Cassol Lina, Silveira Graudenz Marcia, Zelmanowicz Alice, Cancela Anna, Werutsky Gustavo, Rovere Rodrigo Kraft, Garicochea Bernardo
Faculty of Medicine, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
Tumori. 2010 Nov-Dec;96(6):966-70.
Basal-like breast cancer is a distinct group of tumors with heterogeneous behavior, and not all have a poor prognosis. The present study analyzed the prevalence and prognosis of early basal-like breast cancer.
A total of 112 patients with stage I and II breast cancer were retrospectively analyzed using immunohistochemical stains for estrogen receptor, progesterone receptor, HER2, cytokeratin 5/6 and epidermal growth factor receptor. Basal-like tumors were defined as being estrogen receptor, progesterone receptor and HER2 negative and cytokeratin 5/6 and/or epidermal growth factor receptor positive.
Of the 112 cases, respectively 13 (11.6%) were basal-like, 77 (68.8%) luminal A or B, 13 (11.6%) HER2 positive and 9 (8%) undefined. In basal-like tumors, epidermal growth factor receptor and cytokeratin 5/6 expression was positive in 5 patients (38.5%) and 12 patients (92%), respectively. There was no significant correlation between basal-like breast cancer and age (P = 0.207), lymph node status (P = 1.0) or clinical stage (P = 0.53). Among all tested biomarkers, positivity was found in 81 (72.3%) for estrogen receptor, 13 (11.6%) for HER2, 11 (9.8%) for epidermal growth factor receptor and 36 (32.1%) for cytokeratin 5/6. Epidermal growth factor receptor expression was significantly correlated with estrogen receptor-negative (P = 0.01) and HER2-positive (P = 0.02) tumors. During a median follow-up of 81 months, there were 26 (23%) disease relapses and 12 (10.7%) deaths. No significant difference relating to disease-free survival and overall survival was noted between basal-like breast cancer and subtypes luminal A and B, HER2 positive and undefined.
The addition of cytokeratin 5/6 and epidermal growth factor receptor defines a small subgroup of patients with basal-like tumors. In a population with early breast cancer, basal-like tumors did not have a prognosis different from the other subtypes. Neither was there a significant association with clinicopathological features. The high frequency of epidermal growth factor receptor positivity in estrogen receptor-negative and HER2-positive tumors represents a potential target in clinical trials.
基底样乳腺癌是一组具有异质性生物学行为的独特肿瘤，并非所有患者预后都差。本研究分析了早期基底样乳腺癌的患病率及预后。
对112例I期和II期乳腺癌患者进行回顾性分析，采用免疫组织化学染色检测雌激素受体、孕激素受体、HER2、细胞角蛋白5/6和表皮生长因子受体。基底样肿瘤定义为雌激素受体、孕激素受体和HER2阴性，细胞角蛋白5/6和/或表皮生长因子受体阳性。
112例患者中，13例（11.6%）为基底样癌，77例（68.8%）为腔面A型或B型，13例（11.6%）为HER2阳性，9例（8%）为未定型。在基底样肿瘤中，5例（38.5%）表皮生长因子受体表达阳性，12例（92%）细胞角蛋白5/6表达阳性。基底样乳腺癌与年龄（P = 0.207）、淋巴结状态（P = 1.0）或临床分期（P = 0.53）之间无显著相关性。在所有检测的生物标志物中，雌激素受体阳性率为81例（72.3%），HER2阳性率为13例（11.6%），表皮生长因子受体阳性率为11例（9.8%），细胞角蛋白5/6阳性率为36例（32.1%）。表皮生长因子受体表达与雌激素受体阴性（P = 0.01）和HER2阳性（P = 0.02）肿瘤显著相关。中位随访81个月期间，有26例（23%）疾病复发，12例（10.7%）死亡。基底样乳腺癌与腔面A型和B型、HER2阳性和未定型亚型之间在无病生存期和总生存期方面未观察到显著差异。
细胞角蛋白5/6和表皮生长因子受体的加入确定了一小部分基底样肿瘤患者亚组。在早期乳腺癌人群中，基底样肿瘤的预后与其他亚型并无差异。与临床病理特征也无显著关联。雌激素受体阴性和HER2阳性肿瘤中表皮生长因子受体阳性率较高，这代表了临床试验中的一个潜在靶点。
