The National Registry of Retinoblastoma in Japan (1983-2014)

To review the clinical findings of retinoblastoma recorded over a period of 32 years by the National Registry of Retinoblastoma in Japan.

Retrospective.

We reviewed the diagnoses, clinical pictures, and treatment data recorded on a yearly basis from 1983 until 2014 by major Japanese medical facilities.

A total of 2360 patients (1225 boys, 1135 girls) were analyzed. Of those, 67.3% had unilateral retinoblastoma, 32.7% had bilateral retinoblastoma, and 6.7% had a family history of retinoblastoma. The average occurrence frequency for retinoblastoma was 1:16,823 births/year. At diagnosis, 89.0% of the patients were aged younger than 3 years and 41.0% were aged younger than 1 year. The most common initial symptom was leukocoria (48.9%), which was followed by cat's eye (17.1%) and strabismus (14.8%). Of the total 3131 eyes, 53.0% were Reese-Ellsworth group V. As per the International Classification of Retinoblastoma, 33.7% of the eyes were group D, and 30.1% were group E. Enucleation was performed in 1545 eyes (52.2%), and subsequent treatment was administered in 379 eyes. Conservative therapy was performed in 1415 eyes (47.8%) of 926 patients. The number of eyes receiving conservative therapy increased every year, even in about 30% of those with advanced group V eyes. Radiation therapy was the primary conservative therapy before the year 2000 and was thereafter replaced by chemotherapy. In the eyes receiving chemotherapy, anticancer agents were administered systematically in one-third of the eyes, locally in another one-third of the eyes, or as a combination of both in the other one-third. Conservative therapy successfully preserved in over 90% of the eyes of groups I to IV and in 78.1% of the eyes of group V.

Retinoblastoma is often diagnosed at an advanced stage. With the development of systemic and local chemotherapy, the number of eyes with advanced retinoblastoma preserved by conservative therapy has been increasing.