Possible Delayed Cut-End Recurrence After Limited Resection for Ground-Glass Opacity Adenocarcinoma, Intraoperatively Diagnosed as Noguchi Type B, in Three Patients

Long-term outcome of patients with peripheral ground-glass opacity-dominant lung cancer after sublobar resections

OBJECTIVE

This study aimed to evaluate the long-term prognosis of patients with peripheral small ground-glass opacity-dominant lung cancer after sublobar resection. We have already reported the 5-year safety and efficacy of sublobar resection and report the long-term outcomes after a 10-year follow-up period.

METHODS

Between May 2009 and April 2011, 333 patients with radiologically noninvasive peripheral lung cancer were enrolled from 51 institutions (median age, 62 years at registration) and followed up until May 6, 2021. Of these patients, sublobar resections with wedge resection as the first choice were performed in 314 patients (258 wedge resections and 56 segmentectomies), conversion lobectomies were performed in 11 patients, and 8 patients were ineligible.

RESULTS

The 10-year relapse-free survival and overall survival for the 314 patients with sublobar resections were 98.6% (95% confidence interval, 96.2-99.5) and 98.5% (95% confidence interval, 96.1-99.4), respectively. There was 1 local recurrence at the resection margin. Among the patients, second cancers were observed in 43 patients (13.4%; 95% confidence interval, 9.8-17.6), of which 18 were second lung cancers (5.8%; 95% confidence interval, 3.5-8.9).

CONCLUSIONS

Peripheral ground-glass opacity-dominant lung cancer is cured by sublobar resection, with wedge resection as the first choice, and the indications for other treatment options should be further investigated. The incidence of second cancer is similar to that in the general Japanese population.

Ten-Year Follow-up Results of Pure Ground-Glass Opacity-Featured Lung Adenocarcinomas After Surgery

BACKGROUND

Previously, we have demonstrated that the 5-year recurrence-free survival after surgery of pure ground-glass opacity (GGO)-featured lung adenocarcinoma is 100%. This study aimed to reveal the long-term outcomes of these patients 10 years after surgery.

METHODS

Lung adenocarcinoma patients who underwent surgery between December 2007 and December 2013 were reviewed. Patients with pure GGO-featured lung adenocarcinoma were enrolled. Postoperative survival and the risk of developing second primary lung cancer were analyzed.

RESULTS

Overall, 308 cases of pure GGO-featured lung adenocarcinomas were included. Of these patients, 226 (73.4%) were female, 268 (87.0%) were nonsmokers, and 187 (60.7%) underwent sublobar resection. The median follow-up period after surgery was 112 months. The 10-year recurrence-free survival rate of these patients was 100%, and 10-year overall survival rate was 96.9%. Both 5-year and 10-year lung cancer-specific survival were 100%. There was no difference in 10-year recurrence-free survival rates between patients who underwent lobectomy or sublobar resection (P = .697). EGFR mutations were detected in 55.6% (84 of 151) of patients who underwent mutational analysis. The risk of developing secondary primary lung cancer for pure GGO-featured lung adenocarcinoma patients at 10 years after resection was 2.4%, and was not correlated with EGFR mutation status (P = .452).

CONCLUSIONS

No recurrence was observed in patients with pure GGO-featured lung adenocarcinomas 10 years after surgery, even when pathologically evaluated as invasive adenocarcinoma. Pure GGO can be cured by surgery. Surgery is recommended for the appropriate time window with the view to cure. Our study emphasizes that radiologic pure GGO-featured lung adenocarcinomas should be distinguished from other lung adenocarcinomas.

Three-Dimensional Near-Infrared Specimen Mapping Can Identify the Distance from the Tumor to the Surgical Margin During Resection of Pulmonary Ground Glass Opacities

BACKGROUND

Lung cancers can recur locally due to inadequate resection margins. Achieving adequate margin distances is challenging in pulmonary ground glass opacities (GGOs) because they are not easily palpable. To improve margin assessment during resection of GGOs, we propose a novel technique, three-dimensional near-infrared specimen mapping (3D-NSM).

METHODS

Twenty patients with a cT1 GGO were enrolled and received a fluorescent tracer preoperatively. After resection, specimens underwent 3D-NSM in the operating room. Margins were graded as positive or negative based upon fluorescence at the staple line. Images were analyzed using ImageJ to quantify the distance from the tumor edge to the nearest staple line. This margin distance calculated by 3D-NSM was compared to the margin distance reported on final pathology several days postoperatively.

RESULTS

3D-NSM identified 20/20 GGOs with no false positive or false negative diagnoses. Mean fluorescence intensity for lesions was 110.92 arbitrary units (A.U.) (IQR: 77.77-122.03 A.U.) compared to 23.68 A.U. (IQR: 19.60-27.06 A.U.) for background lung parenchyma (p < 0.0001). There were 4 tumor-positive or close margins in the study cohort, and all 4 (100%) were identified by 3D-NSM. 3D-NSM margin distances were nearly identical to margin distances reported on final pathology (R2 = 0.9362). 3D-NSM slightly under-predicted margin distance, and the median difference in margins was 1.9 mm (IQR 0.5-4.3 mm).

CONCLUSIONS

3D-NSM rapidly localizes GGOs by fluorescence and detects tumor-positive or close surgical margins. 3D-NSM can accurately quantify the resection margin distance as compared to formal pathology, which allows surgeons to rapidly determine whether sublobar resection margin distances are adequate.

Using the robotic platform in the therapy of multifocal ground glass opacities

Due to their association with invasive adenocarcinoma, ground glass opacities that reach 3 cm in size, develop a solid component ≥2 mm on mediastinal windows, or exhibit ≥25% annual growth warrant operative resection. Minimally invasive techniques are preferred given that approximately one third of patients will present with multifocal focal disease and may require additional operations. A robotic-assisted thoracoscopic surgical approach can be used with percutaneous or bronchoscopic localization techniques and are compatible with developing intraoperative molecular targeting techniques.

A guide for managing patients with stage I NSCLC: deciding between lobectomy, segmentectomy, wedge, SBRT and ablation-part 3: systematic review of evidence regarding surgery in compromised patients or specific tumors

Background

Clinical decision-making for patients with stage I lung cancer is complex. It involves multiple options [lobectomy, segmentectomy, wedge, stereotactic body radiotherapy (SBRT), thermal ablation], weighing multiple outcomes (e.g., short-, intermediate-, long-term) and multiple aspects of each (e.g., magnitude of a difference, the degree of confidence in the evidence, and the applicability to the patient and setting at hand). A structure is needed to summarize the relevant evidence for an individual patient and to identify which outcomes have the greatest impact on the decision-making.

Methods

A PubMed systematic review from 2000-2021 of outcomes after lobectomy, segmentectomy and wedge resection in older patients, patients with limited pulmonary reserve and favorable tumors is the focus of this paper. Evidence was abstracted from randomized trials and non-randomized comparisons (NRCs) with adjustment for confounders. The analysis involved careful assessment, including characteristics of patients, settings, residual confounding etc. to expose degrees of uncertainty and applicability to individual patients. Evidence is summarized that provides an at-a-glance overall impression as well as the ability to delve into layers of details of the patients, settings and treatments involved.

Results

In older patients, perioperative mortality is minimally altered by resection extent and only slightly affected by increasing age; sublobar resection may slightly decrease morbidity. Long-term outcomes are worse after lesser resection; the difference is slightly attenuated with increasing age. Reported short-term outcomes are quite acceptable in (selected) patients with severely limited pulmonary reserve, not clearly altered by resection extent but substantially improved by a minimally invasive approach. Quality-of-life (QOL) and impact on pulmonary function hasn't been well studied, but there appears to be little difference by resection extent in older or compromised patients. Patient selection is paramount but not well defined. Ground-glass and screen-detected tumors exhibit favorable long-term outcomes regardless of resection extent; however solid tumors <1 cm are not a reliably favorable group.

Conclusions

A systematic, comprehensive summary of evidence regarding resection extent in compromised patients and favorable tumors with attention to aspects of applicability, uncertainty and effect modifiers provides a foundation for a framework for individualized decision-making.

Intraoperative computed tomography of a resected lung inflated with air to verify safety surgical margin

Background

During sublobar resection for small, indistinct lung cancer, surgeons may be uncertain as to whether or not the target lesion has been resected and the surgical margin is sufficient. We herein report our procedure for confirming the success of sublobar resection without incising the resected specimen.

Methods

We reviewed our initial experience of 12 patients with intrapulmonary lesions (consolidation diameter ≤1 cm) who underwent thoracoscopic pulmonary wedge resection using autostapler. Six patients had primary adenocarcinoma showing part solid lesion, and remaining six patients had metastatic carcinoma showing purely solid lesion. Intraoperatively, the resected specimen was inflated with air and subjected to computed tomography (CT). The maximum tumor diameter and surgical margin length were measured intraoperatively on CT and postoperatively on formalin-fixed specimen. Surgical stump cytology was also done to verify surgical margin.

Results

According to the intraoperative CT, complete resection was confirmed in all patients. The intraoperative CT-based maximum tumor diameter closely correlated with the macroscopically measured one (r=0.971, P<0.0001). However, the tumor shrunk after formalin-fixation by 16.0% in patients with primary lung cancer (P<0.01), but not in patients with metastatic lung cancer. The intraoperative CT-based margin length closely correlated with the macroscopically measured one (r=0.984, P<0.0001). However, the margin shrunk after formalin-fixation in both patients with primary lung cancer and metastatic lung cancer, by 15.1% and 15.7%, respectively. Stump cytology was negative in all patients. Consequently, no recurrence was found during postoperative follow-up of 23 months (range, 14-31 months).

Conclusions

Intraoperative CT is reliable for diagnosing the presence of a target lesion within the resected specimen as well as for estimating the surgical margin length in patients undergoing sublobar resection for intrapulmonary indistinct lesions.

Stapler-lavage cytology using a new rapid immunocytochemistry for evaluating surgical margin status after pulmonary sublobar resection

OBJECTIVE

Sublobar resection is considered the gold standard for selected patients with pulmonary metastasis or who are compromised in some way. However, an unfavorable outcome after sublobar resection is local/margin recurrence. The aim of this study was to evaluate the clinical reliability of a new rapid-stapler lavage immunocytochemistry (ICC) technique for assessing margin malignancy. The method uses non-contact alternating current (AC) mixing to achieve more stable staining.

METHODS

Twenty-one patients who underwent sublobar resection, including 16 wedge resections, for pulmonary metastasis or lung cancer in a compromised host between September 2016 and December 2017 were retrospectively reviewed. All margin specimens were intraoperatively evaluated with HE staining of frozen sections and stapler lavage cytology using Papanicolaou staining and rapid-ICC.

RESULTS

Rapid-stapler lavage ICC can be used to diagnose surgically safe margins within 20 min during sublobar resections. Although in all cases margins were diagnosed as cancer free based on HE staining of frozen sections, two of four patients diagnosed with malignant-positive margins based on rapid ICC experienced local/margin recurrence.

CONCLUSIONS

Rapid-stapler lavage ICC with AC mixing could potentially serve as a clinical tool for prompt determination of margin malignant status after pulmonary sublobar resection.

Long-Term Outcomes in Stage I Lung Cancer After Segmentectomy with a Close Resection Margin

Background

In general, a 2-cm surgical margin is recommended for limited resection to obtain equivalent oncologic outcomes to lobectomy for lung cancer. This study aimed to examine the patterns of recurrence and prognostic factors for recurrence in patients with a close parenchymal resection margin.

Methods

From January 2009 to April 2017, 156 patients with stage I lung cancer who underwent segmentectomy with a close resection margin (<2 cm) were enrolled. Recurrence-free survival and overall survival were assessed. In addition, predisposing factors for recurrence were evaluated.

Results

The mean tumor size was 1.7±0.8 cm and the parenchymal resection margin was 1.1±0.6 cm. Recurrence developed in 17 (10.7%) of the 156 patients, and the 5-year recurrence-free survival rate was 88.9%. Distant metastasis (7.7%) was the predominant recurrence pattern. The isolated local recurrence rate was 1.9%. Multivariate Cox regression analysis revealed that age, tumor size, mediastinal lymph node dissection, postoperative complications, and histologic type were significant predisposing factors for recurrence. However, parenchymal margin distance did not significantly affect the long-term prognosis.

Conclusion

Segmentectomy with a close resection margin for early-stage lung cancer in selected patients resulted in acceptable recurrence and survival. However, patients with tumors larger than 2 cm, squamous cell carcinoma histology, and insufficient mediastinal evaluation should be carefully followed up for recurrence.

Long-Term Prognosis of Patients With Resected Adenocarcinoma In Situ and Minimally Invasive Adenocarcinoma of the Lung

INTRODUCTION

The WHO classification of lung tumors defines adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) as cancers with no or limited histologic invasive components. The probability of patients with AIS or MIA being recurrence free for 5 years postoperatively has been found to be 100%. This study aimed to analyze the prognosis of patients with AIS or MIA after more than 5 postoperative years.

METHODS

We reviewed the pathologic findings of 4768 patients who underwent resection for lung cancer between 1998 and 2010. Of these, 524 patients with curative resection for AIS (207 cases, 39.5%) and MIA (317 cases, 60.5%) were included. Postoperative recurrence, survival, and development of secondary primary lung cancer (SPLC) were analyzed.

RESULTS

Of the included patients, 342 (65.3%) were of female sex, 333 (63.5%) were nonsmokers, and 229 (43.7%) underwent sublobar resection. Average pathologic total tumor diameter was 15.2 plus or minus 5.5 mm. Median postoperative follow-up period was 100 months (range: 1-237). No recurrence of lung cancer was observed for either AIS or MIA cases. Estimated 10-year postoperative disease-specific survival rates were 100% and 100% (p = 0.72), and overall survival rates were 95.3% and 97.8% (p = 0.94) for AIS and MIA cases, respectively. Estimated incidence rates of metachronous SPLC at 10 years after surgery were 5.6% and 7.7% for AIS and MIA, respectively (p = 0.45), and these were not correlated with the EGFR mutation status.

CONCLUSIONS

Although the development of metachronous SPLC should be noted, the risk of recurrence is quite low at more than 5 years after resection of AIS and MIA. This finding strengthens the clinical value of distinguishing AIS and MIA from other adenocarcinomas of the lung.

Can computed tomography differentiate adenocarcinoma in situ from minimally invasive adenocarcinoma?

BACKGROUND

Given the subtle pathological signs of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA), effective differentiation between the two entities is crucial. However, it is difficult to predict these conditions using preoperative computed tomography (CT) imaging. In this study, we investigated whether histological diagnosis of AIS and MIA using quantitative three-dimensional CT imaging analysis could be predicted.

METHODS

We retrospectively analyzed the images and histopathological findings of patients with lung cancer who were diagnosed with AIS or MIA between January 2017 and June 2018. We used Synapse Vincent (v. 4.3) (Fujifilm) software to analyze the CT attenuation values and performed a histogram analysis.

RESULTS

There were 22 patients with AIS and 22 with MIA. The ground-glass nodule (GGN) rate was significantly higher in patients with AIS (p < 0.001), whereas the solid volume (p < 0.001) and solid rate (p = 0.001) were significantly higher in those with MIA. The mean (p = 0.002) and maximum (p = 0.025) CT values were significantly higher in patients with MIA. The 25th, 50th, 75th, and 97.5th percentiles (all p < 0.05) for the CT values were significantly higher in patients with MIA.

CONCLUSIONS

We demonstrated that quantitative analysis of 3D-CT imaging data using software can help distinguish AIS from MIA. These analyses are useful for guiding decision-making in the surgical management of early lung cancer, as well as subsequent follow-up.

Differentiation between suture recurrence and suture granuloma after pulmonary resection for lung cancer by diffusion-weighted magnetic resonance imaging or FDG-PET / CT

There has been no publication which supports the usefulness of DWI differentiating for suture recurrence and suture granuloma after resection for lung cancer. We presented efficacy of DWI or FDG-PET/CT for an assessment of suture lesions after resection for lung cancer. Thirteen suture recurrences and 15 suture granulomas were examined. There were 24 adenocarcinomas and 4 squamous cell carcinomas, and 26 partial resections and 2 segmentectomies. The period of time (907±907 days) between surgery and suture recurrence was not significantly longer than that (546±547 days) between surgery and suture granuloma. Diffusion detectability scores (a 5-point scale) of suture recurrences was significantly higher than that of suture granulomas. The ADC value (1.35±0.24 × 10^-3mm²/sec) of suture recurrences was significantly lower than that (1.85±0.60 × 10^-3mm²/sec) of suture granulomas. The SUVmax (6.1 ± 5.0) of suture recurrences was not significantly higher than that (4.2 ± 2.5) of suture granulmas. The sensitivity of 85% (11/13) with DWI was not significantly higher than 69% (9/13) with FDG-PET/CT for suture recurrences. The specificity of 73% (11/15) with DWI was not significantly higher than the 60% (9/15) with FDG-PET/CT for suture granulomas. The accuracy of 79% (22/28) with DWI was not significantly higher than that of 64% (18/28) with FDG-PET/CT for suture recurrences and granulomas. DWI can differentiate suture granuloma from suture recurrence after resection of lung cancer. DWI is more useful than FDG-PET/CT for the differentiation between suture recurrence and suture granuloma after resection for lung cancer.

A single-arm study of sublobar resection for ground-glass opacity dominant peripheral lung cancer

BACKGROUND

The optimal mode of surgery for ground-glass opacity dominant peripheral lung cancer defined with thoracic thin-section computed tomography remains unknown.

METHODS

We conducted a single-arm confirmatory trial to evaluate the efficacy and safety of sublobar resection for ground-glass opacity dominant peripheral lung cancer. Lung cancer with maximum tumor diameter 2.0 cm or less and with consolidation tumor ratio 0.25 or less based on thin-section computed tomography were registered. The primary end point was 5-year relapse-free survival. The planned sample size was 330 with the expected 5-year relapse-free survival of 98%, threshold of 95%, 1-sided α of 5%, and power of 90%. The trial is registered with University Hospital Medical Information Network Clinical Trials Registry, number University Hospital Medical Information Network 000002008.

RESULTS

Between May 2009 and April 2011, 333 patients were enrolled from 51 institutions. Median age was 62 years (interquartile range, 56-68), and 109 were smokers. Median maximum tumor diameter was 1.20 cm (1.00-1.54). Median maximum tumor diameter of consolidation was 0 (0.00-0.20). The primary end point, 5-year relapse-free survival, was estimated on 314 patients who underwent sublobar resection. Operative modes were 258 wide wedge resections and 56 segmentectomies. Median pathological surgical margin was 15 mm (0-55). The 5-year relapse-free survival was 99.7% (90% confidence interval, 98.3-99.9), which met the primary end point. There was no local relapse. Grade 3 or higher postoperative complications based on Common Terminology Criteria for Adverse Effect v3.0 were observed in 17 patients (5.4%), without any grade 4 or 5.

CONCLUSIONS

Sublobar resection with enough surgical margin offered sufficient local control and relapse-free survival for lung cancer clinically resectable N0 staged by computed tomography with 3 or fewer peripheral lesions 2.0 cm or less amenable to sublobar resection and with a consolidation tumor ratio of 0.25 or less.

Feasibility of limited resection for peripheral small-sized non-small cell lung cancer: a retrospective single-center-based study

PURPOSE

This study aimed to establish new criteria for limited resection of non-small cell lung cancer (NSCLC) based on computed tomography findings and maximum standardized uptake value (SUVmax).

METHODS

Between December 2007 and December 2015, 611 patients underwent lung cancer surgery; of these, 70 with cT1aN0M0 who underwent limited resection were enrolled. Criteria for undergoing intentional limited resection (ILR) were (1) tumor ground-glass opacity (GGO) ratio of ≥ 0.75 and (2) tumor SUVmax ≤ 1.5. Patients who met criteria (1) and (2) underwent partial resection, and those who only met criteria (2) underwent segmentectomy as ILR. The control group was subjected to limited surgery without meeting the criteria.

RESULTS

Overall, 45 and 25 patients who met the criteria were included in the ILR and control groups, respectively. In the ILR group, 13 patients underwent partial resection, and 32 underwent segmentectomy; in the control group, 18 patients underwent partial resection and 7 underwent segmentectomy. According to our criteria, no relapsed cases occurred in the ILR group, although six patients showed recurrence of lung cancer in the control group. The 5-year overall survival (OS) rates in the ILR and control groups were 100% and 67.7%, respectively, and the relapse-free survival (RFS) rates were 100% and 61.6%, respectively. The log-rank test showed that this difference was statistically significant (OS: P < 0.0001, RFS: P < 0.0001).

CONCLUSIONS

SUVmax may serve as a predictive marker of recurrence to determine the treatment strategy for patients with NSCLC. Patients with low GGO ratio and low SUVmax may be cured by limited resection.

Approach to the Subsolid Nodule

Most focal persistent ground glass nodules (GGNs) do not progress over 10 years. Research suggests that GGNs that do not progress, those that do, and solid lung cancers are fundamentally different diseases, although histologically they seem similar. Surveillance of GGNs to identify those that gradually progress is safe and does not risk losing a window. GGNs with 5 mm solid component or less than 10 mm consolidation (mediastinal and lung windows, respectively, on thin slice CT) are highly curable with resection. The optimal type of resection is unclear; sublobar resection is reasonable but an adequate margin is critically important.

Delayed cut-end recurrence after wedge resection for pulmonary ground-glass opacity adenocarcinoma despite negative surgical margin

Most pulmonary ground-glass opacity (GGO) nodules are pathologically well differentiated adenocarcinomas. We performed a limited resection trial of GGO lesions 2 cm or smaller from 2003 to 2009, in which 95 patients were accumulated. We confirmed negative surgical cut-end during surgery by margin lavage cytology. In the trial, a 51-year-old man underwent right lower lobe wedge resection for a 1.7 cm mixed GGO lesion. The tumor was papillary predominant adenocarcinoma, pT1NxM0. The resection scar became thicker and was diagnosed as adenocarcinoma by needle biopsy 10 years after the initial surgery. We performed a right lower lobectomy and lymph node dissection. Pathologically, the second tumor was adenocarcinoma similar to the initial one, papillary predominant, and was diagnosed as cut-end recurrence. Small papillary predominant adenocarcinoma might develop delayed cut-end recurrence more than 5 years after limited resection. Careful follow-up with special attention to the cut-end is necessary ideally for 10 years.

Nodule around the staple line after pulmonary resection: benign granuloma or cancer recurrence?

Purpose

When a mass develops around the staple line after lung cancer surgery, differential diagnosis between lung cancer recurrence and benign granuloma can be clinically problematic. Therefore, we investigated the clinical characteristics of benign granuloma and cancer recurrence around the staple line to determine clinical factors that can distinguish staple line granuloma and cancer recurrence.

Methods

We retrospectively investigated the clinical records of 25 patients who developed a nodule around the staple line after pulmonary resection for lung cancer and conducted a comparative study of staple line granuloma and cancer recurrence.

Results

Among 25 patients, the nodule was diagnosed as benign granuloma in 9, recurrence of primary lung cancer in 8, and recurrence of metastatic lung cancer in 8. Among these three groups, there were no significant differences in age, maximum standardized uptake value of fluoro-deoxyglucose, laboratory data, or radiological findings. However, in comparison with the cancer recurrence cases, the proportion of patients who had undergone segmentectomy as initial surgery was significantly higher in the granuloma group. Moreover, in five patients in the granuloma group, mycobacterium was detected.

Conclusion

It seemed difficult to differentiate between cancer recurrence and granuloma on the basis of radiological examination and laboratory findings. However, if a mass shadow around the staple line appeared after segmentectomy, the mass is likely to be a granuloma. Mycobacterial infection may be an important factor for development of granuloma on the staple line.

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.

Preoperative Watchful-Waiting Time and Surgical Outcome of Patients with Non-small Cell Lung Cancer Found by Chest Low-Dose CT Screening

BACKGROUNDS

Chest low-dose CT screening (LDCTS) has been finding unprecedented numbers of peripheral non-small cell lung cancers (NSCLC) at an early stage and increased the number of patients with surgical indication. It is important to explore the influence of preoperative watchful-waiting time (WWT) on surgical outcomes. Objective is to clarify relationship between WWT and surgical outcomes of LDCTS-finding NSCLC from the view point of treatment delay.

METHODS

Total 283 cases of NSCLC, found by LDCTS and consecutively resected, were surveyed for preoperative WWT and surgical outcomes. Validity of the present guideline for management of pulmonary nodules detected by LDCTS was verified whether WWT before surgery was suitable for eradication of NSCLC.

RESULTS

The median value of WWT was 4.0 months in total, and the distribution of WWT exhibited long-tail-type pattern. That was 5.0 months in the group of pure ground-glass nodule (pGGN), 4.0 months in the group of part-solid nodule (PSN), and 1.7 months in the group of solid nodule (SON). During long-term postoperative observation time (median 79 months), 10-year progression-free survival rates were 100% in pGGN, 96% in PSN, and 72% in SON (P < .0001). They decreased significantly depending on enlargement of size: 91% or higher in size of 2 cm or smaller, and 71% or lower in size of larger than 2 cm (P < .0001).

CONCLUSIONS

Limited to LDCTS-finding nodules, surgical outcome will depend mainly on some malignant potential of NSCLC per se, rather than on duration of WWT or treatment delay.

Significance of stereotactic body radiotherapy in older patients with early stage non-small cell lung cancer

OBJECTIVES

Our aim was to investigate long-term treatment outcomes in older patients with early stage non-small cell lung cancer (NSCLC) and the presence or absence of therapeutic benefits, using the G8 screening tool.

METHODS

We retrospectively studied 43 older patients (median age 78 years, range 65-89 years) with stage I lung tumors (T1 and T2 tumors in 34 and 9 patients, respectively), who underwent stereotactic body radiotherapy (SBRT). This study assessed outcomes in a cohort of patients who received geriatric assessments, performed between 2004 and 2011, before the start of their SBRT regimen. Any questions asked to patients before undergoing treatment were applied to the G8 screening tool.

RESULTS

G8 scores ranged from 8 to 16 (median, 12) in all patients (n = 43), while G8 scores in the T1 and T2 groups ranged from 9 to 16 (median, 13) and 8 to 15 (median, 12), respectively. In patients with G8 scores ≤12, the 2-year and 5-year survival rates were 56.1% and 28% respectively, while the rates were 94.1% and 68.4%, respectively, in patients with G8 scores ≥13 (P = 0.0014). During long-term follow-up, 25.9% of the patients (n = 43) died of the primary disease, NSCLC, and 34.9% of patients died of other diseases or other types of cancer.

CONCLUSION

SBRT may be effective, even in older adults. Regardless of age, SBRT improved the long-term survival of patients only with G8 scores ≥13. The G8 screening tool may aid in determining whether older patients with comorbidities would benefit from SBRT.

Pulmonary adenocarcinoma possibly developed from the cut-end of small-sized adenocarcinoma in the lung periphery as recurrence 13 years after its wedge resection

Background

It is a big topic for general thoracic surgery whether still curability can be obtained by limited resection for peripheral small-sized nodules of non-small cell lung cancer (NSCLC) in the current era of frequent computed tomography (CT) use. Accumulation of information on problematic cases would be meaningful for surgeons to select better surgical procedures.

Case presentation

A 69-year-old man was pointed out an enlarged 2.1-cm solid nodule on the edge of staple line of the residual right upper lobe by chest CT. He had past history of the lung cancer surgery, wedge resection of the same right upper lobe 13 years ago. The pathological findings were 1.1-cm, p-TlbN0M0, p-stage IA2-adenocarcinoma. Thereafter, he received no adjuvant therapy. This time, the trans-bronchial lung biopsy revealed adenocarcinoma. After the completion lobectomy of the residual right upper lobe, the tumor was diagnosed as adenocarcinoma consistent with recurrence of small-sized adenocarcinoma in the lung periphery developed from the cut-end because of similarities between present and previous tumors on histopathology and p53-positivity.

Conclusions

When limited resection has been performed for small-sized NSCLC presenting solid nodule on thin-slice CT images, long-term postoperative follow-up time will be necessary for monitoring, considering the possibility of cut-end recurrence.

The impact of chemotherapy on persistent ground-glass nodules in patients with lung adenocarcinoma

Backgrounds

To evaluate the response of persistent ground glass nodules (GGNs) in patients with lung adenocarcinoma treated with platinum-based chemotherapy on computed tomography (CT).

Methods

We retrospectively studied patients with GGNs that met the following criteria: (I) GGNs found in patients with lung adenocarcinoma, which persist for more than 3 months; (II) patients treated with platinum-based (cisplatin or carboplatin) chemotherapy for at least 2 cycles; (III) ground glass proportion ¡Ý50%. For each patient, if more than two CTs satisfied the inclusion criteria, then the baseline and last CTs were used for analysis, defined as CT1 and CT2. A total of 91 persistent pulmonary GGNs in 51 patients fulfilled the inclusion criteria. We defined growth as a nodule ¡Ý2 mm increase in diameter or showing up a solid portion. GGN response to therapy was assessed and compared with the baseline CT. Differences in CT findings were analyzed using a paired t-test and Pearson ¦Ö² test.

Results

Between 2010 and 2015, 25 of the 51 (49%) were male and 26 of the 51 (51%) were female. The average age at time of detection of a GGN was 63.8 (range, 36-84) years. Mean follow-up duration was 24.1¡À17.9 months. During the follow-up periods, on a per-nodule basis, 94.5% of GGNs (n=86) remained unchanged in size. Only 5.5% GGNs (n=5) in 5 patients increased in size. The nodules CT feature in each lung adenocarcinoma clinical stage show no difference. No significant difference was found in the size, attenuation, volume, and mass of GGN between baseline and post-treatment measurements, regardless of the type of chemotherapy (P>0.05).

Conclusions

The clinical course of GGNs in patients with lung adenocarcinoma is predominantly indolent, and platinum-based chemotherapy may have no effect on the growth of persistent GGNs.

[Advance in Diagnose and Treatment Strategies of Adenocarcinoma in Situ]

Adenocarcinoma in situ (AIS) is a new concept which was introduced to the 2011 The International Association for the Study of Cancer (IASLC)/ American Thoracic Society (ATS)/ European Respiratory Society (ERS) International Multidisciplinary Classification of Lung Adenocarcinoma firstly and an important supplement of The 2015 World Health Organization Classification of Lung Tumors. Because AIS is at an early stage of development of lung adenocarcinoma, the deepening understanding of its pathology, differential diagnosis, treatment strategies, has an important significance for the improvement of the prognosis of lung adenocarcinoma. This review will provide a systematic review of the main progress of occurrence and development, pathological characteristics, differential diagnosis and treatment strategy of AIS, in order to provide theoretical basis for the further research of AIS.

Detection of tumor spread through airspaces by airway secretion cytology from resected lung cancer specimens

It currently remains unclear whether tumor spread through airspaces (STAS) actually exist in vivo or are an artifact. The morphologies of STAS and tumor cell clusters in airway secretions collected from the segmental or lobar bronchus of resected lung adenocarcinomas and squamous cell carcinomas were compared among 48 patients. The EGFR status of tumor cell clusters in airway secretions was also compared with that of the main tumor in EGFR mutant adenocarcinomas. Tumor cell clusters were observed in the airway secretion cytology of ten patients (20.8%), and eight patients were adenocarcinoma (20.0% of adenocarcinoma). The morphology of STAS closely resembled that of tumor cell clusters detected in airway secretion cytology. The positive rates of airway secretion cytology were 83.3%, 100%, and 50% in papillary adenocarcinoma, micropapillary adenocarcinoma, and invasive mucinous adenocarcinoma, respectively. Among three EGFR mutant adenocarcinomas, the EGFR mutation subtypes of the main tumors in FFPE sections and tumor cell clusters in airway secretions were identical. These indicate that STAS may be detected in the airway secretion cytology. STAS is common in papillary or micropapillary adenocarcinoma and may spread as far as the segmental or lobar bronchus at the time of surgery.

Whack-a-mole strategy for multifocal ground glass opacities of the lung

Ground glass opacity (GGO) is a good prognostic indicator for lung cancer and is useful for physicians to predict prognosis. Due to recent advances in computed tomography (CT), the chance to encounter GGO is rapidly increasing in clinical practice. Based on the studies on radiological pathological correlation, GGO represents pathological lepidic growth and consolidation on CT represents pathologically invasive components. Thus, consolidation tumor ratio 0.5 or less means pathological less invasiveness for lung cancer. Not a few studies have shown that sublobar resection is equivalent to lobectomy for radiological early lung cancers. Additionally, observation of GGO is one of the options for physicians. Indication of surgical intervention remains unclear. Physician observing GGO in practice should know the natural history of GGO to reach an optimal treatment decision. For multifocal GGO lesions clinical management is surely challenging. Whack-a-mole strategy, which means sublobar resection for radiological invasive cancer is one of the most promising strategies for such lesions.

Long-term Outcomes of Patients With Ground-Glass Opacities Detected Using CT Scanning

BACKGROUND

The long-term outcomes of follow-up care for ground-glass opacity (GGO) lesions need to be clarified.

METHODS

Between 2000 and 2005, a total of 226 patients with pure or mixed GGO lesions ≤ 3 cm in size were registered. The CT findings and changes in the findings during the follow-up period and the outcomes of the 226 patients were subsequently reviewed.

RESULTS

Overall, 124 patients underwent resections, 57 did not receive follow-up examinations after 68 months because of stable disease or disease reduction, and 45 are continuing to receive follow-up examinations. Thirty-nine patients exhibited tumor growth during the follow-up period. Among the patients with a ratio of the diameter of consolidation relative to the tumor diameter (CTR) > 0, all cases with tumor growth were identified within 3 years; meanwhile, > 3 years were required to identify tumor growth in 16% of the patients with a CTR of 0. Aggressive cancer occurred in 4% of patients with a CTR of 0 and in 70% of patients with a CTR > 25%. Aggressive cancer was observed in 46% of the patients whose CTR increased during the follow-up period and in 8% of the patients whose tumors increased in size.

CONCLUSIONS

A higher CTR and an increase in CTR during follow-up were associated with invasive cancer. A follow-up period of 3 years is considered to be adequate for judging tumor growth in patients with a CTR > 0, whereas a longer follow-up period might be needed for patients with a CTR of 0.

Early and late recurrence after intentional limited resection for cT1aN0M0, non-small cell lung cancer: from a multi-institutional, retrospective analysis in Japan

OBJECTIVES

In 2015, we reported the outcomes of patients undergoing intentional limited resection (ILR) for non-small-cell lung cancer (NSCLC) from a retrospective, multi-institutional large database in Japan. Here, we analyse the clinicopathological characteristics of the patients extracted from this database with late recurrence and compare them with those with early recurrence.

METHODS

Of 1538 patients in the database with cT1aN0M0 NSCLC, 92 (6%) had recurrence. In this study, early recurrence was defined as recurrence within 5 years and late recurrence as recurrence beyond 5 years after surgery. We compared the clinicopathological characteristics and post-recurrence survival (PRS) between patients with early and late recurrence.

RESULTS

Of the 92 patients with recurrence, 21 (23%) had late recurrence. Compared with the early recurrence group, there were significantly more adenocarcinomas and local recurrences in the late recurrence group (P = 0.04 for both). The 3- and 5-year PRS rates were 53 and 24%, respectively, and the median PRS period was 38 months. There were no significant differences in the PRS curves between patients with early and late recurrence (P = 0.12). Only 3 patients (0.2%) had recurrence more than 10 years after ILR. Of the 21 late-recurrence patients, 17 (81%) had tumours with a consolidation/tumour ratio (CTR) >0.25.

CONCLUSIONS

Late recurrence occurred in 21 (23%) of 92 patients with recurrence after ILR for cT1aN0M0 NSCLC. Late recurrence was more likely to involve adenocarcinoma and local recurrence. It is thus considered reasonable to follow patients with a CTR >0.25 for 10 years after ILR.

The IASLC Lung Cancer Staging Project: Proposals for Coding T Categories for Subsolid Nodules and Assessment of Tumor Size in Part-Solid Tumors in the Forthcoming Eighth Edition of the TNM Classification of Lung Cancer

This article proposes codes for the primary tumor categories of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) and a uniform way to measure tumor size in part-solid tumors for the eighth edition of the tumor, node, and metastasis classification of lung cancer. In 2011, new entities of AIS, MIA, and lepidic predominant adenocarcinoma were defined, and they were later incorporated into the 2015 World Health Organization classification of lung cancer. To fit these entities into the T component of the staging system, the Tis category is proposed for AIS, with Tis (AIS) specified if it is to be distinguished from squamous cell carcinoma in situ (SCIS), which is to be designated Tis (SCIS). We also propose that MIA be classified as T1mi. Furthermore, the use of the invasive size for T descriptor size follows a recommendation made in three editions of the Union for International Cancer Control tumor, node, and metastasis supplement since 2003. For tumor size, the greatest dimension should be reported both clinically and pathologically. In nonmucinous lung adenocarcinomas, the computed tomography (CT) findings of ground glass versus solid opacities tend to correspond respectively to lepidic versus invasive patterns seen pathologically. However, this correlation is not absolute; so when CT features suggest nonmucinous AIS, MIA, and lepidic predominant adenocarcinoma, the suspected diagnosis and clinical staging should be regarded as a preliminary assessment that is subject to revision after pathologic evaluation of resected specimens. The ability to predict invasive versus noninvasive size on the basis of solid versus ground glass components is not applicable to mucinous AIS, MIA, or invasive mucinous adenocarcinomas because they generally show solid nodules or consolidation on CT.

The difference in Ezrin-pAkt signaling axis between lepidic and papillary predominant invasive adenocarcinomas of the lung

PURPOSE

Histologic classification of invasive lung adenocarcinomas by predominant subtype has prognostic value. Papillary predominant adenocarcinoma (PPA) reportedly shows poorer prognosis than lepidic predominant adenocarcinoma (LPA); however, biological differences between PPA and LPA are unclear. The purpose of this study was to clarify biological differences between PPA and LPA.

METHODS

Clinicopathological characteristics of invasive 62 PPAs and 117 LPAs smaller than 30 mm were investigated. Furthermore, we compared immunochemical staining scores of 9 molecular markers (E-cadherin, S100A4, fibronectin, integrinβ1, ezrin, GLUT1, ALDH1, SOX2 and Nanog) between PPA and LPA. We performed Western blot analysis using ezrin shRNA-knockdown lung adenocarcinoma cell lines to examine whether molecules that are highly expressed in PPA, such as ezrin, affect pAkt. Finally, we performed immunochemical staining to compare pAkt expression level in PPA and LPA.

RESULTS

Lymphovascular and pleural invasion and lymph node metastasis were significantly more often detected in PPA than in LPA (lymphatic permeation: 31 vs 3 %, vascular invasion: 35 vs 3 %, pleural invasion: 29 vs 5 %, lymph node metastasis: 18 vs 1 %; all P < 0.01). Immunohistochemical (IHC) study revealed that expression score of ezrin was significantly higher in PPA than in LPA (38.3 vs 15.0; P < 0.01). The level of pAkt decreased in shEzrin-induced PC-9 and A549 cancer cells. Moreover, the IHC staining score of pAkt was significantly higher in PPA than in LPA (13.3 vs 0.0; P < 0.01).

CONCLUSIONS

Our results show that the activation of the ezrin-pAkt signaling axis is associated with the more aggressive clinicopathological features of PPA compared with LPA.

Surgical treatment of early-stage non-small-cell lung cancer

Surgical resection remains the standard of care for functionally operable early-stage non-small-cell lung cancer (NSCLC) and resectable stage IIIA disease. The role of invasive staging and restaging techniques is currently being debated, but they provide the largest biopsy samples which allow for precise mediastinal staging. Different types of operative procedures are currently available to the thoracic surgeon, and some of these interventions can be performed by video-assisted thoracic surgery (VATS) with the same oncological results as those by open thoracotomy. The principal aim of surgical treatment for NSCLC is to obtain a complete resection which has been precisely defined by a working group of the International Association for the Study of Lung Cancer (IASLC). Intraoperative staging of lung cancer is of utmost importance to decide on the extent of resection according to the intraoperative tumour (T) and nodal (N) status. Systematic nodal dissection is generally advocated to evaluate the hilar and mediastinal lymph nodes which are subdivided into seven zones according to the most recent 7th tumour-node-metastasis (TNM) classification. Lymph-node involvement not only determines prognosis but also the administration of adjuvant therapy.

In 2011, a new multidisciplinary adenocarcinoma classification was published introducing the concepts of adenocarcinoma in situ and minimally invasive adenocarcinoma. This classification has profound surgical implications. The role of limited or sublobar resection, comprising anatomical segmentectomy and wide wedge resection, is reconsidered for early-stage lesions which are more frequently encountered with the recently introduced large screening programmes. Numerous retrospective non-randomised studies suggest that sublobar resection may be an acceptable surgical treatment for early lung cancers, also when performed by VATS.

More tailored, personalised therapy has recently been introduced. Quality-of-life parameters and surgical quality indicators become increasingly important to determine the short-term and long-term impact of a surgical procedure. International databases currently collect extensive surgical data, allowing more precise calculation of mortality and morbidity according to predefined risk factors. Centralisation of care has been shown to improve results. Evidence-based guidelines should be further developed to provide optimal staging and therapeutic algorithms.

The lung adenocarcinoma guidelines: what to be considered by surgeons

In 2011 the International Association for the Study of Lung Cancer (IASLC), the American Thoracic Society (ATS), and the European Respiratory Society (ERS), have proposed a new subclassification of lung adenocarcinomas. This new classification was founded on an evidence-based approach to a systematic review of 11,368 citations from the related literature. Validation has involved projects relating to histologic and cytologic analysis of small biopsy specimens, histologic subtyping, grading, and observer variation among expert pathologists. As enormous resources are being spent on trials involving molecular and therapeutic aspects of adenocarcinoma of the lung, the development of standardized criteria is of great importance and should help advance the field, increasing the impact of research, and improving patient care. This classification is needed to assist in determining patient therapy and predicting outcome. The 2011 IASLC/ATS/ERS adenocarcinoma classification can have an impact on TNM staging. It may help in comparing histologic characteristics of multiple lung adenocarcinomas to determine whether they are intrapulmonary metastases versus separate primaries. Use of comprehensive histologic subtyping along with other histologic characteristics has been shown to have good correlation with molecular analyses and clinical behavior. Also, it may be more meaningful clinically to measure tumor size in lung adenocarcinomas that have a lepidic component by using invasive size rather than total size to determine the size T factor.

The new IASLC-ATS-ERS lung adenocarcinoma classification: what the surgeon should know

In 2011, a new histologic classification of lung adenocarcinomas was proposed from a joint working group of the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society, based on the recommendation of an international and multidisciplinary panel. This classification proposed a method of comprehensive histologic subtyping (lepidic, acinar, papillary, micropapillary, and solid pattern) based on semiquantitative assessment of histologic patterns (in 5% increments), with the ultimate goal of choosing a single, predominant pattern. Prognostic subsets could then be described for the classification. Patients with completely resected adenocarcinoma in situ and minimally invasive adenocarcinomas experienced low risk of recurrence. Patients with micropapillary or solid predominant tumors have a high risk of recurrence or cancer-related death. Patients with acinar and papillary predominant tumors comprise an intermediate-risk group. Herein, we review the outline of the proposed International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society classification, a summary of published validation studies of this new classification, and then discuss the key surgical issues; we mainly focused on limited resection as an adequate treatment for early-stage lung adenocarcinomas, as well as preoperative and intraoperative diagnoses. We also review the published studies that identified the importance of histologic subtypes in predicting recurrence, both rates and patterns, in early-stage lung adenocarcinomas. This new classification for the most common type of lung cancer is useful for surgeons, as its implementation would require only hematoxylin-and-eosin histology slides, which is the common type of stain used in hospitals. It can be implemented with routine pathology evaluation and with no additional costs.

Can image analysis on high-resolution computed tomography predict non-invasive growth in adenocarcinoma of the lung?

PURPOSE

Preoperative radiological predictions of pathological invasiveness must be objective and reproducible in addition to being accurate when considering limited surgery for early lung cancer.

METHODS

Two cohorts were used for the analysis. Two independent observers traced lesion edges and measured areas and proportions of solid component on tumor images with the largest diameter by high resolution computed tomography images and "Image J" software.

RESULTS

The value of the intraclass correlation was 0.997 (95% confidence interval [CI], 0.996-0.998) for the area of solid component and 0.979 (95%CI, 0.958-0.986) for the proportion of solid component, suggesting such parameters were reliable in terms of reproducibility. Az value was 0.898 (95%CI, 0.842-0.953) for the area of solid component and 0.882 (95%CI, 0.816-0.949) for the proportion of solid component, demonstrating 2 parameters were both highly predictive of non-invasive adenocarcinoma. The optimal prediction of non-invasive adenocarcinoma with a cut-off value of 7.5 mm(2) for the area of solid component resulted in a sensitivity of 85.3% and specificity of 86.2% in Cohort 1 and a sensitivity of 66.7% and specificity of 88.5% in Cohort 2.

CONCLUSION

Image analysis using "Image J" software was promising for predicting non-invasive adenocarcinoma with its limited inter-observer variability and high predictive performance.

Tumour standardized uptake value on positron emission tomography is a novel predictor of adenocarcinoma in situ for c-Stage IA lung cancer patients with a part-solid nodule on thin-section computed tomography scan

OBJECTIVES

Adenocarcinoma in situ (AIS), which is considered to be pathologically non-invasive in the new International Association for the Study of Lung Cancer/the American Thoracic Society/the European Respiratory Society classification, might be present in patients who show a part-solid nodule on thin-section computed tomography (CT) scan.

METHODS

Between 2008 and 2011, 556 clinical Stage IA (c-Stage IA) lung cancer patients underwent pulmonary resection. For all the patients, the findings obtained by preoperative thin-section CT were reviewed and categorized as pure ground-glass nodule (GGN), part-solid nodule or pure-solid nodule based on the findings on thin-section CT, i.e. based on the consolidation/tumour ratio (CTR). A part-solid nodule was defined as a tumour with 0 < CTR < 1.0, which indicated focal nodular opacity that contained both solid and GGN components. All the patients were evaluated by positron emission tomography (PET), and the maximum standardized uptake value (SUVmax) was recorded. Several clinicopathological features were investigated to identify predictors of AIS in clinical Stage IA lung cancer patients with a part-solid nodule radiologically, using multivariate analyses.

RESULTS

One-hundred and twelve c-Stage IA lung cancer patients showed a part-solid appearance on thin-section CT. Among them, AIS was found in 10 (32%) of the tumours with 0 < CTR ≤ 0.5, in contrast to 3 (5%) with 0.5 < CTR < 1.0. According to multivariate analyses, SUVmax and CTR significantly predicted AIS in patients with a part-solid nodule (P = 0.04, 0.02). The mean SUVmax of the patients with AIS was 0.57 (0-1.6). Moreover, in the subgroup of part-solid nodule with a SUVmax of ≤1.0 and a CTR of ≤0.40, which were calculated as cut-off values for AIS based on the results for a receiver operating characteristic curve, 6 (40%) patients with these criteria showed a pathological non-invasive nature, even patients with a part-solid nodule.

CONCLUSIONS

Among c-Stage IA adenocarcinoma with a part-solid nodule on thin-section CT scan, an extremely low level of SUVmax could reflect a pure GGN equivalent radiologically and AIS pathologically. The preoperative tumour SUVmax on PET could yield important information for predicting non-invasiveness in patients with a part-solid nodule.

Pathologic classification of adenocarcinoma of lung

Recently, the 1999/2004 World Health Organization (WHO) classification of adenocarcinoma became less useful from a clinical standpoint as most adenocarcinomas belonged to the mixed subtype and the term bronchioloalveolar carcinoma (BAC) gave rise to much confusion among clinicians. For these reasons a new adenocarcinoma classification was introduced in 2011 by a joint working group of the International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory Society (ERS). This represents an international, multidisciplinary effort joining pathologists, molecular biologists, pulmonary physicians, thoracic oncologists, radiologists, and thoracic surgeons. Currently, a distinction is made between pre-invasive lesions, minimally invasive and invasive lesions. The confusing term BAC is not used anymore and new subcategories include adenocarcinoma in situ and minimally invasive adenocarcinoma. Several aspects of this classification are discussed with main emphasis on its correlation with imaging techniques and its impact on diagnosis, treatment and prognosis. On chest computed tomography (CT) a distinction is made between solid and subsolid nodules, the latter comprising ground glass opacities (GGO), and partly solid lesions. Several studies incorporating CT and positron emission tomographic (PET) data show a good imaging-pathologic correlation. With the implementation of screening programs early lung cancer has become a hotly debated topic and sublobar resection is currently reconsidered for early lesions without lymph node involvement. This new classification will also have an impact on the TNM classification. Thoracic surgeons will continue to play a major role in the application, evaluation and further refinement of this new adenocarcinoma classification.

Limited resection and two-staged lobectomy for non-small cell lung cancer with ground-glass opacity

Background

Lung tumors showing ground-glass opacities on high-resolution computed tomography indicate the presence of inflammation, atypical adenomatous hyperplasia, or localized bronchioloalveolar carcinoma. We adopted a two-staged video-assisted thoracoscopic lobectomy strategy involving completion lobectomy for localized bronchioloalveolar carcinoma with an invasive component according to postoperative pathological examination by permanent section after partial resection.

Methods

Forty-one patients with undiagnosed small peripheral ground-glass opacity lesions underwent partial resection from 2001 to 2007 in Hokkaido University Hospital. Localized bronchioloalveolar carcinoma was classified according to the Noguchi classification for adenocarcinoma. Malignant lesions other than Noguchi types A and B were considered for completion lobectomy and systemic mediastinal lymphadenectomy. Perioperative data of completion video-assisted thoracoscopic lobectomies were compared with data of 67 upfront video-assisted thoracoscopic lobectomies for clinical stage IA adenocarcinoma performed during the same period.

Results

Postoperative pathological examination revealed 35 malignant and 6 non-malignant diseases. Histologically, all of the malignant diseases were adenocarcinomas of Noguchi type A (n = 7), B (n = 9), C (n = 18), and F (n = 1). Eleven of 19 patients (58%) with Noguchi type C or F underwent two-staged video-assisted thoracoscopic lobectomy. Three patients refused a second surgery. There was no cancer recurrence. The two-staged lobectomy group had a significantly longer operative time and more blood loss than the upfront lobectomy group. There was no surgical mortality or cancer recurrence.

Conclusions

Two-staged lobectomy for undiagnosed small peripheral ground-glass opacity lesions showed satisfactory oncological results. However, low compliance for and invasiveness of the second surgery are concerns associated with this strategy.

Radical treatment of non-small cell lung cancer during the last 5 years

The management of non-small cell lung cancer (NSCLC) has continued to improve over the last 5 years due to advances in surgery, radiological staging, combined modality therapies and advances in radiation technology. We have an updated staging classification (7th Edition American Joint Committee on Cancer staging) and now in 2011, a new histology classification introducing the concepts of adenocarcinoma in situ and minimally invasive adenocarcinoma. This classification has profound surgical implications as the role of limited resection is reconsidered for early stage lesions. Surgery is curative in early stage disease. The role of surgery in locally advanced NSCLC remains controversial. The principal aim is a complete resection as this will determine long-term prognosis. Intraoperative staging of lung cancer is extremely important to determine the extent of resection according to the tumour and nodal status. Systematic nodal dissection is generally advocated to obtain accurate intraoperative staging and to help decide on adjuvant therapy. Radiotherapy currently plays a major role in the management of lung cancer as most patients are not surgical candidates due to disease stage, fitness and co-morbidities. In the last 5 years we have seen continuing optimisation of chemo-radiotherapy combinations and technological advances including the development of image guided radiotherapy (IGRT), stereotactic ablative body radiotherapy (SABR) and intensity modulated radiotherapy (IMRT). Quality of life evaluation is becoming increasingly important and should be considered when deciding on a specific treatment, especially in a multimodality setting.

Lung cancer with scattered consolidation: detection of new independent radiological category of peripheral lung cancer on thin-section computed tomography

OBJECTIVES

Ground glass opacity (GGO) on thin-section computed tomography (CT) has been reported to be a favourable prognostic marker in lung cancer, and the size or area of GGO is commonly used for preoperative evaluation. However, it can sometimes be difficult to evaluate the status of GGO.

METHODS

A retrospective study was conducted on 572 consecutive patients with resected lung cancer of clinical stage IA between 2004 and 2011. All patients underwent preoperative CT and their radiological findings were reviewed. The areas of consolidation and GGO were evaluated for all lung cancers. Lung cancers were divided into three categories on the basis of the status of GGO: GGO, part solid and pure solid. Lung cancers in which it was difficult to measure GGO were selected and their clinicopathological features were investigated.

RESULTS

Seventy-one (12.4%) patients had lung cancer in whom it was difficult to measure GGO. In all these cases, consolidation and GGO were not easily measured because of their scattered distribution. In this cohort, nodal metastases were not observed at all. The frequency of other pathological factors, such as lymphatic and/or vascular invasion, was significantly lower (P < 0.0001).

CONCLUSIONS

This new category of lung cancer with scattered consolidation on thin-section CT scan tended to be pathologically less invasive. When lung cancer has GGO and is difficult to measure because of a scattered distribution, its prognosis could be favourable regardless of the area of GGO. This new category could be useful for the preoperative evaluation of lung cancer.