Retinoblastoma in Victoria, 1976-2000: changing management trends and outcomes.

PURPOSE

To describe changes in the management of retinoblastoma in Victoria and to review the effect of newer, conservative treatments on preservation of eyes, visual outcome and mortality by comparing a similar group of patients treated over successive time intervals.

METHODS

A retrospective analysis of all cases of retinoblastoma diagnosed and treated in Victoria between 1956 and 2000 was conducted. Historical data on 77 cases previously published by O'Day et al. was used for the period 1956-1976 (series 1). Data on 88 cases recorded in the Royal Children's Hospital (Melbourne) Retinoblastoma Database was used for the period 1976-2000. The latter group was subdivided into those treated between 1976 and 1989 (series 2), prior to the advent of modern eye saving treatments, and those treated subsequent to their introduction from 1990 to 2000 (series 3).

RESULTS

In unilateral retinoblastoma, final enucleation rates for 1956-1976 (series 1) and 1976-1989 (series 2) were almost identical, being 98% and 97% of affected eyes, respectively (P = 1.00). Despite the newer treatments used after 1990 (series 3), 88% of affected eyes were still enucleated, representing a statistically similar outcome to series 2 (P = 0.33). In bilateral retinoblastoma, primary enucleation of the more involved eye was similar for series 1 (84%) and 2 (80%) but series 3 (41%) was substantially less than series 2 (P = 0.04) following the increased use of conservative treatments. In series 3, 59% of more involved eyes were treated conservatively compared with 16% (P = 0.007) and 20% (P = 0.04) for series 1 and 2, respectively. Despite attempts at eye salvage, the failure rate was higher in series 3 (29%) yielding a final enucleation rate of 70%, which represented a modest downward trend in the numbers of eyes finally enucleated; 84% (series 1), 73% (series 2) and 70% (series 3) (test for trend, P = 0.33). Bilateral enucleation rates were significantly lower, from 36% and 30% in series 1 and 2, respectively, to 7% in series 3 (test for trend, P = 0.02). As a consequence, more eyes were preserved over time, being 20/50 (40%) in series 1, 15/30 (50%) in series 2 and 21/34 (62%) in series 3. Comparison of visual outcome was hampered by incomplete data in series 1 but it appeared series 2 and 3 achieved better visual acuities with 67% and 62% of preserved eyes in bilateral cases measuring equal to or better than 6/12. Mortality rates in all series were low, being 7.8% in series 1, 4.5% in series 2 and nil in series 3.

CONCLUSIONS

Following the introduction of new conservative treatments, there has been an increase in preservation of eyes and improved visual outcome, and a dramatic decrease in numbers of bilateral enucleations without adversely affecting survival.