Results of surgical treatment and impact on T staging of non-small-cell lung cancer adjacent lobe invasion

Abstract

Objectives: To assess the results of surgical treatment of T-ALI (adjacent lobe invasion) tumours in patients with non-small-cell lung carcinoma.

Methods: Multicentric retrospective analysis of a prospectively maintained database of 13 065 patients, aged 32-89 years (mean 52.9, median 63 years), who underwent resection between January 2009 and September 2014.

Results: In the whole study group, T-ALI was observed in 324 patients (2.5%): 201 patients (62.0%) with a tumour invading the pleura in the inter-lobar fissure (T-ALI-A), and 123 patients (38.0%) with a tumour in the adjacent lobe but without pleural invasion in the fissure (T-ALI-D). With regard to N0 patients, the 3- and 5-year survival rates in the T2 group were significantly higher than that of the T-ALI group (76.1 and 68.4%, P = 0.002 vs 58.3 and 51.0%, P = 0.008, respectively). On the other hand, when the N1 group was analysed, the 5-year survival rates were 54.3 and 48%, respectively (P = 0.041). In the N2 group, the 5-year survival rates in the T2 and T-ALI groups were 40.2 and 35.0%, respectively (P = 0.241). The comparison of the T-ALI and T3 groups for stages N0, N1 and N2 revealed differences in 5-year survival rates as follows: 68.4 vs 62.9% (P = 0.048), 48.0 vs 37.6% (P = 0.08) and 35.0 vs 27.6% (P = 0.121), respectively. In the whole group, the difference in survival rate between T-ALI N0 and T2N0 was statistically significant (P = 0.008) and statistically significant for the T3N0 group (P = 0.048). The 3-year survival rate in the T-ALI N0 group was statistically lower following pneumonectomy than following lobectomy (56.4 vs 61.3%, P = 0.03). The best survival rate was observed following bilobectomy (75.6%).

Conclusions: In our study, a tumour with ALI (T-ALI) represented a separate stage of cancer between T2 and T3. The survival rate in the T-ALI-A group was significantly poorer than that in the T-ALI-D group. Overall treatment results were similar for stage T3, suggesting that it may be necessary to divide this group into T3a and T3b. We would suggest that all tumours between 5 and 7 cm be classified as T3b, and any tumour smaller than 5 cm but with ALI be classified as T3a. Treatment of choice should include lobectomy or bilobectomy. Pneumonectomy should be performed only in a selected group of patients.

Keywords: Adjacent lobe invasion; Lung cancer; Prognostic factors.