Unusual tumor response and toxicity from radiation and concurrent erlotinib for non-small-cell lung cancer.

We report a case of a never-smoker female with non-small-cell lung cancer (NSCLC) who experienced a striking tumor response to combined low-dose radiation and the epidermal growth factor receptor inhibitor erlotinib, even though erlotinib alone was not effective in preventing tumor progression. Furthermore, the patient developed symptomatic pneumonitis, which is unusual for the small volume of lung that was exposed to a significant dose of radiation. This case demonstrates that combination therapy with radiation and erlotinib has the potential to significantly benefit a subset of patients with NSCLC in addition to those approximately 10% who have tumors which respond to erlotinib alone. It also highlights the potential risks of molecular targeted radiation therapy.