Significant difference in recurrence according to the proportion of high grade patterns in stage IA lung...

Patients with early lung cancer are the best candidates for surgical resection. However, those patients with high grade patterns (micropapillary or solid) do not have a good prognosis, even if they have been diagnosed with stage I lung adenocarcinoma. A new modified grading system has been introduced and this study aimed to identify the prognostic role of the new grading system in patients with stage IA lung adenocarcinoma.

Patients with pathological stage IA lung adenocarcinoma, according to the eighth TNM classification who underwent curative resection, were reviewed. The pathological data of stage IA adenocarcinoma was reviewed 1 (grade 1: lepidic predominant with no or less than 20% of high grade patterns, grade 2: acinar or papillary predominant with no or less than 20% of high grade patterns, grade 3: any tumor with 20% or more of high grade patterns). Prognostic factors were analyzed for disease-free interval (DFI) and overall survival (OS) using Cox proportional models.

The medical records of 429 patients with stage IA lung adenocarcinoma were reviewed. DFI (p < 0.001) and OS (p < 0.001) were significantly lower in patients diagnosed with grade 3 compared with grade 1 and grade 2. Multivariate analysis showed that smoking (p = 0.013), value of SUVmax (p = 0.005), lymphovascular invasion (p = 0.004) and grade 3 (p = 0.008) were significant prognostic factors for DFI.

The proportion of high grade patterns showed a different prognosis, even if curative resection had been performed for stage IA adenocarcinoma. This new grading system is more simple and useful in the prediction of a prognosis in patients with stage IA lung adenocarcinoma.