Estrogen Receptor Values Research Articles

Abstract ED02-04: Identifying targets for breast and ovarian cancer prevention

Abstract ED02-04: Identifying targets for breast and ovarian cancer prevention

Facilitating consensus by examining patterns of treatment effects

Randomized clinical trials are necessary to provide reliable evidence concerning the effectiveness and safety of adjuvant therapies for breast cancer. Such trials, however, are not sufficient to provide information needed to tailor therapies to individual patients. Trials focus on testing treatments on average for heterogeneous patient populations, while attention to the specific characteristics of the disease and the patient are needed to assess the potential benefit for the individual. While 'across the board' results are useful from a population perspective, examination of patterns of treatment response during the course of follow up and for subpopulations of patients is required to make progress and solidify consensus on how to treat individual patients. For example, for several decades it has been known that the pattern of recurrence risk from time of diagnosis is different for estrogen receptor (ER)-negative and ER-positive disease. Assuming that ER status is accurately assessed and distinguishing absence of receptors from low, intermediate and high expression cohorts, one can recognize patterns of relapse risk that are early versus later during follow up. Treatments effective against ER-negative disease reduce the risk of early relapse, while those acting on ER-positive disease demonstrate effectiveness later during the course of follow up. Another example is HER2-positive disease, where a relatively high proportion of patients tend to relapse early, and treatments such as trastuzumab that reduce the risk of early relapse have demonstrated efficacy. For premenopausal patients with ER-positive disease, ovarian function suppression and endocrine effects of chemotherapy are effective to reduce the risk of late occurring relapses. Examining the influence of patient and disease-related factors on the patterns of recurrence over time and treatment responsiveness within subpopulations in multiple randomized trials can facilitate consensus on progress that has been made and identify areas for improving the care of patients with breast cancer.

Properties of estrogen binding components in the plasma membrane of neurohypophysis in hens and changes in its binding before and after oviposition

The present study was performed to elucidate whether the estrogen binding component regarded as a receptor exists in the plasma membrane fraction of neurohypophysis in hens and whether the binding of receptor changes with relation to oviposition. The specific binding for estradiol-17β (E2) in the neurohypophysis of hens was demonstrated by the use of radioligand binding assays on the plasma membrane fraction of the tissue. The binding to [3 H]E2 had a binding specificity to E2 and diethylstilbestrol, reversibility, and saturation. Scatchard analysis revealed that the binding sites are of a single class. The equilibrium dissociation constant obtained by Scatchard analysis and kinetic analysis suggested a high affinity, and the maximum binding capacity obtained by Scatchard analysis suggested a limited capacity. These properties are characteristics of a receptor, which suggests that an estrogen receptor exists in the plasma membrane of hen neurohypophysis. The equilibrium dissociation constant value of estrogen receptor of the neurohypophysis was not significantly different between laying hens and nonlaying hens, but the maximum binding capacity value was statistically smaller (the binding affinity is higher) in laying hens than in nonlaying hens. The specific binding of estrogen receptor showed a decrease at 1 h after an injection of diethylstilbestrol in nonlaying hens. The specific binding also decreased 3 h before oviposition in laying hens and maintained low value until just after oviposition. The present study suggests that estrogen may act directly on the neurohypophysis during 3 h before oviposition in hens.

Multiplexed AQUA-based assessment of SWOG 9313 shows prognostic value of continuous ER, PR and HER2 assessment.

Abstract Abstract #704 Introduction: HER2 is expressed at high levels due to gene amplification in about 15% of breast cancer cases and it has been shown to be a poor prognostic marker. However, HER2 is also expressed in normal breast duct tissue, albeit a much lower levels. We hypothesized that continuous analysis of expression using AQUA will provide prognostic information beyond that attainable with conventional methods.
 Methods: A tissue microarray was made from 2123 cases of the 3122 patients accrued to SWOG 9313, in which sequential doxorubicin and cyclophosphamide (A-C) was compared to combination AC. A multiplexed assessment of HER2 and estrogen receptor (ER) was performed on the same slide using the immunofluoresence-based AQUA® method of automated quantitative analysis. Reproducibility and fidelity of multiplexing were determined for each marker by regression analysis.
 Results: As expected, both ER and PR were significantly predictive of disease-free survival (DFS) when both are tested as continuous variables, both adjusted for node status, tumor size, treatment and menopausal status (p-values 0.005 and <0.001, respectively). HER2, measured as a continuous variable showed a bi-phasic effect. It has been previously reported (Camp et al, Cancer Research 2003, 63;1445) that both the high and low expressers of HER2 have worse outcome (low levels are equivalent to that seen in normal breast ducts). Splitting the SWOG cohort by deciles shows that both the top and bottom decile have worse DFS than the middle 80% (log rank p=0.012). Also, modeling the hazard ratio as a function of concentration shows a U-shape relationship showing both high and low HER2 expression is associated with poorer DFS.
 Conclusions: The AQUA method provides a reproducible method of continuous measurement of ER, and HER2 on the same slide. In this cohort both ER and PR as continuous variable are highly prognostic, as expected, but multiplexing with HER2 did not affect outcome. Quantitative analysis demonstrated that both low and high levels of HER2 expression were associated with poor outcome. Studies are ongoing to determine the significance of this observation with respect to biological classifications of breast cancer and relationships with breast cancer therapies. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 704.

Value of Intraoperative Examination of Axillary Sentinel Nodes in Carcinoma of the Breast

The value of frozen sections in the intraoperative examination of sentinel nodes (SN) remains controversial. Accurate frozen sections will spare those patients with node metastasis from a second procedure to complete the axillary dissection. We examined our own experience with intraoperative examination of SN. Between January 1, 2006, and December 31, 2006, we performed 236 sentinel lymph node biopsy procedures that were read as "frozen-section-negative." An additional 47 sentinel lymph node biopsy patients were frozen-section-positive for metastatic disease and underwent immediate completion axillary dissection. At least 1 SN was found in all 283 women (100%). The number of patients with false-negative frozen sections was tallied; patient data were reviewed for a number of variables to see which factors might be associated with a false-negative result. Eleven patients had positive nodes on subsequent examination of the formalin-fixed, hematoxylin and eosin-stained slides; the false-negative rate of intraoperative frozen section was 4.7%. The sensitivity of the negative frozen section was > 95%. The following variables were compared for significance: pathologist, nuclear grade, histologic grade, margins, lymphovascular invasion, tumor type (ductal versus lobular), and estrogen receptor and progesterone receptor values. The only significant variables were lymphovascular invasion (p = 0.019) and presence of in situ ductal carcinoma (p = 0.001). Our data confirm the value of intraoperative examination of SN: > 95% sensitivity. Presence of in situ ductal carcinoma or lymphovascular invasion makes these tumors more likely than others to have micrometastases to SN overlooked.

Gene expression of estrogen receptor, progesterone receptor and microtubule-associated protein Tau in high-risk early breast cancer: a quest for molecular predictors of treatment benefit in the context of a Hellenic Cooperative Oncology Group trial

Estrogen receptor (ER) and progesterone receptor (PgR) protein expression carry weak prognostic and moderate predictive utility for the outcome of early breast cancer patients on adjuvant chemohormonotherapy. We sought to study the predictive significance and correlations of transcriptional profiling of the ER, PgR and microtubule-associated protein Tau (MAP-Tau) genes in early breast cancer. Messenger RNA (mRNA) was extracted from 279 formalin-fixed paraffin-embedded breast carcinomas (T1-3N0-1M0) of patients enrolled in the Hellenic Cooperative Oncology Group (HeCOG) trial HE 10/97, evaluating epirubicin-alkylator based adjuvant chemotherapy with or without paclitaxel (E-T-CMF versus E-CMF). Kinetic reverse transcription polymerase chain reaction (kRT-PCR) was applied for assessment of the expression of estrogen receptor, progesterone receptor and MAP-Tau genes in 274 evaluable patients. Cohort-based cut-offs were defined at the 25th percentile mRNA value for ER and PgR and the median for MAP-Tau. Two hundred and ten patients (77%) were ER and/or PgR-positive by immunohistochemistry (IHC). Positive ER and MAP-Tau mRNA status was significantly associated with administration of hormonal therapy and low grade, while MAP-Tau mRNA status correlated with premenopausal patient status. MAP-Tau strongly correlated with ER and PgR mRNA status (Spearmann r = 0.52 and 0.64, P < 0.001). The observed chance corrected agreement between determination of hormonal receptor status by kRT-PCR and IHC was moderate (Kappa = 0.41) for ER and fair (Kappa = 0.33) for PgR. At a median follow-up of 8 years, univariate analysis adjusted for treatment showed positive ER mRNA status to be of borderline significance for reduced risk of relapse (HR = 0.65, 95% CI 0.41-1.01, P = 0.055) and death (HR = 0.62, 95% CI 0.36-1.05, P = 0.077), while positive MAP-Tau mRNA status was significantly associated with reduced risk of relapse (HR = 0.50, 95% CI 0.32-0.78, P = 0.002) and death (HR = 0.49, 95% CI 0.29-0.83, P = 0.008). In multivariate analysis, only axillary nodal metastases (HR = 2.33, 95% CI 1.05-5.16, P = 0.04) and MAP-Tau mRNA status (HR = 0.46, 95% CI 0.25-0.85, P = 0.01) independently predicted patient outcome. However, MAP-Tau mRNA levels did not predict enhanced benefit from inclusion of paclitaxel in the adjuvant chemotherapy regimen (test for interaction P = 0.99). No correlation was evident between increasing ER and PgR mRNA transcription and increasing benefit from endocrine therapy in 203 ER and/or PgR IHC-positive patients receiving adjuvant hormone therapy (Wald P = 0.54 for ER, 0.51 for PR). ER gene transcription carries weak predictive significance for benefit from endocrine therapy or for outcome, with no apparent dose-response association. The predictive significance is possibly exerted via MAP-Tau gene expression, an ER-inducible tubulin modulator with strong predictive significance for patient outcome. However, MAP-Tau mRNA did not predict benefit from the addition of a taxane to adjuvant chemotherapy. Further study of the biologic function and utility of MAP-Tau for individualising adjuvant therapy is warranted.

Clinical Classification ofBRCA1andBRCA2DNA Sequence Variants: The Value of Cytokeratin Profiles and Evolutionary Analysis—A Report From the kConFab Investigators

Rare missense substitutions and in-frame deletions of BRCA1 and BRCA2 genes present a challenge for genetic counseling of individuals carrying such unclassified variants. We assessed the value of tumor immunohistochemical markers in conjunction with genetic and evolutionary approaches for investigating the clinical significance of unclassified variants. We studied 10 BRCA1 and 12 BRCA2 variants identified in Australian families with breast cancer. Analyses assumed a prior probability based on revised cross-species sequence alignment methods assessing amino acid evolutionary conservation and position, combined with likelihoods from data on co-occurrence with pathogenic mutations in the same gene, segregation analysis, and immunohistochemistry. We specifically explored the value of estrogen receptor, cytokeratin 5/6, and cytokeratin 14 as tumor markers of BRCA1 mutation status. Posterior probabilities classified 72% of variants. BRCA1 variants IVS18+1 G>T (del exon 18) and 5632 T >A (V1838E) were classified as pathogenic, with >99% posterior probability of being deleterious, and tumor histopathology was particularly important for their classification. BRCA2 variant classification was improved over previous studies, largely by incorporating the prior probability of pathogenicity based on amino acid cross-species sequence alignments. Variant classification was considerably improved by analysis of estrogen receptor, cytokeratin 5/6, and cytokeratin 14 tumor expression, and use of updated methods estimating the clinical relevance of amino acid evolutionary conservation and position. These methodologies may assist genetic counseling of individuals with unclassified sequence variants.

Interactions Between Treatment and Continuous Covariates: A Step Toward Individualizing Therapy

Interactions Between Treatment and Continuous Covariates: A Step Toward Individualizing Therapy

Prognostic value of estrogen receptor and progesterone receptor tumor expression in Danish ovarian cancer patients: From the ‘MALOVA’ Ovarian Cancer Study

Estrogen and progesterone are important hormones secreted by the ovary acting through specific receptors. Tumor tissue expression profiles of these have demonstrated prognostic value in malignancies such as breast, uterine and prostate cancer. In this study, including tissue samples from 773 Danish patients with an ovarian tumor, we evaluated whether estrogen receptor (ER) and progesterone receptor (PR) expression correlated with clinico-pathological parameters, and a possible prognostic impact on ovarian cancer (OC) patients was investigated. Using tissue array and immunohistochemistry, we analyzed the ER and PR expression levels in tissues from 582 women with OC and 191 women with low malignancy potential (LMP) ovarian tumors. Our results demonstrated that ER was expressed in 30 of the 191 LMP tumors (16%) and in 207 of the 582 OC (36%). PR was expressed in 38 LMP tumors (20%) and in 115 OC (20%). For both tumor types an excess of positive tumors was found in the serous compared to the mucinous subtype (p< or =0.00001). The frequency of ER expression-positive OC increased with increasing FIGO stage (p=0.0003), and the frequency of PR-positive tumors increased with increasing histological grade (p=0.0006). In a Cox survival analysis, a tissue ER and PR expression 10% or higher was found to imply an independent significant advantageous course of patient disease-specific survival (ER: hazard ratio (HR), 0.80; 95% confidence interval (CI), 0.63-0.99; PR: HR, 0.69; 95% CI, 0.51-0.94) together with FIGO stage, residual tumor after primary surgery, age at diagnosis and other histological types vs. serous adenocarcinoma. The histological grade of tumor was found to have no independent prognostic value. The prognostic value of ER and PR was found additive with a HR for patients with high ER and PR expression of 0.48 (95% CI, 0.31-0.74) compared to patients with <10% expression for both receptors. In conclusion, our results predict that an elevated expression of ER and PR, alone and in combination, point to a favorable outcome for patients with OC.

Expression of Estrogen Receptor β Wild-type and its Variant ERβcx/β2 is Correlated with Better Prognosis in Breast Cancer

The clinical value of estrogen receptor (ER) beta and its variants has been investigated. However, reported results have frequently been discordant. We investigated mRNA and protein expression of ERbeta wild type (ERbeta1) and its variant, ERbetacx/beta2, by quantitative real-time reverse transcriptase-polymerase chain reaction and immunohistochemistry in 150 breast cancer tissues, and analyzed association between their expression and clinicopathological factors and prognosis. ERbeta1 mRNA expression was significantly correlated with progesterone receptor expression and low histological grade. ERbeta1 protein expression was significantly correlated with small tumor size, negative lymph node status and low histological grade. ERbetacx/beta2 protein expression was significantly correlated with ERalpha expression and low histological grade. Patients with high expression of ERbeta1 or ERbetacx/beta2 had a significantly better disease-free and overall survival than those with low expression. In multivariate analysis, ERbetacx/beta2 mRNA expression was identified as a prognostic factor in disease-free and overall survival. Our results indicate that ERbetacx/beta2 mRNA expression is an independent prognostic factor in breast cancer. ERbeta expression status, both wild-type and the variant cx/beta2, might represent significant predictors of breast cancer prognosis.

Semi‐automated imaging system to quantitate estrogen and progesterone receptor immunoreactivity in human breast cancer

A semi-automated imaging system is described to quantitate estrogen and progesterone receptor immunoreactivity in human breast cancer. The system works for any conventional method of image acquisition using microscopic slides that have been processed for immunohistochemical analysis of the estrogen receptor and progesterone receptor. Estrogen receptor and progesterone receptor immunohistochemical staining produce colorimetric differences in nuclear staining that conventionally have been interpreted manually by pathologists and expressed as percentage of positive tumoral nuclei. The estrogen receptor and progesterone receptor status of human breast cancer represent important prognostic and predictive markers of human breast cancer that dictate therapeutic decisions but their subjective interpretation result in interobserver, intraobserver and fatigue variability. Subjective measurements are traditionally limited to a determination of percentage of tumoral nuclei that show positive immunoreactivity. To address these limitations, imaging algorithms utilizing both colorimetric (RGB) as well as intensity (gray scale) determinations were used to analyze pixels of the acquired image. Image acquisition utilized either scanner or microscope with attached digital or analogue camera capable of producing images with a resolution of 20 pixels /10 mu. Areas of each image were screened and the area of interest richest in tumour cells manually selected for image processing. Images were processed initially by JPG conversion of SVS scanned virtual slides or direct JPG photomicrograph capture. Following image acquisition, images were screened for quality, enhanced and processed. The algorithm-based values for estrogen receptor and progesterone receptor percentage nuclear positivity both strongly correlated with the subjective measurements (intraclass correlation: 0.77; 95% confidence interval: 0.59, 0.95) yet exhibited no interobserver, intraobserver or fatigue variability. In addition the algorithms provided measurements of nuclear estrogen receptor and progesterone receptor staining intensity (mean, mode and median staining intensity of positive staining nuclei), parameters that subjective review could not assess. Other semi-automated image analysis systems have been used to measure estrogen receptor and progesterone receptor immunoreactivity but these either have required proprietary hardware or have been based on luminosity differences alone. By contrast our algorithms were independent of proprietary hardware and were based on not just luminosity and colour but also many other imaging features including epithelial pattern recognition and nuclear morphology. These features provide a more accurate, versatile and robust imaging analysis platform that can be fully automated in the near future. Because of all these properties, our semi-automated imaging system 'adds value' as a means of measuring these important nuclear biomarkers of human breast cancer.

Comparison of Evaluations for Hormone Receptors in Breast Carcinoma Using Two Manual and Three Automated Immunohistochemical Assays

The aims of this study were to compare the quality of immunohistochemical assays of estrogen receptor (ER) and progesterone receptor (PR) and to compare the intermethod variability of assays from different manufacturers. Immunohistochemical staining was entrusted to the following laboratories in Japan: Kyowa Medex, dealing with the products of BioGenex (Mishima, Shizuoka), DAKO Japan (Kyoto), and Ventana Japan (Yokohama). All slides were semiquantitatively evaluated according to the Allred score. Intermethod variability showed fair to moderate multirater values for ER and PR (for total score, ER, κ = 0.34; PR, κ = 0.45). Another scoring system was also applied in which, irrespective of the intensity of nuclear staining, the proportion of cells stained in each specimen was recorded as 0; less than 1%; 1% or more and less than 10%; or 10% or more. Intermethod variability showed substantial multirater values for ER and PR (according to percentage of positive cells, ER, κ = 0.67; PR, κ = 0.72). Concerning intermethod consistency, the scoring system based on the percentage of positive cells was advantageous over other scoring systems.

Comparison of Evaluations for Hormone Receptors in Breast Carcinoma Using Two Manual and Three Automated Immunohistochemical Assays

The aims of this study were to compare the quality of immunohistochemical assays of estrogen receptor (ER) and progesterone receptor (PR) and to compare the intermethod variability of assays from different manufacturers. immunohistochemical staining was entrusted to the following laboratories in Japan: Kyowa Medex, dealing with the products of BioGenex (Mishima, Shizuoka), DAKO Japan (Kyoto) and Ventana Japan (Yokohama). All slides were semiquantitatively evaluated according to the Allred score. Intermethod variability showed fair to moderate multirater kappa values for ER and PR (for total score, ER, kappa = 0.34; PR, kappa = 0.45). Another scoring system was also applied in which, irrespective of the intensity of nuclear staining, the proportion of cells stained in each specimen was recorded as 0; less than 1%; 1% or more and less than 10%; or 10% or more. Intermethod variability showed substantial multirater kappa values for ER and PR (according to percentage of positive cells, ER, kappa = 0.67; PR, kappa = 0.72). Concerning intermethod consistency, the scoring system based on the percentage of positive cells was advantageous over other scoring systems.

Estrogen Receptor Testing of Breast Cancer in Current Clinical Practice: What's the Question?

Estrogen Receptor Testing of Breast Cancer in Current Clinical Practice: What's the Question?

Prognosis of operable breast cancer in young patients treated in a single institution: independent pejorative value of postive Estrogen Receptor

Prognosis of operable breast cancer in young patients treated in a single institution: independent pejorative value of postive Estrogen Receptor

Steroid receptor expressions in endometrial cancer: Clinical significance and epidemiological implication

The evaluation of expression levels of the estrogen receptor (ER) and progesterone receptor (PR) in endometrial cancer is a very common procedure in modern practice. However, the significance of such tests remains controversial, and the evaluation of the status of steroid receptors seems to be a more thoroughly justified practice. The present study was carried out with 145 endometrial cancer patients, all of whom had undergone operations at the Seoul National University Hospital, from 1993 to 2002. Paraffin-embedded tissue blocks were sectioned and immunostained with monoclonal anti-ER and anti-PR antibodies. Clinicopathological variables were also analyzed, with 10% cutoff values for ER and PR positivity. A multivariate Cox regression analysis was performed in order to estimate the influences of several clinicopathological and immunohistochemical covariates on patient survival. Forty seven specimens (32.4%) stained as ER positive, and 110 (75.9%) stained as PR-positive. Patients with PR-positive tumor tended to be both younger and more obese than patients with PR-negative tumors ( P=0.020, 0.016). Well-differentiated tumors were found to be positive for ER or PR more frequently ( P=0.015, <0.001). ER or PR-positive tumors exhibited significantly less myometrial invasion ( P=0.042, 0.002). However, multivariate Cox regression analyses revealed that the expressions of ER and PR were not significantly associated with patient survival, and only advanced FIGO stage constituted an independent prognostic factor. Our results suggested that the evaluation of steroid receptors might prove helpful prior to surgery. Low ER and high PR values suggest that racial differences and/or sequential loss of receptors during carcinogenesis might be involved in the expression of steroid receptors in cases of endometrial cancer.

Tissue microarray immunohistochemical expression of estrogen, progesterone, and androgen receptors in uterine leiomyomata and leiomyosarcoma.

Benign uterine leiomyomata (LMA) are hormonally responsive neoplasms. To the authors' knowledge, little is known regarding the hormonal expression patterns of leiomyosarcomas (LMSs) of the uterus. The objective of the current study was to assess the immunohistochemical (IHC) patterns of estrogen receptor (ER), progesterone receptor (PR), and androgen receptor (AR) expression in LMA and LMS of the uterus using a tissue microarray. The authors also sought to assess the prognostic value of ER, PR, and AR expression in LMS. Between January 1991 and March 2001, 25 patients were identified with primary uterine LMS for whom tissue was available. A tissue microarray was created with 3 representative cores from each of the LMS cases, as well as from 19 cases with benign uterine LMA. IHC staining was scored as follows: negative (0-1) and positive (2-3). Outcome analyses were performed for LMS only. First recurrence was determined from the time of the initial diagnosis. Survival was determined from the time of the initial diagnosis to last follow-up. ER, PR, and AR positivity in LMA compared with LMS was as follows: ER, 78% versus 40% (P = 0.03); PR, 88% versus 38% (P = 0.001); and AR, 32% versus 40% (P = 0.75). There was no difference noted with regard to IHC expression based on stage of LMS. The median overall survival for patients with LMS was 23.5 months (95% confidence interval, 19.5, NR). When adjusted for stage, PR and AR were found to be predictive of a lower risk of recurrence (P = 0.01 and P = 0.035, respectively). ER, PR, and AR were not found to be associated with overall survival after adjustment for stage. Tumor stage was found to be associated with survival (P = 0.005). The rate of ER and PR expression was found to be significantly less in uterine LMS compared with LMA. ER, PR, and AR expression was observed in approximately 30-40% of uterine LMS cases. In the current series, PR and AR expression appeared to be associated with disease-free survival but were not found to correlate with overall survival.

Prognosis of breast cancer patients with familial history classified according to their menopausal status.

Breast cancer patients were classified in the family history positive (FHP) group when they had at least one second-degree relative who was a breast cancer patient. The results of a comparative study with patients classified in the family history negative (FHN) group showed the prognosis of the FHP group was significantly better than that of the FHN group. However, when those patients were classified according to their menopausal status at onset, there were no significant differences in survival rates between the FHP and FHN groups with onset before menopause, whereas the survival rate of the FHP group was significantly higher than that of the FHN group with onset after menopause. The same results were found when the FHP group was subgrouped into the FHP group with first-degree relatives and the FHP group with second-degree relatives. Further investigations on background factors revealed that the patients with onset before menopause showed no significant differences between the FHP and FHN groups in age at surgery, diameter of the tumor, histologic grade, the number of metastatic lymph nodes, body weight, estrogen receptor (ER) status, and the values of CEA and CA15-3 before surgery. On the other hand, the FHP patients with onset after menopause showed significantly lower numbers of metastatic lymph nodes and trends showing higher ER values and lower CA15-3-values. Therefore the favorable prognosis in the FHP group seems to be attributable to the higher survival rate of the FHP patients with onset after menopause.

Prognosis in node-negative primary breast cancer: a neural network analysis of risk profiles using routinely assessed factors

BackgroundThe present study investigated complex time-dependent effects of routinely assessed factors on the risk of breast cancer recurrence over follow-up time, with a partial logistic artificial neural network (PLANN) model. Patients and methodsPLANN was applied to data from 1793 patients with node-negative breast cancer, not submitted to any adjuvant treatment and with a minimal potential follow-up of 10 years. ResultsThe shape of the hazard function changed according to histology, which showed a time-dependent effect, partly modulated by estrogen receptors (ERs). Age and progesterone receptors (PgR) showed protective effects; the latter was more evident for short follow-up and high ER values. Tumour size and ER content showed time-dependent unfavourable effects at early and long follow-up times, respectively. Predicted values of disease recurrence probability at 2 years of follow-up showed that low steroid-receptor content, young age and large tumour size were associated with the highest risk of relapse. Although the oldest patients with high ER content seem to be those most protected overall, high risk predictions tend to spread also to higher steroid-receptor contents, intermediate ages and small tumour size, with an increase in follow-up time. ConclusionPLANN with suitable visualisation techniques provided thorough insights into the dynamics of breast cancer recurrence for improving individual risk staging of node-negative breast cancer patients.

Minimum formalin fixation time for consistent estrogen receptor immunohistochemical staining of invasive breast carcinoma.

To identify the minimum time necessary for consistent immunohistochemical estrogen receptor (ER) results in our laboratory, we evaluated results in timed fixation blocks and cases with disparate and similar needle core biopsy and partial mastectomy specimens. Tissue sections of 24 ER-positive, invasive breast carcinomas were fixed for 3, 6, 8, and 12 hours and 1, 2, and 7 days. ER values were quantified using the Q score (0-7). In timed fixation blocks, the mean Q score per block was 2.46 for blocks fixed for 3 hours, 5.75 for blocks fixed for 6 hours, and 6.70 for blocks fixed for 8 hours (P < .001). The difference between the case maximum and mean block Q scores was a plateau of almost 0 at 6 to 8 hours of formalin fixation. For needle core biopsy specimen fixation times, the means for specimens with ER-disparate and ER-similar results were 1.2 and 6.3 hours, respectively (P = .01). The minimum formalin fixation time for reliable immunohistochemical ER results is 6 to 8 hours in our laboratory, regardless of the type or size of specimen.