Prognostic factors in patients after lobectomy for p-T1aN0M0 adenocarcinoma.

Objectives: The seventh edition of the TNM Classification of Malignant Tumours was published in 2009. This study was conducted to investigate the prognostic factors of p-T1aN0M0 pulmonary adenocarcinoma, which is the earliest stage defined in the new TNM classification.

Methods: We retrospectively studied 122 patients who underwent lobectomy at our institution for p-T1aN0M0 adenocarcinoma, as re-categorized in the seventh TNM classification. The patients were separated into groups on the basis of the following clinicopathologic parameters: age, < 70 vs. > 70 years; gender, male vs. female; preoperative serum carcinoembryonic antigen (CEA) level, < 5.0 vs. ≥ 5.0 ng/dl; tumour size, <10 vs. >10 mm; intratumoral vascular or lymphatic invasion, positive vs. negative. Univariate and multivariate analyses of disease-free survival were performed.

Results: The median follow-up period was 41.4 months. Univariate analysis showed that prognostic factors such as age, CEA elevation and intratumoral vascular or lymphatic invasion were significant (age, < 70 vs. > 70 years; 97.1% vs. 82.0%, P = 0.0027; preoperative serum CEA level, < 5.0 vs. > 5.0 ng/dl; 93.3% vs. 33.3%, P < 0.0001; intratumoral vascular or lymphatic invasion, positive vs. negative; 31.3% vs. 96.5%, P < 0.0001). Multivariate analysis demonstrated that only intratumoral vascular or lymphatic invasion was a significantly independent prognostic factor (P = 0.0039, Hazard Ratio, 0.066; 95% Confidence Interval, 0.011-0.419).

Conclusions: Intratumoral vascular or lymphatic invasion should always be studied and included in the final pathology report in order to consider potential clinical and therapeutic relevance. The efficacy of adjuvant chemotherapy for these patients should also be evaluated in clinical trials.