The Diagnostic Value of Pretreatment Serum LDH in Patients with Limited Disease Small-cell Lung Carcinoma

Background: In patients with limited disease SCLC, the overall survival is still poor. Therefore, a retrospective study was performed involving 48 patients with limited disease SCLC to select a parameter which can identify prognostic subgroups at the time of diagnosis.

Materials And Methods: Follow-up ranged from 3 to 96 months, during which period 38 patients died. Based on clinical outcome, patients were classified into 3 groups: complete remission (CR) (n = 16), local recurrence (LOC) (n = 7) and distant recurrence (DIS) (n = 25). Age, gender and pretreatment biochemical parameters were correlated with clinical outcome and survival. For survival 70 patients staged as having extensive disease (ED) served as a control group.

Results: No differences in survival were found in patients with LOC (14% 2 year survival) and DIS (16% 2-year survival) (p = 0.67). Patients achieving a complete remission had a significantly better survival (75% two-year survival). LDH was found to be the only significant correlate of both tumor progression and survival. All patients with pretreatment LDH levels < 240 U/L (n = 13) had tumor recurrence. The survival rate of patients with LDH levels, 240 U/L (41% 2-year survival) was much better than that of patients with LDH levels > 240 U/L 8% 2-year survival) (p = 0.0001). No significant difference in survival (p = 0.33) was found between patients with LD and LDH > 240 U/L and patients with ED and LDH < 400 U/L. Patients with ED and LDH values > 400 U/L showed the poorest outcome.

Conclusion: LDH may be used for the identification of prognostic subgroups in SCLC. Patients showing pretreatment LDH levels > 240 U/L have an extremely high risk of tumor recurrence, while their survival is poor and comparable to that of patients staged as having extensive disease and LDH values < 400 U/L.