Co-Authors:
Jen Poynter, Michelle Roesler & Jeannette Sample

Advisor:
Jen Poynter

Keywords:
Pediatrics, Germ Cell Tumor

Abstract

Platinum-based chemotherapy is commonly used to treat germ cell tumors (GCT) but can cause detrimental health effects, including ototoxicity and tinnitus. Years after the completion of treatment, survivors can have detectible levels of platinum in their blood serum. Although there have been previous studies among adult GCT survivors, there have yet to be studies among the pediatric population. 

Probands were identified through Germ Cell Tumor Epidemiology Study (GaMETES) and invited to participate in a longitudinal study to learn more about the long-term effects of GCTs. Probands who re-consented were recruited for blood collection. Blood samples were sent to the Wisconsin State Laboratory of Hygiene (WSLH) for analysis by high-resolution inductively coupled plasma mass spectrometry (ICP-MS). 

Pearson correlation coefficients were used to measure linear correlation between blood serum platinum levels and time since diagnosis. 

Platinum was measured in 46 serum samples from our blood collection pilot study. Three platinum isotopes were measured with consistent measurements across isotopes. Platinum levels ranged from 0.030 ug/L to 0.87ug/L at time points from 6-13 years after diagnosis with higher levels in cases who received chemotherapy (0.19ug/L vs 0.07ug/L, p=0.002). Platinum levels were inversely correlated with time since diagnosis (Figure; r= -0.39).

We will measure the association between blood serum platinum levels and ototoxicity, while adjusting for age at treatment, time since diagnosis, tumor location and sex, once we have data for the complete pilot study (N=100 cases).

Our results demonstrate that residual platinum is detectible in pediatric GCT survivors more than 10 years after diagnosis.