Impact of Tumor Size and Differentiation Grade on Survival After Lobectomy and Segmentectomy for Patients with Early-Stage Lung Adenocarcinoma.

BACKGROUND: The purpose of this study was to investigate the effect of tumor size and differentiation grade on long term survival in patients with early-stage lung adenocarcinoma (LUAD) after lobectomy and segmentectomy. PATIENTS AND METHODS: Patients with stage T1-2N0M0 LUAD who underwent lobectomy and segmentectomy were identified from the Surveillance, Epidemiology, and End Results database. Patients were stratified as grade I (well differentiated), grade II (moderately differentiated), and grade III/IV (poorly differentiated/undifferentiated) carcinomas. The effect of tumor size on overall survival (OS) and lung cancer-specific survival (LCSS) was evaluated using the multivariate Cox regression model, including the interaction between tumor size, type of surgery, and tumor differentiation grade. The inverse probability of treatment weighting method was used to adjust for bias between the groups. RESULTS: A total of 19,857 patients were identified, including 18,759 (94.4%) who underwent lobectomy and 1098 (5.5%) who underwent segmentectomy. A three-way interaction among tumor size, differentiation grade, and type of surgery was observed in the overall cohort. After stratifying by differentiation grade, plots of interaction revealed that lobectomy was associated with improved survival compared with segmentectomy when the tumor size exceeded 23 mm for grade I LUAD and 14 mm for grade II LUAD. No interaction was observed between the studied factors in grade III/IV carcinomas. CONCLUSIONS: This study interpreted the interaction between tumor size and type of surgery on long-term survival in patients with early stage LUAD and established a tumor size threshold beyond which lobectomy provided survival benefits compared with segmentectomy.

Effect of Resected Lung Volume on Pulmonary Function and Residual Lung Volume in Patients Undergoing Segmentectomy: A Retrospective Study.

PURPOSE: We elucidated the effects of planned resection volume on postoperative pulmonary function and changes in residual lung volume during segmentectomy. METHODS: This study included patients who underwent thoracoscopic segmentectomy between January 2017 and December 2022 and met eligibility criteria. Pre- and post-resection spirometry and computed tomography were performed. Three-dimensional reconstructions were performed by using computed tomography images to calculate the volumes of the resected, remaining, and nonoperative side regions. Based on the resected region volume, patients were divided into the higher and lower volume segmentectomy groups. Changes in lung volume and pulmonary function before and after the surgery were comparatively analyzed. RESULTS: The median percentage of resected lung volume was 10.9%, forming the basis for categorizing patients into the two groups. Postoperative forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) ratios to preoperative measurements in both groups did not differ significantly (FEV1, p = 0.254; FVC, p = 0.777). Postoperative FEV1 and FVC ratios to their predicted postoperative values were significantly higher in the higher volume segmentectomy group than in the lower volume segmentectomy group (FEV1, p = 0003; FVC, p < 0.001). The higher volume segmentectomy group showed significantly greater post-to-preoperative lung volume ratio in overall, contralateral, ipsilateral, residual lobe and residual segment than the lower volume segmentectomy group. CONCLUSIONS: Postoperative respiratory function did not differ significantly between the higher- and lower-volume segmentectomy groups, indicating improved respiratory function because of substantial postoperative residual lung expansion. Our findings would aid in determining the extent of resection during segmentectomy.

Uniportal Thoracoscopic Complex Combined Seg-Sub-subsegmentectomy of RS9+10bii: Dual-Display Method and Combined Approaches (Trans-fissure and Trans-ligament).

BACKGROUND: Uniportal thoracoscopic lateral basal segmentectomy is the most technically challenging anatomic segmentectomy,1-3 especially when it involves combined subsegmentectomy or sub-subsegmentectomy. Therefore, there are very few reports detailing its technical aspect. PATIENT AND METHOD: In this multimedia article, we describe a very complex uniportal thoracoscopic combined seg-sub-subsegmentectomy of RS9+10bii through the oblique fissure approach and the inferior pulmonary ligament approach, following a single-direction strategy4,5 to advance the procedure, utilizing the stem-branch method3,6 for segmental/subsegmental/sub-subsegmental structure tracking, and employing dual-display method, which comprises the intravenous ICG injection method and the inflation/deflation method, to identify intersegmental and inter-seg-sub-subsegmental planes. RESULTS: The operation lasted 169 min, with approximately 20 mL of blood loss. The patient experienced an active hemothorax and two spontaneous pneumothoraxes on postoperative days 1, 4, and 19, respectively, all of which resolved promptly after treatment. Histopathological examination of the specimen documented invasive non-mucinous adenocarcinoma with negative surgical margins and lymph nodes. The staging was determined as pT1bN0M0, stage IA2. During the 14-month follow-up period, there were no signs of tumor recurrence or metastasis observed. The FVC, FEV1, and FEV1%pred decreased by 11.9%, 12.5%, and 12.8%, respectively, at postoperative month 6. CONCLUSIONS: Complex basal segmentectomies, which necessitate combined subsegmental or sub-subsegmental resections, such as RS9+10bii, are feasible using the dual-display and combined approaches method. This method simplifies the steps of the very complex combined subsegmentectomy, averting the need for extensive lung resection. In addition, when performing these combined segmentectomies, precise anatomical dissection is crucial to prevent complications such as minor bronchopleural fistulas.

Left Upper Division Segmentectomy Compared with Lobectomy for Lung Expansion and Bronchus Tortuosity.

BACKGROUND: For patients with left upper lobe lesions, the functional benefit of left upper division segmentectomy over left upper lobectomy remains controversial. This study evaluated the clinical and functional outcomes after these two procedures. METHODS: This retrospective study included 135 patients with left upper lobe lesions (left upper lobectomy, 110; left upper division segmentectomy, 25). Propensity score matching was used to compare the two groups. Spirometry and computed tomography volume assessments were performed to evaluate bronchus angle and tortuosity. Short-term clinical respiratory symptoms were assessed via medical record reviews. RESULTS: Patients in both groups had similar preoperative characteristics, apart from tumor size (left upper division segmentectomy, 1.6 ± 0.9 cm; left upper lobectomy, 2.8 ± 1.7 cm; p = 0.002). After propensity score matching, both groups had similar preoperative spirometry and pathological results. The postoperative spirometry results were similar; however, the left upper division segmentectomy group had a significantly smaller decrease in left-side computed tomography lung volume compared with that in the left upper lobectomy group (left upper division segmentectomy, 323.6 ± 521.4 mL; left upper lobectomy, 690.7 ± 332.8 mL; p = 0.004). The left main bronchus-curvature index was higher in the left upper lobectomy group (left upper division segmentectomy, 1.074 ± 0.035; left upper lobectomy, 1.097 ± 0.036; p = 0.013), and more patients had persistent cough in the left upper lobectomy group (p = 0.001). CONCLUSIONS: Left upper division segmentectomy may be a promising option for preventing marked bronchial angulation and decreasing postoperative persistent cough in patients with left upper lobe lung cancer.

MIDOS: a novel stochastic model towards a treatment planning system for microsphere dosimetry in liver tumors.

PURPOSE: Transarterial radioembolization (TARE) procedures treat liver tumors by injecting radioactive microspheres into the hepatic artery. Currently, there is a critical need to optimize TARE towards a personalized dosimetry approach. To this aim, we present a novel microsphere dosimetry (MIDOS) stochastic model to estimate the activity delivered to the tumor(s), normal liver, and lung. METHODS: MIDOS incorporates adult male/female liver computational phantoms with the hepatic arterial, hepatic portal venous, and hepatic venous vascular trees. Tumors can be placed in both models at user discretion. The perfusion of microspheres follows cluster patterns, and a Markov chain approach was applied to microsphere navigation, with the terminal location of microspheres determined to be in either normal hepatic parenchyma, hepatic tumor, or lung. A tumor uptake model was implemented to determine if microspheres get lodged in the tumor, and a probability was included in determining the shunt of microspheres to the lung. A sensitivity analysis of the model parameters was performed, and radiation segmentectomy/lobectomy procedures were simulated over a wide range of activity perfused. Then, the impact of using different microspheres, i.e., SIR-Sphere®, TheraSphere®, and QuiremSphere®, on the tumor-to-normal ratio (TNR), lung shunt fraction (LSF), and mean absorbed dose was analyzed. RESULTS: Highly vascularized tumors translated into increased TNR. Treatment results (TNR and LSF) were significantly more variable for microspheres with high particle load. In our scenarios with 1.5 GBq perfusion, TNR was maximum for TheraSphere® at calibration time in segmentectomy/lobar technique, for SIR-Sphere® at 1-3 days post-calibration, and regarding QuiremSphere® at 3 days post-calibration. CONCLUSION: This novel approach is a decisive step towards developing a personalized dosimetry framework for TARE. MIDOS assists in making clinical decisions in TARE treatment planning by assessing various delivery parameters and simulating different tumor uptakes. MIDOS offers evaluation of treatment outcomes, such as TNR and LSF, and quantitative scenario-specific decisions.

Is Lobectomy Actually Worse Than Segmentectomy for All Stage I Non-Small Cell Lung Cancer?

INTRODUCTION: The recent results of the JCOG 0802 and CALGB 140503 studies suggest that segmentectomy should be considered instead of lobectomy for patients with peripheral <2 cm node-negative non-small cell lung cancer (NSCLC). This study aimed to test this hypothesis in a retrospective analysis of a larger dataset of patients with stage I NSCLC recorded in the Surveillance, Epidemiology, and End Results database. METHODS: Patients with all stage I NSCLC (≤4 cm in size) who underwent either segmentectomy or lobectomy from 2000 to 2017 were analyzed. The primary endpoints were overall survival and lung cancer-specific survival, while the secondary endpoints were the 30-day and 90-day mortality. RESULTS: Overall, 32,673 patients treated by lobectomy and 2166 patients treated by segmentectomy were included in the initial data collection. After 1:1 propensity score matching (PSM), 2016 patients in each group were enrolled in the final analysis with well-balanced baseline characteristics. After PSM, there was no difference between segmentectomy and lobectomy for all stage IA NSCLC (≤3 cm in size) in both overall survival and lung cancer-specific survival (hazard ratio: 0.87 [0.74-1.02], P value: 0.09 and hazard ratio: 0.81 [0.4-1.03], P value: 0.09, respectively). Furthermore, lobectomy had higher 30-day mortality than segmentectomy: 1.1% versus 2.1%, P value: 0.01. However, this difference was not significant for 90-day mortality, even after PSM (3.9% versus 3.0%, P value: 0.17). CONCLUSIONS: We found no evidence to support the use of lobectomy rather than segmentectomy in stage IA NSCLC in terms of either overall or lung cancer-specific long-term survival. The choice of lobectomy may also be detrimental to early postoperative recovery.

Oncological Outcomes of Sub-Lobar Resection Versus Lobectomy for Stage I Non-Small Cell Lung Cancer.

INTRODUCTION: Although lobectomy has been the treatment of choice for early-stage non-small cell lung cancer (NSCLC), sub-lobar resection (i.e., segmentectomy or wedge resection) has emerged as an alternative over time due to its ability to preserve additional lung function. This meta-analysis explores the survival outcomes of sub-lobar resection versus lobectomy in patients with stage I NSCLC (tumor size: ≤2 cm). MATERIAL AND METHODS: We conducted a systematic search of PubMed, EMBASE, and the Cochrane Library from inception up to July 28, 2023. The hazard ratios and odds ratios for overall survival (OS), disease-free survival (DFS), and mortality were calculated using the random effects model. RESULTS: A total of 27 studies, comprising 10,449 patients, were included. Sub-lobar resection demonstrated comparable OS and DFS to that of lobectomy. Similarly, there was no significant risk of mortality associated with any of the groups. However, the subgroup analysis according to patient selection (intentional, compromised, not specified, and both [intentional and compromised]) showed that the patients in the compromised subgroup had a poor DFS with sub-lobar resection as compared to lobectomy (hazard ratio: 1.52, confidence interval: 1.14-2.02, P = 0.004). Additionally, there was no significant difference in OS, DFS, or overall mortality in the results stratified by surgical procedure or patient selection. CONCLUSIONS: The patients with stage I NSCLC who underwent sub-lobar resection showed a significantly worse DFS and OS in the "compromised group." However, there was no overall significant difference in OS, DFS, or mortality in the sub-lobar resection group as compared to lobectomy.

Comparing Robotic, Thoracoscopic, and Open Segmentectomy: A National Cancer Database Analysis.

INTRODUCTION: Minimally invasive approaches to lung resection have become widely acceptable and more recently, segmentectomy has demonstrated equivalent oncologic outcomes when compared to lobectomy for early-stage non-small cell lung cancer (NSCLC). However, studies comparing outcomes following segmentectomy by different surgical approaches are lacking. Our objective was to investigate the outcomes of patients undergoing robotic, video-assisted thoracoscopic surgery (VATS), or open segmentectomy for NSCLC using the National Cancer Database. METHODS: NSCLC patients with clinical stage I who underwent segmentectomy from 2010 to 2016 were identified. After propensity-score matching (1:4:1), multivariate logistic regression analyses were performed to determine predictors of 30-d readmissions, 90-d mortality, and overall survival. RESULTS: 22,792 patients met study inclusion. After matching, approaches included robotic (n = 2493; 17%), VATS (n = 9972; 66%), and open (n = 2493; 17%). An open approach was associated with higher 30-d readmissions (7% open versus 5.5% VATS versus 5.6% robot, P = 0.033) and 90-d mortality (4.4% open versus 2.2% VATS versus 2.5% robot, P < 0.001). A robotic approach was associated with improved 5-y survival (50% open versus 58% VATS versus 63% robot, P < 0.001). CONCLUSIONS: For patients with clinical stage I NSCLC undergoing segmentectomy, compared to the open approach, a VATS approach was associated with lower 30-d readmission and 90-d mortality. A robotic approach was associated with improved 5-y survival compared to open and VATS approaches when matched. Additional studies are necessary to determine if unrecognized covariates contribute to these differences.

Survival and pulmonary function in stage IA non-small cell lung cancer after sublobar resection versus lobectomy: An updated meta-analysis.

Traditionally, lobectomy was standard for stage IA non-small-cell lung cancer (NSCLC). Recent RCTs suggest sublobar resection's comparable outcomes. Our meta-analysis, incorporating 30 studies (including four RCTs), assessed sublobar resection's efficacy. Employing a random-effects model and I2 statistics for heterogeneity, we found sublobar resection reduced DFS (HR 1.31, p < 0.01) and OS (HR 1.27, p < 0.01) overall. However, RCT subgroup analysis showed no significant differences in DFS (p = 0.28) or OS (p = 0.62). Sublobar resection is a viable option for well-selected patients.

Risk of Death From Other Diseases in Lung Cancer Patients After Sublobar Resection Versus Lobectomy.

BACKGROUND AND OBJECTIVES: A recent Japanese phase three clinical trial for lung cancer suggested a possible advantage of segmentectomy over lobectomy in terms of death from other diseases. This study aimed to compare the risk of death from other diseases based on surgical procedures in lung cancer patients without recurrence. METHODS: We retrospectively reviewed 2121 patients without disease recurrence after curative resection for lung cancer at our institution. Patient characteristics and overall survival were compared between sublobar resection and lobectomy. RESULTS: The sublobar group (n = 595) had a significantly higher proportion of women, non-smokers, patients without comorbidities, patients with a history of other cancers, and patients with earlier-staged disease when compared with the lobectomy group (n = 1526). The overall survival was significantly longer in the sublobar group than in the lobectomy group (p = 0.0034). After adjusting for background characteristics in an analysis of 488 patients, the overall survival had a trend to be longer in the sublobar group than in the lobectomy group (p = 0.071). CONCLUSIONS: Our results suggested that the risk of death from other diseases was potentially higher after lobectomy than after sublobar resection. Although several clinical factors could influence the results, these results may support the benefit of sublobar resection, assuming that the curability of both procedures is similar.