Small-sized Non-small Cell Lung Research Articles

Metastatic Patterns of Mediastinal Lymph Nodes in Small-Size Non-small Cell Lung Cancer (T1b).

Background: Lymph node metastasis (LNM) status is critical to the treatment. Fewer studies has focused on LNM in patients with small-size non-small cell lung cancer (NSCLC). This study aims to investigate clinicopathological characteristics associated with skip N2 (SN2) and non-skip N2 (NSN2) metastasis, and their metastatic patterns in NSCLC with tumor size of 1–2 cm.Methods: We reviewed the records of NSCLC patients with tumor size of 1–2 cm who underwent lobectomy with systematic lymph node dissection (LND) between January 2013 and June 2019. Clinical, radiographical, and pathological characteristics were compared among N1, SN2, and NSN2 groups. Metastatic patterns of mediastinal lymph node were analyzed based on final pathology.Results: A total of 63 NSCLC patients with tumor size of 1–2 cm were staged as pN2, including 25 (39.7%) SN2 and 38 (60.3%) NSN2. The incidence rates of SN2 and NSN2 were 2.8% (25/884) and 4.3% (38/884), respectively. For all clinicopathological characteristics, no significant difference was observed among the groups of N1, SN2, and NSN2. For the tumor located in each lobe, specific nodal drainage stations were identified: 2R/4R for right upper lobe; 2R/4R and subcarinal node (#7) for right middle lobe and right lower lobe; 4L and subaortic node (#5) for left upper lobe; #7 for left lower lobe. However, there were still a few patients (10.9%, 5/46) had the involvement of lower zone for tumors of upper lobe and the involvement of upper zone for lower lobe.Conclusions: SN2 occurs frequently in patients with small-size NSCLC. Whether lobe-specific selective LND is suitable for all small-size patients deserves more studies to confirm. Surgeons should be more careful when performing selective LND for tumors located in the lower and upper lobes.

An Externally-Validated Dynamic Nomogram Based on Clinicopathological Characteristics for Evaluating the Risk of Lymph Node Metastasis in Small-Size Non-small Cell Lung Cancer.

Background: Lymph node metastasis (LNM) status is of key importance for the decision-making on treatment and survival prediction. There is no reliable method to precisely evaluate the risk of LNM in NSCLC patients. This study aims to develop and validate a dynamic nomogram to evaluate the risk of LNM in small-size NSCLC.Methods: The NSCLC ≤ 2 cm patients who underwent initial pulmonary surgery were retrospectively reviewed and randomly divided into a training cohort and a validation cohort as a ratio of 7:3. The training cohort was used for the least absolute shrinkage and selection operator (LASSO) regression to select optimal variables. Based on variables selected, the logistic regression models were developed, and were compared by areas under the receiver operating characteristic curve (AUCs) and decision curve analysis (DCA). The optimal model was used to plot a dynamic nomogram for calculating the risk of LNM and was internally and externally well-validated by calibration curves.Results: LNM was observed in 12.0% (83/774) of the training cohort and 10.1% (33/328) of the validation cohort (P = 0.743). The optimal model was used to plot a nomogram with six variables incorporated, including tumor size, carcinoembryonic antigen, imaging density, pathological type (adenocarcinoma or non-adenocarcinoma), lymphovascular invasion, and pleural invasion. The nomogram model showed excellent discrimination (AUC = 0.895 vs. 0.931) and great calibration in both the training and validation cohorts. At the threshold probability of 0–0.8, our nomogram adds more net benefits than the treat-none and treat-all lines in the decision curve.Conclusions: This study firstly developed a cost-efficient dynamic nomogram to precisely and expediently evaluate the risk of LNM in small-size NSCLC and would be helpful for clinicians in decision-making.

Characteristics and risk factors of recurrence in clinical stage I non-small cell lung cancer patients undergoing anatomic segmentectomy.

Although lobectomy is the standard surgical procedure for small-sized non-small cell lung cancer (NSCLC), segmentectomy has been performed for various reasons. The aim of this study was to investigate the characteristics of and risk factors for recurrence in early-stage NSCLC patients undergoing segmentectomy. We retrospectively reviewed 179 patients with clinical stage I NSCLC who underwent segmentectomy. Preoperative factors were analyzed using the log-rank test for univariate analyses. Multivariate analyses were performed using a Cox proportional hazards regression model to identify independent risk factors for recurrence. For the significant factors, optimal cutoff points were determined by receiver operating characteristic (ROC) analysis. During the follow-up period of 51months, 18 patients developed recurrence; 5 had locoregional (including 2 with margin recurrences only), 9 had distant, and 4 had both locoregional and distant recurrence. Multivariate and ROC analysis identified radiologic solid tumor size with a cutoff point of 1.5cm as an independent risk factor for recurrence. Three patients in the solid size < 1.5cm group (n = 119) developed recurrence, 2 of whom had surgical margin recurrence, compared to 15 patients in the solid size ≥ 1.5cm group (n = 60). The indication for segmentectomy should be decided upon with caution, and the segments to be resected should be carefully considered to secure an appropriate surgical margin in this low-risk subgroup of patients because they may have a relatively higher risk of surgical margin recurrence, despite being at decreased risk.

Comparison of outcomes following segmentectomy or lobectomy for patients with clinical N0 invasive lung adenocarcinoma of 2cm or less in diameter.

Previous studies have reported similar survival between segmentectomy and lobectomy for patients with small-sized non-small cell lung cancer. However, part of those patients were with adenocarcinoma in situ or minimally invasive adenocarcinoma, which were considered to have a favorable prognosis. We compared survival outcomes of patients with clinical N0 invasive lung adenocarcinomas of no more than 2cm who underwent segmentectomy or lobectomy. Between June 1, 2008, and May 31, 2018, 1018 patients with clinical N0 invasive lung adenocarcinomas of no more than 2cm in diameter on thin-section chest CT scans were retrospectively included in this study. Of them, 214 underwent segmentectomy and 804 underwent lobectomy. Propensity-score matching of preoperative factors, such as gender, age, smoking status, forced expiratory volume in 1 s predicted%, tumor's CT appearance, tumor size on CT scan and tumor location was used to compare survival outcomes of those patients receiving different surgical treatments. Cox proportional hazard regression model was used to identify independent prognostic factors. This study was approved by the Committee for Ethical Review of Research (Fudan University Shanghai Cancer Center IRB# 090977-1). Informed consent was waived because of the retrospective nature of this study. Average follow-up time was 42.5months. Before matching, the lobectomy group had a shorter recurrence-free survival (P = 0.02), but similar overall survival (P = 0.60). After matching, no significant difference of overall survival or recurrence-free survival was found between the two groups (P = 0.70 and P = 0.40, respectively). Our results suggest that segmentectomy achieved similar recurrence-free and overall survival compared with lobectomy for patients with clinical N0 invasive lung adenocarcinomas of no more than 2cm. Therefore, segmentectomy could be an alternative approach. These results need to be further validated by randomized trials.

MS07.04 Stage I (Resectable) NSCLC: Surgery

MS07.04 Stage I (Resectable) NSCLC: Surgery

P3.16-20 Feasibility of Limited Resection for Peripheral Small-Sized Non-Small Cell Lung Cancer According to FDG Accumulation and Imaging Findings

With the progress of diagnostic imaging modalities, such as CT and FDG-PET, the number of resectable lung cancer, particularly small peripheral lung cancer, is increasing. We focused on the SUVmax of FDG-PET as a prognostic factor for lung cancer and established criteria for limited resection on the basis of CT findings and SUVmax. Since 2007, we continuously monitored the recurrence and prognosis of non-small cell lung cancers (NSCLCs) resected using our criteria. Here, we report the results of this study. Between December 2007 and December 2015, 611 consecutive patients underwent surgery for NSCLC at our institution. Of these, 73patients with cT1aN0M0 who underwent limited resection (partial resection or segmentectomy) were enrolled. The criteria for undergoing limited resection were as follows: ①tumor GGO ratio of ≥0.75and ② tumor SUVmax of ≤1.5. GGO ratio was calculated using the following equation: GGO ratio=[(maximum diameter of the tumor) – (maximum diameter of tumor consolidation)] / (maximum diameter of the tumor). The group that met our criteria and underwent limited resection was designated as intended limited resection group (ILR group), and the group subjected to limited surgery without meeting the criteria treated as control group. The study included 35 men and 38 women with a median age of 65 (range, 36–84) years. In total, 51 patients who met our criteria were included in the ILR group, and 21 patients who did not meet the criteria were included in the control group. The control group was selected for limited resection in terms of complications, pulmonary hypofunction, and heart failure. Regarding surgical approach, in the ILR group, 19 patients underwent partial resection and 32 underwent segmentectomy; in the control group, 13 patients underwent partial resection and 8 underwent segmentectomy. According to our criteria, no relapsed cases were reported in the ILR group. Moreover, the 5-year overall survival rates of the ILR and control groups were 100% and 60.5%, respectively, and the disease-free survival rates were 100% and 56.0%, respectively, indicating a significant difference (P < 0.0001). In the control group, 6 patients showed the recurrence of lung cancer. In this study, we analyzed the feasibility of our criteria for performing limited resection on the basis of CT findings and SUVmax. In the ILR group, no relapsed cases were reported, suggesting that our criteria may be useful in determining patient’s eligibility for undergoing reduction surgery.

Appropriate lymphadenectomy significantly reduced recurrence after segmentectomy for patients with non-small cell lung cancer.

Segmentectomy has been widely used for small-sized non-small cell lung cancer (NSCLC). The objective of this study is to determine the impact of number of harvested lymph nodes (LNs) on survival for patients undergoing segmentectomy. The clinicopathologic data of patients undergoing segmentectomy for NSCLC from July 2011 to December 2014 were retrospectively analyzed. Survival analysis was performed by Kaplan-Meier method and Cox regression analysis. A total of 259 patients with NSCLC were eligible for analysis. Patients with harvested LN ≥6 had higher frequency of nodal metastasis in pathologic examination (9.4% vs. 1.5%, P=0.005). The 3-year recurrence-free survival (RFS) of patients with harvested LN ≥6 (90.2%) was significantly higher than that of patients with harvested LN <6 (73.7%, log-rank P=0.038). Multivariable Cox analysis identified harvested LN ≥6 as an independent predictor for improved RFS [hazard ratio (HR) =0.35; 95% confidence interval (CI): 0.14-0.90; P=0.029]. There was no significant difference in RFS between patients with harvested LN station ≥3 and <3 (log-rank P=0.34). The number of harvest LN ≥6 was independently associated with improved RFS for NSCLC patients undergoing segmentectomy, supporting the National Comprehensive Cancer Network (NCCN) guidelines of appropriate LN sampling.

Lobectomy versus Sublobar Resection in Non-Lepidic Small-Sized Non-Small Cell Lung Cancer.

BackgroundRecently, many surgeons have chosen sublobar resection for the curative treatment of lung tumors with ground-glass opacity, which is a hallmark of lepidic lung cancer. The purpose of this study was to evaluate the oncological results of sublobar resection for non-lepidic lung cancer in comparison with lobectomy.MethodsWe conducted a retrospective chart review of 328 patients with clinical N0 non-small cell lung cancer sized ≤2 cm who underwent curative surgical resection from January 2009 to December 2014. The patients were classified on the basis of their lesions into non-lepidic and lepidic groups. The survival rates following lobectomy and sublobar resection were compared within each of these 2 groups.ResultsThe non-lepidic group contained a total of 191 patients. The 5-year recurrence-free survival rate was not significantly different between patients who received sublobar resection or lobectomy in the non-lepidic group (80.1% vs. 79.2%, p=0.822) or in the lepidic group (100% vs. 97.4%, p=0.283). Multivariate analysis indicated that only lymphatic invasion was a significant risk factor for recurrence in the non-lepidic group. Sublobar resection was not a risk factor for recurrence in the non-lepidic group.ConclusionThe oncological outcomes of sublobar resection and lobectomy in small-sized non-small cell lung cancer did not significantly differ according to histological type.

PC 01.01 SABR as First Line Treatment Option

SBRT for small-sized non-small cell lung cancer: Surgery has historically been the primary treatment option for patients with Stage I non–small-cell lung cancer (NSCLC). Although Stage I NSCLC is technically curable, the presence of significant co morbidity increases the risk of postoperative complications and reduces the potential role of surgery even early stage NSCLC. Because nonsurgical treatment options such as conventional radiotherapy have historically achieved suboptimal outcomes, some have argued that the risks associated with surgery in patients with severe COPD were justified. The reason for poor tumor control with conventional radiation therapy has been shown to be due to insufficient total radiation doses, which is usually 60 Gy or lower. Dose escalation with CRT have shown that a total dose of just above 80 Gy seems to be tolerable while doses exceeding 90 Gy, necessary for optimal tumor control, were associated with high risk of unacceptable lung toxicity. Since the 2000s, stereotactic body radiation therapy has rapidly spread as medical physics improved. Stereotactic body radiation therapy has been revealed to be equivalent to surgery in tumor ablation. With stereotactic body radiotherapy (SBRT) the radiation dose to normal tissue is minimized and the dose per fraction can be increased resulting in biologic doses up to twice as high as in CRT. This has resulted in improvement of local tumor control rates up to 88% to 100%, comparable to the rates after surgery. SBRT is a safe and effective treatment option for these patients, with outcomes that do not appear to be inferior to surgery. SBRT is not associated with the considerable initial risks of operative mortality and prolonged hospitalization. Patients who do undergo surgery may benefit from avoiding open lobectomy, instead using less invasive approaches such as video-assisted thoracoscopic surgery or open segmentectomy. All patients with Stage I NSCLC and severe COPD should be evaluated in a multidisciplinary setting and afforded an informed decision of the risks and benefits of both surgery and SBRT. In role of SBRT can also be extended even in patients with oligometastases and oligo-recurrence, the oligometastases and oligo-recurrence who sometimes cured with only local therapy. Radiotherapy (RT) can cause immunogenic tumor cell death resulting in cross-priming of tumor-specific T-cells, acting as an in situ tumor vaccine; however, SBRT alone has limit in inducing effective anti-tumor immunity resulting in systemic tumor rejection. Immunotherapy can complement SBRT to help overcome tumor-induced immune suppression, as demonstrated in many pre-clinical tumor models. There are many trials underway for combinations of different immunotherapies and SBRT. SBRT, early stage NSCLC, inoperable

P3.04-011 A Prospective Study to Optimize the Extent of Pulmonary Resection According to Decision-Making Algorithm in cStage IA NSCLC

Recent advances in imaging technology and the widespread use of low-dose computed tomography screening have greatly increased the chance of detecting small-sized non-small cell lung cancer (NSCLC) with indolent features (radiologically ground-glass opacity and histopathologically lepidic pattern adenocarcinoma). This change in the disease pattern of NSCLC has led to a resurgence of interest in sublobar resection. The purpose of this study is to determine the outcome of patients with clinical stage IA NSCLC treated by 3 types of surgical resection (wide wedge resection, segmentectomy, or lobectomy) according to the institutional decision-making algorithm.

Invited Commentary

Invited Commentary

Impact of multiple malignancies on surgical outcomes in patients with 1cm or smaller non-small cell lung cancer.

Because most patients with small-sized non-small cell lung cancer (NSCLC) are asymptomatic, their lesions are detected by cancer screenings or routine checkups for other diseases. Incidences of multiple malignancies have been reported to be 27% in patients with stage I-III NSCLC. Some patients have treatment histories for other malignancies, and their small-sized NSCLC was incidentally detected during follow-up. There is no established report regarding the influence of multiple malignancies on small-sized NSCLC prognosis. Therefore, we investigated the correlation between multiple malignancies and surgical outcomes in patients with small-sized NSCLC. In total, 44 patients underwent definitive pulmonary resection for NSCLC of 1cm or smaller between January 2003 and December 2012. Tumor size was measured by macroscopic findings of the resected specimens, and we then retrospectively investigated their clinical courses. One patient had hemoptysis symptoms, whereas 43 patients were asymptomatic; among them, NSCLC was detected by examinations for other diseases in 31 patients and by cancer screening in 12 patients. In total, 20 patients (45%) had multiple malignancies. The median follow-up period was 68months. One patient had a recurrence from current NSCLC. No patients died of current NSCLC. The overall 5-year survival rate was 90% for all patients. Patients with multiple malignancies had significantly poorer prognoses compared with those without multiple malignancies (P=0.016). However, patients with treatment intervals of more than 5years had prognoses equivalent to those of patients without multiple malignancies (P=0.829). Only the presence of multiple malignancies was a significantly poor prognostic factor in univariate and multivariate analyses. NSCLC of 1cm or smaller showed good prognoses. The presence of multiple malignancies was a significantly poor prognostic factor, and short treatment intervals also correlated with poor prognosis.

How to manage tumor located between upper division and lingular segment "S3+S4 segmentectomy and S3b+S4 segmentectomy".

Segmentectomy is one of the treatment of choice for small-sized non-small cell lung cancer (NSCLC). Although simple segmentectomy is feasible even if under thoracoscopy, complicated segmentectomy which contains more than two segmental plane divisions is difficult especially thoracoscopic surgery. We here present the case of totally thoracoscopic segmentectomy between upper division and lingular segment. In the first case, the 64-year-old female patient admitted for further examination and treatment of left lung ground glass nodule. Tumor located between upper division (S3) and lingular (S4) segment was operated by bi-segmentectomy and intraoperative frozen section pathology showed minimally invasive adenocarcinoma. Systematic nodal dissection was followed after retrieval of specimens. A3b A3a+c, and A4 was individually divided and followed by division of B3 and B4. Finally, intersegmental veins V1+2a and V1+2d was identified between segments and V3a+b was divided. In the second case, the 76-year-old female patient with left lung nodule between upper division (S3b) and lingular (S4) segment was operated by bi-segmentectomy. Since sealing test revealed air leakage from resected segmental planes, fibrin glue was applied to stop air leakage and direct suturing by 4-0 prolene between S3a+S3c and S5 was performed. Target lesion between upper division and lingular segments may be resected safely if appropriate demarcation lines are identified regardless of without highly sophisticated imaging systems.

Prognosis After Sublobar Resection of Small-sized Non-small Cell Lung Cancer with Visceral Pleural or Lymphovascular Invasion.

Although standard surgical treatment of stage I non-small cell lung cancer (NSCLC) is lobectomy, sublobar resection may be elected for small-sized (≤2cm) peripheral tumors. Our aim was examine the need for completion lobectomy in the event of confirmed pleural or lymphovascular invasion after sublobar resection of NSCLC. A total of 271 consecutive patients undergoing curative resection of stage I NSCLC ≤2cm were reviewed retrospectively, analyzing clinicopathologic findings and survival times of those with invasion-positive (visceral pleural or lymphovascular invasion) or invasion-negative (neither visceral pleural nor lymphovascular invasion) tumors by surgical approach (sublobar resection vs lobectomy). Aside from age and pulmonary function, clinicopathologic characteristics of the patient subsets did not differ significantly, nor did 5-year recurrence-free survival rates of surgical subsets (sublobar resection vs lobectomy) in respective tumor groups (invasion-positive 78.9 vs 79.8%, p=0.928; invasion-negative 80.2 vs 85.4%, p=0.505). In multivariate analysis, dissected lymph node count was the sole parameter significantly impacting recurrence of stage I invasion-positive NSCLC (hazard ratio=0.914, 95% confidence interval 0.845-0.988; p=0.023). Sublobar resection was not a risk factor for recurrence. Survival rates for patients with small-sized (≤2cm) NSCLC and visceral pleural or lymphovascular invasion did not differ significantly, whether sublobar resection or lobectomy was done. Hence, completion lobectomy is unnecessary in this setting.

P2.02-017 A Clinical Outcome of Resected Small-Sized Non-Small Cell Lung Cancer 1 cm or Less in Diameter with N2 Lymph Node Metastasis

The detection of small-sized (≤ 1cm) non-small cell lung cancer (NSCLC) has increased with the development of high-resolution computed tomography. The reported 5-year survival rate of T1a (≤ 2cm) N0M0 patients is more than 80%, and that of p-T1a (≤ 2cm) N2M0 patients has also steadily improved. Between 1991 and 2011, a total of 917 patients with small-sized (≤ 2cm) NSCLC underwent curative pulmonary resection with systematic lymph node dissection at Tokyo Medical University Hospital and Tokyo Medical University Ibaraki Medical Center. We retrospectively evaluated their postoperative clinical outcomes and survival rates. Survival was analyzed using the Kaplan-Meier method and log-rank test. There were 46 (5.0%) patients with mediastinal lymph node metastasis in pT1a (≤ 2cm). And there were 6 (0.6%) patients with pT1a (≤ 1cm) N2M0. The histological types were 3 cases of adenocarcinoma, 2 case of squamous cell carcinoma, and one large cell carcinoma. The respectively status of lymph node metastasis was single station in 2 cases and multiple station in 4 cases. Skip lymph node metastasis was observed in 2 cases. There were 26 cases (56.5%) that were upstaged from clinical diagnosis in pT1a (≤ 2 cm) N2M0 patients. There was one upstaging case from cT1a (≤ 1 cm) N0M0 to pT1a (≤ 2 cm) N2M0. The median overall survival period and 5-year survival of patients in pT1 (≤ 2 cm) N2M0 was 52.1 months and 45%. And patients with pT1a (≤ 1 cm) N2M0 has 29.8 months and 0% (3 year overall survival rate was 33.3%). The recurrence rate was 71.7% (5/6) and disease free survival was 13.2 months. This study showed that 5.0% of small-sized (≤ 2 cm) NSCLC had N2 disease and 0.6% of T1a (≤ 1 cm) NSCLC has pN2. Moreover, 56.5% of small-sized (≤ 2 cm) NSCLC was upstaged from clinical diagnosis to pathological diagnosis. The patients with pT1a (≤ 1 cm) N2M0 had worse survival data than the patients with pT1a (≤ 2 cm) N2M0. We recommend systematic lymph node dissection for local treatment as well as accurate diagnosis. As multiple mediastinal node metastases showed an unfavorable prognosis, surgery combined with systematic treatment is recommended.

SC08.01 Impact and Management of Co-Morbidities

SC08.01 Impact and Management of Co-Morbidities

The Lung Cancer Surgical Study Group of the Japan Clinical Oncology Group: past activities, current status and future direction.

The Lung Cancer Surgical Study Group of the Japan Clinical Oncology Group was organized in 1986. Initially, 26 collaborative institutions participated. In the early period, the Lung Cancer Surgical Study Group focused on combined modality therapies and conducted nine trials, including JCOG9101: adjuvant chemotherapy for resected small-cell lung cancer, and JCOG9806: induction chemoradiotherapy followed by surgery for superior sulcus tumor, which greatly impacted the treatment strategies for some special kinds of lung cancer. Since the 2000s, the Lung Cancer Surgical Study Group has defined radiologically noninvasive adenocarcinoma: JCOG0201 and investigated adequate modes of surgical resection for small-sized non-small cell lung cancer: JCOG0802, JCOG0804 and JCOG1211. The accrual of these trials is now complete and we are waiting for the maturation of follow-up data. In addition, two adjuvant trials have been conducted: JCOG0707; a Phase III study of adjuvant chemotherapy for resected pathological stage I (T1 > 2 cm) non-small cell lung cancer, and JCOG1205; a Phase III study of adjuvant chemotherapy for completely resected pulmonary high-grade neuroendocrine tumor. The accrual of JCOG0707 is complete and we are waiting for the maturation of follow-up data. At present, 44 institutions are active members of the Lung Cancer Surgical Study Group. In addition to thoracic surgeons, medical oncologists, pathologists and radiotherapists are participating in the Lung Cancer Surgical Study Group. The Lung Cancer Surgical Study Group continues to conduct various clinical trials in an effort to improve survival in patients with lung cancer. In this review, we provide an overview of the past 30 years, as well as the present status and future direction of the Lung Cancer Surgical Study Group.

Evaluation of locoregional invasiveness of small-sized non-small cell lung cancers by enhanced dual-energy computed tomography.

BackgroundTo investigate the correlation between iodine-related attenuation of dual-energy computed tomography (DE-CT) and the histopathological invasiveness of surgically resected primary non-small cell lung cancers (NSCLCs) ≤ 3 cm in diameter.MethodsWe selected 63 consecutive NSCLC lesions from 60 patients (32 males, 28 females; age range, 39–85 years; mean age, 68 years). After injection of iodinated contrast media, arterial phases were scanned using 140-kVp and 80-kVp tube voltages. Three-dimensional iodine-related attenuation (3D-IRA) of primary tumors at the arterial phase was computed using “lung nodule” application software. The corrected 3D-IRA normalized to the patient’s body weight and contrast medium concentration was then calculated. Single-factor analysis of variance (ANOVA) was used for comparison among tumor differentiation grade groups. Univariate and multivariate logistic regression analysis was used for the correlation between locoregional invasive tumor and clinical factors.ResultsResected tumors were histopathologically classified into well-differentiated (G1; n = 24), moderately-differentiated (G2; n = 28), and poorly-differentiated (G3; n = 11) groups by degree of tumor differentiation. The mean ± standard deviation of the 3D-IRA was 56.1 ± 22.6 HU in G1 tumours, 48.5 ± 23.9 HU in G2 tumours, and 28.4 ± 15.8 HU in G3 tumours; significant differences were observed between groups by ANOVA. (p = 0.005). Univariate logistic analysis showed that the 3D-IRA and corrected 3D-IRAs were significantly correlated with locoregional invasive tumors (p = 0.002 and p < 0.001, respectively). Multivariate logistic analysis revealed that only the corrected 3D-IRA was significantly correlated with tumor invasiveness (p = 0.003), while gender, clinical size, and solid/subsolid type were not (p = 0.950, p = 0.057 and p = 0.456, respectively).ConclusionsThe 3D-IRA of small-sized NSCLCs was significantly associated with and invasiveness. Low 3D-IRA tumors tended to have greater invasiveness than high 3D-IRA tumors.

Lobectomy Versus Segmentectomy in Radiologically Pure Solid Small-Sized Non-Small Cell Lung Cancer

The indication for limited resection of radiologically pure solid non-small cell lung cancer (NSCLC) is controversial owing to its invasive pathologic characteristics. This study was performed to compare the outcomes after lobectomy and segmentectomy in these NSCLC patients. We retrospectively reviewed 251 patients with radiologically pure solid cT1a N0 M0 NSCLC who underwent lobectomy or segmentectomy, and the preoperative characteristics of the patients treated with the two operative techniques were matched using propensity score methods. Overall survival (OS) and disease-free survival (DFS) curves were compared using the log rank test, and differences in survival were also evaluated by the McNemar test. The preoperative factors and surgical procedure were analyzed with the multivariate Cox proportional hazards regression model to identify independent predictors of poor OS and DFS. In the propensity score matched lobectomy and segmentectomy groups (87 patients per group), the 5-year and 10-year OS rates were 85% versus 84% and 66% versus 63%, respectively; and the 5-year and 10-year DFS rates were 80% versus 77% and 64% versus 58%, respectively. There were no significant differences between the two groups in OS or DFS by the log rank test, and also no significant differences in 3-year, 5-year, or 7-year OS or DFS by the McNemar test. Although age, smoking status, pulmonary function, and carcinoembryonic antigen were identified as significant predictors of both OS and DFS, the surgical procedure was not identified. Similar oncologic outcomes after lobectomy and segmentectomy were indicated among patients with radiologically pure solid small-sized NSCLC.

Segmentectomy versus Lobectomy for Clinical Stage IA Lung Adenocarcinoma

Objectives: Despite the increasing prevalence of the early discovery of small-sized non-small cell lung cancers (NSCLCs), particularly adenocarcinoma, sublobar resection has not yet gained acceptance for patients who can tolerate lobectomy.