Oshita F, Nomura I, Yamada K, Kato Y, Tanaka G, Noda K
Division of Thoracic Disease, Kanagawa Cancer Center, Yokohama, Japan.
Clin Cancer Res. 1999 Mar;5(3):617-20.
An increased prevalence of K-ras oncogene mutation in lung adenocarcinoma has been shown by PCR-primer-introduced restriction with enrichment for mutation alleles (PCR-PIREMA) experiments. In the present study we investigated whether this method is useful for the diagnosis of lung cancer in small pulmonary lesions, which are difficult to diagnose cytologically as lung cancer by bronchoscopic examination. We examined bronchoalveolar lavage fluid (BALF) cells from 33 patients with single nodular pulmonary lesions of less than 2 cm in diameter (measured on chest computed tomography scans) for K-ras (codon 12) mutation, by PCR-PIREMA. Transbronchial fiberscopic examinations had not revealed lung cancer cytologically in any of the patients. The final diagnoses for the 33 lesions were 20 adenocarcinomas, 5 cases of focal fibrosis, 5 cases of pneumonia, 1 case of tuberculosis, 1 hamartoma, and 1 case of lymph node swelling. BALF cell lysates were amplified and digested with a restriction enzyme to detect the K-ras oncogene. Only the normal K-ras was observed after the first amplification and digestion for each of the 33 patients. Three amplifications and digestions were performed for each sample. We detected mutation of K-ras in BALF cells from 15 (75%) of 20 lung cancer patients and in cells from only 4 (31%) of 13 patients with nonmalignant lesions. The detection rate of the K-ras mutation in lung cancer was significantly greater than that in nonmalignant lesions (P = 0.012). Our results indicate that the detection of the codon 12 K-ras mutation in BALF cells by PCR-PIREMA aids the diagnosis of lung cancer in patients with small pulmonary lesions with negative cytological findings.
通过聚合酶链反应引物引入限制并富集突变等位基因（PCR - PIREMA）实验已表明，肺腺癌中K - ras癌基因突变的患病率增加。在本研究中，我们调查了该方法对于直径小于2 cm的肺部小结节病变（经胸部计算机断层扫描测量）的肺癌诊断是否有用，这些病变通过支气管镜检查在细胞学上难以诊断为肺癌。我们采用PCR - PIREMA检测了33例直径小于2 cm的单个结节性肺部病变患者（经胸部计算机断层扫描测量）的支气管肺泡灌洗（BALF）细胞中的K - ras（密码子12）突变。经支气管纤维镜检查在所有患者中均未在细胞学上发现肺癌。33个病变的最终诊断为20例腺癌、5例局灶性纤维化、5例肺炎、1例肺结核、1例错构瘤和1例淋巴结肿大。BALF细胞裂解物经扩增并用限制性酶消化以检测K - ras癌基因。对33例患者中的每例进行首次扩增和消化后，仅观察到正常的K - ras。每个样本进行三次扩增和消化。我们在20例肺癌患者中的15例（75%）的BALF细胞中检测到K - ras突变，而在13例非恶性病变患者的细胞中仅4例（31%）检测到突变。肺癌中K - ras突变的检测率显著高于非恶性病变（P = 0.012）。我们的结果表明，通过PCR - PIREMA检测BALF细胞中密码子12的K - ras突变有助于诊断细胞学检查结果为阴性的肺部小结节病变患者的肺癌。
