Background: Few prospective studies about the management of unilateral retinoblastoma with pathology risk factors (PRFs) have been published.
Methods: Patients (n = 114) were divided into four groups: Group 1 (initial chemoreduction) (n = 17). Groups 2 and 3, included patients initially enucleated with no, or lower risk PRFs: (n = 65) and with higher risk PRFs (n = 30), respectively. The later included postlaminar optic nerve involvement (PLONI) (n = 23), tumor at resection margin of optic nerve (n = 5) or isolated scleral invasion (n = 2). Group 3 received adjuvant chemotherapy including a total eight cycles of carboplatin and etoposide, alternating with cyclophosphamide, idarubicin, and vincristine. Orbital radiotherapy (45 Gy) was given to patients with invasion to the resection margin. Group 4 included patients with metastatic disease (n = 2). They were given neoadjuvant therapy followed by surgery and high-dose chemotherapy and autologous stem cell rescue.
Results: Five-year event-free survival is 0.94 (1 for Group 1, 0.94 for Group 2, 0.96 for Group 3, and 0 for Group 4). Events included. Group 2: Systemic relapse (n = 2) and combined orbital and CNS relapse (n = 1). Relapsing patients had PLONI (n = 2) and isolated focal choroidal invasion (n = 1). Group 3: CNS relapse (n = 1) in a patient with tumor at the resection margin of optic nerve. Group 4: CNS relapse (n = 2). Only one relapsed patient survived. Eight of 17 eyes treated conservatively were preserved.
Conclusions: The survival of patients with unilateral retinoblastoma was excellent and 60% were spared from adjuvant treatment. Our intensive regimen was likely to be effective for prevention of metastasis in patients with higher risk PRFs.