Comprehensive Summary
The paper proposes a new framework, MorphoITH, which uses histopathologic slides to deconvolve intra-tumor heterogeneity (ITH) through identification of mutation states, molecular subtypes, and diagnostically distinct areas. Representing a critical challenge in precision oncology, ITH is driven by cancer cell evolution and contributes to tumor aggressiveness. The method aims to construct a self-supervised deep learning model that can accurately recognize morphological difference, quantify phenotypic diversity, and control for spurious sources of variation. The model was then prototyped on clear cell renal cell carcinoma (ccRCC) to evaluate the effect of key driver gene mutations in ccRCC and capture clinically-relevant features and morphological patterns. To investigate the role of morphological ITH in tumor evolution, multi-region whole-exome sequencing data was obtained from three patients (26 samples total), with their phylogenetic trees with the morphological similarity assessed by the framework. It was found that the morphological heterogeneity predicted by MorphoITH aligned with genetic evolutionary patterns, while observing exceptions that may reflect factors such as convergent evolution. This study presents MorphoITH as a promising framework for studying intra-tumor heterogeneity from histopathologic slides, as well as demonstrating potential to improve tumor sampling and advance precision oncology.
Outcomes and Implications
This study introduces MorphoITH, a deep learning framework that evaluates standard histopathology slides for intra-tumor heterogeneity. The ability of the framework to predict morphological heterogeneity that aligns with genetic heterogeneity is meaningful, as it allows routinely-collected pathology slides to provide insights into tumor evolution and reduces reliance on expensive multi-region sequencing approaches. By informing more efficient sampling strategies, the framework may help medical professionals to better understand tumor aggressiveness and refine treatment decisions, supporting precision oncology efforts.