Laminin β3 expression as a prognostic factor and a predictive marker of chemoresistance in colorectal cancer

Laminin-332, a marker of epithelial-mesenchymal transition, is composed of a heterotrimer of alpha 3, beta 3 and gamma 2 chains that regulates cell adhesion and migration. This study aimed to disclose the respective clinical significance of laminin beta 3 immunoexpression in colorectal cancer as a prognostic factor and a predictive marker of chemoresistance. Tissue specimens from 323 Stage II and 232 Stage III colorectal cancer patients who underwent curative resection were assessed using laminin beta 3 immunostaining. Among Stage III colorectal cancer patients, comparisons of 5-year disease-free survival rates revealed a poorer prognosis for the laminin beta 3-high group than for the laminin beta 3-low group (52.3 vs. 70.7%, P = 0.038), while there was no significant difference among Stage II patients. Among laminin beta 3-low Stage III patients, those who received adjuvant chemotherapy showed marginally better disease-free survival than those who did not receive it (75.8 vs. 62.8%; P = 0.096). Furthermore, multivariate analysis corroborated a distinct benefit of adjuvant chemotherapy in laminin beta 3-low patients (P = 0.035; hazard risk ratio = 1.66). Analyses of the laminin beta 3-high group, however, failed to show significance. Laminin beta 3 chain immunoreactivity was a poor prognostic factor for Stage III colorectal cancer patients, and laminin beta 3-high patients of Stage III colorectal cancer derived no survival benefit from adjuvant chemotherapy.