Abstract
Abstract only
e17549
Background: MUC4 has been shown to play a key role in breast and pancreatic cancer. MUC4 expression is seen in the normal bronchial epithelium, but its role in non-small cell lung cancer (NSCLC) is unclear. Here we study the association between MUC4 overexpression and clinical features of NSCLC. Methods: The diagnosis of lung cancer was confirmed in H&E sections. MUC4 level was semi-quantified by immunohistochemistry. Each sample was given a composite score based on intensity and extent of staining. The intensity was graded on a 4 point scale: – (0), + (1), ++ (2), and +++ (3). The extent of staining too was graded on a 4 point scale: 1 (1-25%), 2 (26-50%), 3 (51-75%), and 4 (76-100%). The composite score was obtained by multiplying the two values, with possible scores of 0-12. Poisson mixed effects models were used to compare the score between groups. Kaplan-Meier method was used to estimate survival distributions and the log-rank test was used to compare them. Wilcoxon sign rank test was used to compare the difference in score between lung tissue and corresponding lymph node. P value <0.05 was considered to be statistically significant. Results: 167 samples from 54 non-metastatic NSCLC patients were analyzed. Of these, 13 (25%) patients had stage I, 33 (63%) had stage II and 6 (12%) patients had stage III disease. Distribution of the composite score differed significantly by stage (p=0.0043). A higher proportion of patients with stage I NSCLC had a score of 12 (77%) compared to stage II (18%) and stage III (57%) (p=0.0001). When patients who had data for both the primary tumor and corresponding metastatic lymph node were analyzed, MUC4 expression was higher in the primary tumor compared to the metastasis (p=0.05). The effect of MUC4 expression on survival was analyzed in 29 patients with survival data. Of these, 16 had a composite score of 12, while 13 had a score <12. Patients with a score <12 had significantly worse survival than those with a score of 12 (p<0.045). Conclusions: MUC4 expression is more common in early stage NSCLC and appears to be associated with a better outcome in patients with non-metastatic NSCLC. The therapeutic implications of this finding need to be investigated further.