The prognostic impact of lung adenocarcinoma predominance classification relating to pathological factors in lobectomy, the Japanese Joint Committee of Lung Cancer Registry Database in 2010

Abstract

Objective: We studied the prognosis and clinicopathological background of lung adenocarcinoma predominance among patients who underwent lobectomy using data from the Japanese Joint Committee of Lung Cancer Registry.

Methods: Two thousand eight hundred sixty-three cases were extracted. Recurrence free survival (RFS) rates, overall survival (OS) rates and clinicopathological factors and epidermal growth factor receptor (EGFR) mutation status were examined.

Results: Median follow-up period was 65.5 months. Adenocarcinoma predominance was sub-grouped according to OS and RFS rate. In pathological stage I, 5-year RFS and OS rates were respectively 92.2% and 95.8% in group A (adenocarcinoma-in-situ + minimally invasive adenocarcinoma), 89.3% and 92.1% in group B (lepidic), 79.2% and 89.7% in group C (papillary + acinar + variants) and 69.0% and 79.0% in group D (solid + micropapillary). In pathological stage II + IIIA, they were, 43.6% and 72.4% in B, 39.5% and 66.9% in C and 31.0% and 53.7% in D. Group D showed significant worst outcome both in stage I and II + IIIA. Up stage rate from clinical stage I to pathological stage II + IIIA was 0.0%, 3.7%, 15.9% and 33.3%. The frequency of lymph-vessel, vascular, pleura invasion and positive EGFR mutation were 0.0%, 0.0%, 0.0% and 57.1% in group A, 15.6%, 10.0%, 12.1% and 55.1% in B, 36.6%, 31.8%, 29.7% and 44.9% in C, 50.2%, 57.8%, 38.9% and 21.3% in D. In group D, lymph-vessel, vascular and pleura invasion were most, EGFR mutation was least frequent not only in pathological stage I but also stage II + IIIA. In multivariate analysis, age, pathological stage, vascular invasion, and group D were independent factors affected RFS and OS.

Conclusion: Limited to lobectomy cases, solid + micropapillary was independent prognostic factor both in early and locally advanced stage. Its malignant degree was related to the frequency of pathological invasive factors and EGFR mutation status.

Keywords: Adenocarcinoma; Adenocarcinoma predominance; Lobectomy; The Japanese lung cancer registry.

Fig. 1

A. RFS curves according to pathological stage. The 5-year RFS rates was 88.5% in patients with stage IA, 72.0% in stage IB, 49.2% in stage IIA, 43.0% in stage IIB and 27.5% in stage IIIA. B. RFS curves according to histologic predominance. The 5-year RFS rates was 94.5% in patients with AIS, 91.7% in MIA, 84.5% in lepidic, 73.6% in variants, 69.0% in papillary, 65.3% in acinar, 51.6% in micropapillary, and 51.4% in solid. C RFS curves for each histological groups in pathological stage I. The 5-year RFS rate was 92.2% in patients with group A (AIS + MIA), 89.3% in group B (lepidic), 79.2% in group C (papillary + acinar + variants) and 69.0% in group D (solid + micropapillary). D RFS curves of each histological groups in pathological stage II + IIIA. The 5-year RFS rates was 43.6% in patients with group B, 39.5% in group C and 31.0% in group D

Fig. 2

A. OS curves according to pathological stage. 5-year OS rates were 92.9% in patients with stage IA, 85.3% in stage IB, 70.9% in p stage IIA, 64.4% in stage IIB and 59.8% in stage IIIA. B. OS curves according to predominant histological subtype. The 5-year OS rates was 94.4% in patients with AIS. 94.0% in MIA, 90.2% in lepidic, 86.7% in variants, 84.1% in papillary, 80.4% in acinar, 78.0% in micropapillary and 65.4% in solid. C. OS curves according to histological groups in pathological stage I. The 5-year OS rates was 95.8% in patients with group A, 92.1% in group B, 89.7% in group C and 79.0% in group D. D. OS curves according to histological groups in pathological stage II + III. The 5-year OS rates was 72.4% in patients with group B, 66.9% in group C and 53.7% in group D