Complex sentence: In non-small cell lung cancer (NSCLC), the methylation status of paired tumors and surrounding histologically uninvolved lung tissue was found to be 69% and 59% respectively, though in more advanced NSCLC the frequency of ATM promoter methylation was lower at 22%.
Split into simpler sentences: In non-small cell lung cancer (NSCLC), the "ATM" promoter methylation status of paired tumors and surrounding histologically uninvolved lung tissue was found to be 69% and 59%, respectively. However, in more advanced NSCLC the frequency of ATM promoter methylation was lower at 22%.