Ocular surface squamous neoplasia with orbital tumour extension: risk factors and outcomes

To describe the risk factors, clinical features, histopathology, treatment, and outcomes of patients with orbital tumour extension of ocular surface squamous neoplasia (OSSN).

Retrospective study of 51 patients with orbital tumour extension (cases) and 360 patients without orbital extension (controls).

Of 1,653 patients with OSSN, orbital tumour extension was noted in 51 (3%) cases. The risk factors for orbital tumour extension included outdoor occupation (p < 0.03; Odds ratio (OR) = 1.96), Human Immunodeficiency Virus (HIV) infection (p < 0.0001; OR = 5.81), prolonged duration of symptoms (p = 0.01; OR = 1.02), tumour bilaterality (p = 0.02; OR = 2.92), forniceal and tarsal conjunctival involvement, diffuse tumour (p < 0.0001; OR = 9.13), inferior quadrantic location (p < 0.0001; OR = 7.51), increased tumour thickness (p = 0.04; OR = 1.59), higher % of ocular surface involvement (p = 0.002; OR = 1.12), nodular (p = 0.002; OR = 2.61) and nodulo-ulcerative (p < 0.0001; OR = 11.05) tumour morphology, poorly differentiated tumours (p = 0.006; OR = 4.23); invasive squamous cell carcinoma (SCC) (p < 0.0001; OR = 29.76), spindle cell and mucoepidermoid variant (p = 0.02; OR = 16.94) tumours. At a mean follow-up period of 27 months, tumour recurrence in the socket was noted in 1 (2%), locoregional lymph node metastasis (LNM) in 15 (29%) patients, and nine (18%) patients died due to systemic metastasis (SM). T4 tumour at presentation was a risk factor for LNM (p = 0.01; Hazard ratio (HR) = 5.60) and SM (p = 0.0003; HR = 5.09).

Orbital extension of OSSN is rare. Outdoor occupation, HIV infection, larger and thicker tumours in the inferior quadrant with forniceal and/or tarsal conjunctival involvement with nodular or noduloulcerative morphology, poor tumour differentiation, SCC, spindle cell and mucoepidermoid variants on histopathology are at increased risk for orbital tumour extension.