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The presence of TP53 gene mutations in breast cancer has been associated with worse prognosis. These mutations interfere with the ability of the p53 protein, a transcription factor, to regulate the expression of target genes. Unlike the wild-type protein, which is rapidly degraded in cells, mutated forms have increased half-life and accumulate in tumor cells. Immunohistochemistry (IHC) is widely used in Brazil in the determination of breast cancer patients' prognosis. However, this technique is not able to detect many altered forms of the p53 protein (false-negative results) and readily detects the accumulation of wild-type p53 (false-positive results) that is associated with non-tumoral processes. For these reasons, we have set out to compare the efficiency of IHC with a molecular technique that detects gene variations at the DNA level in the evaluation of Brazilian patients with sporadic breast cancer. We have used denaturing gradient gel electrophoresis (DGGE) to study the TP53 status in 45 tumors, finding 26 allelic variants, most of them located in exon 4. Comparing the two techniques, IHC showed a false-negative rate of 64% and a false-positive rate of 50%. These results confirm the inability of IHC to correctly detect TP53 status, reason because it should not be routinely used to establish prognosis of breast cancer patients in Brazilian Pathology Laboratories. We recommend the utilization of a screening method, such as DGGE, followed by sequencing of altered exonic fragments to correctly detect TP53 gene variants and establish the prognosis of breast cancer patients.

There are several risk factors related to Breast Cancer (BC) risks and response to chemotherapy with SERMs. Recently some single nucleotide polymorphisms (SNPs) on ESR1 gene have been associated to this disease. However, data are still inconclusive. The present study aimed to investigate the association of SNPs c454-397T>C (also called PvuII) and c454-351A>G (so called XbaI) to incidence of sporadic BC; ERα expression in BC; tamoxifen hormonetherapy (HT-TMX) responsiveness. To do so, a cohort of BC patients was analyzed through retrospective data collection, immunohistochemistry to ERα protein, and genotyping for PvuII and XbaI SNPs by PCR-RFLP, confirmed by sequencing. Significant difference in PvuII alleles frequencies were found BC patients when compared to control samples. Patients with P allele have a 5.14-fold increased BC risk. We found higher P and X alleles frequencies in ERα positive BC and the pp and xx genotypes were observed exclusively in patients with HT-TMX-responsive BC. Taken together, data indicates that P allele as a novel sporadic BC biomarker whereas p and x alleles enhanced chemotherapy responsiveness.

In the present study, we aimed to evaluate estrogen receptor ER-alpha status in 61 breast cancer cases using Sp1 and 1D5 monoclonal antibodies. Tissue array platforms were generated containing samples of breast cancer and positive controls that were assayed by immunohistochemistry applying monoclonal primary antibodies anti-ER alpha, SP1 and 1D5. We noted a high concordance rate (96.7%) between the referred antibodies. Moreover, we calculated the Kappa factor (0.921), indicating that 1D5 and SP1 provided overlapping ERα expression results. Indeed, we observed controversial results only in 2 samples studied, which were ER-negative when stained with 1D5 and ER-positive when assessed with SP1. Total concordance of PS was obtained (Pearson and intraclass CF, 0.7351 and 0.6193, respectively). However, concordance between the antibodies seems to be more accurate in higher PS values. An excellent IS correlation between antibodies was observed throughout the population (Spearman's CF, ρ=0.9150). Following the Allred score, 17 out of 42 positive BC samples diverged, with 1D5 always pointing to weaker staining than SP1. When calculating Spearman's CF of Total Score (TS) within the population, an excellent correlation between both the antibodies (ρ=0.9238) was noted. Nonetheless, the results were less concordant among the BC-positive cases (ρ=0.7743). Indeed, 20 samples were differentially classified using the antibodies (only 3 had higher TS with 1D5). Considering the mean TS of all samples or of invasive ductal carcinoma, SP1 provided higher scores than 1D5 (p

Abstract: Breast cancer (BC) hormonal receptors (progesterone, PgR and estrogen) status is assessed by immunohistochemistry (IHC), a specific, sensitive, and accessible method that guide BC treatment. We evaluated PgR expression in 53 BC cases using 3 anti-PgR antibodies (AB): monoclonal (SP42 and RP636) and polyclonal ab62621. Methods: Primary BC cases (with signed informed consent) were used to generate tissue microarray platforms, where PgR expression was accessed by IHC and evaluated by the Allred score. Categorical and quantitative data are shown in percentage and mean, respectively. Concordance (CON) and correlation among ABs were analyzed by Kappa factor (K), Spearman's correlation coefficient (ρ) or intraclass correlation coefficient. Staining patterns of each AB were compared by paired T-Test. Findings: We noted poor CON and K between ab62621 vs SP42 (CON=64.1%; K=0.247), and ab62621 vs RP636 (CON=62.3%; K=0.204), but higher CON between SP42 vs RP636 (CON 90.6%; K =0.738). Data were corroborated by Mc Nemar statistical test (p=0.019, p=0.014 and p>0.05, respectively). Regarding staining intensity among PgR+ samples, we found higher proportion of weak staining and lower IS for ab62621 (48.3%; mean IS=1.6), when compared to SP42 (20.0%, mean IS=2.1, T-test p Interpretation: Our data indicate that anti-PgR monoclonal ABs, RP636 and SP42, are, unlike ab62621, equally suitable to test BC PgR status by IHC due to their higher accuracy. Therefore, we suggest their clinical use during BC diagnosis; thus, enabling more precise therapeutic decisions to treat BC. Citation Format: Klesia P. Madeira, Renata Daltoe, Alex Carvalho, Lucas Rezende, Ian Silva, Leticia Rangel. Evaluation of the progesterone receptor status using three different antibodies: A comparison by Allred score system. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4760. doi:10.1158/1538-7445.AM2013-4760 Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.

Background: Accurate pathological analysis of biopsies is crucial for conclusive and precise disease diagnosis, prognosis and therapeutic guidelines. Evaluation of estrogen receptor (ER) expression in breast cancer (BC) is imperative in determining the disease prognosis, and patients' eligibility for hormonotherapy. Herein, ER alpha status was evaluated in 61 BC cases using two different anti-ER alpha monoclonal antibodies, SP1 (rabbit) and 1D5 (mouse). Methods: Primary BC cases registered in two reference hospitals, with correspondent written informed consent, were used to generate in house tissue microarray platforms. ER alpha expression was accessed by immunohistochemistry using the monoclonal antibodies anti-ER alpha, SP1 and 1D5. Staining scoring followed the Allred method (PS, proportion score or percentage of stained cells; IS, intensity score). Concordance and correlation parameters were calculated using Kappa factor; Pearson, Spearman's, or intraclass correlation coefficient (CF). Staining patterns were compared by paired T-Test and Wilcoxon test. Findings: SP1 and 1D5 provided equivalent results (Concordance rate, 96.7%; Kappa factor, 0.921), whereas SP1 was more prone for positive results than 1D5 (2 samples diverged). Total concordance of PS was obtained (Pearson and intraclass CF, 0.7351 and 0.6193, respectively); however, concordance between the antibodies seems more accurate in higher PS values. Excellent SI correlation between antibodies was observed throughout the population (Spearman's CF, ρ=0.9150). Following the Allred score, 17 out of 42 positive BC samples diverged; always pointing 1D5 to weaker staining than SP1. When calculating Spearman's CF of Total Score (TS) within the population, excellent correlation between both the antibodies (ρ=0.9238) was noted; nonetheless, results were less concordant result among the BC positive cases (ρ=0.7743). Indeed, 20 samples were differentially classified using the antibodies (only 3 had higher TS with 1D5). Considering the mean TS of all samples, or of invasive ductal carcinoma, SP1 provided higher scores than 1D5 (p < 0.05). Interpretation: Despite the equivalence between the anti-ER alpha monoclonal antibodies, SP1 and 1D5, the former has proven superior to the latter with respect to the IS and TS. Therefore, we suggest the clinical use of SP1 while diagnosing BC, due to its higher accuracy in examining ER status; thus, enabling more accurate therapeutic decisions to treat the disease. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-01-15.

Background Ovarian cancer is sixth most common cancer among women and the leading cause of death in women with gynecological malignancies. Despite the great impact ovarian cancer has on women's health and its great impact in public economy, Brazil still lacks valuable information concerning epidemiological aspects of this disease Methods We've compiled clinical data of all ovarian tumors registered at the two public hospitals of reference (1997 - 2007), such as: patients' age at diagnosis, tumor histological type, tumor stage, chemotherapy regimens, chemotherapy responsiveness, disease-free survival, and overall survival. Results Women's mean age at diagnosis was 54.67 ± 13.84 for ovarian cancer, 46.15 ± 11.15 for borderline tumors, and 42.01 ± 15.06 for adenomas. Among epithelial ovarian cancer cases, 30.1% were of serous, 13.7% were of mucinous, and 13.7% were of endometrioid type; exceptionally serous carcinoma was diagnosed in women younger than 30 years old. Endometrioid cancer had lower disease-free survival than others (p < 0.05). Cases were predominantly diagnosed as poor prognosis disease (FIGO III and IV, 56.2%). Regarding responsiveness to platinum-based therapy, 17.1% of patients were resistant, whereas 24.6%, susceptible. From these, we found equally responsiveness to platinum alone or its association with paclitaxel or cyclophosphamide. Discussion Our data agreed with other studies regarding mean patients' age at diagnosis, histological type frequency, FIGO stages distribution, and chemotherapy regimens. However, the histological type distribution, with equal contribution of mucinous and endometrioid types seems to be a unique characteristic of the studied highly miscegenated population. Conclusion We have enlighten the profile of the studied ovarian cancer population, which might enable the development of more efficient political strategies to control this malignancy that is the fifth leading cause of cancer-related deaths among women.