Laboratory variables as additional staging parameters in patients with small-cell lung carcinoma. A systematic review.

We have reviewed the biomedical literature published over the last 25 years in order to try to establish which of four frequently evaluated laboratory parameters (i.e. serum, or plasma, NSE, LDH, sodium or albumin) might, alone or in combination, give the "best" pretreatment prognostic information in small-cell lung cancer (SCLC) patients, independent of the usual radiological and clinical parameters. From the 45 studies included in this review, the only clear conclusion that can be derived is that it has not yet been clearly demonstrated that the "new" tests (NSE or other tumor markers) are superior to the "old" tests (LDH, sodium, albumin etc.). From the only seven studies that used the same powerful statistical methodologies (Cox's models in association with recursive partitioning and amalgamation procedure (RECPAM) analysis) it could be concluded that LDH and albumin might have independent prognostic significance in SCLC and in advanced SCLC respectively. Provided that, in the future, both laboratory and statistical expertises are clearly guaranteed in the primary studies in this field, it might become possible to propose laboratory parameters as additional staging parameters in SCLC.