Objective: We conducted a validation of the treatment of satellite nodules in the UICC TNM classification of 1993 and 1997.
Patients and methods: The clinical records of the 352 patients with T2-4 lung cancer who underwent curative resection were reviewed. The UICC classification of 1993 was used to classify the pathologic stage. No satellite nodule was found in 305 cases (PM0 group), 39 cases had a satellite nodule in the same lobe as that of the primary tumor (PM1 group), and 8 cases had a satellite nodule in another ipsilateral lobe (PM2 group). Outcome was compared based on the T classification.
Results: The differences of the survival rates between the PM0 and PM1 groups were not statistically significant for T2 and T3 cases. For T4 cases, the 5-year survival rate was 0% in the PM0 group, 33.3% in the PM1 group, and 0% in the PM2 group.
Conclusion: It was appropriate for T2 and T3 cases that the rank of T classification was up-staged for a satellite nodule in the same lobe according to the 1993 classification. For T4 cases, however, the PM1 group had a significantly better outcome. If all PM1 cases with any T and N factor are included in T4 according to the 1997 classification, it may elevate the survival rate of T4 better than that of T4 by the former classification.