Influence of Ground Glass Opacity and the Corresponding Pathological Findings on Survival in Patients with Clinical Stage I Non–Small Cell Lung Cancer

New revisions and current issues in the eighth edition of the TNM classification for non-small cell lung cancer

In the eighth edition of the TNM classification of lung cancer, the prognostic impact of tumor size is emphasized as a descriptor of all T categories. Especially in lung cancer where tumor size is 5 cm or less, the 1-cm cutoff point significantly differentiated the survival outcome. In addition, the new staging categories were assigned, namely, Tis (adenocarcinoma in situ) and T1mi (minimally invasive adenocarcinoma). Furthermore, the measurement of a radiological solid component size excluding the ground glass opacity component or pathological invasive size without a lepidic component was proposed for deciding the cT/pT categories for lung adenocarcinoma. The N descriptors were kept the same as in the eventh edition on the whole, however, quantification of nodal disease had a prognostic impact based on the number of nodal stations involved in the eighth edition, i.e. N1a as a single N1 station, N1b as a multiple N1 station, N2a1 as a single N2 station without N1 (skip metastasis), N2a2 as a single N2 station with N1 disease, and N2b as a multiple N2 station. In the M descriptors, subclassification was performed based on the location or numbers of distantly metastatic lesions, i.e. M1a as any intrathoracic metastases, M1b as a single distant metastatic lesion in one organ, and M1c as multiple distant metastases in either a single organ or multiple organs. Survival analysis of the eighth edition of the TNM classification clearly separated the distinct groups, however, unsolved issues still remain that should be discussed and further revised for the forthcoming TNM staging system.

Stapling cartridge lavage cytology in limited resection for pulmonary malignant tumors: assessment of cytological status of the surgical margin

INTRODUCTION

Sublobar resection in primary lung cancer and pulmonary metastatic tumor can result in recurrence at the surgical margin. Confirming the absence of tumor cells at the cut-end is important. We sought to evaluate the efficacy of intraoperative lavage cytology (ILC) of autostapling cartridges in preventing local failure.

MATERIALS AND METHODS

An intraoperative cytology examination was performed in 262 consecutive patients undergoing wedge or segmental resection for 311 lesions, including primary lung cancers and pulmonary metastatic tumors, between April 2004 and April 2010. The data of patients with positive cytology results and those who developed local failure were retrospectively reviewed.

RESULTS

A total of 139 primary lung cancers and 172 pulmonary metastatic tumors (primary site: 120 colorectal and 52 others) were investigated. The results revealed 22 (7%) positive cytology results (11 primary and 11 metastatic). The resection margins of 19 of the 22 lesions with positive cytology were additionally resected. With a median follow-up period of 42 months, recurrence at the margin developed in 2 of the 19 lesions in which additional resection was performed (11%, 1 primary and 1 metastatic). Recurrence at the margin developed in 2 (67%, 1 primary and 1 metastatic) of the 3 lesions in which additional resection was abandoned. Among the 289 lesions showing negative cytology results, recurrence at the margin developed in 7 (2%, 6 primary and 1 metastatic).

CONCLUSIONS

ILC of autostapling cartridges in sublobar resection for pulmonary malignant tumor may be useful for assessing the cytological status of the surgical margin.

Long-term outcomes of video-assisted thoracoscopic surgery lobectomy vs. thoracotomy lobectomy for stage IA non-small cell lung cancer

OBJECTIVES

Video-assisted thoracoscopic surgery (VATS) lobectomy is performed widely for patients with clinical stage I non-small cell lung cancer (NSCLC) because of its superior short-term outcomes to those of thoracotomy lobectomy. However, the long-term outcomes of VATS lobectomy vs. thoracotomy lobectomy remain controversial.

METHODS

We reviewed the clinical data of 202 consecutive patients who underwent lobectomy for clinical stage IA NSCLC at our institution between January, 2008 and December, 2013. Stage IA NSCLC was confirmed pathologically in 162 of these patients, 60 of whom underwent VATS lobectomy and 102 of whom underwent thoracotomy lobectomy. We compared the perioperative clinical factors and outcomes of these two groups, using a propensity score-matched analysis.

RESULTS

In an analysis of 58 matched cases, the VATS group showed less blood loss, a shorter duration of chest tube placement, a shorter postoperative hospital stay, and a lower peak C-reactive protein value, despite a longer operative time. The VATS group also had significantly longer survival than the thoracotomy group [5-year overall survival, 100% vs. 87%, respectively (p = 0.01); 5-year disease-free survival, 100% vs. 86% (p = 0.03)].

CONCLUSIONS

These findings suggest that VATS may have better long-term as well as short-term outcomes than thoracotomy for patients with early-stage NSCLC.

Implication of total tumor size on the prognosis of patients with clinical stage IA lung adenocarcinomas appearing as part-solid nodules: Does only the solid portion size matter?

OBJECTIVES

The aim was to investigate the effect of clinico-radiologic variables, including total tumor (T_total) size and clinical T category, on the prognosis of patients with stage IA (T1N0M0) lung adenocarcinomas appearing as part-solid nodules (PSNs).

METHODS

This institutional review board-approved retrospective study included 506 patients (male:female = 200:306; median age, 62 years) with PSNs of the adenocarcinoma spectrum in clinical stage IA who underwent standard lobectomy at a single tertiary medical center. Prognostic stratification of the patients in terms of disease-free survival was analyzed with variables including age, sex, T_total size, solid portion size, clinical T category, and tumor location using univariate and subsequent multivariate Cox regression analysis. Subgroup analysis was performed to reveal the effect of the T_total size at each clinical T category.

RESULTS

Multivariate Cox regression analysis demonstrated that T_total size*cT1b [interaction term; hazard ratio (HR) = 1.091; 95% confidence interval (CI): 1.015, 1.173; p = 0.019] and cT1c (HR = 68.436; 95% CI: 2.797, 1674.415; p = 0.010) were independent risk factors for the tumor recurrence. When patients with cT1b were dichotomized based on a T_total size cutoff of 3.0 cm, PSNs with T_total > 3.0 cm showed a significantly worse outcome (HR = 3.796; 95% CI: 1.006, 14.317; p = 0.049). No significant difference was observed in the probability of recurrence between cT1b with T_total > 3.0 cm and cT1c (p = 0.915).

CONCLUSIONS

T_total size is a significant prognostic factor in adenocarcinoma patients in cT1b without lymph node or distant metastasis. PSNs in cT1b with T_total > 3.0 cm have a comparable risk of lung cancer recurrence to those in cT1c.

KEY POINTS

• Current T descriptor was a powerful prognostic factor in stage IA adenocarcinomas appearing as part-solid nodules. • Total tumor size further stratified risk of recurrence of adenocarcinomas in cT1b. • Upstaging of tumors in cT1b with total tumor size > 3.0 cm may be more appropriate.