Level of pleural invasion effects on prognosis in lung cancer

To analyze the extent of visceral pleural invasion (VPI) and its effect on survival along with its place in determining the T descriptor in TNM staging in our patients.

A total of 233 patients underwent lung resection. The data were retrospectively analyzed in terms of sex, age, histopathologic type, stage of the tumor, extent of VPI, and survival. Patients who had neoadjuvant chemotherapy or chemoradiotherapy, distant metastasis, parietal pleural invasion, and operative mortality were excluded.

The median follow-up was 59 months (range 4-126). The extent of VPI was PL0 in 119 (65.7%) patients, PL1 in 47 (26%) patients, and PL2 in 15 (8%) patients. The median survival rates were 65 (range 43-96) months for PL0, 54 (range 37-72) months for PL1, and 39 (range 12-69) months for PL2. The 5-year overall survival rates were 74.7% for PL0, 77.8% for PL1, and 53.3% for PL2. There were statistically significant differences in overall survival among PL0, PL1, and PL2 ( p = 0.03). In subgroup analysis, the difference was insignificant in PL0 vs PL1 ( p = 0.81), but significant in PL0 vs PL2 ( p = 0.02) and PL1 vs PL2 ( p = 0.04) groups.

This study emphasizes that the presence of VPI is related with poor prognosis independent of lymph node positivity, histologic subtypes, and tumor size. As the study shows, PL0 and PL1 have similar survival rates and these two groups may be considered as VPI (-) patients whereas PL2 disease affects survival outcomes.