Sacrococcygeal teratoma growth rate predicts adverse outcomes.

PURPOSE: The purpose of this study was to characterize the growth rate of sacrococcygeal teratomas (SCTs) and determine its relationship to adverse outcomes.

METHODS: A retrospective review of all pathology-confirmed isolated SCT patients evaluated with at least two documented ultrasounds and followed through hospital discharge between 2005 and 2012 was conducted. SCT growth rate was calculated as the difference between tumor volumes on a late- and early-gestation ultrasound divided by the difference in time. Outcomes were death, high-output cardiac failure (HOCF), hydrops, and preterm delivery. Student's t-test, receiver operator characteristics, Fisher's Exact test, and Pearson's correlation were performed.

RESULTS: Of the 28 study subjects, there were 3 in utero demises and 2 neonatal deaths. Significantly faster SCT growth rates were seen in all adverse outcomes, including death (p<0.0001), HOCF (p=0.005), and preterm delivery (p=0.009). There was a significant association with adverse outcomes at >61cm(3)/week (AUC=0.87, p=0.001, LR=4.52). Furthermore, there was an even greater association with death at >165cm(3)/week (AUC=0.93, p=0.003, LR=18.42). Growth rate was directly correlated with the percent of solid tumor (r=0.60, p=0.0008).

CONCLUSION: Faster SCT growth is associated with adverse outcomes. SCT growth rate determined by ultrasound is an effective prognostic indicator for adverse outcomes and easily applied to patient management.