High pretreatment serum lactate dehydrogenase level correlates with disease relapse and predicts an inferior outcome in locally advanced nasopharyngeal carcinoma.

PURPOSE: Here, we evaluate the prognostic effect of pretreatment serum lactate dehydrogenase (LDH) in locally advanced nasopharyngeal carcinoma (NPC).

METHODS AND MATERIALS: Pretreatment serum samples from a randomized controlled trial, which contained 199 neoadjuvant chemoradiotherapy patients and 201 neoadjuvant-concurrent chemoradiotherapy cases with locally advanced NPC, were collected and examined for LDH. With 5-year follow-up, the prognostic effect of pretreatment serum LDH was analysed by Kaplan-Meier analysis and multivariate Cox regression model.

RESULTS: Three hundred and sixty-seven patients (91.75%) had a normal (109.0-245.0 U/L) pretreatment LDH level, compared to 33 cases (8.25%) that had a higher (≥245.0 U/L) LDH level. The mean and median pretreatment LDH levels of these 400 patients were 186.6 and 174.0 U/L (range, 83.0-751.0 U/L), respectively. Compared with the normal subset, elevated LDH level predicted an inferior 5-year overall survival (56.9% versus 76.8%, P=0.004), disease-free survival (DFS, 45.4% versus 64.7%, P=0.001), local relapse-free survival (76.1% versus 89.6%, P=0.019) and distant metastasis-free survival (DMFS, 54.3% versus 72.2%, P=0.001). Multivariate analysis confirmed that the LDH level was an independent prognostic factor to predict death, disease progression, local relapse and distant metastasis. For the subgroup with normal LDH (median point of 177.0 U/L), we detected an evident 5-year DFS (68.8% versus 59.5%, P=0.047) and DMFS advantage (77.3% versus 65.3%, P=0.016) in 109.0-177.0 U/L subset than that of 178.0-245.0 U/L subgroup.

CONCLUSIONS: Serological LDH level was an independent prognostic factor for locally advanced NPC. Combining pretreatment LDH with TNM staging might lead to more accurate risk definition.