Confirmation of a prognostic index for patients with inoperable non-small cell lung cancer

The prognostic index derived from a group of 502 patients with inoperable stages I-IIIb non-small cell lung cancer (NSCLC) from 1974 to 1981 has been tested in an independent population of patients with NSCLC from 1989 to 1993 for the relationship between this index and survival.

This recent population comprised 210 patients treated with radiotherapy; for staging and treatment planning more advanced technology (CT-imaging, CT-based dose-planning) was used. The five most powerful determinants, established in the previous study, were disease extent, clinical symptom score by Feinstein, performance status, tumour size and haemoglobin level. These key prognostic variables of the index had equal impact on survival. Thus, based only on the number of adverse factors, the patient falls into one of the six possible prognostic groups.

In the present study we verified with the new patient material that the index applies to patients with inoperable NSCLC. All five factors were significantly predictive of survival and the inclusion of the other known prognostic variables in the multivariate analyses did not result in any further improvement. Furthermore, the composite index turned out to be as informative as the five variables separately and the index discriminates effectively between the low and high risk groups. Ninety-eight patients (47%) with three or more risk factors had a 2-year survival rate of less than 2%, whereas 17 patients (8%) with no risk factor had a survival of 53% during a minimum follow up of 2 years.

As each of the five variables has the advantage of being routinely available the index is simple and can easily be used to guide management in daily clinical practice. The scoring system may also help to design new treatment strategies and facilitate the comparison of different studies.