Based on a database with more than 100,000 submitted cases, modifications to the international system for staging nonsmall cell lung cancer promise to more closely reflect the connection between disease progression and the patient's prospects for survival.

The International Association for the Study of Lung Cancer (IASLC) has published its recommendations for change in the upcoming seventh ed iti on of the tumor, node, and me tastas is classifications this year. Changes to the 12-year-old sixth edition were drawn from the surgically staged case experience at 46 academic hospitals in 19 countries, said Dr. Johnny Vlahos, an honorary senior lecturer at St. George's, University of London.

The effort invested in the new standards contrasts with planning for the last edition. Sixth edition classifications were based on just over 5300 surgically staged cases from a single institution in the 1970s, Vlahos said.

Revisions were needed because of changes in histology epidemiology, our understanding of tumor spread and outcome data, and improvements in the accuracy of imaging staging, according to Vlahos.

Patient survival data guided the effort. With the new system, clinicians will be able to say confidently that a patient with a correctly staged T1a lung cancer will have a 77% chance of surviving five years.

For stage T2a cancer, survival probability drops to 58%, and patients with metastatic T3 cancer have less than a one in three chance of living five more years.

The new standards generally predict longer survival for patients with a given set of clinical findings than the current classifications.

“We are aware— conservatively — that patients previously suspected to have a poor prognosis may have a better prognosis than originally thought,” Vlahos said in a presentation at the 2009 International Symposium on Multidetector-Row CT.