Pretreatment serum LDH as additional staging parameter in small-cell lung carcinoma

In patients with limited disease staged small-cell lung cancer (SCLC), overall survival is still poor. Therefore, a retrospective study was carried out of 48 patients with limited disease staged SCLC to select a parameter which can identify prognostic subgroups at the time of diagnosis.

Follow-up varied from 3 to 96 months during which 38 patients died. Based on clinical outcome, patients were clustered into three 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.

No differences in survival were found in patients with LOC (14% 2-year survival) and DIS (16% 2-year survival) (P = 0.67). Patients with complete remission demonstrated a significantly better survival (75% 2-year survival). LDH was found to be the only significant correlate of both tumour progression and survival. All patients with pretreatment LDH levels > 240 IU/l (n = 13) demonstrated tumour recurrence. The survival rate of patients with LDH levels < 240 IU/l (41% 2-year survival) was much better than that of patients with LDH levels > 240 IU/l (8% 2-year survival) (P = 0.0001).

LDH may be used for the identification of prognostic subgroups in limited disease SCLC. Patients showing pretreatment LDH levels > 240 IU/l have an extremely high risk of tumour recurrence, whereas survival is poor. In patients with LDH levels, < 240 IU/l survival is significantly better.