Abstract：
OBJECTIVE: Our aim was to compare the PIK3CA mutation status in matched primary and recurrent tumors of hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) breast cancer (BC) to gain insight into the optimization of patient selection and detection time for PIK3CA-targeted therapy.
METHODS: The data were from 3035 patients with BC diagnosed at the Breast Disease Center, Peking University First Hospital, between January 2008 and December 2017. Matched primary and recurrent samples were profiled using amplification-refractory mutation system-polymerase chain reaction covering 11 mutational hotspots in PIK3CA.
RESULTS: PIK3CA mutations were detected in 54.3% primary tumors and 48.6% corresponding recurrences. PIK3CA mutation was detected in 37.5% cases in the locoregional recurrent group and 40.0% of distant metastasis, without a statistical difference. Besides, PIK3CA mutations were concordant in 88.6% of the matched pairs. For patients treated with neoadjuvant chemotherapy, 100% concordance was observed. However, PIK3CA mutation was neither correlated with clinicopathological features nor associated with clinical outcomes.
CONCLUSIONS: Mutations in PIK3CA in HR+/HER2- BC generally progressed to recurrent tumors. The high concordance rate of PIK3CA mutation status between primary tumors and corresponding recurrences suggests that the detection of primary tumors could be a substitute approach when recurrent samples are not easily obtainable.
METHODS: The data were from 3035 patients with BC diagnosed at the Breast Disease Center, Peking University First Hospital, between January 2008 and December 2017. Matched primary and recurrent samples were profiled using amplification-refractory mutation system-polymerase chain reaction covering 11 mutational hotspots in PIK3CA.
RESULTS: PIK3CA mutations were detected in 54.3% primary tumors and 48.6% corresponding recurrences. PIK3CA mutation was detected in 37.5% cases in the locoregional recurrent group and 40.0% of distant metastasis, without a statistical difference. Besides, PIK3CA mutations were concordant in 88.6% of the matched pairs. For patients treated with neoadjuvant chemotherapy, 100% concordance was observed. However, PIK3CA mutation was neither correlated with clinicopathological features nor associated with clinical outcomes.
CONCLUSIONS: Mutations in PIK3CA in HR+/HER2- BC generally progressed to recurrent tumors. The high concordance rate of PIK3CA mutation status between primary tumors and corresponding recurrences suggests that the detection of primary tumors could be a substitute approach when recurrent samples are not easily obtainable.
摘要：
目的：我们的目的是比较激素受体阳性/人类表皮生长因子受体2阴性（HR+/HER2-）乳腺癌（BC）的匹配原发性和复发性肿瘤中的PIK3CA突变状态，以深入了解PIK3CA靶向治疗的患者选择和检测时间的优化。
方法：数据来自乳腺疾病中心诊断的3035例BC患者，北京大学第一医院,2008年1月至2017年12月。使用覆盖PIK3CA中11个突变热点的扩增-难治性突变系统-聚合酶链反应对匹配的原代和复发性样品进行了分析。
结果：在54.3%的原发肿瘤和48.6%的相应复发中检测到PIK3CA突变。在局部复发组中37.5%的病例和40.0%的远处转移组中检测到PIK3CA突变,没有统计学差异。此外,在88.6%的匹配对中,PIK3CA突变是一致的。对于接受新辅助化疗的患者，观察到100%的一致性。然而,PIK3CA突变与临床病理特征无关，也与临床结局无关。
结论：HR+/HER2-BC中PIK3CA的突变通常进展为复发性肿瘤。原发性肿瘤和相应复发之间的PIK3CA突变状态的高一致性表明，当不容易获得复发样品时，原发性肿瘤的检测可能是一种替代方法。
方法：数据来自乳腺疾病中心诊断的3035例BC患者，北京大学第一医院,2008年1月至2017年12月。使用覆盖PIK3CA中11个突变热点的扩增-难治性突变系统-聚合酶链反应对匹配的原代和复发性样品进行了分析。
结果：在54.3%的原发肿瘤和48.6%的相应复发中检测到PIK3CA突变。在局部复发组中37.5%的病例和40.0%的远处转移组中检测到PIK3CA突变,没有统计学差异。此外,在88.6%的匹配对中,PIK3CA突变是一致的。对于接受新辅助化疗的患者，观察到100%的一致性。然而,PIK3CA突变与临床病理特征无关，也与临床结局无关。
结论：HR+/HER2-BC中PIK3CA的突变通常进展为复发性肿瘤。原发性肿瘤和相应复发之间的PIK3CA突变状态的高一致性表明，当不容易获得复发样品时，原发性肿瘤的检测可能是一种替代方法。
