{'fraction_non_alphanumeric': 0.030855018587360596, 'fraction_numerical': 0.016356877323420074, 'mean_word_length': 4.993318485523385, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Comparison is beyond IPASS and OPTIMAL.

Now that first-line epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) is recognised as a standard therapy for non–small-cell lung cancer (NSCLC) with activating mutations,1-7 it is only natural for some of us to ask which TKI is the best. In the absence of a direct head-to-head randomised controlled study, Lee et al8 used an indirect comparison method to compare the efficacy and cost-effectiveness of gefitinib and erlotinib, results of which are published in this issue. The authors concluded that erlotinib has better efficacy and is more cost-effective than gefitinib.8 Is this a trustworthy conclusion? For reason that is not entirely clear to us, authors chose to use data from only the OPTIMAL and IPASS studies. Truth is that there are four randomised studies on gefitinib (IPASS, FIRST-SIGNAL, NEJ002, and WJTOG 345) and three randomised studies on erlotinib (OPTIMAL, EURTAC, and ENSURE) in patients with activating EGFR mutation–positive NSCLC. The authors excluded EURTAC study from the comparison because of the differences in baseline demographic data and ethnicity. Similar to IPASS, EURTAC is a registration study using stringent criteria for documentation of treatment outcomes and toxicity. The OPTIMAL study was not considered a registration study by the China Food and Drug Administration, and that was exactly the reason for the replication of OPTIMAL study (ENSURE study) in China. Grade 3 or above skin rash rate was higher in the EURTAC study (13%) as compared with IPASS study (3.1%), and this is a fact that should not be ignored. The median progressionfree survival (PFS) and hazard ratio were comparable between EURTAC and IPASS and, again, this fact was ignored. Lee et al8 should incorporate data from more relevant clinical trials into the indirect comparison to provide a non-biased estimate of the true treatment effect. As erlotinib is slightly more expensive than gefitinib in the Hong Kong public health care system, it will be unrealistic to conclude a better cost-effectiveness if the two drugs were shown to have similar efficacy in an honest manner. Kim et al9 conducted a prospective openlabel randomised non-comparative parallel study in a single Korean hospital to evaluate the efficacy of erlotinib and gefitinib in those EGFR mutation– positive NSCLC patients or patients with at least two Hong Kong Med J 2014;20:176–7 DOI: 10.12809/hkmj144267 1 KC Lam *, FHKAM (Medicine), 2 Tony SK Mok, FHKCP, FHKAM (Medicine) 1 Department of Clinical Oncology, Prince of Wales Hospital, Shatin, Hong Kong 2 Department of Clinical Oncology, The Chinese University of Hong Kong, Shatin, Hong Kong