Cyclooxygenase-2 (COX2) and p53 protein expression are interdependent in breast cancer but not associated with clinico-pathological surrogate subtypes, tumor aggressiveness and patient survival.

UNLABELLED: In the last decade, different molecular subtypes of breast cancer have been proposed. Although displaying appreciable association with disease prognosis and the prognostic value of cytotoxic and endocrine therapeutic modalities, the subtypes seem to fail at completely explaining disease behavior and response to treatment. Molecules such as those of the cyclocooxigenase (COX) family, currently composed of three entities (COX 1, 2 and 3) have been shown to be associated with breast carcinogenesis, and the analysis of p53 expression in breast tumors may also offer some additional prognostic clues. Our study is aimed at assessing COX2 and p53 expression in these clinico-pathological surrogate subtypes, and to evaluate whether the expression of these molecules can help further explain the variability in prognosis still found within the clinico-pathological subtypes groups of breast cancer. METHODS: A total of 183 breast cancer samples were obtained from women treated at the Womens Hospital of Campinas State University, Campinas, Brazil, between June 2008 and January 2011. Immunohistochemistry was performed to detect the expression of ER, PR, ki67, COX2, and p53 and the HER2 status of the 183 specimens was assessed using FISH. Two COX2 staining thresholds were used to define COX2 positivity: low threshold (LT): moderate and intense staining were considered positive; high-threshold (HT): only intense staining was considered positive. RESULTS: There was no trend in COX2 overexpression from Luminal A-like to Triple-negative subtypes. By contrast, p53 was expressed in roughly 67% of the Luminal A-like tumors, 50% of the Luminal B-like HER2 positive tumors, 60.9% of the Luminal B-like HER2 negative, approximately 82% of the HER2 positive (non-luminal) and 87% of the Triple-negative tumors (p for trends=0.06). There was a significantly higher proportion of COX2 positive (LT) tumors (66.9%) when p53 was also positive compared to when the tumor was negative for p53 (in which case only18.0% of the tumors were positive for COX2; p<0.001). Neither marker was found to be associated with patients' survival. CONCLUSIONS: There seems to be a positive association between the expressions of COX2 and p53. Otherwise, neither the expression of COX nor that of p53 was associated with clinico-pathological subtypes, tumor features and prognosis. It seems to be too early to elect the detection of COX2 using IHC as prognostic or predictive tool, but incipient evidence points toward a possible role for the marker.

[The new classification of breast cancers: finding the luminal A]. / Nova classificação dos carcinomas da mama: procurando o luminal A.

PURPOSE: To compare the distributions of patients with clinical-pathological subtypes of luminal B-like breast cancer according to the 2011 and 2013 St. Gallen International Breast Cancer Conference Expert Panel. METHODS: We studied 142 women with breast cancer who were positive to estrogen receptor and had been treated in São Paulo state, southeast Brazil. The expression of the following receptors was assessed by immunohistochemistry: estrogen, progesterone (PR) and Ki-67. The expression of HER-2 was measured by fluorescent in situ hybridization analysis in tissue microarray. RESULTS: There were 29 cases of luminal A breast cancers according to the 2011 St. Gallen International Breast Cancer Conference Expert Panel that were classified as luminal B-like in the 2013 version. Among the 65 luminal B-like breast cancer cases, 29 (45%) were previous luminal A tumors, 15 cases (20%) had a Ki-67 >14% and were at least 20% PR positive and 21 cases (35%) had Ki-67 >14% and more than 20% were PR positive. CONCLUSIONS: The 2013 St. Gallen consensus updated the definition of intrinsic molecular subtypes and increased the number of patients classified as having luminal B-like breast cancer in our series, for whom the use of cytotoxic drugs will probably be proposed with additional treatment cost.

Nova classificação dos carcinomas da mama: procurando o luminal A / The new classification of breast cancers: finding the luminal A

OBJETIVO: Comparar a distribuição das pacientes segundo os subtipos clínico-patológicos de carcinomas de mama luminais like segundo o consenso de St. Gallen 2011 e 2013. MÉTODOS: Foram selecionadas 142 pacientes com carcinoma invasivo da mama que eram positivas para receptor de estrógeno, diagnosticadas e tratadas no estado de São Paulo, região Sudeste do Brasil. A expressão dos receptores de estrógeno, progesterona (RP) e Ki-67 foi avaliada por imunoistoquímica em microarranjo de tecidos. A expressão de HER-2 foi avaliada por hibridização fluorescente in situ. RESULTADOS: Observamos que 29 casos classificados como luminais A na classificação de St. Gallen 2011 eram luminais B na classificação de 2013. Dentre os 65 casos luminais B like da classificação de 2013, além dos 29 (45%) casos que migraram, observamos 15 casos (20%) com Ki-67 >14% e pelo menos 20% das células coradas; e 21 casos (35%) com Ki-67 >14% e RP positivo em mais de 20% das células coradas. CONCLUSÕES: Comparando a distribuição das pacientes com carcinomas luminais da mama segundo a classificação de St. Gallen 2011 e 2013 observamos que houve um aumento no número de carcinomas da mama luminais B like. Consequentemente, estima-se um aumento nas indicações de quimioterapia adjuvante e no custo do tratamento. .

PURPOSE: To compare the distributions of patients with clinical-pathological subtypes of luminal B-like breast cancer according to the 2011 and 2013 St. Gallen International Breast Cancer Conference Expert Panel. METHODS: We studied 142 women with breast cancer who were positive to estrogen receptor and had been treated in São Paulo state, southeast Brazil. The expression of the following receptors was assessed by immunohistochemistry: estrogen, progesterone (PR) and Ki-67. The expression of HER-2 was measured by fluorescent in situ hybridization analysis in tissue microarray. RESULTS: There were 29 cases of luminal A breast cancers according to the 2011 St. Gallen International Breast Cancer Conference Expert Panel that were classified as luminal B-like in the 2013 version. Among the 65 luminal B-like breast cancer cases, 29 (45%) were previous luminal A tumors, 15 cases (20%) had a Ki-67 >14% and were at least 20% PR positive and 21 cases (35%) had Ki-67 >14% and more than 20% were PR positive. CONCLUSIONS: The 2013 St. Gallen consensus updated the definition of intrinsic molecular subtypes and increased the number of patients classified as having luminal B-like breast cancer in our series, for whom the use of cytotoxic drugs will probably be proposed with additional treatment cost. .