Primary enucleation for group D retinoblastoma in the era of systemic and targeted chemotherapy: The price of retaining an eye

Background Chemotherapy is increasingly used as primary treatment for group D retinoblastoma, whereas primary enucleation is considered to have a diminishing role. This study aimed to compare the management course, including number of examinations under anaesthesia (EUAs), of group D patients treated by enucleation versus chemotherapy. Methods A retrospective analysis of 92 group D patients, of which 40 (37 unilateral) underwent primary enucleation and 52 (17 unilateral) were treated with intravenous chemotherapy. Number of EUAs was compared between the treatment groups with respect to the whole cohort, using univariate and multivariate analysis, and to unilateral cases only. Results Patients were followed up for a median of 61 months (mean: 66, range: 14-156), in which time primary enucleated patients had on average seven EUAs and chemotherapy-treated patients 21 EUAs (p<0.001). Chemotherapy, young age, bilateral disease, multifocal tumours, familial and germline retinoblastoma were found on univariate analysis to correlate with increased number of EUAs (p≤0.019). On multivariate analysis, however, only treatment type and presentation age were found significant (p≤0.001). On subanalysis of the unilateral cases, patients undergoing primary enucleation had in average seven EUAs, as compared with 16 in the chemotherapy group (p<0.001). Of the 55 unilateral-presenting patients, a new tumour developed in the fellow eye only in a single familial case. Conclusion Group D patients' families should be counselled regarding the significant difference in number of EUAs following primary enucleation versus chemotherapy when deciding on a treatment strategy. In this regard, primary enucleation would be most beneficial for older patients with unilateral disease.