Epidermal growth factor receptor mutations in small cell lung cancer: a brief report

Knowledge about the current status of the epidermal growth factor receptor (EGFR) has resulted in an improvement in the treatment of non-small cell lung cancer. In contrast, small cell lung cancer (SCLC) continues to frustrate clinicians with its tendency toward early metastasis and chemotherapy resistance. Recent studies have reported the EGFR mutation and its response to gefitinib treatment in SCLC. We would like to share our experience of EGFR studies on SCLC patients.

Between 2004 and 2009, we prospectively collected 76 specimens from patients with SCLC at the National Taiwan University Hospital, Taiwan. These specimens included 10 computed tomography-guided biopsy specimens, 17 echo-guided aspiration specimens, 37 echo-guided biopsy specimens, 1 surgical lobectomy specimen, and 11 malignant pleural effusion specimens. Molecular genetic analysis of the specimens was conducted to detect the EGFR mutation.

Among the 76 SCLC specimens we examined, 2 (2.6%) tested positive for the EGFR mutation and both were deletions in exon 19. One patient was administered gefitinib after several lines of chemotherapy but showed no treatment response. To date, only 11 EGFR mutant-positive SCLC patients, including our 2 patients, have been reported. Most of these patients were never smokers. The SCLC harboring EGFR mutation were more likely to be combined with adenocarcinoma compared with the whole SCLC population.

The EGFR mutation is rare in SCLC patients. Despite the presence of the EGFR mutation, gefitinib may not be effective in treating SCLC patients.