비소세포 폐암환자의 객담 내 ERCC1 발현정도와 cisplatin 복합화학요법 후 치료반응

Background : Excision repair cross complementing gene 1 (ERCC1) not only has a protective role against carcinogens, but plays an important role in cisplatin-resistance via the repair of cisplatin-DNA adducts. This study investigated the association between the ERCC1 expression levels in sputum and survival after cisplatin-based chemotherapy in patients with inoperable non-small cell lung cancer (NSCLC). Methods : Using the sputum collected from 67 inoperable (stage IIIa-IV) NSCLC patients treated with either taxanes (33 cases) or gemcitabine (34 cases) plus cisplatin, the relative expression levels of ERCC1 and the expression of the tumor specific antigen, MAGE, were examined by the quantitative RT-PCR and RT-PCR, respectively. The response and survival were compared with the relative level of ERCC1 or MAGE expression and the treatment modality. Results : In the sputum, ERCC1 and MAGE was detected in 74.6% and 40.2% of patients, respectively. Using the median ERCC1 level, the patients were classified as having high or low ERCC1 expression. The median overall survival (MST) was significantly longer in patients with a high ERCC1 expression level than those with a low expression level (84 weeks vs. 44 weeks respectively, P=0.017). In the taxene-based treatment group, the MST was longer than the gemcitabine group (79 weeks vs. 47 weeks, respectively, P=0.03). The levels of ERCC1 were significantly higher in patients who were MAGE-positive (P=0.003). In the MAGE-negative patients, the MST was longer in the high ERCC1 group (103 weeks vs. 43 weeks, P=0.008), but not in the MAGE-positive patients (62 weeks vs. 44 weeks, P=0.348). Conclusion : ERCC1 expression in the sputum can be a prognostic factor for survival after chemotherapy in patients with inoperable NSCLC. 목 적 : 폐암치료에 가장 널리 사용되는 cisplatin은 DNA와 결합하여 DNA 복제를 방해한다. 이렇게 손상된 부위를 복구하는 과정에 excision repair cross complementing gene 1 (ERCC1)이 작용한다. ERCC1이 활성화 되면, 정상세포는 DNA 손상을 줄일 수 있지만 종양세포의 경우 cisplatin의 효과는 감소하게 된다. 비소세포 폐암(non-small cell lung cancer, NSCLC) 환자에서 cisplatin을 포함하는 화학치료를 할 경우 예후인자로서 객담 ERCC1 정량측정의 의의를 조사하였다. 대상 및 방법 : 2001년 4월부터 2003년 8월 사이에 NSCLC로 진단되어 cisplatin과 taxane계(33명) 혹은 cisplatin과 gemcitabine(34명) 복합 화학치료를 받은 환자를 대상으로 하였다. 기관지 내시경검사를 실시한 후에 즉각 채취한 객담을 처리하여 c-DNA를 분리한 후, 객담속의 종양특이 유전자인 melanoma antigen gene (MAGE) 발현 여부는 RT-PCR로, ERCC1의 상대적 정량적 측정은 real-time PCR로 하였다. 환자의 치료반응 및 생존기간과 MAGE 발현여부 및 ERCC1의 발현정도와의 상관관계를 조사하였다. 결 과 : 객담에서 MAGE는 40.2%, ERCC1은 74.6%에서 발현되었다. ERCC1이 중앙값 이상인 경우와