Sublobar resection for adenocarcinoma and minimally invasive adenocarcinoma diagnosed by intraoperative frozen section (ECTOP-1019): a study protocol of prospective, single-arm, multicenter, phase III study.

Background: Our previous retrospective study revealed that sublobar resection was appropriate for adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) diagnosed by intraoperative frozen section (FS). However, high-level evidence-based medical data confirming this treatment are still lacking. The aim of the ongoing study is to confirm the efficacy and safety of sublobar resection for AIS and MIA diagnosed by FS.

Methods: Since October 2023, we have initiated a prospective, single-arm, multicenter, confirmatory phase III trial in China. We plan to enroll a total of 390 patients diagnosed as AIS or MIA by intraoperative FS and who will undergo sublobar resection. The primary endpoint is five-year recurrence-free survival; the secondary endpoints are five-year overall survival, the concordance rate between FS and final pathology, adverse events, proportion of local recurrence and metastasis, the completion rate of sublobar resection and R0 resection.

Discussion: Surgical strategies for small-sized lung cancer that contains ground glass opacity lesions are still controversial. This study will deliver new evidence on the efficacy and safety of sublobar resection without lymph node dissection for cT1N0M0 non-small cell lung cancer (NSCLC) which are diagnosed as AIS or MIA by FS.

Trial Registration: ClinicalTrials.gov identifier: NCT06031181.