Presence of Even a Small Ground-Glass Component in Lung Adenocarcinoma Predicts Better Survival

Oncological characteristics of epidermal growth factor receptor-mutated clinical stage IA lung adenocarcinoma with radiologically pure-solid appearance

OBJECTIVES

We evaluated the clinicopathological and oncological characteristics of epidermal growth factor receptor-mutated clinical stage IA radiological pure-solid lung adenocarcinoma and compared them with those of a ground-glass opacity component.

METHODS

Between 2008 and 2020, data from 1014 surgically resected clinical stage 0-IA epidermal growth factor receptor-mutated lung adenocarcinomas were evaluated. Oncological outcomes were assessed using multivariable analysis. Overall survival was estimated using Kaplan-Meier analysis and the log-rank test. The cumulative incidence of recurrence was estimated using the Gray's test.

RESULTS

Of these, 233 (23%) were radiologically pure-solid tumors, which demonstrated a higher proportion of nodal metastasis, micropapillary component, spread through alveolar space, and Ex19 subtype compared with those of tumors with ground-glass opacity (P < .001). Multivariable analysis revealed that the presence of ground-glass opacity was an independently significant factor for overall survival (P = .037) and cumulative incidence of recurrence (P < .001). In cases where the oncological outcomes were stratified by the presence of ground-glass opacity component, the 5-year overall survival was excellent at more than 90% in tumors with ground-glass opacity despite clinical-T categories (P = .2044); however, tumor size significantly affected survival only in pure-solid tumors (T1a, 100%; T1b, 77.7%; T1c, 68.5%; P = .0056). Furthermore, the cumulative incidence of recurrence was low in tumors with ground-glass opacity despite the clinical-T categories, whereas tumor size significantly affected the cumulative incidence of recurrence only in pure-solid tumors (5-year cumulative incidence of recurrence: T1a-b, 18.9%; T1c, 41.3%; P < .001).

CONCLUSIONS

Oncologic behavior and prognosis of radiologically pure-solid tumors were significantly poorer than those of tumors with ground-glass opacity among patients with epidermal growth factor receptor-mutated early-stage lung adenocarcinoma. These findings imply distinct tumorigenesis based on the presence of ground-glass opacity, even in tumors with epidermal growth factor receptor mutations.

Ten-Year Follow-Up of Lung Cancer Patients with Resected Stage IA Invasive Non-Small Cell Lung Cancer

OBJECTIVE

The purpose of this study was to assess 10-year follow-up outcomes after surgical resection in patients with stage IA invasive non-small cell lung cancer (NSCLC) based on postoperative pathological diagnosis.

METHODS

Patients with stage IA invasive NSCLC who underwent resection between December 2008 and December 2013 were reviewed. Patients were categorized into the pure-ground glass opacity (pGGO), mixed-ground glass opacity (mGGO), and solid groups based on consolidation to tumor ratio (CTR). Postoperative survival and risk of recurrence and developing secondary primary lung cancer were analyzed in each group.

RESULTS

Among the 645 stage IA invasive NSCLC, the 10-year overall survival and recurrence-free survival rate was 79.38% and 77.44%, respectively. The 10-year overall survival for pGGO, mGGO, and solid group of patients was 95.08%, 86.21%, and 72.39%, respectively. The respective recurrence-free survival rate was 100%, 89.82%, and 65.83%. Multivariable Cox regression analysis associated tumor size and GGO components with recurrence and younger age, and tumors with GGO components were associated with longer overall survival. The cumulative incidence curve indicated no recurrence of GGO lung cancer ≥ 5 years postoperatively. Our cohort indicated that the number and stations of dissected lymph node did not influence long-term prognosis of IA invasive NSCLC.

CONCLUSIONS

Recurrence of invasive stage IA NSCLC with GGO was more prevalent in patients with tumor size >1 cm and CTR > 0.5, occurring within 5 years after surgery. This will provide important evidence for follow-up strategies in these patients.

The Role of Emphysema on Postoperative Prognosis in Early-Stage Nonsmall Cell Lung Cancer

BACKGROUND

Emphysema is generally considered a poor prognostic factor for patients with nonsmall cell lung cancer; however, whether the poor prognosis is due to highly malignant tumors or emphysema itself remains unclear. This study was designed to determine the prognostic value of emphysema in patients with early-stage nonsmall cell lung cancer.

METHODS

A total of 721 patients with clinical stage IA nonsmall cell lung cancer who underwent complete resection between April 2007 and December 2018 were retrospectively analyzed regarding clinicopathological findings and prognosis related to emphysema.

RESULTS

The emphysematous and normal lung groups comprised 197 and 524 patients, respectively. Compared with the normal lung group, lymphatic invasion (23.9% vs. 14.1%, P = 0.003), vascular invasion (37.6% vs. 17.2%, P < 0.001), and pleural invasion (18.8% vs. 10.9%, P = 0.006) were observed more frequently in the emphysema group. Additionally, the 5-year overall survival rate was lower (77.1% vs. 91.4%, P < 0.001), and the cumulative incidence of other causes of death was higher in the emphysema group (14.0% vs. 3.50%, P < 0.001). Multivariable Cox regression analysis of overall survival revealed that emphysema (vs. normal lung, hazard ratio 2.02, P = 0.0052), age > 70 years (vs. < 70 years, hazard ratio 4.03, P < 0.001), and SUVmax > 1.8 (vs. ≤ 1.8, hazard ratio 2.20, P = 0.0043) were independent prognostic factors.

CONCLUSIONS

Early-stage nonsmall cell lung cancer with emphysema has a tendency for the development of highly malignant tumors. Additionally, emphysema itself may have an impact on poor prognosis.

The novel DNA methylation marker FIBIN suppresses non-small cell lung cancer metastasis by negatively regulating ANXA2

OBJECTIVES

The clinical T1 stage solid lung cancer with metastasis is a serious threat to human life and health. In this study, we performed RNA sequencing on T1 advanced-stage lung cancer and adjacent tissues to identify a novel biomarker and explore its roles in lung cancer.

METHODS

Quantitative reversed-transcription PCR, reverse transcription PCR and Western blot, MSP and Methtarget were utilized to evaluate FIBIN expression levels at both the transcriptional and protein levels as well as its methylation status. Differential target protein was evaluated for relative and absolute quantitation by isobaric tags. Co-IP was performed to detect the interactions between target protein. Precise location and expression levels of target proteins were revealed by immunofluorescence staining and component protein extraction using specific kits, respectively.

RESULTS

We reported that FIBIN was frequently silenced due to promoter hypermethylation in lung cancer. Additionally, both in vitro and in vivo experiments confirmed the significant anti-proliferation and anti-metastasis capabilities of FIBIN. Mechanistically, FIBIN decreased the nuclear accumulation of β-catenin by reducing the binding activity of GSK3β with ANXA2 while promoting interaction between GSK3β and β-catenin.

CONCLUSION

Our findings firstly identify FIBIN is a tumor suppressor, frequently silenced due to promoter hypermethylation. FIBIN may serve as a predictive biomarker for progression or metastasis among early-stage lung cancer patients.

Thoracoscopic segmentectomy for trans-fissure ground-glass opacity

OBJECTIVES

The trans-fissure ground-glass opacity (GGO) is a special category of lesions, with a diameter always exceeding 2 cm. It is located on a fused fissure, 'seizing' 2 neighbouring lobes simultaneously. The segmentectomy for the trans-fissure GGO is never reported.

METHODS

Between August 2016 and December 2022, patients operated with a trans-fissure GGO were included. The patients' backgrounds and surgical data were summarized. All procedures were performed with the help of preoperative three-dimensional computed tomography bronchography and angiography.

RESULTS

A total of 84 patients were included. The selection criteria included a consolidation tumour ratio <50% and a lesion size >2 and ≤3 cm. Thirty-six patients were operated with lobectomy + wedge (the traditional method group) and 48 patients were operated with anatomical segmentectomy + function-preserving sublobectomy (the new method group). The median operative time was 87 min in the traditional group and 98 min in the new method group, and the median blood loss was 60 ml in the traditional group and 70 ml in the new method group. The median duration of hospital stays was 4 days in the traditional group and 2 days in the new method group. In the traditional method group, there was 1 case of postoperative air leakage and 5 cases of haemoptysis. In the new method group, 2 cases of postoperative air leakage were identified. The median size of the tumour in the resected segment was 2.6 cm in the traditional group and 2.5 cm in the new method group. The median margin was 2.5 cm in the traditional group and 3.3 cm in the new method group.

CONCLUSIONS

The trans-fissure GGO could be safely resected en bloc by segmentectomy with a well-designed surgical procedure and appropriate preoperative planning.

Recurrence-Free Survival in Patients With Surgically Resected Non-Small Cell Lung Cancer: A Systematic Literature Review and Meta-Analysis

BACKGROUND

Standard treatment for early-stage or locoregionally advanced non-small cell lung cancer (NSCLC) includes surgical resection. Recurrence after surgery is commonly reported, but a summary estimate for postsurgical recurrence-free survival (RFS) in patients with NSCLC is lacking.

RESEARCH QUESTION

What is the RFS after surgery in patients with stage I-III NSCLC at different time points, and what factors are associated with RFS?

STUDY DESIGN AND METHODS

A systematic search was performed in MEDLINE, EMBASE, and Cochrane databases between January 2011 and June 2021. The primary outcome was RFS at 1, 2, 3, and 5 years postresection. Single-arm, random-effects meta-analyses were done to calculate effect estimates and 95% CIs. Analyses were stratified by stage/substage as per the AJCC Cancer Staging Manual, and RFS was estimated (1) after pooling studies, using seventh or eighth edition staging criteria; and (2) among studies using only the eighth edition. Meta-regressions were performed to assess associations between RFS and patient demographic/clinical characteristics of interest.

RESULTS

Data from 471 studies comprising 1,060 surgical study arms were extracted. RFS estimates from 60,695 patients staged with the seventh or eighth edition were analyzed. RFS ranged from 96% at 1 year postresection to 82% at 5 years for stage I, and from 68% at 1 year to 34% at 5 years for stage III. Estimates for patients staged using only eighth edition criteria were slightly higher. Older age, higher percentage of male patients, advancing stage, larger tumor size, and geographic region (North America/Europe vs Asia) were significantly associated with worse RFS.

INTERPRETATION

This study presents a comprehensive assessment of reported RFS from published clinical literature, offering estimates at multiple postsurgical time points and by geographic region. Findings can inform treatment decisions, clinical trial design, and future research to improve outcomes among patients with NSCLC.

Prognostic implications of CT-defined ground glass opacity in clinical stage I-IIA grade 3 invasive non-mucinous pulmonary adenocarcinoma

AIM

To investigate the prognostic impact of computed tomography (CT)-defined ground glass opacity (GGO) in patients with clinical stage I-IIA grade 3 invasive non-mucinous pulmonary adenocarcinoma (INPA).

MATERIALS AND METHODS

The present study retrospectively enrolled 187 patients diagnosed with stage I-IIA grade 3 INPA. Their clinicopathological, radiological, and genetic information was evaluated systematically, and a 5-year follow-up was conducted to monitor disease recurrence and mortality. Patients were stratified based on the presence of a GGO component, and the Cox proportional hazard model was employed to assess the influence of clinicopathological factors and genetic variables on tumour outcomes. Recurrence-free survival (RFS) and overall survival (OS) were estimated using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

Significant differences were observed in both OS and RFS based on the presence of a GGO component. The group with GGO exhibited superior OS (p=0.002) and RFS (p=0.029). Multivariate analysis revealed that the presence of a GGO component (hazard ratio [HR] = 0.412, 95% confidence interval [CI]: 0.177-0.959, p=0.040), clinical T2 stage (HR=2.473, 95% CI: 1.498-4.083, p<0.001), pathological N2 stage (HR=3.049, 95% CI: 1.800-5.167, p<0.001), and mixed high-grade patterns (HR=2.392, 95% CI: 1.418-4.036, p=0.001) were predictors of RFS.

CONCLUSION

The presence of a GGO component is strongly associated with a favourable prognosis in grade 3 INPA.

Segmentectomy versus lobectomy in small-sized peripheral non-small-cell lung cancer with radiologically pure-solid appearance in Japan (JCOG0802/WJOG4607L): a post-hoc supplemental analysis of a multicentre, open-label, phase 3 trial

BACKGROUND

Although segmentectomy was better than lobectomy in terms of overall survival for patients with non-small-cell lung cancer (NSCLC) with a pure-solid tumour appearance on thin-section CT in the open-label, multicentre, randomised, controlled, phase 3 JCOG0802/WJOG4607L trial, the reasons why segmentectomy was associated with better overall survival were unclear. We aimed to compare the survival, cause of death, and recurrence patterns after segmentectomy versus lobectomy in trial participants with NSCLC with a pure-solid appearance METHODS: We conducted a post-hoc supplemental analysis of the JCO0802/WJOG4607L randomised, controlled, non-inferiority trial for the patients (aged 20-85 years) with small-sized NSCLC with radiologically pure-solid appearance on thin-section CT (≤2 cm, consolidation tumour ratio 1·0). The primary aim was to compare the overall and relapse-free survival, cause of death, and recurrence patterns associated with segmentectomy and lobectomy for patients with radiologically pure-solid NSCLC to determine why the overall survival of segmentectomy was superior to that of lobectomy, even for oncologically invasive lung cancers. JCO0802/WJOG4607L is registered with the UMIN Clinical Trials Registry, UMIN000002317, and is complete.

FINDINGS

Between Aug 10, 2009, and Oct 21, 2014, 1106 patients were randomly assigned to undergo either lobectomy or segmentectomy. Of these participants, 553 (50%) had radiologically pure-solid NSCLC and were eligible for this post-hoc supplemental analysis. Of these 553 participants, 274 (50%) patients underwent lobectomy and 279 (50%) underwent segmentectomy. Median patient age was 67 years (IQR 61-73), 347 (63%) of 553 patients were male and 206 (37%) were female, and data on race and ethnicity were not collected. As of data cutoff (June 13, 2020), after a median follow-up of 7·3 years (IQR 6·0-8·5), the 5-year overall survival rate was significantly higher after segmentectomy than after lobectomy (86·1% [95% CI 81·4-89·7] in the lobectomy group, with 55 deaths vs 92·4% [88·6-95·0] in the segmentectomy group, with 38 deaths; hazard ratio (HR) 0·64 [95% CI 0·41-0·97]; log-rank test p=0·033), whereas the 5-year relapse-free survival was similar between the groups (81·7% [95% CI 76·5-85·8], with 34 events vs 82·0% [76·9-86·0], with 52 events; HR 1·01 [95% CI 0·72-1·42]; p=0·94). Deaths after a median follow-up of 7·3 years due to lung cancer occurred in 20 (7%) of 274 patients after lobectomy and 19 (7%) of 279 after segmentectomy, and deaths due to other causes occurred in 35 (13%) patients after lobectomy compared with 19 (7%) after segmentectomy (lung cancer death vs other cause of death, p=0·19). The locoregional recurrence was higher after segmentectomy (21 [8%] vs 45 [16%]; p=0·0021). In subgroup analyses, better 5-year overall survival after segmentectomy than after lobectomy was observed in the subgroup of patients aged 70 years or older (77·1% [95% CI 68·2-83·8] with lobectomy vs 85·6% [77·5-90·9] with segmentectomy; p=0·013) and in male patients (80·5% [73·7-85·7] vs 92·1% [87·0-95·2]; p=0·0085). By contrast, better 5-year relapse-free survival after lobectomy than after segmentectomy was observed in the subgroup younger than 70 years (87·4% [95% CI 81·2-91·7] with lobectomy vs 84·4% [77·9-89·1] with segmentectomy; p=0·049) and in female patients (94·2% [87·6-97·4] vs 82·2% [73·2-88·4]; p=0·047).

INTERPRETATION

This post-hoc analysis showed improved overall survival after segmentectomy in patients with pure-solid NSCLC compared with lobectomy. However, survival outcomes of segmentectomy depend on the patient's age and sex. Given the results of this exploratory analysis, further research is necessary to determine clinically relevant indications for segmentectomy in radiologically pure-solid NSCLC.

FUNDING

Japanese National Cancer Center Research and Development Fund and Practical Research for Innovative Cancer Control Fund, and a Grant-in-Aid for Scientific Research from the Ministry of Health, Labor, and Welfare of Japan.

Evaluation of Prognosis in Patients with Lung Adenocarcinoma with Atypical Solid Nodules on Thin-Section CT Images

Purpose To evaluate the clinicopathologic characteristics and prognosis of patients with clinical stage IA lung adenocarcinoma with atypical solid nodules (ASNs) on thin-section CT images. Materials and Methods Data from patients with clinical stage IA lung adenocarcinoma who underwent resection between January 2005 and December 2012 were retrospectively reviewed. According to their manifestations on thin-section CT images, nodules were classified as ASNs, subsolid nodules (SSNs), and typical solid nodules (TSNs). The clinicopathologic characteristics of the ASNs were investigated, and the differences across the three groups were analyzed. The Kaplan-Meier method and multivariable Cox analysis were used to evaluate survival differences among patients with ASNs, SSNs, and TSNs. Results Of the 254 patients (median age, 58 years [IQR, 53-66]; 152 women) evaluated, 49 had ASNs, 123 had SSNs, and 82 had TSNs. Compared with patients with SSNs, those with ASNs were more likely to have nonsmall adenocarcinoma (P < .001), advanced-stage adenocarcinoma (P = .004), nonlepidic growth adenocarcinoma (P < .001), and middle- or low-grade differentiation tumors (P < .001). Compared with patients with TSNs, those with ASNs were more likely to have no lymph node involvement (P = .009) and epidermal growth factor receptor mutation positivity (P = .018). Average disease-free survival in patients with ASNs was significantly longer than that in patients with TSNs (P < .001) but was not distinguishable from that in patients with SSNs (P = .051). Conclusion ASNs were associated with better clinical outcomes than TSNs in patients with clinical stage IA lung adenocarcinoma. Keywords: Adenocarcinoma, Atypical Solid Nodules, CT, Disease-free Survival, Lung, Prognosis, Pulmonary Supplemental material is available for this article. Published under a CC BY 4.0 license.

Oncologic outcomes of segmentectomy versus lobectomy for clinical T1c radiological pure-solid non-small-cell lung cancer

OBJECTIVES

We aimed to compare the outcomes of segmentectomy with those of lobectomy in T1c (>2-3 cm) radiological pure-solid non-small-cell lung cancer detected on thin-section computed tomography.

METHODS

This retrospective review compared the survival outcomes, causes of death and recurrence patterns between the segmentectomy and lobectomy in patients with c-T1cN0M0 radiological pure-solid non-small-cell lung cancer. Multivariable analysis was performed to control for confounders of survival. The overall survival (OS) and recurrence-free survival were analysed using the Kaplan-Meier method. Differences in cumulative incidence of recurrence between groups were assessed using the methods of Gray.

RESULTS

Of the 426 patients, lobectomy was performed in 381 patients and segmentectomy in 45 patients. Nodal metastasis was noted in 104 (24.4%) patients. Multivariable analysis revealed that lobectomy was an independent prognosticator of better OS (hazard ratio 0.596, 95% confidence interval 0.366-0.969; P = 0.037). Lobectomy arm showed favourable 5-year OS and recurrence-free survival (OS: 72.9% vs 59.7%, log-rank test P = 0.007; recurrence-free survival: 64.4% vs 48.7%, P = 0.034) (median follow-up: 53 months). Approximately 14% of the patients in the lobectomy group and 27% in the segmentectomy group died of lung cancer. Furthermore, 5-year cumulative incidence of loco-regional recurrence rate was significantly higher in the segmentectomy group (35.5% vs 15.8%, P < 0.001).

CONCLUSIONS

In T1c radiological pure-solid non-small-cell lung cancer, segmentectomy was significantly associated with worse survival and insufficient loco-regional cancer control. Lobectomy remains the standard surgical treatment; meanwhile, segmentectomy should be applied with great caution.

A Nomogram Based on Consolidation Tumor Ratio Combined with Solid or Micropapillary Patterns for Postoperative Recurrence in Pathological Stage IA Lung Adenocarcinoma

BACKGROUND

Patients with pathological stage IA lung adenocarcinoma (LUAD) are at risk of relapse. The value of the TNM staging system is limited in predicting recurrence. Our study aimed to develop a precise recurrence prediction model for stage IA LUAD.

MATERIALS AND METHODS

Patients with pathological stage IA LUAD who received surgical treatment at Zhongshan Hospital Fudan University were retrospectively analyzed. Multivariate Cox proportional hazards regression models were used to create nomograms for recurrence-free survival (RFS). The predictive performance of the model was assessed using calibration plots and the concordance index (C-index).

RESULTS

The multivariate Cox regression analysis revealed that CTR (0.75 < CTR ≤ 1; HR = 9.882, 95% CI: 2.036-47.959, p = 0.004) and solid/micropapillary-predominance (SMPP; >5% and the most dominant) (HR = 4.743, 95% CI: 1.506-14.933, p = 0.008) were independent prognostic factors of RFS. These risk factors were used to construct a nomogram to predict postoperative recurrence in these patients. The C-index of the nomogram for predicting RFS was higher than that of the eighth T-stage system (0.873 for the nomogram and 0.643 for the eighth T stage). The nomogram also achieved good predictive performance for RFS with a well-fitted calibration curve.

CONCLUSIONS

We developed and validated a nomogram based on CTR and SMP patterns for predicting postoperative recurrence in pathological stage IA LUAD. This model is simple to operate and has better predictive performance than the eighth T stage system, making it suitable for selecting further adjuvant treatment and follow-up.

KRAS(G12D) drives lepidic adenocarcinoma through stem-cell reprogramming

Many cancers originate from stem or progenitor cells hijacked by somatic mutations that drive replication, exemplified by adenomatous transformation of pulmonary alveolar epithelial type II (AT2) cells1. Here we demonstrate a different scenario: expression of KRAS(G12D) in differentiated AT1 cells reprograms them slowly and asynchronously back into AT2 stem cells that go on to generate indolent tumours. Like human lepidic adenocarcinoma, the tumour cells slowly spread along alveolar walls in a non-destructive manner and have low ERK activity. We find that AT1 and AT2 cells act as distinct cells of origin and manifest divergent responses to concomitant WNT activation and KRAS(G12D) induction, which accelerates AT2-derived but inhibits AT1-derived adenoma proliferation. Augmentation of ERK activity in KRAS(G12D)-induced AT1 cells increases transformation efficiency, proliferation and progression from lepidic to mixed tumour histology. Overall, we have identified a new cell of origin for lung adenocarcinoma, the AT1 cell, which recapitulates features of human lepidic cancer. In so doing, we also uncover a capacity for oncogenic KRAS to reprogram a differentiated and quiescent cell back into its parent stem cell en route to adenomatous transformation. Our work further reveals that irrespective of a given cancer's current molecular profile and driver oncogene, the cell of origin exerts a pervasive and perduring influence on its subsequent behaviour.

Deep learning predicts malignancy and metastasis of solid pulmonary nodules from CT scans

In the clinic, it is difficult to distinguish the malignancy and aggressiveness of solid pulmonary nodules (PNs). Incorrect assessments may lead to delayed diagnosis and an increased risk of complications. We developed and validated a deep learning-based model for the prediction of malignancy as well as local or distant metastasis in solid PNs based on CT images of primary lesions during initial diagnosis. In this study, we reviewed the data from multiple patients with solid PNs at our institution from 1 January 2019 to 30 April 2022. The patients were divided into three groups: benign, Ia-stage lung cancer, and T1-stage lung cancer with metastasis. Each cohort was further split into training and testing groups. The deep learning system predicted the malignancy and metastasis status of solid PNs based on CT images, and then we compared the malignancy prediction results among four different levels of clinicians. Experiments confirmed that human-computer collaboration can further enhance diagnostic accuracy. We made a held-out testing set of 134 cases, with 689 cases in total. Our convolutional neural network model reached an area under the ROC (AUC) of 80.37% for malignancy prediction and an AUC of 86.44% for metastasis prediction. In observer studies involving four clinicians, the proposed deep learning method outperformed a junior respiratory clinician and a 5-year respiratory clinician by considerable margins; it was on par with a senior respiratory clinician and was only slightly inferior to a senior radiologist. Our human-computer collaboration experiment showed that by simply adding binary human diagnosis into model prediction probabilities, model AUC scores improved to 81.80-88.70% when combined with three out of four clinicians. In summary, the deep learning method can accurately diagnose the malignancy of solid PNs, improve its performance when collaborating with human experts, predict local or distant metastasis in patients with T1-stage lung cancer, and facilitate the application of precision medicine.

Risk of adenocarcinoma in patients with a suspicious ground-glass opacity: a retrospective review

BACKGROUND

Both primary lung adenocarcinoma and benign processes can have a ground-glass opacity (GGO) appearance on imaging. This study evaluated the incidence of and risk factors for malignancy in a diverse cohort of patients who underwent resection of a GGO suspicious for lung cancer.

METHODS

All patients who underwent resection of a pulmonary nodule with a GGO component and suspected to be primary lung cancer at a single institution from 2001-2017 were retrospectively reviewed. Risk factors for malignancy were evaluated using multivariable logistic regression analysis that included nodule size, age, sex, and race as potential predictors.

RESULTS

The incidence of pulmonary adenocarcinoma in the 243 patients who met inclusion criteria was 86% (n=208). The most common pathologic findings in 35 patients with a benign pathology was granulomatous inflammation (n=14, 40%). Risk factors for adenocarcinoma in multivariable logistic regression were age [odds ratio (OR) 1.06, P=0.003], GGO size (OR 2.76, P<0.001), female sex (OR 4.47, P=0.002), and Asian race (OR 8.35, P=0.002). In this cohort, adenocarcinoma was found in 100% (44/44) of Asian females, 86% (25/29) of Asian males, 84% (98/117) of non-Asian females, and 77% (41/53) of non-Asian males.

CONCLUSIONS

The likelihood of adenocarcinoma in lung nodules with a ground-glass component is influenced by sex and race. Asian females with a GGO have a much higher likelihood of having adenocarcinoma than men and non-Asians. This data can be used when deciding whether to pursue nodule resection or surveillance in a patient with a GGO.

Distinct Prognostic Factors of Ground Glass Opacity and Pure-Solid Lesion in Pathological Stage I Invasive Lung Adenocarcinoma

BACKGROUND

Ground glass opacity (GGO) is associated with favorable survival in lung cancer. However, the relevant evidence of the difference in prognostic factors between GGO and pure-solid nodules for pathological stage I invasive adenocarcinoma (IAC) is limited. We aimed to identify the impact of GGO on survival and find prognostic factor for part-GGO and pure-solid patients.

METHODS

Between December 2007 and August 2018, patients with pathological stage I IAC were retrospectively reviewed and categorized into the pure-GGO, part-GGO, and pure-solid groups. Survival curves were analyzed by the Kaplan-Meier method and compared by log-rank tests. Least absolute shrinkage and selection operator and Cox regression models were used to obtained prognostic factors for disease-free survival (DFS) and overall survival (OS).

RESULTS

The number of patients with pure-GGO, part-GGO, and pure-solid was 134, 540, and 396, respectively. Part-GGO patients with consolidation-tumor-ratio (CTR) > 0.75 had similar outcome to those with pure-solid nodules. In part-GGO patients, CTR was negatively associated with OS (P = 0.007) and solid tumor size (STS) was negatively associated with DFS (P < 0.001). Visceral pleural invasion (VPI) was negatively associated with OS (P = 0.040) and DFS (P = 0.002). Sublobectomy was negatively associated with OS (P = 0.008) and DFS (P = 0.005), while extended N1 stations examination was associated with improved DFS (P = 0.005) in pure-solid patients.

CONCLUSIONS

Though GGO component is a positively prognostic factors of patients with pathological stage I IAC, a small proportion of GGO components is not associated with favorable survival. VPI, STS and CTR are the significant predictors for part-GGO patients. Sublobectomy, especially wedge resection should be used cautiously in pure-solid patients.

Prognostic Impact of Very Small Ground-Glass Opacity Component in Stage IA Solid Predominant Non-small Cell Lung Cancer

We evaluated the prognostic role of the presence of a very small ground glass opacity (GGO) component in stage IA solid-predominant non-small cell lung cancer (NSCLC). We evaluated surgically resected 1471 patients diagnosed with stage IA solid-predominant NSCLC. They were classified into 3 groups; that is, GGO group (0.5 Collapse

Key Words

• Clinical stage IA
• Ground-glass opacity
• Lung cancer
• Prognosis

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MESH Headings

• Humans
• Carcinoma, Non-Small-Cell Lung/mortality
• Carcinoma, Non-Small-Cell Lung/diagnostic imaging
• Carcinoma, Non-Small-Cell Lung/surgery
• Carcinoma, Non-Small-Cell Lung/pathology
• Lung Neoplasms/mortality
• Lung Neoplasms/pathology
• Lung Neoplasms/diagnostic imaging
• Lung Neoplasms/surgery
• Male
• Female
• Neoplasm Staging
• Middle Aged
• Aged
• Pneumonectomy/mortality
• Time Factors
• Risk Factors
• Retrospective Studies
• Predictive Value of Tests
• Risk Assessment
• Tomography, X-Ray Computed
• Adult
• Treatment Outcome
• Aged, 80 and over

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Affiliation(s)

Aritoshi Hattori Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan.
Takeshi Matsunaga Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan
Mariko Fukui Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan
Kazuhiro Suzuki Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan
Kazuya Takamochi Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan
Kenji Suzuki Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan

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Oncologic outcomes of segmentectomy for stage IA radiological solid-predominant lung cancer >2 cm in maximum tumour size

OBJECTIVES

We aimed to compare the outcomes of segmentectomy with those of lobectomy in clinical-stage IA radiological solid-predominant non-small-cell lung cancer (NSCLC) >2 cm in maximum tumour size.

METHODS

A retrospective review was performed for radiological solid-predominant NSCLC >2-3 cm in maximum tumour size with a ground-glass opacity component on thin-section computed tomography. Multivariable or propensity score-matched analyses were performed to control for confounders for survival. Overall survival (OS) was analysed using a Kaplan-Meier estimation.

RESULTS

Of the 215 eligible cases, segmentectomy and lobectomy were performed in 46 and 169 patients. Multivariable analysis revealed that standardized uptake value (hazard ratio: 1.148, 95% confidence interval: 1.032-1.276, P = 0.011) was an independently significant prognosticators of OS, while the operative mode was not associated (hazard ratio: 0.635, 95% confidence interval: 0.132-3.049, P = 0.570). The 5 y-OS was excellent and did not differ significantly between segmentectomy and lobectomy (95.5% vs 90.2%; P = 0.697), which was also shown in the propensity score analysis (96.8% vs 94.0%; P = 0.406), with a median follow-up time of 5.2 years. Locoregional recurrence was found in 2 (4.3%) segmentectomy and 13 (7.7%) lobectomy (P = 0.443). In the subgroup analysis stratified by solid component size, the 5 y-OS was similar between segmentectomy and lobectomy in the c-T1b and c-T1c groups, respectively [c-T1b (n = 163): 94.1% vs 91.8%; P = 0.887 and c-T1c (n = 52): 100% vs 84.9%; P = 0.197].

CONCLUSIONS

Segmentectomy showed similar oncological results compared to lobectomy in solid-predominant NSCLC with a ground-glass opacity component >2-3 cm in maximum tumour size. More prospective randomized trials are needed to adequately expand the indication of anatomic segmentectomy for early-stage NSCLC.

Radiological classification, gene-mutation status, and surgical prognosis of synchronous multiple primary lung cancer

OBJECTIVE

To investigate the radiological classification, gene-mutation status, and surgical prognosis of synchronous multiple primary lung cancer (sMPLC).

METHODS

From January 2013 to October 2019, 192 consecutive patients with sMPLC were investigated. The clinical, CT, molecular, and pathological features of all patients were analyzed. Furthermore, the prognosis of 89 patients who only underwent surgical resection was evaluated.

RESULTS

Among 192 patients, all lesions pathologically confirmed or highly suspected as tumors based on radiological findings were retrospectively analyzed, and the CT findings of sMPLC were classified into three types: (I) all lesions manifested as solid nodules/masses (14.06%, 27/192), (II) all lesions manifested as subsolid nodules/masses (43.23%, 83/192), and (III) tumor lesions manifested as a combination of ≥ 2 of the following patterns: solid nodules/masses, subsolid nodules/masses, cystic airspace, and focal consolidation (42.71%, 82/192). For 252 tumors undergoing epidermal growth factor receptor (EGFR)-mutation testing, the EGFR-mutation rate was higher in subsolid tumors than that in solid tumors (p < 0.05). Among 19 patients with all tumors undergoing surgery and driver-gene testing, genetic heterogeneity was prevalent among the multiple tumors (63.16%,12/19). The highest clinical stage of non-I, ipsilateral distribution of tumors, and CT classification of I indicated a poor prognosis for patients with sMPLC (all p < 0.05).

CONCLUSION

Subsolid lesions are the most common presentation of sMPLC. Genetic heterogeneity in driver mutations among sMPLC may be present. Prognosis in patients with sMPLC is determined by the highest clinical TNM stage, distribution, and radiological classification among the multiple tumors.

KEY POINTS

• Synchronous multiple primary lung cancer (sMPLC) has three types of CT findings. • Genetic heterogeneity may be prevalent among the multiple tumors. • Prognosis in patients with sMPLC is associated with the highest clinical TNM stage, distribution, and radiological classification among the multiple tumors.

Latest Clinical Evidence and Operative Strategy for Small-Sized Lung Cancers

Many thoracic surgeons revealed that consolidation tumor ratio or solid component size on thin-section computed tomography has been considered more prognostic than maximum tumor size in non-small cell lung cancer (NCSLC). According to the results, the 8th TNM classification drastically changed the staging system, i.e., clinical T category was determined based on the invasive or solid component size excluding a ground-glass opacity (GGO). However, several debates are arising over the application of radiological solid size for the clinical T staging. Meanwhile, recent several institutional reports have noticed a significantly simple fact that the presence of a GGO denotes an influence on the favorable prognosis of NSCLC. More important, radiologic pure-solid lung cancers without a GGO exhibit more malignant behaviors with regard to both the clinical and pathological aspects, and show several histologic types that have a poorer prognosis than radiologic part-solid lung cancer. In contrast, favorable prognostic impact of the presence of a GGO component was demonstrated, which was irrespective of the solid component size in cases in which the tumor showed a GGO component. Recently, this concept has been gradually noticed on a nationwide level. Obvious distinctions regarding the several baseline characteristics between the tumor with/without GGO component is a fundamental biological feature of early-stage lung cancer, which would result in a big difference in prognosis, modes of recurrence, overall behavior, and appropriate operative strategies. As a future perspective, the presence or absence of a GGO should be considered as an important parameter in the next clinical T classification.

Prognostic stratification according to size and dominance of radiologic solid component in clinical stage IA lung adenocarcinoma

Introduction

Although several studies have investigated the prognostic significance of the radiographic appearance of stage IA lung adenocarcinoma, the prognostic impact of solid component size or consolidation-to-tumor ratio (CTR) of part-solid nodules (PSNs) still remains controversial. This study aimed to clarify the combined prognostic impact of the mentioned radiographic features of PSNs and compare it with that of pure solid nodules in the current TNM classification.

Methods

We retrospectively investigated 1014 patients with clinical stage IA (TNM eighth edition) adenocarcinoma who underwent curative resection. Overall survival (OS) and pathologic characteristics of pure solid nodules, solid-dominant PSNs (CTR > 0.5), and ground-glass opacity (GGO)-dominant PSNs (CTR ≤ 0.5) were compared according to T category.

Results

Patients with pure solid nodules (297 cases) had significantly shorter OS compared with those with PSNs (717 cases) (p < 0.001) but a marginal difference compared with those with solid-dominant PSNs (286 cases) (p = 0.051). No significant difference in OS was found according to T category in those with GGO-dominant PSNs (431 cases). Patients with cT1b and T1c solid-dominant PSNs had significantly worse prognosis compared with those with other PSNs and had comparable prognosis with those with cT1b pure solid nodules (p = 0.892). Higher frequency of nodal and lymphovascular involvement and pathologic upstaging was observed with T category progression in solid-dominant PSNs.

Conclusions

An hierarchy of prognosis and pathologic malignant characteristics was observed according to T category in patients with solid-dominant PSNs but not in those with GGO-dominant PSNs, suggesting the importance of classifying PSNs on the basis of solid component size and CTR for accurate prognostic comparison with pure solid nodules.

Prognostic Nomograms Based on Ground Glass Opacity and Subtype of Lung Adenocarcinoma for Patients with Pathological Stage IA Lung Adenocarcinoma

The value of lung adenocarcinoma (LUAD) subtypes and ground glass opacity (GGO) in pathological stage IA invasive adenocarcinoma (IAC) has been poorly understood, and reports of their association with each other have been limited. In the current study, we retrospectively reviewed 484 patients with pathological stage IA invasive adenocarcinoma (IAC) at Sun Yat-sen University Cancer Center from March 2011 to August 2018. Patients with at least 5% solid or micropapillary presence were categorized as high-risk subtypes. Independent indicators for disease-free survival (DFS) and overall survival (OS) were identified by multivariate Cox regression analysis. Based on these indicators, we developed prognostic nomograms of OS and DFS. The predictive performance of the two nomograms were assessed by calibration plots. A total of 412 patients were recognized as having the low-risk subtype, and 359 patients had a GGO. Patients with the low-risk subtype had a high rate of GGO nodules (p < 0.001). Multivariate Cox regression analysis showed that the high-risk subtype and GGO components were independent prognostic factors for OS (LUAD subtype: p = 0.002; HR 3.624; 95% CI 1.263–10.397; GGO component: p = 0.001; HR 3.186; 95% CI 1.155–8.792) and DFS (LUAD subtype: p = 0.001; HR 2.284; 95% CI 1.448–5.509; GGO component: p = 0.003; HR 1.877; 95% CI 1.013–3.476). The C-indices of the nomogram based on the LUAD subtype and GGO components to predict OS and DFS were 0.866 (95% CI 0.841–0.891) and 0.667 (95% CI 0.586–0.748), respectively. Therefore, the high-risk subtype and GGO components were potential prognostic biomarkers for patients with stage IA IAC, and prognostic models based on these indicators showed good predictive performance and satisfactory agreement between observational and predicted survival.

Prognosis of epidermal growth factor receptor-mutated stage I lung adenocarcinoma with radiologically solid features

OBJECTIVES

The prognostic role of the epidermal growth factor receptor (EGFR) mutation remains controversial, especially in early-stage lung adenocarcinoma with a solid appearance. We evaluated the oncological outcomes of clinical stage I (c-stage I) radiologically invasive lung adenocarcinoma by EGFR mutation status.

METHODS

Between 2008 and 2013, the data from 463 surgically resected c-stage I radiologically invasive, i.e. solid-dominant lung adenocarcinomas subjected to EGFR mutant analysis, were evaluated. Oncological outcomes were assessed using multivariable Cox regression analysis. Recurrence-free survival (RFS) was estimated using Kaplan-Meier analysis and the log-rank test.

RESULTS

A total of 229 (49%) samples harboured the EGFR-mutant adenocarcinoma. Overall, the 5-year RFS did not differ significantly between the EGFR-mutant and EGFR wild-type groups (67.3% vs 64.9%; P = 0.639). However, among the clinical T1c/T2a tumour subset (n = 177), a multivariable Cox hazard model revealed that radiologically pure-solid tumour (P = 0.024), EGFR-mutant (P = 0.027) and pathological stage II/III (P < 0.001) were significant predictors of a poor RFS. Furthermore, in the c-T1c/T2a radiologically pure-solid lung adenocarcinoma subset, the EGFR-mutant group showed marginally lower 5-year RFS compared to that with the EGFR wild-type group (n = 134; 34.9% vs 53.0%; P = 0.062). Among them, multivariable Cox regression analysis revealed that EGFR mutant (P = 0.037) and pathological stage II/III (P = 0.011) were independently and significantly prognostic for worse RFS.

CONCLUSIONS

Among the c-stage I radiologically invasive lung adenocarcinomas, the EGFR mutation-positive type was correlated with an increased risk of recurrence in the c-T1c/T2a radiologically pure-solid tumour subset. When considering the prognostic value of EGFR mutations in early-stage lung adenocarcinoma, it is necessary to stratify them based on the presence of a ground-glass opacity component.

Prognostic influence of a ground-glass opacity component in hypermetabolic lung adenocarcinoma

OBJECTIVES

We evaluated the oncological role of a ground-glass opacity (GGO) component in hypermetabolic lung adenocarcinoma with a high maximum standardized uptake value.

METHODS

Between 2008 and 2017, we retrospectively reviewed the data of surgically resected clinically node-negative lung adenocarcinomas with a hypermetabolic activity. Furthermore, they were classified based on the presence of GGO. The prognostic significance of a GGO in hypermetabolic tumours was evaluated using the Cox proportional-hazards model. The overall survival (OS) was estimated by the Kaplan-Meier method using a log-rank test.

RESULTS

Of the 1134 surgically resected clinically node-negative lung adenocarcinoma, 603 cases with hypermetabolic activity (maximum standardized uptake value ≥3.0 mg/dl) were evaluated. Among them, there were 120 (20%) cases in the With GGO group and 483 (80%) in the Solid group. The 5-year OS of patients with hypermetabolic lung adenocarcinoma was significantly different between the With GGO and Solid groups (83.1% vs 59.4%, P < 0.001). After stratifying by the presence of GGO, maximum standardized uptake value and maximum tumour size were independently significant prognosticators in the Solid group by multivariable analysis; however, no clinical factors were associated with survival among the With GGO group. The 5-year OS was favourable despite the solid component size among the With GGO group (T1a + T1b: 85.5%, T1c: 80.0%, T2a or more: 84.2%, P = 0.904). For the Solid group, survival diminished drastically with increasing tumour size (T1a + T1b: 68.7%, T1c: 62.8%, T2a or more: 48.0%, P < 0.001).

CONCLUSIONS

The prognosis of lung adenocarcinoma with GGO was favourable even in hypermetabolic tumours. Accordingly, the presence of GGO should be considered as an important parameter in the next clinical T classification.

Clinical significance of part-solid lung cancer in the eighth edition TNM staging system

 

OBJECTIVES

The ground-glass component of part-solid tumour (PST) was eliminated as a clinical T (cT) descriptor in the eighth edition of the tumour, node and metastasis (TNM) staging system. We aimed to validate the new cT descriptor and investigate the prognostic impact of PST in the new staging system.

METHODS

Non-small-cell lung cancer (NSCLC) patients (n = 1061) who underwent lung resection and were available for the assessment of thin-section computed tomography images were retrospectively reviewed. Tumours with a solid component (SC) size-to-whole tumour size (STR) ratio of 0, those with 0 < STR < 1 and those with an STR of 1 were defined as pure ground-glass tumours, PSTs and solid tumours (STs), respectively.

RESULTS

Tumours with an SC diameter of >30 mm were less frequently observed among PSTs than among STs (4.83% vs 32.6%, P < 0.001). The postoperative 5-year survival of NSCLC patients with ground-glass tumour, PST and ST was 97.6%, 89.0% and 76.3%, respectively. In the survival analysis of patients with an SC diameter ≤30 mm, significant differences were observed among PST and ST (5-year survival, 90.7% vs 74.6%, P < 0.001). The multivariable analysis showed that age <70 years old, female sex, procedures with a lobectomy or more, SC size, pN0 disease and PST were independent predictors of a better survival among all PST and ST patients.

CONCLUSIONS

Among patients with cT1 tumours, those with PST showed a significantly better survival than did those with ST. Small-sized PST tumours may not be suitable for the new cT descriptor.

Lymph node metastasis and predictive factors in clinical stage IA squamous cell carcinoma of the lung based on radiological findings

OBJECTIVES

We aimed to clarify the incidence of lymph node (LN) metastasis and its predictive factors in clinical stage IA squamous cell carcinoma (SqCC) based on radiological classification to provide surgical indications for segmentectomy.

METHODS

We retrospectively reviewed 192 patients with clinical stage IA SqCC who underwent complete resection with lobectomy and LN dissection at our institution between 2003 and 2019. To evaluate the incidence of LN metastasis from the perspective of indications for segmentectomy, we classified them into outer and inner groups based on the location of the tumor in the radiological findings.

RESULTS

Regarding tumor location, 123 patients had tumors in the outer location and 69 patients had tumors in the inner location. The incidence of LN metastasis was 6% in clinical stage IA SqCC, which included 6% in the outer location and 7% in the inner location (p = 0.669). In the outer location, all LN metastases were in N1 (6%); whereas in the inner location, the incidence of N1 and N2 metastasis were 6% and 1%, respectively. Only tumors sized > 2.0 cm were found to be significantly associated with LN metastasis in clinical stage IA SqCC.

CONCLUSIONS

We demonstrated that the incidence of LN metastasis in clinical stage IA SqCC was comparable to that of the previously reported clinical stage IA NSCLC. The incidence of LN metastasis in the outer location was similar to that in the inner location. Tumor size was only a significant factor affecting LN metastasis in clinical stage IA SqCC.

Do ground-glass opacity-dominant features have prognostic significance in node-negative adenocarcinomas with invasive components of similar sizes?

OBJECTIVES

The purpose of this study was to analyse the prognostic significance of the dominant features of ground-glass opacities (GGOs) in part-solid node-negative adenocarcinomas with invasive components of similar sizes.

METHODS

From 2004 to 2017, a total of 544 patients with a diagnosis of part-solid pathological node-negative adenocarcinoma with an invasive component <20 mm in size were selected. The enrolled patients were categorized into 2 groups: a GGO-dominant [50% < GGO (%) < 100%, n = 245] group (group 1) and a solid-dominant [0% < GGO (%) ≤ 50%, n = 299] group (group 2). To analyse the prognostic significance of GGO-dominant features, propensity score matching incorporating variables such as age, sex, preoperative pulmonary function, operation methods and size of the solid component was performed.

RESULTS

Propensity score matching produced 92 patients in each group for the prognostic analysis. The mean size of the solid part was 8.8 mm in the GGO-dominant group and 9.0 mm in the solid-dominant group (P = 0.34); the mean size of the total lesion was 22.2 mm in the GGO-dominant group and 14.9 mm in the solid-dominant group (P < 0.001). The 5-year overall survival rates were 96.7% in group 1 and 96.2% in group 2 (P = 0.52), and the 5-year disease-free survival rates were 96.7% in group 1 and 94.3% in group 2 (P = 0.48).

CONCLUSIONS

Although the total sizes of the GGO-dominant lesions were larger than those of the solid-dominant lesions, the prognosis of patients with GGO-dominant lesions was not significantly different from that of patients with solid-dominant lesions in node-negative adenocarcinomas with a similar invasive component size <20 mm.

Management of pulmonary ground-glass opacities: a position paper from a panel of experts of the Italian Society of Thoracic Surgery (SICT)

OBJECTIVES

A significant gap in our knowledge of how to manage pulmonary ground-glass opacities (GGOs) still exists. Accordingly, there is a lack of consensus among clinicians on this topic. The Italian Society of Thoracic Surgery (Società Italiana di Chirurgia Toracica, SICT) promoted a national expert meeting to provide insightful guidance for clinical practice. Our goal was to publish herein the final consensus document from this conference.

METHODS

The working panel of the PNR group (Pulmonary Nodules Recommendation Group, a branch of the SICT) together with 5 scientific supervisors (nominated by the SICT) identified a jury of expert thoracic surgeons who organized a multidisciplinary meeting to propose specific statements (n = 29); 73 participants discussed and voted on statements using a modified Delphi process (repeated iterations of anonymous voting over 2 rounds with electronic support) requiring 70% agreement to reach consensus on a statement.

RESULTS

Consensus was reached on several critical points in GGO management, in particular on the definition of GGO, radiological and radiometabolic evaluation, indications for a non-surgical biopsy, GGO management based on radiological characteristics, surgical strategies (extension of pulmonary resection and lymphadenectomy) and radiological surveillance. A list of 29 statements was finally approved.

CONCLUSIONS

The participants at this national expert meeting analysed this challenging topic and provided a list of suggestions for health institutions and physicians with practical indications for GGO management.

Subsolid lesions exceeding 3 centimeters: the ground-glass opacity component still matters

BACKGROUND

Recent studies on the favorable prognosis of ground-glass opacities (GGO) featured lung adenocarcinoma compared with solid nodules were limited to small tumors measuring ≤3.0 cm. This study aimed to investigate whether GGO component could predict better prognosis in patients with large subsolid lesions exceeding 3cm compared with small solid nodules within the same clinical T category.

METHODS

From 2010 to 2015, a total of 1010 patients with completely resected clinical N0 lung adenocarcinoma were enrolled, including 860 solid lesions and 150 subsolid lesions exceeding 3cm. To analyze the prognostic significance of GGO component, propensity score matching adjusting solid component size was performed.

RESULTS

After propensity score matching, 144 pairs of patients were finally analyzed. The mean size of the solid component was 23.7mm in the GGO group and 24.4mm in the solid group(p=0.450). The GGO group had significantly better overall survival and recurrence-free survival (p=0.011 and p=0.003, respectively), which were also validated in patients with solid-predominant lesions. Subgroup analysis showed the GGO group was associated with better prognosis in each clinical T category.

CONCLUSIONS

The prognosis of patients with GGO lesions exceeding 3cm was better than that of patients with small solid lesions even within the same clinical T category. Clinical T classification incorporating GGO component may provide better prognostic prediction for patients with lung cancer exceeding 3cm.

Extent of mediastinal nodal dissection in stage I non-small cell lung cancer with a radiological pure-solid appearance

BACKGROUND

Radiological pure-solid lung cancer denotes a high invasive nature compared to one that is part-solid. Mediastinal lymph nodal dissection (mLND) is a standard surgical procedure for nodal management in lung cancer surgery, however, the prognostic impact of the extent of mLND in pure-solid lung cancer is still unknown.

METHODS

We reviewed 459 patients with c-stage I radiological pure-solid lung cancer that underwent pulmonary lobectomy with mLND. Pure-solid was defined as a tumor showing only a consolidation without any ground glass opacity. The extent of mLND was classified into lobe-specific (L-mLND) and systematic (S-mLND). Prognostic significance of mLND was assessed by a multivariable analysis using propensity-score matching. Survivals were calculated by Kaplan-Meier methods using log-rank test.

RESULTS

Pathological nodal metastasis was found in 127 (27.6%) patients (hilar: 52 (11.3%), mediastinal: 75 (16.3%)). L-mLND was performed in 278 (61%) patients. A multivariable analysis did not show the survival difference for the extent of mLND (p = 0.266). The 5-year overall survival (OS) was not significantly different between S-mLND and L-mLND (74.3% vs. 72.7%, p = 0.712), which was similar even in 114 propensity-score matched pairs (78.8% vs. 79.9%, p = 0.665). While S-mLND showed a trend for survival benefit compared to L-mLND provided that the tumor showed higher standardized uptake value (SUVmax) (5y-OS: 70.0% vs. 59.2%, p = 0.093).

CONCLUSIONS

Prognostic impact of L-mLND was similar to S-mLND in c-stage I radiological pure-solid lung cancers in the propensity-score matched comparison. Among them, higher SUVmax value might be a promising indicator to decide the extent of mediastinal lymphadenectomy.

Clinical impact of a small component of ground-glass opacity in solid-dominant clinical stage IA non-small cell lung cancer

OBJECTIVE

Non-small cell lung cancers with a ground-glass opacity component have better prognosis than those with solid nodules of equivalent consolidation size. However, the impact of small ground-glass opacity components on prognosis is unknown. Therefore, we aimed to evaluate the significance of a small ground-glass opacity component in solid-dominant clinical stage IA non-small cell lung cancers.

METHODS

We reviewed the cases of 543 surgically resected solid-dominant c-stage IA non-small cell lung cancers, which was defined as a tumor with consolidation tumor ratio of 0.75 or more on computed tomography. The patients were classified into 2 groups: 0.75 or less consolidation tumor ratio less than 1 (n = 126) and consolidation tumor ratio of 1 (n = 417). The prognoses were compared between the 2 groups.

RESULTS

Among the 543 cases, multivariable analyses revealed that pure-solid appearance was a predictor of worse overall survival (hazard ratio, 2.051; 95% confidence interval, 1.044-4.028). Compared with the part-solid group, the pure-solid group was associated with poor survival in c-stages IA2 (5-year overall survival: 91.5% vs 76.8%, hazard ratio, 2.942; 95% confidence interval, 1.402-6.173; recurrence-free survival: 89.0% vs 68.8%, hazard ratio, 3.439; 95% confidence interval, 1.776-6.669) and IA3 (5-year overall survival: 93.5% vs 63.0%, hazard ratio, 5.110; 95% confidence interval, 1.607-16.241; recurrence-free survival: 80.5% vs 54.1%, hazard ratio, 2.789; 95% confidence interval, 1.290-6.027). The T categories significantly affected 5-year overall survival only in the pure-solid group (cT1a, 89.3%; cT1b, 76.8%; cT1c, 63.0%).

CONCLUSIONS

A small ground-glass opacity component has an impact on the prognosis of patients with solid-dominant c-stage IA non-small cell lung cancer. Therefore, c-stage IA non-small cell lung cancers should be evaluated separately for tumors with ground-glass opacity and pure-solid tumors.

Solid component ratio influences prognosis of GGO-featured IA stage invasive lung adenocarcinoma

Background

The computed tomography (CT) characteristic of ground glass opacity (GGO) were shown to be associated with clinical significance in lung adenocarcinoma. We evaluated the prognostic value of the solid component ratio of GGO IA invasive lung adenocarcinoma.

Methods

We retrospectively analyzed the records of GGO IA patients who received surgical resection from April 2012 to December 2015. The solid component ratio was calculated based on thin-slice CT scans. Baseline features were compared stratified by the ratio. Cox proportional hazard models and survival analyses were adopted to explore potential prognostic value regarding overall survival (OS) and disease-free survival (DFS).

Results

Four hundred fifteen patients were included. The higher ratio was significantly associated with larger tumor diameter, pathological subtypes and choice of surgical type. There was a significantly worse DFS with a > 50% ratio. The subgroups of 0% and ≤ 50% ratio showed close survival curves of DFS. Similar trends were observed in OS. Multivariate analyses revealed that the ratio was a significant predictor for DFS, but not for OS. No significant prognostic difference was observed between lobectomy and limited resections.

Conclusion

A higher solid component ratio may help to predict a significantly worse prognosis of GGO IA lung adenocarcinoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40644-020-00363-6.

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.

Genetic Features of Lung Adenocarcinoma with Ground- Glass Opacity: What Causes the Invasiveness of Lung Adenocarcinoma?

Background

Lung adenocarcinoma (LUAD) with ground-glass opacity (GGO) can become aggravated, but the reasons for this aggravation are not fully understood. The goal of this study was to analyze the genetic features and causes of progression of GGO LUAD.

Methods

LUAD tumor samples and normal tissues were analyzed using an Illumina HiSeq 4000 system. After the tumor mutational burden (TMB) was calculated, the identified mutations were classified as those found only in GGO LUAD, those present only in non- GGO LUAD, and those common to both tissue types. Ten high-frequency genes were selected from each domain, after which protein interaction network analysis was conducted.

Results

Overall, 227 mutations in GGO LUAD, 212 in non-GGO LUAD, and 48 that were common to both tumor types were found. The TMB was 8.8 in GGO and 7.8 in non-GGO samples. In GGO LUAD, mutations of FCGBP and SFTPA1 were identified. FOXQ1, IRF5, and MAGEC1 mutations were common to both types, and CDC27 and NOTCH4 mutations were identified in the non-GGO LUAD. Protein interaction network analysis indicated that IRF5 (common to both tissue types) and CDC27 (found in the non-GGO LUAD) had significant biological functions related to the cell cycle and proliferation.

Conclusion

In conclusion, GGO LUAD exhibited a higher TMB than non-GGO LUAD. No clinically meaningful mutations were found to be specific to GGO LUAD, but mutations involved in the epithelial-mesenchymal transition or cell cycle were found in both tumor types and in non-GGO tissue alone. These findings could explain the non-invasiveness of GGO-type LUAD.

The Epidemiology of Ground Glass Opacity Lung Adenocarcinoma: A Network-Based Cumulative Meta-Analysis

Introduction: Due to the introduction of low-dose computed tomography (CT) and screening procedures, the proportion of early-stage lung cancer with ground glass opacity (GGO) manifestation is increasing in clinical practice. However, its epidemiological characteristics is still not fully investigated.

Methods: We retrieved all solitary GGO adenocarcinoma lung cancer (ADLC) on the PubMed, Cochrane Library, and Embase databases until January 1, 2019 and extracted the general information to perform the meta-analysis, mainly focusing on age, gender, and smoking status.

Results: A total of 8,793 solitary GGO ADLC patients from 53 studies were included in this analysis. The final pooled analysis showed that the female proportion, average diagnosis age, and non-smoking proportion of solitary GGO ADLC was 0.62 (95% CI, 0.60–0.64), 56.97 (95% CI, 54.56–59.37), and 0.72 (95% CI, 0.66–0.77), respectively. The cumulative meta-analysis and meta-trend analysis confirmed that the average age at diagnosis has been decreasing while the non-smoking proportion significantly increased in the past two decades.

Conclusions: From our epidemiological analysis, it demonstrates that the clinical characteristics of GGO lung cancer patients may be out of the high-risk factors. Therefore, we propose to reconsider the risk assessment and current lung cancer screening criteria.

Sub-solid lung adenocarcinoma in Asian versus Caucasian patients: different biology but similar outcomes

Background

Asian and Caucasian patients with lung cancer have been compared in several database studies, with conflicting findings regarding survival. However, these studies did not include proportion of ground-glass opacity or mutational status in their analyses. Asian patients commonly develop sub-solid lung adenocarcinomas that harbor EGFR mutations, which have a better prognosis. We hypothesized that among patients undergoing surgery for sub-solid lung adenocarcinomas, Asian patients have better survival compared to Caucasian patients.

Methods

We identified Asian and Caucasian patients who underwent surgical resection for a sub-solid lung adenocarcinoma from 2002 to 2015 at our institution. Sub-solid was defined as ≥10% ground-glass opacity on preoperative CT scan or ≥10% lepidic component on surgical pathology. Time-to-event multivariable analysis was performed to determine which characteristics were associated with recurrence and survival.

Results

Two hundred twenty-four patients were included with median follow up 48 months. Asian patients were more likely to be never smokers (76.3% vs. 29.0%, P<0.01) and have an EGFR mutation (69.4% vs. 25.6% of those tested, P<0.01), while Caucasian patients were more likely to have a KRAS mutation (23.5% vs. 4.9% of those tested, P<0.01). There was a trend towards Asian patients having a higher proportion of ground-glass opacity (38.8% vs. 30.5%, P=0.11). Time-to-event multivariable analysis showed that higher proportion of ground-glass opacity was significantly associated with better recurrence-free survival (HR 0.76 per 20% increase, P=0.02). However, mutational status and race did not have a significant impact on recurrence-free or overall survival.

Conclusions

Asian and Caucasian patients with sub-solid lung adenocarcinoma have different tumor biology, but recurrence-free and overall survival after surgical resection is similar.

Prognostic impact of a ground-glass opacity component in clinical stage IA non-small cell lung cancer

OBJECTIVE

We performed a validation study to confirm the prognostic importance of the presence of a ground-glass opacity component based on data of the Japan Clinical Oncology Group study, JCOG0201, which was a prospective observational study to predict the pathological noninvasiveness of clinical stage IA lung cancer in Japan.

METHODS

Among the 811 patients registered in JCOG0201, 671 were confirmed eligible by study monitoring and a central review of computed tomography. Registered c-stage IA lung cancer was less than 30 mm in maximum tumor size, which was classified into a with ground-glass opacity group (pure ground-glass opacity and part-solid tumor) or solid group based on the status of a ground-glass opacity component. T staging was reassigned in accordance with the 8th edition of the TNM staging system. To validate the prognostic impact, overall survival was estimated.

RESULTS

Of the cases, 432 (64%) were in the with ground-glass opacity group and 239 (36%) were in the solid group with a median follow-up time of 10.1 years. The 5-year overall survival was significantly different between the with ground-glass opacity group and solid group (95.1% vs 81.1%). The 5-year overall survival was excellent regardless of the solid component size in the with ground-glass opacity group (c-T1a or less: 97.2%, c-T1b: 93.4%, c-T1c: 91.7%). In contrast, prognostic impact of the tumor size was definitive in the solid group (c-T1a: 87.5%, c-T1b: 85.9%, c-T1c: 73.7%).

CONCLUSIONS

Favorable prognostic impact of the presence of a ground-glass opacity component was demonstrated in JCOG0201. The presence or absence of a ground-glass opacity should be considered as an important parameter in the next clinical T classification.

Radiomics Signature Predicts the Recurrence-Free Survival in Stage I Non-Small Cell Lung Cancer

BACKGROUND

We aimed to explore the predictive value of radiomics signature for the recurrence-free survival (RFS) in patients with resected stage I non-small cell lung cancer.

METHODS

From January 2009 to December 2011, patients with resected stage I non-small cell lung cancer were divided into sub-solid and pure-solid groups according to presence of ground glass opacity in computed tomography. A total of 107 extracted radiomics features were reduced to 8 features by using LASSO Cox analysis to develop a radiomics signature for RFS prediction. Univariate and multivariate survival analyses were applied to identify independent prognostic variables, the Harrell concordance index (C-index) was measured to assess their prediction performance.

RESULTS

Our study included 378 patients with a median follow-up time of 63.2 months. The radiomics signature could stratify all patients into high-risk (180 of 378) and low-risk group (198 of 378) with different RFS (P < .001). In the sub-solid group (n = 115), 3 patients who occurred relapse were categorized into the high-risk group by the radiomics signature. In the pure-solid group, patients with low risk (141 of 263) had a better outcome than those with high risk (122 of 263) (P < .001). Multivariate analyses revealed that the histology (P < .001) and the developed radiomics signature (P < .001) remained independent prognostic factors for RFS.

CONCLUSIONS

Radiomics signature may be an independent imaging biomarker for predicting the survival, which may guide for personalizing treatment option in patients with stage I non-small cell lung cancer.

The efficiency of 18F-FDG PET-CT for predicting the major pathologic response to the neoadjuvant PD-1 blockade in resectable non-small cell lung cancer

PURPOSE

Investigate whether ¹⁸F-FDG PET-CT has the potential to predict the major pathologic response (MPR) to neoadjuvant sintilimab in resectable NSCLC patients, and the potential of sifting patients who probably benefit from immunotherapy.

METHODS

Treatment-naive patients with resectable NSCLC (stage IA-IIIB) received two cycles of sintilimab (200 mg, intravenously, day 1 and 22). Surgery was performed between day 29 and 43. PET-CT was obtained at baseline and prior to surgery. The following lean body mass-corrected metabolic parameters were calculated by PET VCAR: SUL_max, SUL_peak, MTV, TLG, ΔSUL_max%, ΔSUL_peak%, ΔMTV%, ΔTLG%. PET responses were classified using PERCIST. The above metabolic information on FDG-PET was correlated with the surgical pathology. (Registration Number: ChiCTR-OIC-17013726).

RESULTS

Thirty-six patients received 2 doses of sintilimab, all of whom underwent PET-CT twice and had radical resection (35) or biopsy (1). MPR occurred in 13 of 36 resected tumors (36.1%, 13/36). The degree of pathological regression was positively correlated with SUL_max (p = 0.036) of scan-1, and was negatively correlated with all metabolic parameters of scan-2, and the percentage changes of the metabolic parameters after neoadjuvant therapy (p < 0.05). According to PERCIST, 13 patients (36.1%, 13/36) showed partial metabolic response (PMR), 21 (58.3%, 21/36) had stable metabolic disease, and 2 (5.6%, 2/36) had progressive metabolic disease (PMD). There was a significant correlation between the pathological response and the PET responses which were classified using PERCIST. All (100.0%) the PMR (ΔSUL_peak% < - 30.0%) tumors showed MPR.

CONCLUSIONS

¹⁸F-FDG PET-CT can predict MPR to neoadjuvant sintilimab in resectable non-small cell lung cancer.

Neoadjuvant PD-1 inhibitor (Sintilimab) in NSCLC

INTRODUCTION

Programmed death receptor-1 (PD-1) inhibitors have shown efficacy in first-line treatment of NSCLC; however, evidence of PD-1 inhibitor as neoadjuvant treatment is limited. This is a phase 1b study to evaluate the safety and outcome of PD-1 inhibitor in neoadjuvant setting.

METHODS

Treatment-naive patients with resectable NSCLC (stage IA-IIIB) received two cycles of sintilimab (200 mg, intravenously, day 1 out of 22). Operation was performed between day 29 and 43. Positron emission tomography-computed tomography scans were obtained at baseline and before the operation. The primary end point was safety. Efficacy end points included rate of major pathologic response (MPR) and objective response rate. Expression of programmed cell death ligand 1 was also evaluated (registration number: ChiCTR-OIC-17013726).

RESULTS

A total of 40 patients enrolled, all of whom received two doses of sintilimab and 37 underwent radical resection. A total of 21 patients (52.5%) experienced neoadjuvant treatment-related adverse events (TRAEs). Four patients (10.0%) experienced grade 3 or higher neoadjuvant TRAEs, and one patient had grade 5 TRAE. Eight patients achieved radiological partial response, resulting in an objective response rate of 20.0%. Among 37 patients, 15 (40.5%) achieved MPR, including six (16.2%) with a pathologic complete response in primary tumor and three (8.1%) in lymph nodes as well. Squamous cell NSCLC exhibited superior response compared with adenocarcinoma (MPR: 48.4% versus 0%). Decrease of maximum standardized uptake values after sintilimab treatment correlated with pathologic remission (p < 0.00001). Baseline programmed cell death ligand 1 expression of stromal cells instead of tumor cells was correlated with pathologic regression (p = 0.0471).

CONCLUSIONS

Neoadjuvant sintilimab was tolerable for patients with NSCLC, and 40.5% MPR rate is encouraging. The decrease of maximum standardized uptake values after sintilimab might predict pathologic response.

Prognostic Classification of Multiple Primary Lung Cancers Based on a Ground-Glass Opacity Component

BACKGROUND

We evaluated the prognostic impact of the presence of a ground-glass opacity (GGO) component on thin-section computed tomography for the refined clinical T classification of multiple primary lung cancers.

METHODS

We reviewed 272 surgically resected, clinically node-negative multiple lung cancers. Dominant tumors were classified into 2 groups based on the presence of a GGO component; that is, a GGO tumor (consolidation tumor ratio, 0 to <1.0) or pure-solid (PS) tumor (consolidation tumor ratio, 1.0). Furthermore, multifocal GGOs (MFGGOs) were defined as lesions showing a GGO component for all tumors. Their prognoses were evaluated using Cox proportional hazard model.

RESULTS

There were 153 MFGGOs (56%) with a significantly better 5-year overall survival than non-MFGGOs (97.2% vs 68.5%, P < .001). A multivariable analysis revealed that MFGGO and absence of nodal involvement were independently significant prognosticators of better survival (P = .007 and P = .012, respectively). Furthermore, among the patients of non-MFGGO groups, multivariate analysis showed that a PS + PS pattern and presence of nodal involvement were independently significant prognosticators of poorer survival (P = .008 and P = .001, respectively). We divided the tumors into 3 groups based on the results and focusing on the presence of a GGO; that is, MFGGO (n = 153), PS + additional GGO (n = 81), and PS + PS (n = 38). The 5-year overall survival was clearly split among them: MFGGO, 97.2%; PS + additional GGO, 82.1%; and PS + PS, 41.3% (P < .001).

CONCLUSIONS

Our results suggest that presence of a GGO component has the ability to distinguish the survival even for multiple lung cancers. Further investigations including multicenter trials are certainly warranted to address the revision of T variable of multiple lung cancers considering a presence of GGO component.

Comparison of PD-L1 Expression Status between Pure-Solid Versus Part-Solid Lung Adenocarcinomas

Although lung adenocarcinomas (LADs) with ground-glass opacity (GGO; part-solid tumors) have been shown to differ from those without GGO (pure-solid tumors) in clinicopathological features and prognoses, whether programmed death ligand-1 (PD-L1) protein expression differs between these two tumor types is unclear. This study included 124 patients with clinical T1a-c LAD who received pulmonary resections during 2007-2009. The E1L3N antibody was used to stain for PD-L1 in primary LAD specimens. The specimens were considered PD-L1⁺ if ≥1% of tumor cells showed membrane staining, and were classified as having a high PD-L1⁺ tumor proportion score (TPS) if ≥50% of the tumor cells did so. Among the 124 patients, 45 had part-solid tumors and 79 had pure-solid tumors. These two groups did not significantly differ in terms of clinical factors. However, the rates for PD-L1 positivity (4% vs. 25%, p < 0.01) and high PD-L1⁺ TPS (2% vs. 16%, p = 0.02) were significantly higher in the pure-solid tumors. The multivariate analyses (logistic regression model) showed that the odds ratios for PD-L1 positivity and high PD-L1⁺ TPS in pure-solid LADs were 5.9 (95% CI; 1.2-29.7) and 8.0 (95% CI; 1.0-63.8), respectively. In conclusion, LADs with GGO were correlated with a lower incidence of PD-L1 expression than pure-solid tumors.

Distinct Prognostic Factors in Patients with Stage I Non-Small Cell Lung Cancer with Radiologic Part-Solid or Solid Lesions

INTRODUCTION

Recent studies have indicated that the presence of ground-glass opacity (GGO) components is associated with favorable survival. The purpose of this study was to reveal the prognostic value of GGO components and differences in prognostic factors for part-solid and solid lesions in invasive stage I NSCLC.

METHODS

The cases of 2010 patients with completely resected invasive pathological stage I NSCLC were reviewed according to the eighth edition of the TNM classification. Patients were categorized into the pure-GGO, part-solid, and solid groups based on consolidation-to-tumor ratio. Cox multivariate proportional hazard analyses were conducted to identify independent prognostic factors in each group.

RESULTS

Of the 2010 patients, 146 (7.3%) were in the pure-GGO group, 732 (36.4%) were in the part-solid group, and 1132 (56.3%) were in the solid group. Cox multivariate analyses revealed that GGO absence was a strong independent risk factor for worse recurrence-free survival (p < 0.001). For the pure-GGO group, there was no recurrence in spite of the invasive stage. For the part-solid group, visceral pleural invasion could not predict recurrence-free survival in general (p = 0.514) or in each tumor size group (for tumors size ≤1 cm, p = 0.664; for tumors size >1 to 2 cm, p = 0.456; for tumors size >2 to 3 cm, p = 0.900; and for tumors size >3 to 4 cm, p = 0.397). For the solid group, adenocarcinoma subtype was not a prognostic factor for recurrence-free survival in general (p = 0.162) or in each tumor size group (for tumors size ≤ 2 cm, p = 0.092; for tumors size >2 to 3 cm, p = 0.330; and for tumors size >3 to 4 cm, p = 0.885).

CONCLUSIONS

The presence of GGO components was a strong predictor in patients with invasive pathological stage I NSCLC. Risk factors were distinct in the part-solid and solid groups. There was no prognostic value of visceral pleural invasion in the part-solid group. Adenocarcinoma subtype did not have prognostic value in the solid group.

Prognostic factors of lung adenocarcinoma manifesting as ground glass nodules larger than 3 cm

OBJECTIVES

The aim of the study was to investigate prognostic factors of lung adenocarcinomas manifesting as ground glass nodules larger than 3 cm on thin-section computed tomography scans, especially comparing the prognostic role of the whole size and the solid size.

METHODS

We included 195 patients with lung adenocarcinomas manifesting as ground glass nodules larger than 3 cm who underwent surgical resection. We identified clinical factors associated with lymph node metastases by binary logistics regression analysis. Kaplan-Meier analysis was performed to determine the association between the whole size or the solid size and overall survival (OS). Multivariable Cox regression analysis was used to identify prognostic factors of OS.

RESULTS

The median follow-up time was 62 months. The median values of the whole size and the solid size were 3.5 cm and 2.3 cm, respectively. The 3-year and 5-year OS rates were 95.5% and 86.2%, respectively. Patients with lesions <2.3 cm had markedly better OS than those with lesions ≥2.3 cm. No significant differences existed between the survival of patients with lesions <3.5 cm and ≥3.5 cm. Multivariable analysis showed that bigger solid size was significantly associated with the presence of lymph node metastases and inferior OS, whereas larger whole size was not. Adjuvant chemotherapy improved the OS of patients with stage Ib and II-IIIa disease, but not that of patients with stage Ia disease.

CONCLUSIONS

Solid size was a better predictor of lymph node metastases and prognosis than whole size in ground glass nodules larger than 3 cm. Clinical T staging should be based on the solid size rather than on the whole size of these lesions.

Meta-analysis of comparing part-solid and pure-solid tumors in patients with clinical stage IA non-small-cell lung cancer in the eighth edition TNM classification

Objective: The aim of the study was to compare the prognoses between part-solid and pure-solid tumors for clinical stage IA non-small-cell lung cancer (NSCLC) patients in the eighth edition TNM classification.

Methods: We searched the literature in PubMed and Web of Science for all eligible articles published before November 31, 2018. The pooled data included overall survival (OS), disease-free survival (DFS) and recurrence-free survival (RFS). The hazard ratio (HR) of OS (pure-solid/part-solid) was used as the measure of differential effects. Pure-solid or part-solid tumors in all studies included were matched according to the solid component size or according to the eighth edition TNM classification.

Results: Seven studies including 2,037 patients with c-stage IA NSCLC were pooled in the meta-analysis. Patients with pure-solid tumors had significantly poorer OS (HR 1.69, 95% CI 1.21‒2.35, P=0.002), DFS (HR 1.27, 95% CI 1.07‒1.51, P=0.006) and RFS (HR 1.74, 95% CI 1.08‒2.80, P=0.020). In subgroup analyses, when the meta-analysis was limited to T1a-1b (≤2 cm) lung cancer, the prognosis for pure-solid tumors was inferior to that for part-solid tumors regarding both OS and RFS. In adenocarcinoma subgroup, there was no difference between the two groups in terms of OS and RFS, but we detected a meaningful difference in DFS.

Conclusion: Part-solid tumors may have a better prognosis than pure-solid tumors in clinical stage IA patients according to the eighth edition TNM classification, and similar results were found for the T1a-1b (≤2 cm) subgroup. There were no substantial differences in OS and RFS between two groups in lung adenocarcinoma. However, we detected a meaningful difference in DFS, which might also suggest a superior prognosis for part-solid tumors. We propose that the part-solid and pure-solid tumors in the same T component category be considered separately.

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.

Correlation between image characteristics and pathologic findings in non small cell lung cancer patients after anatomic resection

Introduction

Tumor characteristics in computed tomography (CT) are correlated to pathologic presentation and survival. However, most studies have been based on thin slice thickness CT while lymph node metastatic pattern has remained unclear. The aim of this study was to analyze the correlation between image characteristics under 5 mm slice thickness and pathology findings in non small lung cancer patients who have received curative resection.

Materials and methods

From January 2010 to May 2014, 440 patients who underwent curative resection were included and medical records were reviewed retrospectively. The tumor size and consolidation tumor ratio were simultaneously evaluated and measured by a physician, a thoracic surgeon, and a radiologist. The correlation between image and pathology characteristics and its survival impact was analyzed.

Results

Tumor sizes, as measured by CT and by pathologic measurement were highly coincident. (p < 0.001) GGO predominant lesions were correlated to well-differentiated adenocarcinoma, (p< 0.001), and less tumor necrosis (p<0.0001), lymphocyte infiltration (p = 0.0042) and tumor purity (p <0.0001). In addition, less risk of visceral pleura (p < 0.0001) and angiolymphatic invasion, and fewer metastases to N1 lymph node (p = 0.004) involvement were identified. No lymph node metastasis (0/12) was identified in sub-centimeter pure GGO lesion. The consolidation tumor ratio could be used to differentiate patients’ survival and excellent 5-year overall survival was identified in pure GGO lesion cases.

Conclusion

No lymph node metastasis was identified in sub-centimeter pure GGO lesion. The consolidation tumor ratio could be used to differentiate patients’ disease status and overall survival, while excellent 5-year overall survival was identified in cases with pure GGO lesion.

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.