Survival analysis of untreated patients with non-small-cell lung cancer

The survival rate analysis of 130 patients with non-small-cell lung cancer who did not receive any specific anticancer therapy showed no statistically significant differences in the survival rates between various TNM combinations classified into stage groups II, IIIa, IIIb, and IV, as proposed by Mountain in 1989 and adopted by the American Joint Committee on Cancer. Following these findings, based on survival probabilities, two distinctive staging groups could be distinguished. The first stage group was composed of only the T1, 2N0, M0 combination, and the second of all other TNM combinations. In a purely biologic sense of tumor growth, the lymph node involvement appeared to be the crucial factor determining the length of survival.