In the group of patients who received chemotherapy , the most common grade @ or @ toxic effect was neutropenia ( @ -LSB- @ % -RSB- vs one -LSB- < @ % -RSB- in the erlotinib group ) , whereas skin toxicity ( one -LSB- < @ % -RSB- vs @ -LSB- @ % -RSB- ) was the most frequent in the erlotinib group .