The effect of age distribution on the prognosis of retroperitoneal neuroblastoma

Retroperitoneal neuroblastoma is a rare subtype of neuroblastoma and the role of age in its clinical prognosis is still unknown. To describe the age distribution and investigate the association between age and survival outcomes in patients diagnosed with retroperitoneal neuroblastoma. We retrospectively analyzed patients registered for retroperitoneal neuroblastoma in the Surveillance, Epidemiology, and End Results (SEER) national database from 1973 to 2015. Age distribution was described and Cox proportional hazard regression was used to evaluate the measured effect of age on overall survival and disease-specific survival. A total of 399 retroperitoneal neuroblastoma patients with a median follow-up of 53.0 (interquartile range 17.0–133.5) months were included. We found a unimodal distribution of age with a median age of diagnosis to be 1.0 (interquartile range 0.0–4.0) years. Univariate analysis suggested that transformed age was associated with an increased risk of total death and disease-specific death (OR = 4.2, 95% CI 3.0–5.9; OR = 4.7, 95% CI 3.2–6.8). Adjusted smoothed plots showed a nonlinear correlation between age and disease-specific death. The risk of disease-specific death did not increase sharply as the age increased until reaching the inflection point (age < 3 years, OR = 0.4, 95% CI 0.2–1.0; age ≥ 3 years, OR = 1.2, 95% CI 0.9–1.5). There was, however, a linear relationship between age and total deaths (OR = 1.0, 95% CI 0.7–1.2). Adjusted multivariate Cox regression analysis showed that ages ≥ 3 years were associated with a significant increased risks of disease-specific death and total death (OR = 2.5, 95% CI 1.7–3.8; OR = 2.3, 95% CI 1.6–3.3, respectively). There was a unimodal age distribution of retroperitoneal neuroblastoma usually presented in infants or younger child. Older age was associated with a lower chance of overall survival and the risk of disease-specific death increased sharply after 3 years of age.