Postneoadjuvant Whipple Resections Show Significant Residual Microscopic Tumor Beyond Grossly Identified Tumor Bed: Implications for Accurate Tumor Staging.

Neoadjuvant chemotherapy plays a vital role in the treatment of pancreatic ductal adenocarcinoma (PDAC), but treatment effect complicates pathologic examination of postneoadjuvant Whipple resections. Institutional practice is variable but current Pancreatobiliary Pathology Society (PBPS) guidelines suggest extensive microscopic examination of the tumor bed (TB). In practice, gross identification of TB is challenging and may lead to an inaccurate assessment of tumor size.

Spatially resolved analysis of pancreatic cancer identifies therapy-associated remodeling of the tumor microenvironment.

In combination with cell-intrinsic properties, interactions in the tumor microenvironment modulate therapeutic response. We leveraged single-cell spatial transcriptomics to dissect the remodeling of multicellular neighborhoods and cell-cell interactions in human pancreatic cancer associated with neoadjuvant chemotherapy and radiotherapy. We developed spatially constrained optimal transport interaction analysis (SCOTIA), an optimal transport model with a cost function that includes both spatial distance and ligand-receptor gene expression.

Concordance of ASCL1, NEUROD1 and POU2F3 transcription factor-based subtype assignment in paired tumour samples from small cell lung carcinoma.

Aims: Small cell lung carcinoma (SCLC) can be classified into transcription factor-based subtypes (ASCL1, NeuroD1, POU2F3). While in-vitro studies suggest intratumoral heterogeneity in the expression of these markers, how SCLC subtypes vary over time and among locations in patients remains unclear.

Methods And Results: We searched a consecutive series of patients at our institution in 2006-22 for those with greater than one available formalin-fixed paraffin-embedded SCLC sample in multiple sites and/or time-points.