[Stage IV NSCLC. Prognostic factors].

INTRODUCTION: Knowledge of prognostic factors is important for therapeutic decisions but also at a population level for the interpretation of literature data and for designing clinical research. For practical usefulness, they must have an independent and reproducible value. Despite an impressive number of publications, few characteristics earn this status for lung cancer in general and for stage IV lung cancer in particular. STATE OF ART: Favorable reproducible factors are host-related: a good performance index and female sex. Among factors related to the tumor itself, we can suggest: a single metastatic site as well as absence of cutaneous metastasis. Finally, biological variables can play a role with a favourable prognostic impact for normal leucocytosis, absence of anemia, normal calcemia, low levels of Cyfra 21-1 and serum LDH. PERSPECTIVES: The independent value of other biological factors has to be studied as well as the prognostic value of standard uptake value, by the primary tumor, of glucose analog as measured by PET-scan. The development and validation of prognostic classifications could also be of great interest. The international collaboration set up by IASLC for TNM revision proposal should go on with the conduct of a worldwide prospective study that should allow to validate or to invalidate the prognostic value of factors potentially interesting but whose independent reproducible value has to be demonstrated.