Segmentectomy Versus Lobectomy for Deep Solid-Dominant Early-Stage NSCLC (SOLID)

Comparison of Segmentectomy and Lobectomy for Deeply Located, Solid-Dominant Early-Stage Non-Small Cell Lung Cancer (<=2 cm): A Multicenter, Open-Label, Randomized, Controlled, Non-Inferiority Clinical Trial

SOLID is a multicenter, open-label, randomized, controlled, phase III non-inferiority trial comparing anatomic segmentectomy with lobectomy in patients with deeply located, solid-dominant, clinical stage IA non-small cell lung cancer (NSCLC) measuring <=2 cm. Eligible participants will undergo centralized imaging review and will be randomized preoperatively in a 1:1 ratio before induction of anesthesia.

The primary endpoint is 5-year overall survival. The key supportive secondary endpoint is 5-year recurrence-free survival. The study will enroll 1,200 participants and will use intention-to-treat analysis for the primary endpoint. An independent Data and Safety Monitoring Board and an independent Endpoint Adjudication Committee will oversee safety, surgical quality, data quality, and endpoint adjudication.

Study Overview

• Status: Not yet recruiting
• Conditions: Non-Small Cell Lung Cancer; Stage IA Non-Small Cell Lung Cancer
• Intervention / Treatment: Procedure: Anatomic Segmentectomy; Procedure: Anatomic Lobectomy

Detailed Description

Segmentectomy has been established as an accepted treatment option for selected small peripheral NSCLC, but high-level randomized evidence is limited for tumors located in the inner two-thirds of the lung parenchyma. Deep, solid-dominant nodules may have higher oncologic risk, more complex anatomy, and greater difficulty achieving conventional linear surgical margins.

This trial evaluates whether standardized anatomic segmentectomy, including surgical quality control and lymph-node dissection requirements, is non-inferior to lobectomy for overall survival in patients with deeply located, solid-dominant, clinical stage IA NSCLC <=2 cm. The trial incorporates centralized pre-randomization imaging review, mandatory recording of margin and surgical quality metrics, systematic or lobe-specific lymph-node dissection, independent endpoint adjudication, and DSMB safety and quality oversight.

Participants randomized to the segmentectomy arm will undergo anatomic segmentectomy when feasible. Conversion to lobectomy is required for intraoperative frozen-section N1/N2 nodal metastasis and may occur for inadequate margins, anatomic difficulty, or safety concerns. Participants randomized to the lobectomy arm will undergo standard anatomic lobectomy. Intraoperative findings and final pathology do not change the original randomized assignment for the primary intention-to-treat analysis.

• Study Type: Interventional
• Enrollment (Estimated): 1200
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China, 200030
      • Shanghai Chest Hospital
      • Contact: Qing Shanghai Chest Hospital; Phone Number: 18516349006; Email: pillawang@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Age 18 to 80 years.
2. Solitary pulmonary nodule with whole-tumor maximal diameter <=2 cm confirmed by preoperative thin-slice CT (<=1 mm) and 3D reconstruction.
3. Solid-dominant nodule with consolidation-to-tumor ratio (CTR) >0.5, including pure-solid nodules.
4. Deeply located lesion, defined as the lesion center located in the inner two-thirds of the lung field on axial, coronal, and sagittal MPR images.
5. Clinically definite suspected primary NSCLC after complete preoperative work-up and MDT discussion, with estimated malignancy probability >=95%. Preoperative pathologic confirmation is not mandatory, but preoperative or intraoperative pathology should be obtained when technically safe and feasible.
6. Complete staging with thin-slice contrast-enhanced chest CT, whole-body PET-CT, brain contrast-enhanced MRI or CT, and serum tumor markers as appropriate; clinical stage IA (cT1a-bN0M0) without regional nodal or distant metastasis.
7. Cardiopulmonary function sufficient to tolerate both lobectomy and segmentectomy, with FEV1 and DLCO >=60% predicted.
8. Written informed consent, including special disclosure that final pathology may be benign.
9. Centralized imaging review confirmation by the lead-center technical committee before randomization.

Exclusion Criteria:

1. Lesion located in the right middle lobe.
2. Lesion located in the inner two-thirds but adjacent to the lung apex or base and judged suitable for wedge resection.
3. Two or more lesions requiring anatomic resection. One secondary lesion requiring only non-anatomic wedge resection is allowed; two main lesions in the same segment are excluded.
4. Prior ipsilateral lung surgery or another malignancy within 5 years.
5. Severe cardiovascular or cerebrovascular disease or other comorbidity making lobectomy or conversion to lobectomy intolerable.
6. Planned basal segmentectomy (S7-10); proper segmentectomy is permitted.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Segmentectomy; Participants assigned to this arm will undergo anatomic pulmonary segmentectomy. Combined segmentectomy or proper segmentectomy is permitted; basal segmentectomy (S7-10) is prohibited. Segmentectomy must include anatomic treatment of the segmental hilar artery, vein, and bronchus, margin assessment, and required lymph-node dissection. Conversion to lobectomy is permitted or required according to protocol-defined clinical and safety criteria.	Procedure: Anatomic Segmentectomy; Anatomical resection of the involved pulmonary segment or segments with lymph-node dissection and surgical quality-control assessment.
Active Comparator: Lobectomy; Participants assigned to this arm will undergo standard anatomic pulmonary lobectomy with required systematic or lobe-specific lymph-node dissection.	Procedure: Anatomic Lobectomy; Anatomical resection of the involved pulmonary lobe with lymph-node dissection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall Survival	Overall survival is defined as the time from randomization to death from any cause. The primary analysis will compare segmentectomy with lobectomy using the intention-to-treat set and a non-inferiority hazard-ratio margin of 1.54.	5 years after randomization

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Recurrence-Free Survival	Recurrence-free survival is defined as the time from randomization to first recurrence, distant metastasis, second primary lung cancer, or death from any cause. Event-free participants will be censored at the last event-free follow-up. RFS will be formally tested only if OS non-inferiority is established.	5 years after randomization
Locoregional Recurrence Rate	Proportion of participants with recurrence at the surgical margin, ipsilateral remaining lung, or ipsilateral hilar/mediastinal lymph nodes.	Up to 5 years after randomization
Distant Metastasis Rate	Proportion of participants with metastasis involving contralateral lung, pleura, N3 lymph nodes, or extrathoracic organs.	Up to 5 years after randomization
Patient-Reported Quality of Life Score (EORTC QLQ-C30)	Patient-reported quality of life measured using EORTC QLQ-C30, with attention to dyspnea, chest pain, and cough.	Baseline and 6, 12, and 36 months after surgery
Six-Minute Walk Distance	Change in 6-minute walk test distance.	Baseline and 6 and 12 months after surgery
FEV1 Change Rate	Change or loss rate in FEV1 (Forced Expiratory Volume in 1 second).	Baseline and 6 and 12 months after surgery
Surgical Quality Metrics	Surgical grade distribution, margin distance, R0 resection rate, lymph-node dissection station and count compliance, and conversion rate from segmentectomy to lobectomy.	Perioperative period
Perioperative Complications	Postoperative adverse events graded by Clavien-Dindo, with emphasis on grade II or higher complications.	Through discharge or 30 days after surgery, whichever came first
30-Day Mortality	All-cause mortality within 30 days after surgery.	30 days after surgery
DLCO Change Rate	Change or loss rate in DLCO (Diffusing Capacity of the Lungs for Carbon Monoxide).	Baseline and 6 and 12 months after surgery
Patient-Reported Lung Cancer Symptom Score (EORTC QLQ-LC13)	Patient-reported lung cancer-specific symptoms measured using EORTC QLQ-LC13, with attention to dyspnea, chest pain, and cough.	Baseline and 3, 6, 12, and 36 months after surgery
90-Day Mortality	All-cause mortality within 90 days after surgery.	90 days after surgery

Collaborators and Investigators

• Sponsor: Shanghai Chest Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): August 21, 2026
• Primary Completion (Estimated): July 1, 2034
• Study Completion (Estimated): July 1, 2034

Study Registration Dates

• First Submitted: June 18, 2026
• First Submitted That Met QC Criteria: July 7, 2026
• First Posted (Actual): July 13, 2026

Study Record Updates

• Last Update Posted (Actual): August 26, 2026
• Last Update Submitted That Met QC Criteria: August 24, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: overall survival; segmentectomy; lobectomy; non-inferiority trial; recurrence-free survival; early-stage NSCLC; deep pulmonary nodule; solid-dominant nodule
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Respiratory Tract Diseases; Lung Diseases; Respiratory Tract Neoplasms; Thoracic Neoplasms; Lung Neoplasms; Carcinoma, Bronchogenic; Bronchial Neoplasms; Carcinoma, Non-Small-Cell Lung
• Other Study ID Numbers: SOLID-V1.9

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No