Retinoblastoma Chemotherapy: Less Is More

A recent randomized clinical trial conducted by a group of Chinese researchers compared three cycles versus six cycles of CEV (carboplatin, etoposide, and vincristine) chemotherapy in high-risk retinoblastoma patients. Their multicenter study aimed to determine whether three cycles of CEV are noninferior to the traditional six-cycle regimen, offering potential benefits in terms of reduced side effects, costs, and patient quality of life.

The trial included 187 children who had undergone enucleation for unilateral retinoblastoma. All patients had high-risk pathological features, such as massive choroidal infiltration, retrolaminar optic nerve invasion, or scleral infiltration, and were randomized to receive either three or six cycles of CEV chemotherapy post-surgery. The primary endpoint was disease-free survival over five years, while secondary endpoints included overall survival, safety, economic burden, and quality of life measures.

After a median follow-up of 79 months, the study found that five-year disease-free survival was 90.4 percent in the three-cycle group and 89.2 percent in the six-cycle group, meeting the prespecified noninferiority margin of 12 percent. Moreover, overall survival rates were similar between the two groups (91.5 percent for the three-cycle group versus 89.3 percent for the six-cycle group), further supporting the noninferiority of the reduced regimen.

But were the expected benefits of reduced side-effects and improved quality of life also met? The shorter chemotherapy regimen resulted in fewer adverse events – especially those related to hematological toxicities, such as neutropenia and anemia – as well as non hematological side-effects, including nausea, vomiting, and weight loss. In terms of quality of life, children in the three-cycle group experienced less decline in physical, emotional, and social functioning compared with those in the six-cycle group.

In conclusion, the authors note that a three-cycle CEV regimen could represent a viable and effective alternative to the standard six-cycle treatment for high-risk retinoblastoma, with fewer side effects, reduced costs, and maintained quality of life.