Clinicopathological predictors of survival in resected primary lung adenocarcinoma

Abstract

Aims: Primary lung adenocarcinoma consists of a spectrum of clinical and pathological subtypes that may impact on overall survival (OS). Our study aims to evaluate the impact of adenocarcinoma subtype and intra-alveolar spread on survival after anatomical lung resection and identify different prognostic factors based on stage and histological subtype.

Methods: Newly diagnosed patients undergoing anatomical lung resections without induction therapy, for pT1-3, N0-2 lung adenocarcinoma from April 2011 to March 2013, were included. The effect of clinical-pathological factors on survival was retrospectively assessed.

Results: Two hundred and sixty-two patients were enrolled. The 1-year, 3-year and 5-year OS were 88.8%, 64.3% and 51.1%, respectively. Univariate analysis showed lymphovascular, parietal pleural and chest wall invasion to confer a worse 1-year and 5-year prognosis (all p<0.0001). Solid predominant adenocarcinomas exhibited a significantly worse OS (p=0.014). Multivariate analysis did not identify solid subtype as an independent prognostic factor; however, identified stage >IIa, lymphovascular invasion (p=0.002) and intra-alveolar spread (p=0.009) as significant independent predictors of worse OS. Co-presence of intra-alveolar spread and solid predominance significantly reduced OS. Disease-free survival (DFS) was reduced with parietal pleural (p=0.0007) and chest wall invasion (p<0.0001), however, adenocarcinoma subtype had no significant impact on DFS.

Conclusions: Our study demonstrates that solid predominant adenocarcinoma, intra-alveolar spread and lymphovascular invasion confer a worse prognosis and should be used as a prognostic tool to determine appropriate adjuvant treatment.

Keywords: carcinoma; lung; lung neoplasms.

Figure 1

Overall survival. 1 year 88.8% (84.2–92.1); 2 years 73.87% (68.0-78.8); 3 years 64.3% (58.1–69.9); 4 years 58.9% (52.5–64.8); 5 years 51.1% (42.8–58.8).

Figure 2

Survival according to disease stage. Stage II and III tumours showed worse overall survival. Stage IB showed no statistical difference to IA.

Figure 3

Effect of tumour subtype on overall survival. Solid adenocarcinomas had a worse overall survival than other subtypes compared with lepidic (p=0.008).

Figure 4

Kaplan-Meier survival based on intra-alveolar spread and solid component. Concomitance of solid predominance and presence of intra-alveolar spread showed significantly worse survival (p=0.01, HR 2.18, CI 1.2 to 3.9).

Figure 5

Effect of tumour subtype on disease-free survival. Solid adenocarcinomas had a shorted disease-free survival overall, but not statistically significant.