Comparative research of anaplastic lymphoma kinase fusion gene detected by immunohistochemistry and reverse transcription-polymerase chain reaction in non-small cell ;lung cancer / 中国医师进修杂志

ABSTRACT

Objective To explore the correlation between anaplastic lymphoma kinase (ALK) fusion gene detected by immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR) in non-small cell lung cancer. Methods The ALK fusion protein/gene in 71 patients of NSCLC which was detected both by IHC (1A4/1H7) and RT-PCR were retrospective studies, and the 2 methods were compared. Results Among the 71 NSCLC patients, the ALK fusion protein positive was in 21 cases and negative was in 50 cases by IHC detected, while the ALK fusion gene positive was in 12 cases and negative was in 59 cases by RT-PCR. The ALK fusion genes detected by RT-PCR were all negative when IHC negative and IHC 1+. All patients with IHC 2+ and IHC 3+ were confirmed ALK fusion genes positive with RT-PCR. The positive rate of ALK fusion protein detected by IHC in large surgical specimens was 28.95%(11/38), and the positive rate of ALK fusion protein detected by IHC in small biopsy specimen was 30.30%(10/33). The positive rate of ALK fusion gene detected by RT-PCR in large surgical specimens was 18.42%(7/38), and the positive rate of ALK fusion gene detected by RT-PCR in small biopsy specimen was 15.15% (5/33). Conclusions Although the ALK fusion protein detected by IHC may have certain false positive, IHC is highly consistent with RT-PCR in IHC 2+and IHC 3+ cases. The combination of IHC and RT-PCR can be used to ALK fusion gene positive NSCLC screening and diagnosis. The small biopsy specimen is also good material for ALK detection, when the surgical specimen can not be got from patients.