Outcomes and predictive factors for pathological node-positive in radiographically pure-solid, small-sized lung adenocarcinoma

[Progress in Survival Prognosis of Segmentectomy for Early-stage Non-small Cell Lung Cancer]

Surgery is currently the most appropriate treatment for early-stage non-small cell lung cancer (NSCLC). Increasing unilateral or bilateral multiple primary lung cancer being found, segmentectomy has attracted wide attention for its unique advantages in the treatment for such tumors. Ground glass opacity dominant early-stage NSCLC is associated with a good prognosis and can be cured by segmentectomy, however, the treatment of solid-dominant NSCLC remains controversial owing to the invasive nature. With the in-depth study on the lymph node metastasis pathway, radiological characteristics and molecular biology of NSCLC, a large part of solid nodules with certain characteristics can also be cured by segmentectomy. This paper reviews the research status and progress about the indication of segmentectomy.
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Predictive Factors for Lymph Node Metastasis in Clinical Stage I Part-Solid Lung Adenocarcinoma

BACKGROUND

Accurate clinical staging of tumors with a small solid portion is essential for developing an appropriate treatment plan. This study evaluated predictive factors for lymph node (LN) metastasis in patients with clinical stage I part-solid lung adenocarcinoma.

METHODS

Medical records of patients with clinical stage I part-solid adenocarcinoma who underwent anatomic pulmonary resection with systematic node evaluation between January 2009 and June 2018 were retrospectively reviewed. To identify predictive factors for LN metastasis, univariate and multivariable logistic regression analyses were performed.

RESULTS

Among the 593 patients in this study, the overall prevalence of LN metastasis was 3.7% (n = 22), which included 3.0% (n = 18) of patients with N1 LN metastasis and 1.5% (n = 9) of patients with N2 LN metastasis. Combined N1 and N2 nodal involvement was observed in 5 patients. Nodal metastasis was not observed in tumors with a solid portion sized 1.1 cm or smaller. The nodal metastasis rates in cT1b, cT1c, and cT2a tumors were 5.5% (13 of 237), 7.1% (6 of 84), and 13.6% (3 of 22), respectively. According to the multivariable analysis, predictive factors included the size of the solid portion (P = .015) and the high maximum standardized uptake value (SUVmax) of the primary tumor (P = .044).

CONCLUSIONS

Large solid portion and high SUVmax of the primary tumor were predictive factors of LN metastasis in patients with clinical stage I part-solid lung adenocarcinoma. Systematic LN evaluation should be performed, especially in those who have a large solid portion and high SUVmax of the primary tumor.

Meta-analysis of segmentectomy versus lobectomy for radiologically pure solid or solid-dominant stage IA non-small cell lung cancer

OBJECTIVE

Whether segmentectomy can be used to treat radiologically determined pure solid or solid-dominant lung cancer remains controversial owing to the invasive pathologic characteristics of these tumors despite their small size. This meta-analysis compared the oncologic outcomes after lobectomy and segmentectomy regarding relapse-free survival (RFS) and overall survival (OS) in patients with radiologically determined pure solid or solid-dominant clinical stage IA non-small cell lung cancer (NSCLC).

METHODS

A literature search was performed in the MEDLINE, EMBASE, and Cochrane Central databases for information from the date of database inception to March 2019. Studies were selected according to predefined eligibility criteria. The hazard ratio (HR) and associated 95% confidence interval (CI) were extracted or calculated as the outcome measure for data combining.

RESULTS

Seven eligible studies published between 2014 and 2018 enrolling 1428 patients were included in the current meta-analysis. Compared with lobectomy, segmentectomy had a significant benefit on the RFS of radiologically determined pure solid or solid-dominant clinical stage IA NSCLC patients (combined HR: 1.46; 95% CI, 1.05-2.03; P = 0.024) and there were no significant differences on the OS of these patients (HR: 1.52; 95% CI, 0.95-2.43; P = 0.08).

CONCLUSIONS

Segmentectomy leads to lower survival than lobectomy for clinical stage IA NSCLC patients with radiologically determined pure solid or solid-dominant tumors. Moreover, applying lobectomy to clinical stage IA NSCLC patients with radiologically determined pure solid or solid-dominant tumors (≤2 cm) could lead to an even bigger survival advantage. However, there are some limitations in the present study, and more evidence is needed to support the conclusion.