Surgical resection for multifocal (T4) non-small cell lung cancer: is the T4 designation valid?

Background: The current international staging system for lung cancer designates intralobar satellites as T4 disease. In this study, we sought to determine the impact of multifocal, intralobar non-small cell lung cancer (NSCLC) on patient survival and its potential relevance to stage designation.
Methods: We conducted a retrospective review of our thoracic surgical cancer registry from 1990 to 2005. Included were 53 patients with a resected lung cancer containing intralobar satellites detected preoperatively (n = 8) or in the resected specimen (n = 45). Patients with multicentric bronchioloalveolar cancer were excluded. All patients had an anatomic resection with mediastinal lymph node dissection. Median follow-up for the entire group was 31 months. Survival was calculated by the Kaplan-Meier method. A Cox proportional hazards regression model was performed to examine simultaneously the effects on overall survival of age, gender, nodal disease, number of satellite lesions, lymphatic invasion, and T status.
Results: The median age of the 53 patients with multifocal, intralobar (T4) disease was 68 years and 31 were women. Ten patients had more than one satellite lesion. Overall 5-year survival was 47.6% (95% confidence interval [CI], 27.36% to 65.30%) for all patients with resected intralobar satellites. Patients without nodal metastases had a 5-year survival of 58.4% (95% CI, 28.76% to 79.30%). The Cox regression identified female gender (adjusted hazard ratio [HR], 0.31; 95% CI, 0.10 to 0.96; p < 0.04) as a significant prognostic variable but only a trend towards significance for nodal status (adjusted HR, 2.3; 95% CI, .83 to 6.26; p < 0.11).
Conclusions: Patients with intralobar multifocal NSCLC detected in the resected specimen have a more favorable prognosis after surgical resection than might be predicted by their stage T4 designation. Five-year survival rates, especially in T4N0 patients, more closely approximate those with stages IB or II NSCLC.