Optimizing core needle biopsy specimen collection techniques to enhance molecular testing adequacy in non-small cell...

Core needle biopsy (CNB) is commonly used for histological diagnosis and molecular testing in patients with non-small cell lung cancer (NSCLC). However, the adequacy of CNB specimens is often compromised by low tumor cell content or insufficient nucleic acid quantity, which can negatively impact the success of downstream analyses. Moreover, variations in specimen collection techniques may further contribute to inconsistency in sample quality. This retrospective study aimed to assess and optimize CNB specimen collection methods to improve sample adequacy for molecular testing in NSCLC.

A total of 546 CNB specimens from NSCLC patients were collected using three different techniques: (I) steam sterilization indicator cards; (II) polypropylene microporous membranes (PPMM) pieces for tissue adherence; and (III) direct rinsing of biopsy needles with sterilized buffer. Cell pellets were harvested from the residual fixative medium after CNB processing. Tumor cellularity was evaluated in formalin-fixed paraffin-embedded (FFPE) tissues and cell pellet samples from each method.

Adequacy rates for molecular testing were 86.4% in FFPE samples and 92.3% in cell pellet samples. Incorporating cell pellet analysis increased overall molecular testing adequacy to 95.2%. Among the evaluated techniques, the steam sterilization indicator cards cohort yielded the lowest adequacy rates for both FFPE and cell pellet samples. The PPMM technique achieved the highest adequacy for FFPE tissues, while the direct needle rinsing technique provided the highest DNA yields in cell pellet samples. Further, cell pellets demonstrated increased sensitivity for detecting actionable mutations compared to plasma-based liquid biopsies.

The use of PPMMs significantly enhances CNB specimen quality and molecular testing adequacy in NSCLC. Routine collection of cell pellets from the residual fixative medium is recommended to maximize diagnostic effectiveness and improve clinical decision-making.