Kozower Benjamin D, Meyers Bryan F, Reed Carolyn E, Jones David R, Decker Paul A, Putnam Joe B
Department of Surgery, University of Virginia Health System, Charlottesville, Virginia 22908-0679, USA.
Ann Thorac Surg. 2008 Apr;85(4):1166-9; discussion 1169-70. doi: 10.1016/j.athoracsur.2008.01.018.
The American College of Surgeons Oncology Group (ACOSOG) Z0050 trial demonstrated that positron emission tomography (PET) prevents nontherapeutic thoracotomies in a substantial fraction of patients with known or suspected non-small cell lung cancer (NSCLC). However, the benefit of PET in clinical stage IA patients has been questioned due to the lower prevalence of metastases and poor ability to discriminate benign from malignant lung lesions. This study evaluates whether PET prevents nontherapeutic pulmonary resections in clinical stage IA patients by finding advanced disease or by declaring a nodule as benign.
We reanalyzed all patients with clinical stage IA NSCLC from ACOSOG Z0050. The clinical, PET, and pathologic stages were compared for this prospective cohort.
One hundred twenty-two clinical stage IA patients were evaluated and 78.7% (96 of 122; 95% confidence interval [CI], 70.4 to 85.6) were eventually shown to have cancer. PET correctly showed 7.4% (9 of 122; 95% CI, 3.4 to 13.5) of patients to have advanced disease (stages IIIA to IV). However, due to a high false positive rate, the positive predictive value for advanced disease was only 33.3% (9 of 27; 95% CI, 16.5 to 54.0). The negative predictive value of PET to predict benign lesions was only 57% (16 of 28; 95% CI, 37.2 to 75.5). Thus, 43% (12 of 28; 95% CI, 24.5 to 62.8) of patients with a PET negative primary lesion actually had cancer, and all of these had resectable disease (stages IA to IIB).
In clinical stage IA lung cancer patients, PET prevents nontherapeutic pulmonary resections less than 10% of the time. If a strategy of no surgery and serial computed tomographic scans is chosen for PET negative lesions, over 40% of patients with NSCLC will have surgery delayed. A prospective trial comparing PET versus resection for clinical stage IA lesions would clarify the value of PET for these patients.
美国外科医师学会肿瘤学组（ACOSOG）Z0050试验表明，正电子发射断层扫描（PET）可在很大一部分已知或疑似非小细胞肺癌（NSCLC）患者中避免进行非治疗性开胸手术。然而，由于转移发生率较低以及区分肺部良性与恶性病变的能力较差，PET在临床IA期患者中的益处受到质疑。本研究评估PET是否通过发现晚期疾病或判定结节为良性来避免临床IA期患者进行非治疗性肺切除术。
我们重新分析了ACOSOG Z0050研究中所有临床IA期NSCLC患者。对这一前瞻性队列的临床、PET及病理分期进行比较。
共评估了122例临床IA期患者，最终78.7%（122例中的96例；95%置信区间[CI]，70.4至85.6）被证实患有癌症。PET正确显示7.4%（122例中的9例；95%CI，3.4至13.5）的患者患有晚期疾病（IIIA至IV期）。然而，由于假阳性率较高，晚期疾病的阳性预测值仅为33.3%（27例中的9例；95%CI，16.5至54.0）。PET预测良性病变的阴性预测值仅为57%（28例中的16例；95%CI，37.2至75.5）。因此，PET原发性病变为阴性的患者中有43%（28例中的12例；95%CI，24.5至62.8）实际上患有癌症，且所有这些患者的疾病均可切除（IA至IIB期）。
在临床IA期肺癌患者中，PET在不到10%的情况下可避免非治疗性肺切除术。如果对于PET阴性病变选择不进行手术并进行系列计算机断层扫描的策略，超过40%的NSCLC患者的手术将被延迟。一项比较PET与手术治疗临床IA期病变的前瞻性试验将明确PET对这些患者的价值。
