CYP3A4 and lung cancer: Notably, pharmacogenomic studies have shown lower incidence of polymorphisms in drug-metabolising enzymes that might negatively affect paclitaxel activity in Asian populations than in Caucasian populations,28 and a post-hoc analysis of three phase 3 advanced lung cancer trials studying 3-weekly carboplatin–paclitaxel in US and Japanese patients determined that the racially associated single nucleotide polymorphisms CYP3A4*1B and ERCC2K751Q were associated with improved outcomes and greater haematological toxicity in Japanese patients than in US patients.29