Loss of p27 has been linked to malignant features in tumours, however the exact role of p27 deregulation in breast cancer regarding prognostic and treatment predictive information has not been fully clarified. We have evaluated p27 expression in 328 primary, stage II breast cancers from premenopausal patients who had been randomised to either tamoxifen treatment or no adjuvant treatment after surgery. p27 was associated with the oestrogen receptor (ER) and cyclin D1, and p27 downregulation was associated with high proliferation. There was no association between recurrence-free-survival (RFS) and p27 (HR=0.800, 95%CI 0.523-1.222, p=0.300), indicating that p27 is not a prognostic marker. The predictive value of p27 was analysed by comparing RFS in tamoxifen treated and untreated patients in subgroups of low and high p27 expression (HR=0.747, 95%CI 0.335-1.664, p=0.474 and HR=0.401, 95%CI 0.240-0.670, p<0.001, respectively). Only patients with p27 high tumours benefited from tamoxifen (multivariate interaction analysis p=0.034). Our study suggests that p27 downregulation is associated with tamoxifen resistance in premenopausal breast cancer but is not linked to impaired prognosis. (c) 2010 UICC

Effects of adjuvant tamoxifen therapy on cardiac disease: results from a randomized trial with long-term follow-up

Tamoxifen is associated with a reduced risk of coronary heart disease (CHD). However, there are few reports on long-term effects. Using data from a large Swedish randomized trial of 5 and 2 years of adjuvant tamoxifen in women with early breast cancer, we here present results on morbidity and mortality from cardiac diseases during treatment and long-term after treatment. A total of 4,150 patients were breast cancer recurrence-free after 2 years. Data from the Swedish National Hospital Discharge Registry combined with information from the Swedish Cause of Death Registry were used to define events of disease. Hazard ratios were estimated using Cox regression. Patients assigned to 5 years in comparison with 2 years of postoperative tamoxifen experienced a reduced incidence of CHD [hazard ratio (HR), 0.83; 95 % CI 0.70-1.00], especially apparent during the active treatment period (HR 0.65; 95 % CI 0.43-1.00). The mortality from CHD was significantly reduced (HR 0.72; 95 % CI 0.53-0.97). During the active treatment, the morbidity of other heart diseases was also significantly reduced (HR 0.40; 95 % CI 0.25-0.64) but not after treatment stopped (HR 1.06; 95 % CI 0.87-1.30). Similar results were seen for both heart failure and atrial fibrillation/flutter. As compared to 2 years of therapy, 5 years of postoperative tamoxifen therapy prevents CHD as well as other heart diseases. The risk reduction is most apparent during the active treatment period, and later tends to diminish

Intra- and inter-laboratory reproducibility of estrogen and progesterone receptor enzyme immunoassay in breast cancer cytosol samples--a Swedish multicenter study. Swedish Society of Cancer Study Group

Estrogen and progesterone receptor analysis results were compared within and between six laboratories in Sweden using frozen breast cancer cytosol samples, and the same technique (enzyme immunoassay, Abbott Laboratories). The concordance in receptor status (positive vs. negative) was excellent (98.4% (571/580)). The discordant results were attributable to values near cut-off (n = 4) or outliers (n = 5), the latter probably being due to analytical errors. One laboratory reported significantly higher ER concentrations than the others; thus caution should be observed when comparing absolute values from different centers. For PgR there were similar differences between the laboratories. However, the intra- and inter-laboratory differences were small compared with the overall variability in ER and PgR content between different samples in a large database. The range of the median intra-laboratory coefficient of variation was 11-23% for ER and 12-19% for PgR, indicating that there is room for improvement in the quality of assay performance