Is alpha-B crystallin an independent marker for prognosis in lung cancer?

Alpha B-crystallin (CRYAB) is an oncogene that increases tumour survival by promoting angiogenesis and preventing apoptosis. CRYAB is an independent prognostic marker in epithelial tumours including head and neck squamous cell carcinoma and breast cancer where it is predictive of nodal status and associated with poor outcome. We explored the role of CRYAB in non-small-cell lung cancer (NSCLC).

Immunohistochemical analysis was performed on 50 samples. Following staining with anti-alpha-B crystallin antibody, a blinded pathologist scored samples for nuclear (N) and cytoplasmic (C) staining intensity. Analysis was performed using Cox's proportional hazards model.

There were 32 adenocarcinomas and 18 squamous cell carcinomas. The median tumour size was T2, grade 2 moderately differentiated, and 10 patients had nodal spread. Recurrence was seen in 22 patients (46%). Mortality was 48%, with median time to mortality 871 days. N staining was detected in eight samples (16%), and C staining in 20 (40%), with both N and C staining positive in five (10%). Staining for CRYAB predicted neither recurrence (N stain p=0.78, C stain p=0.38) nor mortality (N stain p=0.86, C stain p=0.66).

CRYAB did not predict outcomes in patients treated for NSCLC. Larger studies are required to validate this finding.