Introduction:

Circulation tumor DNA (ctDNA) has been gaining popularity in directing and personalizing treatment modalities in solid cancers. ctDNA utility before and after diagnosis of testicular cancer has not yet been well-characterized. We seek to characterize the utility of ctDNA in correlation with pathologic and clinical features in patients with testicular cancer.

Methods:

Our single institution prospectively maintained database identified consecutive patients who underwent radical orchiectomy between 2020 and May 2023, included were patients who had a ctDNA (Natera™) performed before or after surgery. Baseline characteristics, pathology results, imaging study results, and oncological treatment follow-ups were collected from electronic medical charts. ctDNA information was collected through the Natera™ portal. Study findings were reported using descriptive statistics. A p-value of <0.05 was considered statistically significant. R programming language version 4.3 were used for all statistical analyses.

Results:

A total of  33 patients were included in the study. The median age was 33 (IQR (26-38).  The median follow-up time was 9 months (6-17). All the 16 patients who had pre-orchiectomy ctDNA test performed, had a positive signal, of them two patients had normal serum tumor markers (STM). Three patients underwent primary RPLND (retroperitoneal lymph node dissection) all had a negative ctDNA, the pathology result was no evidence of tumor in all the patients. Of the 5 patients with positive ctDNA status after radical orchiectomy, 2 underwent RPLND with GCT found on the pathology (of them one had normal tumor markers). Three patients underwent chemotherapy and are on surveillance without evidence of recurrence, ctDNA became negative in all three patients in correlation with STM.  The baseline and oncological characteristics of the cohort are shown in Table 1. 

Conclusion:

ctDNA signal was found to be correlated with different stages of testicular cancer, the test may have a role in patients with negative serum tumor markers. In a small cohort of patients who underwent primary RPLND without evidence of RP mass and who had negative ctDNA, no viable tumor was found on pathology. Those patients who underwent RPLND with positive ctDNA, viable GCT was found on pathology. The sensitivity and the specificity of this test in different stages of the disease are yet to be determined. Larger cohort with longer follow-up time is necessary to validate these initial results.

Funding: N/A