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

Comparison of segmentectomy and wedge resection for cT1cN0M0 non-small cell lung cancer

OBJECTIVE

Sublobar resection is considered a standard surgical procedure for early non-small cell lung cancer, although the survival of patients undergoing sublobar resection for clinical T1cN0M0 non-small cell lung cancer remains unclear. This study aimed to compare survival between segmentectomy and wedge resection for clinical T1cN0M0 non-small cell lung cancer.

METHODS

This retrospective study included patients who had undergone curative surgery for cT1cN0M0 stage IA3 non-small cell lung cancer. The overall and recurrence-free survival rates of 91 patients who underwent segmentectomy or wedge resection were compared.

RESULTS

Thirty-nine (42.9%) and 52 patients (57.1%) were included in the segmentectomy and wedge resection groups, respectively. The median length of follow-up was 6.0 years (95% confidence interval 4.2 - - years) (Kaplan-Meier estimate). The 5 year overall survival rates were not significantly different between the segmentectomy and wedge resection groups (67.7% vs 52.0%, P = 0.132). The 5 year recurrence-free survival rate was worse in the wedge resection group than in the segmentectomy group (66.6% vs 46.9%, P = 0.047). In univariable analysis, spread through air spaces (hazard ratio, 5.889; 95% confidence interval, 2.357-14.715; P < 0.001) was an important prognostic factor for recurrence-free survival in the wedge resection group.

CONCLUSIONS

The overall survival of patients who underwent segmentectomy for clinical T1cN0M0 non-small cell lung cancer was not significantly different from that of patients who underwent wedge resection. However, patients with cT1cN0M0 non-small cell lung cancer who underwent wedge resection tended to have a worse recurrence-free survival prognosis than those who underwent segmentectomy.

A Multi-Institutional, Randomized, Phase III Trial Comparing Anatomical Segmentectomy and Lobectomy for Clinical Stage IA3 Pure-Solid Non-Small-Cell Lung Cancer: West Japan Oncology Group Study WJOG16923L (STEP UP Trial)

INTRODUCTION

Although the standard treatment for patients with resectable early-stage non-small-cell lung cancer (NSCLC) is pulmonary lobectomy, recent clinical trials have demonstrated the efficacy of anatomical segmentectomy for small-sized early-stage NSCLC measuring ≤2 cm. Segmentectomy is gaining attention as an alternative procedure to lobectomy for early-stage NSCLC.

PATIENTS AND METHODS

In January 2024, we have initiated a randomized phase III trial in Japan to confirm the noninferiority of anatomical segmentectomy to lobectomy in patients with peripheral clinical stage IA3 pure-solid NSCLC (tumor measuring >2 cm and ≤3 cm; consolidation-to-tumor ratio = 1.0). We plan to enroll 520 patients from 61 institutions over a period of 5 years. The primary endpoint is overall survival, and the secondary endpoints include relapse-free survival, postoperative respiratory function, proportion of patients with respiratory failure and cerebrovascular disease, cumulative incidence of death from other diseases, cumulative incidence of local recurrence, proportion of patients who undergo segmentectomy, number of resected segments, operative time, blood loss, and adverse events. This trial has been registered in the UMIN Clinical Trials Registry under the code UMIN000052064.

CONCLUSIONS

This trial will help establish a novel treatment strategy for patients with peripheral clinical stage IA3 pure-solid NSCLC.

Distinct impacts of radiological appearance on lymph node metastasis and prognosis based on solid size in clinical T1 non-small cell lung cancer

BACKGROUND

Solid nodules (SN) had more aggressive features and a poorer prognosis than part-solid nodules (PSN). This study aimed to evaluate the specific impacts of nodule radiological appearance (SN vs. PSN) on lymph node metastasis and prognosis based on solid size in cT1 non-small cell lung cancer (NSCLC).

METHODS

Patients with cT1 NSCLC who underwent anatomical resection between 2010 and 2019 were retrospectively screened. Univariable and multivariable logistic regression analyses were adopted to evaluate the associations between nodule radiological appearance and lymph node metastasis. The log-rank test and Cox regression analyses were applied for prognostic evaluation. The cumulative recurrence risk was evaluated by the competing risk model.

RESULTS

There were 958 and 665 NSCLC patients with PSN and SN. Compared to the PSN group, the SN arm had a higher overall lymph node metastasis rate (21.7% vs. 2.7%, P < 0.001), including nodal metastasis at N1 stations (17.7% vs. 2.1%), N2 stations (14.0% vs. 1.6%), and skip nodal metastasis (3.9% vs. 0.6%). However, for cT1a NSCLC, no significant difference existed between SN and PSN (0 vs. 0.4%, P = 1). In addition, the impacts of nodule radiological appearance on lymph node metastasis varied between nodal stations. Solid NSCLC had an inferior prognosis than part-solid patients (5-year disease-free survival: 79.3% vs. 96.2%, P < 0.001). The survival inferiority only existed for cT1b and cT1c NSCLC, but not for cT1a. Strikingly, even for patients with nodal involvement, SN still had a poorer disease-free survival (P = 0.048) and a higher cumulative incidence of recurrence (P < 0.001) than PSN. Specifically, SN had a higher recurrence risk than PSN at each site. Nevertheless, the distribution of recurrences between SN and PSN was similar, except that N2 lymph node recurrences were more frequent in solid NSCLC (28.21% vs. 7.69%, P = 0.041).

CONCLUSION

SN had higher risks of lymph node metastasis and poorer prognosis than PSN for cT1b and cT1c NSCLC, but not for cT1a. SN exhibited a greater proportion of N2 lymph node recurrence than PSN. SN and PSN needed distinct strategies for nodal evaluation and postoperative follow-up.

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.