Prognostic impact of Notch1 receptor and clinicopathological High-Risk Predictors in lacrimal gland adenoid cystic carcinoma.

PURPOSE: Adenoid Cystic Carcinoma (ACC) is an aggressive malignant lacrimal gland tumour associated with poor prognosis. Aberrant Notch signalling has been investigated in various tumours. However, very few studies on Notch signalling in lacrimal gland ACC are reported. The aim of the present study was to evaluate the status of Notch1 receptor and activated Notch1 (NICD1) in lacrimal gland ACC and to correlate it with high-risk clinicopathological features.

METHODS

A total of 23 cases of histopathologically proven lacrimal gland ACC, who underwent surgical treatment, were included in this study. Expression of Notch1 receptor and NICD1 was evaluated by immunohistochemistry on formalin fixed paraffin embedded tissues. The results obtained were correlated with clinicopathological high-risk features and survival of the patients. Kaplan-Meier survival and multivariate analysis was performed to determine the prognostic significance.

RESULTS

Overexpression of Notch1 receptor and NICD1 was observed in 65% and 39% of lacrimal gland ACC cases, respectively. On Kaplan-Meier survival analysis, patients with Notch1 receptor overexpression had reduced disease free survival. On univariate analysis, male gender, bone erosion, perineural invasion, solid histologic pattern, intracranial extension and advanced tumour stage were also indicators of poor prognosis. On multivariate analysis bone erosion was the most significant poor prognostic indicator.

CONCLUSION

Our study demonstrates that overexpression of Notch1 receptor plays a critical role in the biology and aggressive behaviour of lacrimal gland ACC. Bone erosion, solid histologic pattern, advanced T stage, perineural invasion and intracranial extension are other high-risk clinicopathological predictors of lacrimal gland ACC.