Retinoblastoma (Rb) in Saudi Arabia- Fifteen Year Retrospective Comparative Review of a Registry: 1983-1997 vs. 1998-2007 at King Khaled Eye Specialist Hospital

Abstract

Purpose: Published data regarding Rb in Saudi Arabia (KSA) is sparse. The objective of this study was to compare the clinical and pathologic features, and evolving patterns of the treatment from 1983-1997 (Early) to 1998-2013 (Late) from an Rb registry; the registry represents all Rb cases in KSA.

Methods: The Rb registry was queried for the following parameters: gender, laterality, age, clinical features and stage at presentation; gender, laterality, regional distribution, history, co-morbid diseases, pathologic features, surgical treatment modality and treatment outcome.

Results: In the early group (EG) 343 patients were identified vs. 461 patients in the late group (LG). The gender distribution was similar in both groups. The median (inter quartile range) age of presentation was 24 (11, 39) months in EG vs. 18(8, 31) months in LG (p <0.001). Unilateral Rb was noted in EG vs. LG [198 (58%) vs. 277 (60%)]. Positive family history was <10% in both groups. However, in EG, 120 (33%) of parents were first cousins vs. 124 (28%) in the LG (p=0.12). Leukocoria was the most common presenting symptom in both groups 255 (80%) EG vs. 346 (75%) in LG (p=0.13). At presentation, tumor confined to the eye was more common the LG group (67% EG vs. 84% LG). Vitreous seeding was more common in LG [302(62%) LG vs.156 (45%) in EG]. In the non-surgical group, photocoagulation rate increased in the LG [106 (23.19%) vs. 13(3.8%) in EG; p<0.001 ]. The rate of chemotherapy increased from 96 (28%) in EG to 158 (34.64%) in LG (p =0.06). The rate of external beam radiation decreased [125 (36.98%) EG vs. 107(23.41%) in LG, (p <0.001)]. The rate of extraocular tumor extension was similar in both groups (53.7% EG vs. 51.6% LG). The rate of full thickness choroidal involvement decreased from 40 (14.4%) EG to 40(10.34%) in LG, p =0.11; ON involvement in LG decreased to 22 (3.4%) compared to 48(9.8%) in EG (p <0.001).

Conclusions: Most Rb clinical parameters remained unchanged over 30 years except an earlier median age of presentation suggesting earlier tumor detection. However, an increasing number of Rb was seen in the last fifteen years. The pathologic features in LG were less advanced suggesting earlier Rb detection. A significant increase in the non-surgical treatment approaches of Rb was noted in the last 15 years.

Keywords: 744 tumors • 703 retinoblastoma • 578 laser