Multi-institutional prospective validation of prognostic mRNA signatures in early stage squamous lung cancer (Alliance) [Cohort II]. Multi-institutional prospective validation of prognostic mRNA signatures in early stage squamous lung cancer (Alliance) [Cohort II]

Purpose: The primary objective of the current study was to validate biomarkers to identify the 10% to 27% of patients with stage I and 35% of patients with stage IIA squamous cell carcinoma of lung (SC) who are likely to recur following surgical resection, so that these patients may be offered enrollment in clinical trials evaluating directed ACT. A secondary objective was to identify patients with stage IIB SC who are unlikely to develop recurrences and might thereby be spared the potential significant toxicity and expense of ACT. Methods: Two-stage validation used independent core laboratories, objective quality control standards, locked test parameters, and large multi-institutional specimen/data sets. First stage validation confirmed a signature’s ability to stratify patient survival. Second stage validation determined which signature(s) optimally improved risk discrimination when added to baseline clinical predictors. Participants were prospectively enrolled on institutional (Cohort I) or cooperative group (Cohort II) biospecimen/data collection protocols. All cases underwent central review of clinical, pathologic and biospecimen parameters using objective criteria to determine final inclusion (Cohort I: n=249; Cohort II: n=234). Primary selection required that a signature significantly predict 3-years survival after surgery in Cohort I. Signatures meeting this criterion were further tested in Cohort II, comparing risk prediction using baseline risk factors alone versus in combination with the signature. Results: Male sex, advanced age, and higher stage were associated with shorter survival in Cohort I and established a baseline clinical model. Of three signatures validated in Cohort I, one signature was validated in Cohort II and statistically significantly enhanced prognosis relative to the baseline model (C-index difference 0.122; p<0.05). Conclusions: These results represent the first rigorous validation of a test appropriate to direct adjuvant treatment or clinical trials for patients with lung squamous cell carcinoma. Overall design: Total RNA from squamous cell carcinoma specimens were extracted for mRNA profiling with microarray analysis.

研究的首要目标为验证生物标志物（biomarker），以识别出10%~27%的Ⅰ期肺鳞状细胞癌（squamous cell carcinoma of lung, SC）患者、35%的ⅡA期肺鳞状细胞癌患者中，术后复发风险较高的人群，进而为这类患者提供入组评估定向辅助治疗（adjuvant therapy, ACT）的临床试验机会。次要目标为识别出ⅡB期肺鳞状细胞癌患者中复发风险极低的人群，使其免于承受辅助治疗可能带来的显著毒性与经济开销。
本研究采用两阶段验证方案，依托独立核心实验室、客观质量控制标准、固化检测参数以及大型多中心标本/数据集开展。第一阶段验证确认了生物标志物特征（signature）对患者生存进行风险分层的能力；第二阶段验证则明确了当联合基线临床预测因素时，何种生物标志物特征可最优提升风险区分效能。研究对象前瞻性入组自机构主导的队列Ⅰ（Cohort I）或协作组主导的队列Ⅱ（Cohort II）生物标本/数据采集方案。所有病例均采用客观标准对临床、病理及生物标本参数进行中心审核，以确定最终入组资格（队列Ⅰ：n=249；队列Ⅱ：n=234）。初步筛选要求生物标志物特征在队列Ⅰ中可显著预测术后3年生存率。符合该筛选标准的特征将在队列Ⅱ中进一步验证，对比仅采用基线风险因素与联合该生物标志物特征的风险预测效能。
在队列Ⅰ中，男性性别、高龄与更高分期均与更短的生存期相关，以此构建了基线临床预测模型。在队列Ⅰ中验证的3种生物标志物特征中，有1种在队列Ⅱ中得到验证，且相较于基线模型，该特征可显著改善预后预测效能，C指数（C-index）差值达0.122，p<0.05。
本研究结果为首例经过严格验证的、可用于指导肺鳞状细胞癌患者辅助治疗方案选择或临床试验入组的检测技术。
本研究的整体实验设计为：从肺鳞状细胞癌标本中提取总RNA，通过微阵列分析（microarray analysis）完成mRNA表达谱检测。