Molecular and biological factors in the prognosis of non-small cell lung cancer

For patients with non-small cell lung cancer the tumour/node/metastasis (TNM) staging system and other conventional prognostic factors fail to predict the outcome of treatment and survival accurately. New prognostic factors are urgently needed to improve understanding of the biological behaviour of the different subtypes of non-small cell lung cancer and to recognize patients with a good or poor prognosis. This review will focus on molecular and biological factors published in the English language literature between 1988 and 1994. To be included in this survey, the predictive value of a specific prognostic factor had to be confirmed by multivariate analysis in at least two different studies. Blood group antigen expression, ras oncogenes, microvessel density, and factors reflecting the proliferative state of the tumour may be important determinants of outcome of treatment. The search for new determinants of prognosis has provided insight in the complex tumour biology of non-small cell lung cancer and indicated possible targets for tumour therapy. Several promising prognostic factors have now been recognized. To validate these factors, prospective studies of a large patient population are needed. This ultimately serves the recognition of subsets of patients who may benefit from adjuvant therapy.