Oncological outcome of segmentectomy for early-stage non-small-cell lung cancer with invasive characteristics: a multicentre study

Impact of Margin Distance on Locoregional Recurrence and Survival After Thoracoscopic Segmentectomy

BACKGROUND

This study aimed to identify the impact of margin distance on locoregional recurrence (LRR) and survival outcomes after thoracoscopic segmentectomy for non-small cell lung cancer.

METHODS

We retrospectively analyzed data from prospectively collected consecutive thoracoscopic segmentectomies in a single center from January 2008 to February 2023. The restricted cubic spline of the adjusted Cox regression model for LRR displayed the breakpoint of margin distance. The Kaplan-Meier estimator with log-rank test evaluated the overall survival between the 2 groups stratified by the breakpoint, and the Aalen-Johansen estimator with the Gray test assessed the LRR-free survival and lung cancer-specific survival in the competing model.

RESULTS

The study included 155 patients. LRR was observed in 22 patients (14.2%), with a median time to LRR of 17.1 months (interquartile range, 6.3-26.3 months). Margin distance was found to be a predictor for LRR (hazard ratio, 0.92; P = .033). The identified breakpoint for margin distance in this cohort was 19.8 mm. Compared with this cutoff, a margin distance of 15 mm increased the risk of LRR by 65%, whereas 25 mm decreased the risk to LRR with 31%. A segmentectomy with a margin distance ≥20 mm resulted in significant improvements in overall survival (P = .020), lung cancer-specific survival (P = .010), and LRR-free survival (P < .001) compared with cases with a margin distance of <20 mm.

CONCLUSIONS

Margin distance ≥20 mm decreased LRR and improved survival outcomes for thoracoscopic segmentectomy in this study.

Segmentectomy for patients with early-stage pure-solid non-small cell lung cancer

For decades, lobectomy has been the recommended surgical procedure for non-small cell lung cancer (NSCLC), including for small-sized lesions. However, two recent pivotal clinical trials conducted by the Japanese Clinical Oncology Group/West Japan Oncology Group (JCOG0802/WJOG4607L) and the Cancer and Leukemia Group B (CALGB140503), which compared the survival outcomes between lobectomy and sublobar resection (the JCOG0802/WJOG4607L included only segmentectomy, not wedge resection), demonstrated the efficacy of sublobar resection in patients with early-stage peripheral lung cancer measuring ≤ 2 cm. The JCOG0802/WJOG4607L demonstrated the superiority of segmentectomy over lobectomy with respect to overall survival, implying the survival benefit conferred by preservation of the lung parenchyma. Subsequently, the JCOG1211 also demonstrated the efficacy of segmentectomy, even for NSCLC, measuring up to 3 cm with the predominant ground-glass opacity phenotype. Segmentectomy has become the standard of care for early-stage NSCLC and its indications are expected to be further expanded to include solid lung cancers > 2 cm. However, local control is still a major concern for segmentectomy for higher-grade malignant tumors. Thus, the indications of segmentectomy, especially for patients with radiologically pure-solid NSCLC, remain controversial due to the aggressive nature of the malignancy. In this study, we reviewed previous studies and discussed the efficacy of segmentectomy for patients with such tumors.

Upstaged from cT1a-c to pT2a lung cancer, related to visceral pleural invasion patients, after segmentectomy: is it an indication to complete resection to lobectomy?

OBJECTIVES

Segmentectomy may be indicated for T1a-cN0 non-small-cell lung cancer. However, several patients are upstaged pT2a at final pathological examination due to visceral pleural invasion (VPI). As resection is usually not completed to lobectomy, this may raise issue of potential worse prognosis. The aim of this study is to compare prognosis of VPI upstaged cT1N0 patients operated on by segmentectomy or lobectomy.

METHODS

Data of patients from 3 centres were analysed. This was a retrospective study, of patients operated on from April 2007 to December 2019. Survival and recurrence were assessed by Kaplan-Meier method and cox regression analysis.

RESULTS

Lobectomy and segmentectomy were performed in 191 (75.4%) and in 62 (24.5%) patients, respectively. No difference in 5-year disease-free survival rate between lobectomy (70%) and segmentectomy (64.7%) was observed. There was no difference in loco-regional recurrence, nor in ipsilateral pleural recurrence. The distant recurrence rate was higher (P = 0.027) in the segmentectomy group. Five-year overall survival rate was similar for both lobectomy (73%) and segmentectomy (75.8%) groups. After propensity score matching, there was no difference in 5-year disease-free survival rate (P = 0.27) between lobectomy (85%) and segmentectomy (66.9%), and in 5-year overall survival rate (P = 0.42) between the 2 groups (lobectomy 76.3% vs segmentectomy 80.1%). Segmentectomy was not impacting neither recurrence, nor survival.

CONCLUSIONS

Detection of VPI (pT2a upstage) in patients who underwent segmentectomy for cT1a-c non-small-cell lung cancer does not seem to be an indication to extend resection to lobectomy.

Segmentectomy for cancer control in radiologically pure-solid clinical stage IA3 lung cancer

OBJECTIVES

This study aimed to compare cancer control after segmentectomy and lobectomy in patients with radiologically pure-solid clinical stage IA3 non-small-cell lung cancer (NSCLC).

METHODS

Patients with radiologically pure-solid clinical stage IA3 NSCLC who underwent lobectomy or segmentectomy at 3 institutions between 2010 and 2019 were identified. We estimated propensity scores to adjust for confounding variables regarding tumour malignancy, including age, sex, smoking history, tumour size, maximum standardized uptake value on 18F-fluorodeoxyglucose positron emission tomography, lymph node dissection, histological type and lymphatic, vascular and pleural invasion. Cumulative incidence of recurrence (CIR) was evaluated as a primary end point.

RESULTS

Among 412 patients, postoperative recurrence occurred in 7 of 44 patients (15.9%) undergoing segmentectomy, and 71 of 368 patients (19.3%) undergoing lobectomy. CIR was comparable between patients undergoing segmentectomy (5-year rate, 21.9%) and those undergoing lobectomy (5-year rate, 20.8%; P = 0.88). Locoregional recurrence did not differ between patients undergoing segmentectomy (6.8%) and those undergoing lobectomy (9.0%). In multivariable analysis, segmentectomy (versus lobectomy) was not identified as an independent prognostic factor for CIR (hazard ratio, 1.045; 95% confidence interval, 0.475-2.298; P = 0.91). In propensity score matching of 40 pairs, CIR was not significantly different between patients undergoing segmentectomy (5-year rate, 20.7%) and those undergoing lobectomy (5-year rate, 18.4%; P = 0.81).

CONCLUSIONS

Cancer control may be comparable between segmentectomy and lobectomy in patients with radiologically pure-solid clinical stage IA3 NSCLC. Further studies are warranted to clarify the survival benefits of segmentectomy in these patients.

Segmentectomy versus lobectomy for small-sized pure solid non-small cell lung cancer

BACKGROUND

Segmentectomy has been recommended for ground glass opacity (GGO)-dominant small-sized non-small cell lung cancer (NSCLC) or those with GGO component. Pure solid NSCLC is a special sub-type and has an inferior prognosis. Whether segmentectomy could achieve comparable long-term outcomes with lobectomy for pure solid small-sized NSCLC remained controversial. This study aimed to compare the prognosis of segmentectomy and lobectomy for pure solid NSCLC.

METHODS

NSCLC patients with a pure solid nodule (≤2 cm) who received segmentectomy or lobectomy between January 2010 and June 2019 were retrospectively screened. Log-rank test, univariable, and multivariable Cox regression analyses were used for prognostic comparison. Further, the propensity score matching analysis was adopted to yield a matched cohort.

RESULTS

After screening, 344 pure solid NSCLC patients with a median follow-up time of 56 months were reserved. Among them, 98 patients underwent segmentectomy and the other 246 subjects received lobectomy. The lobectomy group had a larger tumor size, a higher rate of lymph node metastasis than the segmentectomy arm. Generally, patients with segmentectomy had a better disease-free survival (DFS) (p = 0.011) and overall survival (OS) (p = 0.028) than those with lobectomy. However, the multivariable Cox regression analysis indicated that no significant survival difference existed between segmentectomy and lobectomy after adjusting the potential confounding factors (DFS: hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.30-1.77, p = 0.476; OS: HR, 0.36; 95% CI, 0.08-1.59, p = 0.178). Consistently, in the propensity score matched cohort, segmentectomy (n = 74) yielded similar DFS (p = 0.960) and OS (p = 0.320) with lobectomy (n = 74).

CONCLUSIONS

Segmentectomy could achieve comparable oncological outcomes with lobectomy for pure solid small-sized NSCLC.

Segmentectomy for clinically early-stage primary squamous cell carcinoma of the lung

BACKGROUND

Squamous cell carcinoma of the lung-the second most common subtype of lung cancer-has a poorer prognosis than lung adenocarcinoma. However, in contrast to lobectomy, the oncological outcomes after segmentectomy for primary squamous cell carcinomas remain unknown; hence, this study investigated these outcomes.

METHODS

Patients who underwent lobectomy or segmentectomy for clinically node-negative primary lung squamous cell carcinoma with a whole tumor size of ≤ 30 mm on preoperative computed tomography scan during April 2010 to December 2020 were included in this study. The cumulative incidence of recurrence (CIR) among all included patients and propensity score-matched patients were compared using the Gray method. Multivariate analysis using propensity scores and surgical procedures was performed using the Fine and Gray method.

RESULTS

Overall, 230 patients were included in this study; of these, 172 (74.8%) underwent lobectomy and 58 (25.2%) underwent segmentectomy. No significant differences were observed in the CIR between patients who underwent lobectomy and those who underwent segmentectomy (5-year rate 18.1% vs. 14.2%; p  =  0.787). Moreover, no significant differences in CIR were observed between the propensity score-matched patients who underwent lobectomy (n = 43) and those who underwent segmentectomy (n   =  43) (8.6% vs. 8.0%; p = 0.571). Multivariable analysis was performed for CIR using the propensity score; it revealed that segmentectomy was not a significant predictor of worse CIR (hazard ratio, 0.987; p =   0.980).

CONCLUSIONS

Segmentectomy may be feasible for treating clinically early-stage lung squamous cell carcinoma; its oncological outcomes are similar to those of lobectomy.