Purpose: To discuss the importance of routine ophthalmic examination of parents and siblings of retinoblastoma (RB) patients.
Methods: Prospective nonrandomized observational/interventional case series of consecutive families of 131 RB patients.
Results: Routine ophthalmic examination of families (parents and siblings) of 131 consecutive newly diagnosed RB patients, including 262 parents and 23 siblings, revealed spontaneously regressed RB in at least 1 parent of 10 (8%) patients and active RB in at least 1 sibling of 3 (2%) patients. Of the 10 parents with spontaneously regressed RB, the lesions were unilateral (n = 7) or bilateral (n = 3). The regression patterns (n = 13) were comparable with postirradiation regression patterns Type 1 (n = 3), Type 2 (n = 2), Type 3 (n = 2), and Type 4 (n = 3), and spontaneous phthisis bulbi (n = 3). Fundus screening of siblings revealed active RB in at least 1 sibling of 3 (2%) patients. Of these 3 siblings, 2 had unilateral and 1 had bilateral disease. The mean age at detection of RB was 15 months (median, 6 months; range, 2-36 months). The disease was unilateral in 2 and bilateral in 1 patient. Based on International Classification of Intraocular Retinoblastoma, the tumors (n = 4) were classified as Group A (n = 2) and Group B (n = 2).
Conclusion: Routine fundus screening of siblings allows for early detection of RB in otherwise asymptomatic children. Detection of spontaneously regressed RB in parents may act as a surrogate marker for germline RB1 mutation and is helpful in genetic counseling.