Monitoring surgical removal of oral squamous cell carcinomas (OSCC) is being routinely performed through clinical and imaging follow-up. We analyzed the potential use of serum lactate, lactate dehydrogenase (LDH), and LDH isoenzymes (LDH 1-5) as biomarkers in blood for the monitoring of surgical removal of OSCC.MATERIALS AND METHODS:
Serum lactate, LDH, and LDH isoenzymes (LDH 1-5) have been prospectively assessed in healthy individuals (n= 19), patients with OSCC (n= 34: primary OSCC,n= 32 and recurrent OSCC,n= 2) before surgery and after curative tumor resection (n= 26). LDHA and LDHB expressions were analyzed by immunohistochemistry (IHC) in the same OSCC tumor specimen.RESULTS:
Positive LDHA tumor tissue expression measured by IHC (n= 34/34, 100%) was significantly associated with increased serum LDH-5 (n= 24/34, 71%,P= 0.0258) but weak significantly associated with increased total serum LDH (n= 23/34, 68%,P= 0.0592). Positive LDHB tumor tissue expression measured by IHC (n= 25/34, 74%) was significantly associated with increased total serum LDH (P= 0.0172). After surgery, serum LDH and LDH-5 isoenzyme significantly decreased and LDH-1 significantly increased in the aftercare. A significantly inverse correlation of LDHA with LDHB IHC scores was found (P< 0.0001).CONCLUSIONS:
The association of LDHA and LDHB measured by IHC with serum LDH indicates that analyzing this enzyme could serve as a favorable ‘liquid biopsy’ (non-invasive diagnostic tool) for OSCC.