2024 World Conference on Lung Cancer (WCLC) - Posters-P1.06B.18 Pathologic Response Assessment of Resected NSCLC Neoadjuvant Therapy Specimens with Tumor Size Larger Than 3cm by Different Sampling Methods

P1.06B.18 Pathologic Response Assessment of Resected NSCLC Neoadjuvant Therapy Specimens with Tumor Size Larger Than 3cm by Different Sampling Methods

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The study focuses on the pathological assessment of resected non-small cell lung cancer (NSCLC) specimens larger than 3 cm after neoadjuvant therapy using different sampling methods. It was conducted at the Shanghai Pulmonary Hospital and involved 90 patients treated between June 2020 and July 2023.<br /><br />Current guidelines from the International Association for the Study of Lung Cancer (IASLC) suggest that if the tumor bed is smaller than 3 cm, it should be entirely sampled, and if larger, only the most representative cross-section should be sampled. The study aims to evaluate the effectiveness of this recommendation.<br /><br />The research compared two sampling methods: the IASLC-multidisciplinary recommendation for sampling (MRS), and a more extensive complete sampling (CS) approach. The core finding is that following the MRS method is feasible and provides results nearly identical to the more extensive CS method.<br /><br />Patients were treated with different therapies, including chemotherapy, targeted therapy, and chemoimmunotherapy. On average, MRS required 8 blocks per case, while CS necessitated 15 blocks. The major pathological response (MPR) rate, defined by less than or equal to 10% residual viable tumor (RVT), was slightly higher in the MRS method than in CS (34 cases vs. 30 cases achieving MPR). For adenocarcinoma specifically, both methods showed a high level of concordance (consistent MPR in approximately 65% of cases).<br /><br />The key takeaway is that the IASLC recommendation for representative sampling is practical and maintains reliability compared to complete sampling. Future research should further explore representative sampling, particularly for very large tumor beds. The study underscores the necessity of standardized approaches to pathologic assessment post-neoadjuvant therapy, facilitating consistency and accuracy in clinical trials and practice.

Asset Subtitle

Guo JunHong

Meta Tag

Speaker Guo JunHong

Topic Pathology & Biomarkers

Keywords

non-small cell lung cancer

NSCLC

neoadjuvant therapy

pathological assessment

sampling methods

Shanghai Pulmonary Hospital

IASLC guidelines

major pathological response

adenocarcinoma

representative sampling