Dose reduction or intermittent administration of erlotinib: which is better for patients suffering from intolerable toxicities?

Erlotinib is an epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor that is widely used in the treatment of non-small cell lung cancer. Skin rashes and diarrhea are frequent side effects of erlotinib therapy. When these toxicities become intolerable, dose reduction is commonly performed. However, dose reduction may not maintain the effective dose levels in some specific situations, such as in cases of wild-type EGFR tumors or central nervous system metastases. We speculate that intermittent administration is better than dose reduction to simultaneously maintain the effective dose levels and reduce toxicities in such situations. We herein present four cases of patients who successfully received intermittent administration of erlotinib.