Molecular predictors of post-mastectomy breast cancer loco-regional recurrence

描述（由申请人提供）：乳腺癌是一种异质性疾病，尽管临床分期相似，但治疗结果明显不同。即使采用最积极和最现代的治疗方法，也有多达15%的患者出现局部-区域复发（LRR），这增加了远处疾病和死亡的风险。个体危险因素如年龄、肿瘤大小和分级在临床上预测预后的能力有限；因此，识别分子特征以更准确地评估风险仍然是一个重要的目标。该概况可以帮助确定LRR，作为局部治疗方案评估的一部分，特别是当传统风险分层参数支持的辅助治疗建议导致风险：收益比较窄时。由于患者数量较少，临床特征和治疗方案不同，先前对LRR基因谱的评估受到阻碍。需要进一步的研究来建立一个不仅可以预测LRR，而且可以适用于不考虑肿瘤大小或年龄等临床因素的患者的概况。对于目前处于中等风险的患者，即T1-T3期伴有0-3个阳性淋巴结的乳腺癌患者，这种工具的需求是最大的。由于新辅助治疗不会改变患者的病理分期，因此接受乳房切除术而不进行新辅助治疗和术后不进行放射治疗的患者将提供最统一的患者亚群。我们假设LRR患者的分子特征不同于无复发患者的分子特征。将进行一项回顾性病例对照研究，将两名没有LRR的对照患者与每名乳房切除术后LRR患者进行匹配。我们的目标是：1)确定低至中等风险乳房切除术后患者中与LRR风险升高相关的分子畸变（DNA、RNA、IHC）；2)确定PIK3CA突变激活PI3K通路和/或PTEN缺失是否与LRR相关；3)通过Ki-67检测肿瘤增殖是否与LRR相关。我们的长期目标是创建一个新的分子图谱来预测该队列中的LRR，然后在1)后续研究中单独的TBCRC（转化性乳腺癌研究联盟）队列中进一步验证这一特征，2)在适当的合作组试验中存储的石蜡块中，3)未来的TBCRC患者试验作为相关和转化成分。在独立队列验证后，我们将进行一项前瞻性研究，使用我们的LRR特征来确定是否需要辅助放射治疗。分子图谱可以提供更多的信息来指导乳腺癌治疗的个体化治疗方法。然后，临床管理将基于女性的个体预后，利用肿瘤的分子特征来确定最佳治疗方案。

DESCRIPTION (provided by applicant): Breast cancer represents a heterogeneous disease process with markedly different treatment outcomes despite similar clinical staging. Even with the most aggressive and modern therapy as much as 15 percent of patients develop local-regional recurrences (LRR) which increase the risk of distant disease and death. Individual risk factors such as age, tumor size and grade are clinically limited in ability to predict outcome; therefore, the identification of a molecular profile to more accurately assess risk remains an important goal. This profile can help determine LRR as part of the evaluation for local therapeutic options, particularly when adjuvant treatment recommendations supported by traditional risk stratification parameters result in a narrow risk: benefit ratio. Previous evaluation of a genetic profile for LRR has been hindered by smaller patient numbers with heterogeneous clinical characteristics and treatment regimens. Additional study is warranted to develop a profile that would not only predict LRR but be applicable to patients regardless of clinical factors such as tumor size or age. The need for such a tool is greatest, in patients currently characterized as being at intermediate risk, i.e. stage T1-T3 breast cancer with 0-3 positive nodes. Patients treated with mastectomy without neoadjuvant therapy and without postoperative radiation therapy would provide the most uniform subset of patients since their pathologic staging is not altered by neoadjuvant therapy. We hypothesize that the molecular profile of patients with a LRR differ than the molecular profile of patients who do not have a recurrence. A retrospective case-control study will be performed, matching two control patients without LRR for each patient with a post-mastectomy LRR. Our aims are 1) To determine molecular aberrations (DNA, RNA, IHC) associated with an elevated risk of LRR in otherwise low to intermediate risk post-mastectomy patients; 2) To determine whether PI3K pathway activation by PIK3CA mutation and/or PTEN loss is associated with LRR; 3) To determine if tumor proliferation, as determined by Ki-67, is associated with LRR. Our long-term goal is to create a novel molecular profile that would predict LRR in this cohort and then further validate this signature in 1) a separate TBCRC (Translational Breast Cancer Research Consortium) cohort in a follow-up study, 2) in paraffin blocks stored from appropriate cooperative group trials, 3) with future TBCRC patient trials as a correlative and translational component. Upon validation in an independent cohort, we will pursue a prospective study to use our LRR signature for determining the need for adjuvant radiation therapy. A molecular profile may provide more information to guide an individualized therapeutic approach to breast cancer therapy. Then clinical management would be based on a women's individual prognosis using the tumor's molecular profile to define the best therapy.