[Delayed diagnosis in retinoblastoma].

Objectives: To identify the main symptoms of retinoblastoma and to determine the mean time between symptom onset and diagnosis (lag time).

Patients And Methods: We carried out a retrospective analysis of the patients diagnosed with retinoblastoma between January 1991 and June 2000, at the Pediatric Department of the Hospital do Cancer, Sao Paulo, Brazil. Statistical analyses performed were: Student's t test, ANOVA, Tukey-HSD test (honest significant differences), Levene's test, multiple regression, ROC curve, logistic regression, Kaplan-Meier, and log rank.

Results: 327 medical records (171 males) were reviewed. The mean age was 25 months. Localized disease was identified in 269 patients. The most frequent symptoms were leukocoria (79%), strabismus (10.7%) and tumor mass (3.4%). Mean lag time was 5.8 months. Patients older than 2 years old had longer lag time in comparison to infants (7.2 vs 4.7 months; p = 0.001). Lag time was longer among patients with strabismus (8.8 months) in comparison to patients with tumor mass (2.3 months) and leukocoria (5.6 months); p = 0.014. Patients with metastatic disease had longer lag time (10.6 months; p < 0.001). Lag time was influenced by advanced disease (OR = 3.25/CI = 1.61:6.55), metastatic disease (OR=3.52/ CI = 1.21:10.21) and strabismus (OR = 2.84/IC = 1.36:5.92). Five-year overall survival rates were higher among patients with localized disease (94.6% ) and among patients with lag time less than 6 months (91%), in comparison to patients with longer lag time (78%; p < 0.001).

Conclusion: Most frequent symptoms of retinoblastoma were leukocoria, strabismus and tumor mass. Mean lag time was 5.8 months. Strabismus and advanced disease were associated to longer lag time. Patients with advanced disease and lag time longer than 6 months had worse prognosis.