Table 5.

Retinoblastoma with Extraocular Extension: Cox Regression Analysis Based on Age, Lag Time, and Treatment Modality

Feature	Systemic Metastasis		Death
	Hazard Ratio (95% CI)	P Value	Hazard Ratio (95% CI)	P Value
Age∗
2–4 yrs	2.459 (0.931–6.497)	0.069	1.773 (0.986–3.187)	0.056
>4 yrs	3.163 (1.149–8.708)	0.026	2.912 (1.603–5.290)	<0.001
Lag time
>2 mos vs. ≤2 mos	0.885 (0.459–1.706)	0.715	1.024 (0.575–1.826)	0.936
Treatment modality†
Trimodal‡ vs. unimodal§ + bimodal‖	2.253 (1.309–3.880)	0.003	1.179 (0.701–1.984)	0.534
Trimodal‡ vs. unimodal (surgery)	2.712 (1.011–7.277)	0.048	0.644 (0.234–1.774)	0.395
Trimodal‡ vs. unimodal (chemotherapy)	4.496 (2.081–9.714)	<0.001	2.023 (1.244–3.240)	0.004
Trimodal‡ vs. bimodal‖	2.187 (0.830–5.763)	0.113	1.819 (1.063–3.177)	0.027
Primary treatment modality in combination therapy¶
Primary surgery	6.500 (1.310–32.246)	0.022	1.117 (0.363–2.704)	0.844

CI = confidence interval.

^∗Reference: Age <2 years.

^†Reference: Trimodal therapy.

^‡Trimodal: Surgery, intravenous chemotherapy, and external beam radiotherapy.

^§Unimodal: Surgery or intravenous chemotherapy.

^‖Bimodal: Surgery and intravenous chemotherapy.

^¶Reference: Primary chemotherapy.