Table 3 Multivariate analysis of predictors associated with overall survival (OS) showing total effect

Mean age (years)

≤ 63

1

>  63

0.75 (0.33, 1.75)

0.519

Mean duration of presenting symptom (weeks)

- Histopathologic diagnosis

≤ 67.9

1

>  67.9

1.19 (0.41, 3.45)

0.751

Restriction of extraocular movements

- Mean duration of presenting symptom

No

1

- Tumor invasiveness

Yes

2.39 (0.71, 7.98)

0.199

- Tumor origin

Mass

No

1

Yes

1.02 (0.40, 2.64)

0.965

Eye pain on presentation

- Histopathologic diagnosis

No

1

Yes

1.40 (0.56, 3.48)

0.476

VA

- Mean age

≥ 20/400

1

- Histopathologic diagnosis

<  20/400

4.67 (1.27, 17.12)

0.003*

- Tumor origin

- Tumor size

Tumor size

- Mean duration of presenting symptom

≤ 20 mm

1

- Histopathologic diagnosis

>  20 mm

3.14 (1.06, 9.32)

0.022*

Histopathologic diagnosis

- Mean age

Non-squamous cell

1

- Tumor origin

Squamous cell

0.58 (0.15, 2.30)

0.435

Tumor origin

Lid

1

Lacrimal, globe, and orbit

1.57 (0.54, 4.59)

0.674

Conjunctiva

1.09 (0.37, 3.16)

Conjunctiva

1

Lacrimal, globe, and orbit

1.44 (0.53, 3.91)

Surgical margins

Clear margin

1

Unclear margin

0.78 (0.32, 1.94)

0.593

Tumor invasiveness (lymphovascular, perineural, bony)

No

1

Yes

1.41 (0.57, 3.48)

0.466

Status of metastasis

- Mean duration of presenting symptom

Negative

1

- Histopathologic diagnosis

Regional nodal metastasis

3.32 (0.76, 14.52)

< 0.001*

- Tumor size

Distant metastasis

15.31 (4.25, 55.19)

Adding resection

- Tumor invasiveness

No

1

- Recurrent disease

Yes

0.57 (0.15, 2.23)

0.403

- Surgical margins

Radiation

- Status of metastasis

No

1

- Surgical margins

Yes

1.27 (0.45, 3.56)

0.654

Chemotherapy

- Status of metastasis

No

1

Yes

1.76 (0.63, 4.93)

0.298

Recurrent disease

No

1

Yes

2.62 (0.99, 6.91)

0.070