916P - Biological assessment of viable germ cell tumor (VT) in patients (pts) with seminoma (S) and non seminoma (S) using miR371

Date 10 September 2017
Event ESMO 2017 Congress
Session Poster display session
Topics Germ Cell Tumours
Genitourinary Cancers
Translational Research
Presenter Lucia Nappi
Citation Annals of Oncology (2017) 28 (suppl_5): v295-v329. 10.1093/annonc/mdx371
Authors L. Nappi1, M. Thi1, L. Fazli1, K. Chi2, B. Eigl2, C. Nichols3, M. Gleave1, C.K. Kollmannsberger2
  • 1Urologic Sciences, Vancouver Prostate Centre, V6H3Z6 - Vancouver/CA
  • 2Medicine, British Columbia Cancer Agency, V5Z 4E6 - Vancouver/CA
  • 3Precision Genomics Cancer Research Clinic, Intermountain Health Care, Murray/US

Abstract

Background

The pathological constitution of residual nodes after chemotherapy or of the borderline enlarged retroperitoneal (RP) lymph nodes in clinical stage I (CSI) germ cell tumor (GCT) pts on surveillance is challenging, especially in tumor markers (TM) negative pts. Currently, accurate assessment requires pathological confirmation with RPLND or clinical follow-up to establish a pattern of growth. A plasma-based approach to identify patients with VT would be uniquely valuable.

Methods

Formalin-fixed paraffin embedded (FFPE) and plasma from GCTs patients were used for miRNAs extraction. Non-cancer FFPE testicular tissue and plasma from healthy volunteers were used as negative controls. miR371 expression was detected by RT-PCR and relative expression calculated by the 2-ΔΔCt method. miR-93-5p was used as positive internal control. Results were analyzed for associations with clinicopathologic features using Fisher’s exact test.

Results

miR371 was over-expressed in all the primary testicular (n = 4) and mediastinal (n = 3) samples while it was undetectable in the atrophic testis (n = 1) and mediastinal or gonadal teratoma (n = 2), confirming the applicability of the technique to the FFPE samples. 21 metastatic samples were analyzed: 2 lung, 1 brain, 17 lymph nodes and 1 IVC tumor thrombus. The samples were collected prior to (n = 2) or after (n = 12) chemotherapy, while 7 pts were treated only with surgery. miR371 was undetectable in any samples (0/9) with no VT on pathological examination and over-expressed in 11/12 (91.6%) of those with viable GCT (OR 145.7; p 

Conclusions

Elevated plasma levels of miR-371 correlate with the presence of active germ cell malignancy. These encouraging findings suggest that plasma miR371 levels may lead to biological rather than radiographic assessment of the presence of active GCT in patients with S and NS.

Clinical trial identification

Legal entity responsible for the study

Lucia Nappi

Funding

None

Disclosure

All authors have declared no conflicts of interest.