Survival of retinoblastoma patients: a cohort study by two Russian medical centers

Abstract

Purpose. To evaluate the overall, disease-specific, event-free, relapse-free survival of retinoblastoma (RB) patients and cumulative probability of eye survival in such patients.Material and methods. The study included 223 children with RB (126 male, 97 female). Monolateral disease was diagnosed in 69.1 % of cases (n = 154), bilateral disease in 30.9 % (n = 69). The median follow-up was 40 months (interquartile range from 27 to 53 months). According to ABC classification, group A was diagnosed in 16 of 292 eyes (5.5 %), group B — in 53 (18.2 %), group C — in 41 (14.0 %), group D — 58 (19.9 %), and group E — in 124 (42.5 %). Group E was detected twice as often in patients with unilateral RB as in bilateral RB (56.5 % versus 26.8 %; p < 0.01). Stage T1 according to TNM classification was diagnosed in 69 cases (23.6 %), stage T2-T3 — in 213 cases (72.9 %). The extraocular form (stage T4) was detected in 3.4 % of cases (n = 10).Results. The overall five-year survival of patients treated for RB (n = 223) was 96.4 ± 1.4 %. The 5-year disease- specific survival (n = 222) was 96.8 ± 1.3 % in the general cohort, 96.5 ± 1.5 % in the group of children with monocular RB, 97.3 ± 2.7 % for binocular RB. Five-year event-free survival rate of children who received treatment (n = 223) was 66.7 ± 3.6 %, with monolateral lesion (n = 154) — 74.1 ± 4.2 %, with bilateral lesion — 50.6 ± 6.2 % (n = 69). Five-year relapse-free survival took place in 83.3 ± 3.1 %, with monolateral RB — 87.8 ± 3.3 %, with bilateral RB — 73.3 ± 6.4 %. Primary enucleation was performed in 121 of the 223 children treated for RB and included in the study. The frequency of primary enucleation with monocular RB was more than twice as high (55.2 %; 85 of 154 eyes) as with binocular RB (26.1 %; 36 of 138 eyes; p < 0.01). Organ-preserving treatment was carried out in 138 cases (171 eyes). It was effective in 123 (89.2 %) children (152 eyes; 88.9 %). 5-year ocular survival was 85.7 ± 3.7 %, with monolateral RB — 78.2 ± 6.6 %, with bilateral RB — 92.2 ± 2.8 %. Ocular survival counted separately for groups A, B, C, D, equaled 100 %, 100%, 76.6 ± 6.9 %, and 71.1 ± 11.9 %, respectively. The five-year disease-specific survival rate of children with monocular lesion given eye-preserving treatment was 100%, significantly higher than after primary enucleation — 93.4 ± 2.9 %.Conclusions. Modern combined retinoblastoma treatment is able to save the sick children’s lifes and and even their eyes and visual functions, which improves social adaptation and quality of life. It has been shown that, with a binocular form, it is possible to save more eyes than with a monocular form. Eye-preserving treatment administered to patients with intraocular RB under strictly observed criteria does not heighten the risk of metastasis. Yet timely enucleation in cases of absolute indications remains the method of choice in saving the life of a child.