Part 1. Based on the histopathological features, construction of a multi-gene mutation prediction AI model for lung adenocarcinoma and analysis of prognostic factors
Objective: This study collected a substantial amount of data from patients with lung adenocarcinoma to construct a comprehensive database. We applied artificial intelligence techniques to develop models that assist pathologists and clinicians in decision-making, providing a scientific basis for personalized treatment of patients. Specifically, the study includes: 1) the integration of digital pathology slides, molecular pathology information, pathological data, and clinical information from 2,221 lung adenocarcinoma samples to establish a database, which facilitates a stratified analysis of the similarities and differences in pathological and clinical information among patients with various pathological subtypes, prognostic risk factors, and gene mutations; 2) the development of an artificial intelligence model for tumor region identification; 3) the establishment of an artificial intelligence model to predict the status of nine gene mutations, further evaluating model performance through three-fold cross-validation, comparisons with other models/pathologists, and testing generalization capabilities using external data; 4) the exploration of independent predictive factors affecting the progression-free survival of lung adenocarcinoma patients selected for molecular testing.
Materials and Methods: Retrospectively collecting clinical and pathological data, as well as molecular pathology information on EGFR, KRAS, ALK, HER2, ROS1, RET, BRAF, PIK3CA, and NRAS status from 2,221 lung adenocarcinoma samples of 1,999 primary lung adenocarcinoma patients treated at the China-Japan Friendship Hospital from September 2015 to April 2023, alongside digital pathology slide data, the patient data were analyzed using SPSS and statistical methods. Subsequently, 297 tumor region samples were annotated, and a ResNet network was trained and tested for tumor region identification and risk factor analysis. A total of 2,119 sample data were used to train and test the self-supervised model DINO for image feature extraction and the two-stage multi-instance model GAMIL for determining the mutation status of each gene. The datasets for all models were divided into training and testing sets in an 8:2 ratio, with images segmented into 256×256 image blocks for training and testing. Comparative performance evaluations included comparisons with different models (UNI, CLAM, Inception V3), external testing dataset comparisons (256 patients from the Cancer Hospital Chinese Academy of Medical Sciences and TCGA database), effectiveness comparisons between 6 pathologists of varying seniority levels and model, and evaluation based on generating high-weight heatmaps for gene mutation identification. Finally, the Log-Rank test was used for univariate analysis of prognostic factors, Kaplan-Meier curves were plotted for survival analysis, and a Cox proportional hazards regression model was employed for multifactor analysis to identify independent prognostic factors of progression-free survival.
Results: Among the 2,221 patients, there was a higher proportion of females and patients aged 60-69 years, with males experiencing onset slightly later. Variations in age and gender were observed among different subtypes of lung adenocarcinoma, and high-risk factors were associated with tumor size, gender, and major subtypes. Genetic analysis revealed correlations between different gene mutations and gender, age, tumor size, and high-risk pathological prognostic factors. The ResNet model established using this dataset and the WSSS4LUAD dataset exhibited AUC values of 0.995 and 0.992, respectively, for tumor region identification, with tumor region heatmaps generated on unannotated slices showing minimal noise in predicted areas. The DINO feature extraction model and the GAMIL classification model predicted gene mutations with AUC values of 0.825 (EGFR), 0.911 (KRAS), 0.987 (ALK), 0.882 (HER2), and 0.900 (for rare gene sets including ROS1, RET, BRAF, PIK3CA, and NRAS), with sensitivities ranging from 0.786 to 0.972, specificities from 0.749 to 0.989, and accuracies from 0.797 to 0.981. As a comparison, the GAMIL classification model using the UNI base model achieved an AUC value of 0.799 for EGFR, while using the DINO base model and the CLAM/Inception v3 classification models for EGFR resulted in AUC values of 0.679 and 0.665, respectively. External testing dataset validations for generalization capability yielded AUC values of 0.800 (EGFR) and 0.843 (ALK) for 256 samples from the Cancer Hospital Chinese Academy of Medical Sciences, and AUC values ranging from 0.508 to 0.716 for the TCGA database. In the comparison of EGFR gene mutation prediction between pathologists and the GAMIL model, the AUC values for senior, mid-level, junior pathologists, and the GAMIL model were 0.510, 0.500, 0.515, and 0.810, respectively. High-weight regions in the generated heatmaps indicated associations of EGFR, KRAS, and ALK genes with lepidic, invasive mucinous adenocarcinoma, and acinar with solid and acinar with mucinous subtypes. Univariate analysis of survival status revealed the influence of nine factors on survival time, whereas in the multifactor analysis using the Cox proportional hazards regression model, only pathological T stage (P=0.013) emerged as an independent predictor of progression-free survival.
Conclusion: The ResNet network model accurately identifies tumor regions and high-risk prognostic factors regions, while the DINO+GAMIL model demonstrates high AUC values for different gene mutations. Three-fold cross-validation reveals stable model performance, with the model outperforming various other models in comparative experiments with pathologists. External validation datasets further confirm the model's generalizability. Additionally, based on the results of multivariate analysis, pathological T stage emerges as an independent predictor of progression-free survival. Furthermore, tumor predominant subtype, KRAS gene mutation status, and the administration of targeted therapy (potentially subject to selection bias) are identified as independent predictors of progression-free survival in T1 stage patients.
Part 2. Integrating Mass Spectrometry and AI for intraoperative analysis of histological features and EGFR status in lung adenocarcinoma
Objective: This study combines probe electrospray ionization mass spectrometry with artificial intelligence algorithms to analyze metabolite variation data from tumor tissues. It trains artificial intelligence models to conduct in-depth analysis of information related to intraoperative frozen section indicators and postoperative targeted therapy indicators that influence surgical approaches for lung adenocarcinoma in fresh tumor tissues. Specifically, this includes the identification of high-risk subtypes (micropapillary/solid types), detection of tumor spread through air spaces, and interpretation of EGFR gene mutation status. This research overcomes the technical bottlenecks of traditional intraoperative frozen pathology for lung adenocarcinoma, providing support for rapid decision-making in surgical planning and the formulation of personalized targeted therapy strategies post-surgery.
Materials and Methods: A total of 131 patients diagnosed with lung adenocarcinoma at the China-Japan Friendship Hospital between July 2023 and October 2024 were collected. Following quality control screening, 99 patients were included in the study and divided into training and testing sets in a 7:3 or 8:2 ratio. For each patient, 10 mg of tumor tissue from intraoperative frozen specimens and corresponding adjacent non-tumor tissue (≥5 cm from the tumor) were collected. The samples underwent a simple preprocessing protocol: tumor and adjacent tissues were separately ground, centrifuged, and diluted using an ethanol-water mixture to obtain the solution for analysis. Metabolite analysis was conducted using the Shimadzu DPiMS-2020 rapid in situ ionization mass spectrometer. Data preprocessing was performed using LabSolutions software, where chromatographic peak integration values from 0.0 to 0.3 minutes were selected. After filtering data features, partial least squares regression was applied for dimensionality reduction, and the VIP method in MetaboAnalyst® software was utilized for feature selection. Four artificial intelligence models were constructed using support vector machines, random forests, multilayer perceptrons, and gradient boosting classification algorithms to: distinguish between tumor and adjacent tissues, identify high-risk subtypes (micropapillary/solid types) of lung adenocarcinoma, determine tumor air cavity dissemination, and predict the EGFR gene mutation status in tumor tissues. The model for determining tumor air cavity dissemination was optimized using an unbalanced dataset sampling method. Finally, the performance of the models was comprehensively evaluated using accuracy, precision, recall, and F1-Score.
Results: In this study, over 10,000 features were extracted from metabolite data of tumor and/or adjacent tissues of 99 lung adenocarcinoma patients. After screening 77-461 highly expressed features, 20 key principal components were generated through dimensionality reduction. Subsequently, four artificial intelligence models were trained and tested. The models achieved an accuracy of 95% in distinguishing between tumor and adjacent tissues, 90% accuracy in identifying high-risk subtypes of lung adenocarcinoma (micropapillary/solid types), 100% accuracy in detecting tumor air cavity dissemination, and after optimization, the EGFR gene mutation status prediction model achieved a remarkable AUC of 1.
Conclusion: This study integrates probe electrospray ionization mass spectrometry technology with various artificial intelligence algorithms to rapidly acquire metabolite data from fresh lung adenocarcinoma and adjacent normal tissue samples within minutes. It enables the differentiation between lung adenocarcinoma and adjacent normal tissues, as well as the assessment of three intraoperative frozen section indicators and postoperative targeted therapy indicators that impact lung adenocarcinoma diagnosis and treatment. The model exhibits high accuracy, surpasses the limitations of traditional morphological diagnosis, and provides further guidance for the selection of clinical procedures and postoperative targeted therapy in lung adenocarcinoma.