ESMO recommendations on microsatellite instability testing for immunotherapy in cancer, and its relationship with PD-1/PD-L1 expression and tumour mutational burden: a systematic review-based approach

Descending duodenal adenocarcinoma treated with pembrolizumab resulting in complete clinical response: A case report and literature review

BACKGROUND

Descending duodenal adenocarcinoma (DDA) is a rare malignancy of the digestive system, typically characterized by microsatellite instability-high (MSI-H). Pembrolizumab is a monoclonal antibody that has been approved for the treatment of MSI-H solid tumors in China.

CASE SUMMARY

We present the case of a 55-year-old female patient diagnosed with DDA. Biopsy findings indicated MSI-H status with high expression of programmed cell death-ligand 1 (PD-L1). The patient was unable to undergo immediate surgery due to multiple metastatic lymph nodes in the retroperitoneum. After one cycle of the SOX (S-1 + oxaliplatin) chemotherapy regimen, the patient’s performance status significantly declined, and she experienced active gastrointestinal bleeding. Following active communication with the patient's family, pembrolizumab treatment was initiated. After two cycles of treatment, the disease was assessed as a partial response. A positron emission tomography/computed tomography scan performed after two years of treatment indicated a clinical complete response (CCR). The patient maintained this CCR for four years. She has now discontinued pembrolizumab for over one year, and no disease recurrence has been observed during re-examination.

CONCLUSION

Patients with MSI-H DDA exhibiting high PD-L1 expression who are treated with pembrolizumab can achieve sustained CCR.

Mitochondrial gene SLC25A24 regulated anti-tumor immunity and inhibited the proliferation and metastasis of colorectal cancer by PKG1-dependent cGMP/PKG1 pathway

Colorectal cancer (CRC) is a leading cause of cancer-related mortality globally, with metastasis playing a key role in its unfavorable prognosis. Emerging research has emphasized the pivotal role of mitochondria in tumor immune regulation. Nevertheless, the clinical relevance and functional role of SLC25A24, a mitochondrial solute carrier, in CRC remain largely unexplored. Through bioinformatics analyses and validation in clinical cohorts, this study identifies SLC25A24 as an independent prognostic marker in CRC, significantly linked to immune infiltration in CRC tissues. Our findings demonstrated that SLC25A24 expression is markedly reduced in CRC cell lines and tissues. Kaplan-Meier survival analysis revealed that lower SLC25A24 expression is associated with worse overall survival and progression-free survival in CRC patients. Interestingly, SLC25A24 expression was higher in microsatellite instability (MSI) CRC, which shows greater responsiveness to immune checkpoint inhibitors (ICIs). Functional experiments indicated that SLC25A24 overexpression suppresses CRC cell proliferation, migration, and invasion. Mechanistic studies revealed that SLC25A24 positively regulates the cGMP/PKG1 signaling pathway in CRC, influencing mitochondrial potential, apoptosis, and proliferation-related markers. This research highlights the SLC25A24-PKG1 axis as a potential therapeutic target to bolster anti-tumor immunity and curb CRC progression.

Artificial intelligence and whole slide imaging, a new tool for the microsatellite instability prediction in colorectal cancer: Friend or foe?

Colorectal cancer (CRC) is the third most common and second most deadly cancer worldwide. Despite advances in screening and treatment, CRC is heterogeneous and the response to therapy varies significantly, limiting personalized treatment options. Certain molecular biomarkers, including microsatellite instability (MSI), are critical in planning personalized treatment, although only a subset of patients may benefit. Currently, the primary methods for assessing MSI status include immunohistochemistry (IHC) for DNA mismatch repair proteins (MMRs), polymerase chain reaction (PCR)-based molecular testing, or next-generation sequencing (NGS). However, these techniques have limitations, are expensive and time-consuming, and often result in inter-method inconsistencies. Deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H) are critical predictive biomarkers of response to immune checkpoint inhibitor (ICI) therapy and MSI testing is recommended to identify patients who may benefit. There is a pressing need for a more robust, reliable, and cost-effective approach that accurately assesses MSI status. Recent advances in computational pathology, in particular the development of technologies that digitally scan whole slide images (WSI) at high resolution, as well as new approaches to artificial intelligence (AI) in medicine, are increasingly gaining ground. This review aims to provide an overview of the latest findings on WSI and advances in AI methods for predicting MSI status, summarize their applications in CRC, and discuss their strengths and limitations in daily clinical practice.

ZOOMit diffusion kurtosis imaging combined with diffusion weighted imaging for the assessment of microsatellite instability in endometrial cancer

PURPOSE

Detecting microsatellite instability (MSI) plays a key role in the management of endometrial cancer (EC), as it is a critical predictive biomarker for Lynch syndrome or immunotherapy response. A pressing need exists for cost-efficient, broadly accessible tools to aid patient for universal testing. Herein, we investigate the value of ZOOMit diffusion kurtosis imaging (DKI) and diffusion weighted imaging (DWI) based on preoperative pelvic magnetic resonance imaging (MRI) images in assessing MSI in EC.

METHODS

Preoperative MRI examination including ZOOMit DKI and DWI of 81 EC patients were retrospectively analyzed. The apparent diffusion coefficient (ADC), mean kurtosis (MK), mean diffusivity (MD) and the largest tumor size based on MRI images, as well as patients' clinicopathological features were compared and analyzed according to different microsatellite statuses.

RESULTS

Of the 81 patients, 59 (72.8%) who were microsatellite stability (MSS) and 22 (27.2%) who were MSI. Interobserver agreement for the quantitative parameter measurements was excellent (ICC 0.78-0.98). The ADC and MD values were significantly lower, while Ki-67 proliferation level and MK values were significantly higher in the MSI group compared to those of the MSS group. The parameters of MD and MK were independent predictors for determining MSI, and their combination showed better diagnostic efficacy with an area under the receiver operating characteristic curve (AUROC) of 0.860 (95% confidence interval, 0.765, 0.927), although there was no significant difference compared to each individual parameter.

CONCLUSION

The microstructural heterogeneity assessment of ZOOMit DKI allowed for characterizing MSI status in EC. Within the current universal MSI testing paradigm, DKI may provide added value as a potential noninvasive imaging biomarker for preoperative assessment of MSI tumors, thereby facilitating clinical decision-making.

HSP110 T17 marker matches the pentaplex panel and outperforms CAT-25 for detecting microsatellite instability in sporadic colorectal cancer

Microsatellite instability (MSI) is an important biomarker in colorectal cancer (CRC), influencing prognosis and treatment decisions. While conventional MSI detection typically relies on the pentaplex panel, newer markers like HSP110 T17 (HT-17) and CAT-25 may offer simpler, more cost-effective alternatives. This study aimed to assess the effectiveness of HT-17 and CAT-25 for detecting MSI in sporadic CRC and to explore any links between MSI status and clinicopathological features. A total of 96 Tunisian sporadic CRC patients were included, with MSI status evaluated using HT-17, CAT-25, and the refined mononucleotide repeat pentaplex panel through microsatellite genotyping. Clinicopathological data, such as tumor location and age at diagnosis, were also analyzed for associations with MSI. Among the 96 patients, 9 (9.38%) showed MSI, while 87 were microsatellite stable (MSS). HT-17 demonstrated 100% accuracy and sensitivity, matching the pentaplex panel's performance, while CAT-25 showed limited detection ability. MSI status was significantly linked to tumors in the proximal colon and, unexpectedly, to younger patients (<50 years old). HT-17 proved to be a reliable MSI marker in CRC, offering equivalent performance to the pentaplex panel, with the added advantages of simplicity and cost efficiency. The associations between MSI, tumor location, and younger age at diagnosis may provide valuable insights into CRC biology and clinical management. Further studies with larger cohorts are needed to validate HT-17' s clinical potential, with the goal of improving personalized treatment strategies and prognostic accuracy for CRC patients.

Predictive value of combined DCE-MRI perfusion parameters and clinical features nomogram for microsatellite instability in colorectal cancer

OBJECTIVES

To develop a nomogram that combines dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) perfusion parameters, ADC values and clinical features to preoperatively identify microsatellite instability (MSI) in patients with colorectal cancer (CRC).

METHODS

This retrospective study included 63 CRC patients who underwent preoperative DCE-MRI and had immunohistochemistry results available. Two radiologists, in a double-blind manner, placed two circular regions of interests in the area with the highest perfusion intensity on the DCE-MRI perfusion map and the corresponding area on the ADC map. Perfusion parameters and ADC values were measured, and the average values from both radiologists were used for subsequent analysis. Univariate analysis was performed to identify independent risk factors for MSI. A nomogram was then constructed by combining the most significant clinical risk factors with DCE-MRI perfusion parameters. The model's performance was evaluated using receiver operating characteristic (ROC) curves. Calibration curves, decision curve analysis (DCA), and clinical impact curves (CIC) were used to assess the nomogram's clinical utility and net benefit.

RESULTS

The nomogram prediction model, which combined PLT, LNM, Ktrans, Kep, iAUC, and ADC, demonstrated good predictive performance. The combined model had an AUC of 0.951 (95% CI: 0.903-0.998), an accuracy of 0.873, a sensitivity of 1.000, and a specificity of 0.818. Both the DCA and CIC demonstrated good clinical applicability and net benefit.

CONCLUSION

The nomogram method demonstrated good potential in the preoperative individualized identification of MSI status in CRC patients. This tool can assist clinicians in adopting appropriate treatment strategies and optimizing personalized stratification for CRC patients.

Immune Checkpoint Inhibitors and Immunosuppressive Tumor Microenvironment: Current Challenges and Strategies to Overcome Resistance

Immune checkpoint inhibitors (ICIs) are shown to improve cancer treatment effectiveness by boosting the immune system of the patient. Nevertheless, the unique and highly suppressive TME poses a significant challenge, causing heterogeneity of response or resistance in a considerable number of patients. This review focuses on the evasive attributes of the TME. Immune evasion mechanism in TME include immunosuppressive cells, cytokine and chemokine signaling, metabolic alterations and overexpression of immune checkpoint molecules such as PD-1, CTLA-4, LAG-3, TIM-3, TIGIT, BTLA and their interactions within the TME. In addition, this review focuses on the overcoming resistance by targeting immunosuppressive cells, normalizing tumor blood vessels, blocking two or three checkpoints simultaneously, combining vaccines, oncolytic viruses and metabolic inhibitors with ICIs or other therapies. This review also focuses on the necessity of finding predictive markers for the stratification of patients and to check response of ICIs treatment. It remains to be made certain by new research and intelligent innovations how these discoveries of the TME and its interplay facilitate ICI treatment and change the face of cancer treatment.

HR eye & MMR eye: one-day assessment of DNA repair-defective tumors eligible for targeted therapy

Homologous recombination (HR) and mismatch repair (MMR) act as guardians of the human genome, and defects in HR or MMR are causative in at least a quarter of all malignant tumors. Although these DNA repair-deficient tumors are eligible for effective targeted therapies, fully reliable diagnostic strategies based on functional assay have yet to be established, potentially limiting safe and proper application of the molecular targeted drugs. Here we show that transient transfection of artificial DNA substrates enables ultrarapid detection of HR and MMR. This finding led us to develop a diagnostic strategy that can determine the cellular HR/MMR status within one day without the need for control cells or tissues. Notably, the accuracy of this method allowed the discovery of a pathogenic RAD51D mutation, which was missed by existing companion diagnostic tests. Our methods, termed HR eye and MMR eye, are applicable to frozen tumor tissues and roughly predict the response to therapy. Overall, the findings presented here could pave the way for accurately assessing malignant tumors with functional defects in HR or MMR, a step forward in accelerating precision medicine.

Preoperative radiomics models using CT and MRI for microsatellite instability in colorectal cancer: a systematic review and meta-analysis

OBJECTIVE

Microsatellite instability (MSI) is a novel predictive biomarker for chemotherapy and immunotherapy response, as well as prognostic indicator in colorectal cancer (CRC). The current standard for MSI identification is polymerase chain reaction (PCR) testing or the immunohistochemical analysis of tumor biopsy samples. However, tumor heterogeneity and procedure complications pose challenges to these techniques. CT and MRI-based radiomics models offer a promising non-invasive approach for this purpose.

MATERIALS AND METHODS

A systematic search of PubMed, Embase, Cochrane Library and Scopus was conducted to identify studies evaluating the diagnostic performance of CT and MRI-based radiomics models for detecting MSI status in CRC. Pooled area under the curve (AUC), sensitivity, and specificity were calculated in RStudio using a random-effects model. Forest plots and a summary ROC curve were generated. Heterogeneity was assessed using I² statistics and explored through sensitivity analyses, threshold effect assessment, subgroup analyses and meta-regression.

RESULTS

17 studies with a total of 6,045 subjects were included in the analysis. All studies extracted radiomic features from CT or MRI images of CRC patients with confirmed MSI status to train machine learning models. The pooled AUC was 0.815 (95% CI: 0.784-0.840) for CT-based studies and 0.900 (95% CI: 0.819-0.943) for MRI-based studies. Significant heterogeneity was identified and addressed through extensive analysis.

CONCLUSION

Radiomics models represent a novel and promising tool for predicting MSI status in CRC patients. These findings may serve as a foundation for future studies aimed at developing and validating improved models, ultimately enhancing the diagnosis, treatment, and prognosis of colorectal cancer.

Pathologic complete response after Sintilimab combined with FOLFOX therapy in MSI-H type patients with locally advanced GC: a case report

As one of the most common gastrointestinal tumors, Gastric Cancer (GC) poses a serious threat to human health due to its high morbidity and mortality. The current treatment strategy is a comprehensive treatment program mainly based on surgery, especially for advanced GC patients. The emergence of immune checkpoint inhibitors has completely changed this status quo, and the synergistic effect of neoadjuvant immunotherapy combined with chemotherapy has significantly improved the resection and radical rate and overall survival of patients with advanced local GC. We present a case of locally advanced GC (cT4N0Mx) with microsatellite instability high (MSI-H) and PD-L1 Combined Positive Score (CPS)=2. The patient received neoadjuvant therapy with Sintilimab combined with FOLFOX (folinic acid (leucovorin), 5-fluorouracil (5-FU), and oxaliplatin), and significantly reduced tumor volume after 3 cycles of treatment. Then she underwent subtotal gastrectomy with gastrojejunostomy and D2 lymph node dissection. The postoperative pathological results showed that no cancerous tissue remained in the tumor tissue, and pathologic complete response (pCR) was achieved. The first cycle of adjuvant therapy with the same protocol was received after surgery. During adjuvant therapy, patients mainly experienced side effects such as dyspepsia, nausea and mild myelosuppression. Therefore, immunotherapy with Sintilimab combined with FOLFOX chemotherapy has the potential to be an effective treatment option for patients with resectable locally advanced MSI-H GC.

PRMT5 Inhibitor Synergizes with Chemotherapy to Induce Resembling Mismatch Repair Deficiency and Enhance Anti-TIGIT Therapy in Microsatellite-Stable Colorectal Cancer

Microsatellite stable (MSS) colorectal cancer (CRC) is considered an "immune-cold" tumor, accounting for ≈85% of all CRC cases. The overall response rate to chemotherapy combined with immune checkpoint inhibitors in MSS CRC is typically less than 10%. The specific mechanism that enhances chemotherapy sensitivity and mediated immunogenicity renders MSS CRC more responsive to immunotherapy remains elusive. Experiments in this study identify a DNA damage repair-related epigenetic gene, protein arginine methyltransferase 5 (PRMT5), whose inhibition enhances Irinotecan (CPT-11) sensitivity and synergistically induces a postmeiotic segregation increased 2 (PMS2)-deficient-like state, leading to the release of cytosolic double-stranded DNA. This activates the cyclic GMP-AMP synthase (cGAS)-stimulator of the IFN gene (STING) signaling pathway, thereby enhancing anti-tumor immunotherapy through dendritic cell-T cell-dependent functions. Importantly, combining the epigenetic anti-tumor drug GSK3326595 with CPT-11 significantly upregulates the immune receptor tyrosine-based inhibitory motif (TIGIT) level on CD8+ T cells and subsequently demonstrates impressive anti-tumor efficacy in vivo when additional anti-TIGIT is included. Collectively, this study reveals the crucial role of PRMT5 blockade combined with CPT-11 in inducing a mismatch repair deficiency-like state and provides a novel triple-drug combination therapy strategy as a potential treatment for patients with MSS CRC.

Clinical Implications of Mismatch Repair Deficiency in Pancreatic Ductal Adenocarcinoma

BACKGROUND

Pancreatic cancer is a highly aggressive and lethal disease, characterized by a limited response to chemotherapy and overall poor prognosis. Pancreatic cancers with a distinct mismatch repair deficiency, although relatively rare, have been shown to be associated with markedly better outcomes in comparison. Furthermore, whereas pancreatic cancers are generally unresponsive to current immunotherapy, this specific group of tumors has been shown to have a notable susceptibility to immune checkpoint inhibitors.

AIMS

In this review, we aim to summarize the relevant literature regarding mismatch-repair associated pancreatic cancers, the impacted biological mechanisms, and the resulting vulnerabilities for potential opportunistic immunotherapeutic treatment approaches. We will also review the current clinical studies assessing survival outcomes of mismatch repair deficient pancreatic cancers and ongoing clinical trials in this emerging field.

RESULTS AND CONCLUSIONS

Patients with dMMR/MSI-H pancreatic cancers harbor a distinct phenotype that has increased immune activation, greater responsiveness to immune checkpoint inhibitor therapy and better overall survival when compared to other pancreatic cancers. Although this molecular subtype makes up a small minority of cases, emerging data suggest immunotherapy may offer benefit to these patients.

Exploring immune checkpoint inhibitors: Focus on PD-1/PD-L1 axis and beyond

Immunotherapy emerges as a promising approach, marked by recent substantial progress in elucidating how the host immune response impacts tumor development and its sensitivity to various treatments. Immune checkpoint inhibitors have revolutionized cancer therapy by unleashing the power of the immune system to recognize and eradicate tumor cells. Among these, inhibitors targeting the programmed cell death protein 1 (PD-1) and its ligand (PD-L1) have garnered significant attention due to their remarkable clinical efficacy across various malignancies. This review delves into the mechanisms of action, clinical applications, and emerging therapeutic strategies surrounding PD-1/PD-L1 blockade. We explore the intricate interactions between PD-1/PD-L1 and other immune checkpoints, shedding light on combinatorial approaches to enhance treatment outcomes and overcome resistance mechanisms. Furthermore, we discuss the expanding landscape of immune checkpoint inhibitors beyond PD-1/PD-L1, including novel targets such as CTLA-4, LAG-3, TIM-3, and TIGIT. Through a comprehensive analysis of preclinical and clinical studies, we highlight the promise and challenges of immune checkpoint blockade in cancer immunotherapy, paving the way for future advancements in the field.

The Potential Role of C4 MYH11+ Fibroblasts and the MDK-SDC2 Ligand-Receptor Pair in Lung Adenocarcinoma: Implications for Prognosis and Therapeutic Strategies

BACKGROUND

Lung adenocarcinoma (LUAD) posed a significant threat to global human health. This study employed single-cell RNA sequencing (scRNA-seq) to analyze transcriptomic data from nine LUAD patients at different stages of tumor infiltration, aiming to elucidate the tumor microenvironment and key biological processes of LUAD.

METHODS

In this study, we processed the scRNA-seq data using the Seurat package and sequentially applied principal component analysis followed by the Harmony package to effectively correct for batch effects, identifying 105,725 high-quality cells. Through cell clustering and gene expression profiling, we identified critical cell subpopulations and gene expression patterns in LUAD patients.

RESULTS

Our analysis revealed that the C4 MYH11+ Fibroblasts subtype was primarily involved in biological processes related to muscle function. Further investigations uncovered the MDK-SDC2 ligand-receptor pair as a critical regulator of tumor cell invasion, proliferation, and migration, driving LUAD progression. Additionally, we developed a gene-based prognostic model that effectively predicted patient survival, providing valuable clinical insights.

CONCLUSION

This study provided a comprehensive atlas of the LUAD tumor microenvironment, highlighted the role of the C4 MYH11+ Fibroblasts in tumor progression. It also proposed the MDK-SDC2 ligand-receptor pair as a novel mechanism, addressing a significant gap in this area of research. And presented a gene-based prognostic model as a novel perspective for research into immunotherapy and drug sensitivity in LUAD.

Artificial intelligence-driven microsatellite instability profiling reveals distinctive genetic features in patients with lung cancer

BACKGROUND

Microsatellite instability (MSI) has emerged as a predictive biomarker for immunotherapy response in various cancers, but its role in non-small cell lung cancer (NSCLC) is not fully understood.

METHODS

The authors used the bioinformatics tool MIAmS to assess microsatellite status from next-generation sequencing (NGS) data using a tailored microsatellite score. Immunohistochemistry (IHC) assays were also performed to evaluate the correspondence between MSI and deficient mismatch repair (dMMR) status. A retrospective analysis of 1547 lung cancer patients was conducted, focusing on those with an MSI phenotype. Clinical characteristics, co-occurring molecular alterations, tumor mutation burden (TMB), and homologous recombination deficiency (HRD) status were evaluated in this subset.

RESULTS

Of the 1547 patients analyzed, eight (0.52%) were identified as having MSI through MIAmS, with six (0.39%) of these cases also being dMMR on IHC. All patients with dMMR had an MS score ≥2 and a history of smoking. Most patients showed loss of MLH1 and PMS2 staining on IHC. No correlation was found between MSI status and programmed death-ligand 1 expression, although all MSI patients exhibited high TMB, averaging 21.4 ± 5.6 mutations per megabase.

DISCUSSION

MSI/dMMR in lung cancer is exceedingly rare, affecting less than 1% of cases. NGS-based analysis combined with bioinformatics tools provides a robust method to identify MSI/dMMR patients, potentially guiding immunotherapy decisions. This comprehensive approach integrates molecular genotyping and MSI detection, offering personalized treatment options for lung cancer patients. NGS-based MSI testing is emerging as the preferred method for detecting microsatellite instability in various tumor types, including rare cancers.

Deciphering ERR family genes as prognostic and immunological biomarkers through pan-cancer analysis with validation in gallbladder cancer

Background

The estrogen-related receptor family genes (ERRs), including ESRRA, ESRRB, and ESRRG, have been implicated in a few tumors, exhibiting distinct roles through diverse mechanisms. The purpose of our research is to explore the commonalities and underlying mechanism of ERRs in malignancies from a pan-cancer perspective and to validate the role and mechanisms of ESRRG in gallbladder cancer (GBC).

Methods

We leveraged public databases such as TCGA and GTEx to systematically investigate the potential functions of ERRs in malignancies. ESRRG expression was analyzed through immunohistochemical staining in gallbladder cancer and cholecystitis tissues. For functional validation, ESRRG was knocked down in GBC cell lines, followed by CCK-8, colony formation, scratch wound healing, Transwell migration, and invasion assays. Western blot, qPCR, and immunofluorescence were performed to evaluate the relationship between ESRRG, PD-L1, and CD8+ T cells.

Results

Compared to adjacent normal tissues, ESRRA is overexpressed in most tumors, ESRRB is generally underexpressed, and ESRRG exhibits significant expression alterations across various tumors. All three ERRs demonstrate significant prognostic value across different cancers. Notably, the strong associations of ERRs with key immunological features-stromal scores, immune cell infiltration, microsatellite instability (MSI), and tumor mutational burden (TMB)-suggest their involvement in immune evasion and their potential utility in guiding immunotherapy strategies. All three ERRs display a positive correlation with advanced tumor stages in cholangiocarcinoma (CHOL). Specifically, in CHOL, ESRRG expression is closely associated with lymphatic metastasis, poorer overall survival, reduced immune infiltration, elevated PD-L1 expression, epithelial-mesenchymal transition (EMT), and DNA damage response. In GBC tissues, we subsequently confirmed that ESRRG expression positively correlates with pathological staging and PD-L1 expression, while negatively correlating with prognosis and CD8+ T cell infiltration. Knockdown of ESRRG in gallbladder cancer cells results in decreased proliferation, migration, and invasion. Moreover, the expression of PD-L1, MSH2, BRCA1, MMP2, and VIMENTIN decreased with ESRRG knockdown.

Conclusion

Our pan-cancer analysis reveals ERRs as critical regulators of tumor immunity and progression, with ESRRG emerging as a key oncogenic driver in GBC. The mechanistic link between ESRRG and PD-L1/EMT suggests its potential as a therapeutic target to enhance immunotherapy efficacy. These findings underscore the need for tissue-specific targeting strategies for ERR family members in precision oncology.

Artificial intelligence entering the pathology arena in oncology: current applications and future perspectives

BACKGROUND

Artificial intelligence (AI) is rapidly transforming the fields of pathology and oncology, offering novel opportunities for advancing diagnosis, prognosis, and treatment of cancer.

METHODS

Through a systematic review-based approach, the representatives from the European Society for Medical Oncology (ESMO) Precision Oncology Working Group (POWG) and international experts identified studies in pathology and oncology that applied AI-based algorithms for tumour diagnosis, molecular biomarker detection, and cancer prognosis assessment. These findings were synthesised to provide a comprehensive overview of current AI applications and future directions in cancer pathology.

RESULTS

The integration of AI tools in digital pathology is markedly improving the accuracy and efficiency of image analysis, allowing for automated tumour detection and classification, identification of prognostic molecular biomarkers, and prediction of treatment response and patient outcomes. Several barriers for the adoption of AI in clinical workflows, such as data availability, explainability, and regulatory considerations, still persist. There are currently no prognostic or predictive AI-based biomarkers supported by level IA or IB evidence. The ongoing advancements in AI algorithms, particularly foundation models, generalist models and transformer-based deep learning, offer immense promise for the future of cancer research and care. AI is also facilitating the integration of multi-omics data, leading to more precise patient stratification and personalised treatment strategies.

CONCLUSIONS

The application of AI in pathology is poised to not only enhance the accuracy and efficiency of cancer diagnosis and prognosis but also facilitate the development of personalised treatment strategies. Although barriers to implementation remain, ongoing research and development in this field coupled with addressing ethical and regulatory considerations will likely lead to a future where AI plays an integral role in cancer management and precision medicine. The continued evolution and adoption of AI in pathology and oncology are anticipated to reshape the landscape of cancer care, heralding a new era of precision medicine and improved patient outcomes.

Prognostic and Predictive Value of Microsatellite Instability Analysis in Circulating Tumor DNA Using Digital Droplet PCR for Patients With Microsatellite Instability Colorectal Cancers

Deficient mismatch repair (dMMR) and/or microsatellite instability (MSI) colorectal cancer (CRC) is highly sensitive to immune checkpoint inhibitors (ICI). It is thus becoming increasingly relevant to monitor circulating tumor DNA (ctDNA) and to determine the MSI status (ctDNA-MSI) in CRC. So far, few studies have explored this, even though it could be particularly relevant in evaluating treatment efficacy in patients with dMMR and/or MSI CRC. The ctDNA DIgestive cancers MSI study (ADI-MSI) aims to assess the value of ctDNA-MSI as a predictor of ICI efficacy. Blood samples were collected prospectively in a single-center cohort to analyze circulating cell-free DNA (cfDNA) and ctDNA-MSI before the start of and during treatment. ctDNA-MSI was measured using digital droplet PCR with the 5 microsatellite markers of the Pentaplex panel (Promega Corporation). The primary endpoint was to evaluate ctDNA-MSI levels as a predictor of progression-free survival (PFS). We included 54 patients with dMMR and/or MSI CRC, most of whom had metastatic disease (77.8%) treated in the first (25.9%) or second line (42.6%) with ICI. High-baseline cfDNA and ctDNA-MSI were associated with worse PFS and overall survival. ctDNA-MSI kinetics, but not cfDNA kinetics, was associated with treatment response (P = .006), PFS (P = .03), and overall survival (P = .04). ctDNA-MSI kinetics divided into 3 groups (increase, decrease, and negative) correlated strongly with PFS (PFS at 24 months was 0%, 53.0%, and 77.0%, respectively; P < .001) and remained significant in multivariate analysis (hazard ratio = 7.93; 95% CI, 2.23-28.21; P = .005). As there is no strong predictor of ICI efficacy in patients with dMMR and/or MSI CRC, these results suggest that ctDNA-MSI could help physicians in treatment decision-making in the future.

Potential Value of AURKA and CDK6 Amplification for the Response of Patients With Gastric Cancer to Neoadjuvant Chemotherapy

Many patients respond poorly to neoadjuvant chemotherapy (NACT), negatively affecting the surgical success rate. Identifying effective biomarkers and understanding the potential resistance mechanisms are urgently needed. Data of 18 patients with advanced stomach cancer who were treated with NACT categorized according to tumor regression grade into major histological response (MJHR) and nonhistological response (NHR) groups were retrospectively analyzed. Genomic signatures associated with the response to NACT were identified using whole-exome and RNA sequencing. Extraction of molecular signatures revealed increased deficient mismatch repair signature and tumor mutation levels in the NHR group. Compared to the MJHR group, the NHR group was also characterized by a greater number of copy number alterations (p = 0.08), which was further confirmed by RNA sequencing, and upregulation of aurora kinase A (AURKA) (p = 0.05) and cyclin-dependent kinase 6 (CDK6) (p = 0.049). Western blot analysis and immunohistochemical analyses further confirmed high CDK6 (p < 0.01/p < 0.0001) and AURKA (p < 0.01/p < 0.001) expression levels in the NHR group. Finally, palbociclib, an inhibitor of CDK4/6, effectively inhibited the proliferation (p < 0.05) and induced apoptosis of oxaliplatin-resistant gastric cancer cells (p < 0.01) in vitro. These findings support the potential value of AURKA and CDK6 amplification, as well as their effects on the tumor microenvironment, in predicting poor outcomes of NACT in patients with locally advanced gastric cancer. Thus, CDK4/6 inhibitors could be used to treat NACT-resistant patients with gastric cancer.

Plasma proteomic biomarkers predict therapeutic responses in advanced biliary tract cancer patients receiving Camrelizumab plus the GEMOX treatment

Biliary tract cancer (BTC) has greatly influenced patient survival for years. Nowadays, immunotherapy represents a promising breakthrough and proteomics is one of powerful technologies in biomarker research. We collected plasma and tissue samples from 37 patients with advanced BTC and 92 proteins were analyzed by proximity extension assay (PEA). Through linear mixed effect models, compared to partial response (PR) group, 8 proteins, IL7, ANGPT2, IL15, HO-1, CXCL1, CXCL5, IL33, and VEGFA, exhibited significantly higher expression in stable disease and progressive disease (SD_PD) group in response-effect analysis. It was also revealed that a subset of proteins increased over time, including PDCD1, TNFRSF4, DCN, CRTAM, VEGFR-2 and ADA in PR group and PDCD1, IL10, ADA, CD28, and PTN in SD_PD group. In interaction-effect analysis, HO-1, ANGPT2, IL15 were three significant differentially expressed proteins (DEPs). Receiver operating characteristic (ROC) analysis further demonstrated that HO-1, ANGPT2, IL15 showed high accuracy in patients with immune checkpoint blockade (ICB) treatment plus chemotherapy (AUC = 0.74). In addition, based on the obtained plasma and tissue samples, two nomogram models were constructed for predicting the prognosis of BTC by genome combined with proteomics. Collectively meaningful proteomic biomarkers are beneficial to evaluate the efficacy of immunotherapy, and these discovered biomarkers may be included in the scope of treatments' evaluation and improvement in future study.

The Role of MSI Testing Methodology and Its Heterogeneity in Predicting Colorectal Cancer Immunotherapy Response

MSI is a crucial biomarker for selecting CRC patients for immunotherapy. Here, we analyze the first results from the observational prospective trial BLOOMSI (NCT06414304), which investigated the impact of MSI/dMMR testing methods and baseline tumor heterogeneity on treatment outcomes. Thirty MSI/dMMR+ CRC patients, who were candidates for immunotherapy, were enrolled. Depending on the local test used for MSI/dMMR, central PCR/IHC was performed. Baseline FFPE and liquid biopsy (LB) were analyzed with NGS. ORR (objective response rate) in the ITT population was 50% (95% CI, 31.3-68.7%). Concordance between local/central dMMR/MSI testing was 81%, and the concordance of IHC, PCR, NGS/FFPE, and NGS/LB was 68.4%. The ORR was similar for IHC+, PCR+, NGS/FFPE+, and NGS/LB+ patients (55.6%, 55.6%, 55%, and 57.9%, respectively). The ORR among patients with discordant IHC/PCR results was 0%, and the ORR among patients with NGS/LB-ORR was 25% (2/8 CR). Next, we performed quantitative MSI analysis, reflecting the clonality of MSI+ tumor cells. Multivariate analysis identified MSI clonality in FFPE (HR 0.63, 95% CI, 0.39-0.99, p = 0.0487) and LB (HR 3.05, 95% CI, 2.01-4.65, p < 0.00001) as independent predictors of progression. The ORR in patients with high clonality (≥7%, n = 4, NGS/LB) was 25%. We describe baseline methodological predictors of non-response to immunotherapy and propose a strategy for selecting potential non-responders. These findings warrant further investigation.

Associations between MRI radiomic phenotypes and clinical outcomes in endometrial cancer: Implications for preoperative risk stratification

OBJECTIVES

This study aimed to investigate the correlation between imaging phenotypes of endometrial cancer (EC) and clinical, pathologic, and molecular characteristics, as well as disease-free survival (DFS).

METHODS

The clinical, pathologic, and molecular characteristics, along with MRI radiomics features, of 356 patients with EC were collected retrospectively. The patients were divided into 2 groups based on radiomics features using unsupervised machine learning. The obtained characteristics and DFS of patients were compared between the various imaging phenotypes.

RESULTS

The lesions with deep myometrial invasion (DMI), lymphovascular space invasion (LVSI), cervical stromal invasion (CSI), lymph node metastasis, aggressive histologic type, advanced postoperative International Federation of Gynecology and Obstetrics (FIGO) stage, overexpression of p53, and absent expression of estrogen receptor or progesterone receptor were associated with poor DFS. Two clusters were identified and defined as imaging phenotype 1 and 2, respectively. Compared with phenotype 2, phenotype 1 exhibited a higher correlation with DMI (33.7 % vs 13.0 %), LVSI (23.8 % vs 9.2 %), CSI (16.3 % vs 3.8 %), aggressive histologic type (36.0 % vs 17.4 %), and advanced FIGO stage (IB or higher, 43.6 % vs 22.3 %) (p < 0.001). The incidence of p53 overexpression was higher in phenotype 1 than in phenotype 2 (20.2 % vs 8.5 %, p = 0.022). Survival analysis exhibited a higher risk of poor DFS in phenotype 1 than in phenotype 2 (log-rank p = 0.002).

CONCLUSION

EC imaging phenotypes identified through MRI radiomics features were associated with pathologic, molecular characteristics, and DFS, suggesting potential for preoperative risk stratification.

Subtype-Specific Patterns of Tumor Purity and Mutation Load Suggest Treatment Implications: A Cross-Sectional Analysis of 7494 Soft Tissue and Bone Sarcomas (MSK Cohort)

OBJECTIVES

Sarcomas are complex mesenchymal malignancies whose molecular characteristics can significantly influence treatment strategies. This study aimed to investigate the relationship between tumor purity, mutation load, and clinical characteristics across sarcoma subtypes, focusing on potential implications for therapeutic stratification.

METHODS

This study analyzed the molecular characteristics of 7494 sarcoma cases from the Soft Tissue and Bone Sarcoma (MSK, Nat Commun 2022) data set using available case analysis. Correlations between tumor purity, mutation load, age, and sex were analyzed using nonparametric methods, with subtype-specific analyses conducted using Kruskal-Wallis tests and Bonferroni-corrected post hoc comparisons. A comprehensive analysis of mutation patterns was performed using microsatellite instability (MSI) status.

RESULTS

Significant correlations between mutation load and tumor purity (ρ=0.320, P <0.001) were identified, with marked heterogeneity across subtypes. Tumor purity ranged from 20.0% in brain sarcomas to 78.5% in dermatofibrosarcoma protuberans. Age-related molecular changes were observed in brain (ρ=0.711, P =0.006) and skin sarcomas (ρ=0.450, P =0.006), suggesting distinct evolutionary patterns. A subset of hypermutated, microsatellite stable cases (0.15%) with mutation loads exceeding 100 mutations/mb were identified, suggesting alternative mechanisms of genomic instability. MSI-high status was rare (0.24%) but associated with higher mutation loads (median: 25.84 vs. 2.42, P <0.001), particularly in uterine sarcomas (0.7% prevalence).

CONCLUSIONS

The identification of distinct molecular patterns across sarcoma subtypes challenge existing morphology-based classification systems and may hold implications for therapeutic stratification. These findings may help inform future immunotherapeutic and molecular-guided approaches to treatment in sarcoma patients, particularly for elderly patients with brain sarcomas or females with uterine sarcomas.

Phase 2b, open-label, single-arm, multicenter pilot study of the efficacy, safety, and tolerability of dostarlimab in women with early-stage mismatch repair-deficient endometrioid endometrial adenocarcinoma

BACKGROUND

The standard treatment for endometrial cancer is hysterectomy with or without bilateral salpingo-oophorectomy; however, this may not be an optimal choice for women who have not completed childbearing or who are at a high risk of surgical complications. Conservative treatment with levonorgestrel intrauterine devices appear to be effective in patients with early-stage endometrial cancer; however, patients with mismatch repair-deficient (dMMR) tumors have a low likelihood of responding to levonorgestrel intrauterine devices.

PRIMARY OBJECTIVE

To assess the efficacy of dostarlimab, an active immune checkpoint inhibitor that targets the programmed cell death protein-1 receptor, in patients with early-stage dMMR endometrioid endometrial adenocarcinoma.

STUDY HYPOTHESIS

Administration of 4 3-weekly cycles of 500 mg dostarlimab followed by a 3-week rest period and 3 6-weekly cycles of 1000 mg dostarlimab will be safe and efficacious in early-stage dMMR endometrial cancer patients.

TRIAL DESIGN

Non-randomized, open-label, pilot, multicenter phase2b study designed to evaluate the efficacy and safety of dostarlimab in 10 women aged ≥18 years with a clinically confirmed diagnosis of early-stage and dMMR endometrioid endometrial adenocarcinoma.

MAJOR INCLUSION/EXCLUSION CRITERIA

Eligible patients must have histologically proven stage I, International Federation of Gynecology and Obstetrics grade 1 or 2 dMMR endometrioid endometrial adenocarcinoma and desire for fertility preservation. Exclusions include, but are not limited to, patients with other high-risk endometrial cancer cell types, a poor medical risk due to uncontrolled medical conditions, or those who experienced grade 3 or higher immune-related adverse events from prior immunotherapy.

PRIMARY ENDPOINT(S)

The primary endpoint is the number of participants achieving investigator-assessed pathological complete response within 6 months of treatment.

SAMPLE SIZE

Ten (10) women ≥18 years of age will be enrolled.

ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS

Accruals are expected to be completed by 2027, with the presentation of results by 2029.

TRIAL REGISTRATION

NCT06278857.

VRK2 promotes colorectal cancer growth and impedes immunotherapy and 5-FU treatment efficacy

Vaccinia-Related Kinase 2 (VRK2), a member of the vaccinia virus-related protein kinase family, is crucial in regulating apoptosis and tumor cell growth signaling pathways. Despite its established roles in various cancers, investigations into its functions in colorectal cancer have been relatively limited. Utilizing The Cancer Genome Atlas and Genotype-Tissue Expression databases, this study assesses VRK2 expression across 33 cancer types, highlighting significant upregulation and diagnostic relevance, particularly in colorectal cancer, where it marks poor prognosis. VRK2's influence extends across multiple cancer-related signaling pathways, with focused experiments confirming its vital role in the E2F signaling pathway through transcriptomic sequencing and dual-luciferase reporter assays. Deletion of VRK2 markedly inhibits proliferation, cell cycle progression, migration, and tumorigenesis in colorectal cancer cells, whereas overexpression enhances these oncogenic traits. Additionally, VRK2 expression correlates with genomic instability and the tumor microenvironment, influencing antitumor immunity and response to immunotherapy. Importantly, our analysis reveals that VRK2 modulates the chemosensitivity of tumor cells, specifically enhancing resistance to the chemotherapeutic agent 5-FU. These findings underscore VRK2's multifaceted role in promoting colorectal cancer development and suggest its potential as a therapeutic target.

Lower Degree of Microsatellite Instability in Colorectal Carcinomas From MSH6-Associated Lynch Syndrome Patients

Numerous observational and molecular studies focusing on Lynch syndrome (LS) have revealed significant variation in the phenotype and molecular characteristics among carriers of pathogenic variants in mismatch repair genes (path_MMR). Recently, we demonstrated that colorectal carcinomas in path_MSH6 carriers exhibit fewer insertion/deletion mutations compared with cumulative colorectal cancers (CRCs) from other MMR groups, raising the question of whether MSH6-mutated CRCs might display a relatively lower degree of microsatellite instability (MSI). Mutations at 20 coding microsatellites (cMS) were analyzed in 39 MSH6-, 18 MLH1-, 16 MSH2-, and 22 PMS2-mutated CRCs and 35 sporadic MSI CRCs, and mutation frequencies and mutant allele ratios were compared among the different MMR-deficient groups. Considering factors such as HLA-A∗02:01 type, B2M status, and the anticipated immunogenicity of frameshift peptides derived from cMS mutations, the identified cMS mutation profiles of MSH6-mutated CRCs were further investigated to assess their potential impact on immunotherapeutic strategies. MSH6-mutated CRCs exhibited lower mutation frequencies and mutant allele ratios across most cMS. Variation in cMS mutation patterns was observed both between different tumor regions and between tumor tissue and adjacent adenomatous tissue. The cMS mutations in MSH6-mutated CRCs demonstrated inverse correlations with the predicted immunogenicity of the resulting frameshift peptides, which may suggest a negative selection of cell clones bearing highly immunogenic frameshift peptides. Overall, MSH6-mutated CRCs display a relatively lower degree of MSI and represent a biologically distinct subgroup of LS-associated CRCs. This lower MSI level may implicate an altered immune response compared with other MSI CRCs, which could have theoretical implications for the success of immunotherapy in MSH6-mutated CRCs. Future studies should carefully evaluate this possibility. If confirmed, these results would reinforce the notion of classifying LS as distinct syndromes associated with specific MMR genes.

Pancreatic cancer: failures and hopes-a review of new promising treatment approaches

Pancreatic cancer is a challenging disease with limited treatment options and a high mortality rate. Just few therapy advances have been made in recent years. Tumor microenvironment, immunosuppressive features and mutational status represent important obstacles in the improvement of survival outcomes. Up to now, first-line therapy did achieve a median overall survival of less than 12 months and this discouraging data lead clinicians all over the world to focus their efforts on various fields of investigation: 1) sequential cycling of different systemic therapy in order to overcome mechanisms of resistance; 2) discovery of new predictive bio-markers, in order to target specific patient population; 3) combination treatment, in order to modulate the tumor microenvironment of pancreatic cancer; 4) new modalities of the delivery of drugs in order to pass the physical barrier of desmoplasia and tumor stroma. This review shows future directions of treatment strategies in advanced pancreatic cancer through a deep analysis of these recent macro areas of research.

Voxel-level radiomics and deep learning for predicting pathologic complete response in esophageal squamous cell carcinoma after neoadjuvant immunotherapy and chemotherapy

BACKGROUND

Accurate prediction of pathologic complete response (pCR) following neoadjuvant immunotherapy combined with chemotherapy (nICT) is crucial for tailoring patient care in esophageal squamous cell carcinoma (ESCC). This study aimed to develop and validate a deep learning model using a novel voxel-level radiomics approach to predict pCR based on preoperative CT images.

METHODS

In this multicenter, retrospective study, 741 patients with ESCC who underwent nICT followed by radical esophagectomy were enrolled from three institutions. Patients from one center were divided into a training set (469 patients) and an internal validation set (118 patients) while the data from the other two centers was used as external validation sets (120 and 34 patients, respectively). The deep learning model, Vision-Mamba, integrated voxel-level radiomics feature maps and CT images for pCR prediction. Additionally, other commonly used deep learning models, including 3D-ResNet and Vision Transformer, as well as traditional radiomics methods, were developed for comparison. Model performance was evaluated using accuracy, area under the curve (AUC), sensitivity, specificity, and prognostic stratification capabilities. The SHapley Additive exPlanations analysis was employed to interpret the model's predictions.

RESULTS

The Vision-Mamba model demonstrated robust predictive performance in the training set (accuracy: 0.89, AUC: 0.91, sensitivity: 0.82, specificity: 0.92) and validation sets (accuracy: 0.83-0.91, AUC: 0.83-0.92, sensitivity: 0.73-0.94, specificity: 0.84-1.0). The model outperformed other deep learning models and traditional radiomics methods. The model's ability to stratify patients into high and low-risk groups was validated, showing superior prognostic stratification compared with traditional methods. SHAP provided quantitative and visual model interpretation.

CONCLUSIONS

We present a voxel-level radiomics-based deep learning model to predict pCR to neoadjuvant immunotherapy combined with chemotherapy based on pretreatment diagnostic CT images with high accuracy and robustness. This model could provide a promising tool for individualized management of patients with ESCC.

Biomarkers in gastroesophageal cancer 2025: an updated consensus statement by the Spanish Society of Medical Oncology (SEOM) and the Spanish Society of Pathology (SEAP)

Gastroesophageal carcinomas, including gastroesophageal adenocarcinoma (GEA) and esophageal squamous cell carcinoma (ESCC), pose a global health challenge due to their heterogeneity. The approach to diagnosis and treatment should first differentiate between GEA and ESCC. Over the past decade, therapies for metastatic or advanced GEA/ESCC have expanded, with several new therapeutic targets alongside trastuzumab for metastatic HER2-positive GEA. Four key biomarkers are essential for targeted therapy: HER2 overexpression/amplification, deficient mismatch repair/microsatellite instability (dMMR/MSI), PD-L1, and Claudin18.2 expression. Immunohistochemistry is the recommended method for these biomarkers evaluation. In addition, the assessment of biomarkers like FGFR2b is likely to become routine in the near future. Experts from the Spanish Society of Pathology (SEAP) and the Spanish Society of Medical Oncology (SEOM) have formed a consensus to optimize biomarker detection and usage in clinical practice. Their recommendations aim to improve personalized treatment strategies for GEA and ESCC patients, integrating new diagnostic insights into routine care.

Society for Immunotherapy of Cancer (SITC) consensus statement on essential biomarkers for immunotherapy clinical protocols

Immunotherapy of cancer is now an essential pillar of treatment for patients with many individual tumor types. Novel immune targets and technical advances are driving a rapid exploration of new treatment strategies incorporating immune agents in cancer clinical practice. Immunotherapies perturb a complex system of interactions among genomically unstable tumor cells, diverse cells within the tumor microenvironment including the systemic adaptive and innate immune cells. The drive to develop increasingly effective immunotherapy regimens is tempered by the risk of immune-related adverse events. Evidence-based biomarkers that measure the potential for therapeutic response and/or toxicity are critical to guide optimal patient care and contextualize the results of immunotherapy clinical trials. Responding to the lack of guidance on biomarker testing in early-phase immunotherapy clinical trials, we propose a definition and listing of essential biomarkers recommended for inclusion in all such protocols. These recommendations are based on consensus provided by the Society for Immunotherapy of Cancer (SITC) Clinical Immuno-Oncology Network (SCION) faculty with input from the SITC Pathology and Biomarker Committees and the Journal for ImmunoTherapy of Cancer readership. A consensus-based selection of essential biomarkers was conducted using a Delphi survey of SCION faculty. Regular updates to these recommendations are planned. The inaugural list of essential biomarkers includes complete blood count with differential to generate a neutrophil-to-lymphocyte ratio or systemic immune-inflammation index, serum lactate dehydrogenase and albumin, programmed death-ligand 1 immunohistochemistry, microsatellite stability assessment, and tumor mutational burden. Inclusion of these biomarkers across early-phase immunotherapy clinical trials will capture variation among trials, provide deeper insight into the novel and established therapies, and support improved patient selection and stratification for later-phase clinical trials.

Revolutionary Cancer Therapy for Personalization and Improved Efficacy: Strategies to Overcome Resistance to Immune Checkpoint Inhibitor Therapy

Cancer remains a significant public health issue worldwide, standing as a primary contributor to global mortality, accounting for approximately 10 million fatalities in 2020 [...].

How do I treat dMMR/MSI gastro-oesophageal adenocarcinoma in 2025? A position paper from the EORTC-GITCG gastro-esophageal task force

In less than a decade, immune checkpoint inhibitors (ICIs) have transformed the management of mismatch repair-deficient (dMMR) and microsatellite instability-high (MSI) cancers. However, beyond colorectal cancer (CRC), much of the evidence is mostly derived from non-randomized phase II studies or post-hoc analyses of broader clinical trials. dMMR/MSI tumours represent a specific subgroup of gastro-esophageal adenocarcinomas (GEA), accounting for approximately 9 % of cases, with a higher prevalence in early-stage compared to advanced-stage disease and older female patients. These tumours are predominantly sporadic, often linked to MLH1 promoter methylation, and rarely exhibit HER2 overexpression/ERBB2 amplification or other oncogenic drivers. The treatment landscape for early stage dMMR/MSI GEA is likely to change substantially soon, as ICIs have shown high pathological complete response (pCR) rates in small phase II trials, raising questions on optimisation of neoadjuvant therapy, and paving the way for organ preservation. The standard of treatment for untreated patients with advanced dMMR/MSI GEA is chemotherapy + ICI irrespectively of PDL-1 status. However, the role of chemotherapy-free regimen consisting of CTLA-4 plus PD-1 inhibitors remains undetermined. This review addresses these and other emerging questions, offering expert opinions and insights into the future therapeutic landscape for dMMR/MSI GEA.

Peptide-based immuno-PET/CT monitoring of dynamic PD-L1 expression during glioblastoma radiotherapy

Real-time, noninvasive programmed death-ligand 1 (PD-L1) testing using molecular imaging has enhanced our understanding of the immune environments of neoplasms and has served as a guide for immunotherapy. However, the utilization of radiotracers in the imaging of human brain tumors using positron emission tomography/computed tomography (PET/CT) remains limited. This investigation involved the synthesis of [18F]AlF-NOTA-PCP2, which is a novel peptide-based radiolabeled tracer that targets PD-L1, and evaluated its imaging capabilities in orthotopic glioblastoma (GBM) models. Using this tracer, we could noninvasively monitor radiation-induced PD-L1 changes in GBM. [18F]AlF-NOTA-PCP2 exhibited high radiochemical purity (>95%) and stability up to 4 h after synthesis. It demonstrated specific, high-affinity binding to PD-L1 in vitro and in vivo, with a dissociation constant of 0.24 nM. PET/CT imaging, integrated with contrast-enhanced magnetic resonance imaging, revealed significant accumulation of [18F]AlF-NOTA-PCP2 in orthotopic tumors, correlating with blood-brain barrier disruption. After radiotherapy (15 Gy), [18F]AlF-NOTA-PCP2 uptake in tumors increased from 9.51% ± 0.73% to 12.04% ± 1.43%, indicating enhanced PD-L1 expression consistent with immunohistochemistry findings. Fractionated radiation (5 Gy × 3) further amplified PD-L1 upregulation (13.9% ± 1.54% ID/cc) compared with a single dose (11.48% ± 1.05% ID/cc). Taken together, [18F]AlF-NOTA-PCP2 may be a valuable tool for noninvasively monitoring PD-L1 expression in brain tumors after radiotherapy.

Lynch Syndrome: Similarities and Differences of Recommendations in Published Guidelines

BACKGROUND

In this review, we aimed to compare the recommendations for Lynch syndrome (LS).

METHODS

We compared the LS's guidelines of different medical societies, including recommendations for cancer surveillance, aspirin treatment, and universal screening.

RESULTS

Most guidelines for LS patients recommend intervals of 1-2 years for performing colonoscopy, though there is disagreement regarding the age to begin CRC screening (dependent on status as a MLH1/MSH2 or MSH6/PMS2 carrier). There are inconsistencies between LS guidelines for gastric cancer surveillance. Most guidelines do not recommend routine surveillance of the pancreas and small bowel. Most but not all of the guidelines support endometrial and ovarian surveillance with transvaginal ultrasound and endometrial biopsy. Only two societies recommend urological surveillance, while others recommend surveillance among high-risk carriers with family history only. There is significant disagreement between the guidelines about the recommendation for limited or extended bowel resection among patients with CRC. Aspirin use is recommended by most societies, though some with reservations, and most of them recommend universal screening.

CONCLUSIONS

There are significant disparities and disagreements in the guidelines and recommendations for patients with LS, causing confusion and difficulties for clinicians. Harmonization and cooperation are needed between the societies creating LS guidelines.

Advances in diagnostic and therapeutic applications of mismatch repair loss in cancer

Mismatch repair (MMR) is a highly conserved, fundamental DNA damage repair pathway that maintains genomic fidelity during cell replication. MMR dysregulation contributes to tumor formation by promoting genomic instability thereby increasing the frequency of potentially oncogenic mutational events. Therefore, MMR dysregulation, in its tumor suppressor role, is largely studied in the context of genomic instability and associated response to immune checkpoint blockade therapies. However, a growing body of literature suggests that the impact of MMR dysregulation on tumor phenotypes is more nuanced than a concerted impact on genomic stability. Rather, loss of individual MMR genes promotes distinct cancer-relevant biological phenotypes, and these phenotypes are further modulated by the tissue of tumor origin. Here, we explore relevant literature and review the prognostic and predictive significance of these non-canonical discoveries.

Multicenter In-House Evaluation of an Amplicon-Based Next-Generation Sequencing Panel for Comprehensive Molecular Profiling

BACKGROUND

Predicting response to targeted cancer therapies increasingly relies on both simple and complex genetic biomarkers. Comprehensive genomic profiling using high-throughput assays must be evaluated for reproducibility and accuracy compared with existing methods.

METHODS

This study is a multicenter evaluation of the Oncomine™ Comprehensive Assay Plus (OCA Plus) Pan-Cancer Research Panel for comprehensive genomic profiling of solid tumors. A series of 193 research samples (125 DNA and 68 RNA samples) was analyzed to evaluate the correlation and concordance of the OCA Plus panel with orthogonal methods, as well as its reproducibility (n = 5 DNA samples) across laboratories.

RESULTS

The success rate for DNA and RNA sequencing was 96.6% and 89.7%, respectively. In a single workflow, the OCA Plus panel provided a detailed genomic profile with a high success rate for all biomarkers tested: single nucleotide variants/indels, copy number variants, and fusions, as well as complex biomarkers such as microsatellite instability, tumor mutational burden, and homologous recombination deficiency. The concordance for single nucleotide variants/indels was 94.8%, for copy number variants 96.5%, for fusions 94.2%, for microsatellite instability 80.8%, for tumor mutational burden 81.3%, and for homologous recombination deficiency 100%. The results showed high reproducibility across the five European research centers, each analyzing shared pre-characterized tissue biopsies (average of 1890 single nucleotide variants/indels per sample).

CONCLUSIONS

This multicenter evaluation of the OCA Plus panel confirms the results of previous single-center studies and demonstrates the high reproducibility and accuracy of this assay.

The Molecular Landscape of 227 Adult Granulosa Cell Tumors of the Ovary: Insights into the Progression from Primary to Recurrence

Adult granulosa cell tumors (AGCTs) of the ovary are characterized by their propensity for late recurrences and are primarily managed surgically due to the limited efficacy of systemic treatment. The FOXL2 p.C134W somatic mutation has been identified in ∼95% of AGCT cases, and TERT promoter alterations have been linked to worse overall survival. This study highlights the potential prognostic significance of FOXO1 mutations, suggesting that they may be associated with poorer overall survival and shorter time to recurrence. A total of 183 primary AGCTs and 44 recurrences without corresponding primary tumors were analyzed. The primary AGCTs were categorized into 3 groups: 77 nonrecurrent tumors, 18 tumors that later recurred (including 9 cases with matched primary-recurrence pairs), and 88 tumors with unknown recurrence status. Targeted next-generation sequencing was conducted on 786 cancer-related genes to investigate their genetic profile. The study aimed to identify the molecular alterations associated with AGCT pathogenesis and recurrence rate, comparing primary versus recurrent tumors, and primary recurrent versus primary nonrecurrent cases. Our findings confirmed the high prevalence (99%) of the FOXL2 p.C134W mutation in AGCTs. Secondary truncating FOXL2 mutations were observed in 5% of cases. Two cases with typical AGCT morphology were FOXL2 wild-type, harboring mutations in KRAS or KMT2D instead, suggesting alternative genetic pathways. TERT promoter mutations were found in 43% of cases, more frequently in recurrences. Other recurrent mutations detected in the cohort included KMT2D (10%), FOXO1 (7%), CHEK2 (5%), TP53 (3.5%), PIK3CA (3.5%), and AKT1 (3%). Two recurrent, FOXL2-mutated cases also carried DICER1 mutations. One tumor exhibited MSI-high status and a tumor mutation burden of 19 mut/Mb.Our results indicate the need for further investigation into the role of FOXO1 as a potential prognostic marker in AGCTs.

Real-World Molecular Testing Rates and Patterns in Patients With Primary Advanced or Recurrent Endometrial Cancer in the United States

PURPOSE

This retrospective cohort study estimated the real-world utilization of biomarker testing among patients with primary advanced/recurrent endometrial cancer (pA/rEC) and characterized testing according to demographic and clinical characteristics.

MATERIALS AND METHODS

A nationwide electronic health record-derived deidentified database was used. Records from January 1, 2013, to August 31, 2023, for women age 18 years and older with pA/rEC were searched for DNA mismatch repair (MMR)/microsatellite instability (MSI), human epidermal growth factor receptor 2 (HER2), and estrogen receptor (ER) or progesterone receptor (PR) testing; a subsample data set (advEndo Spotlight) was searched from April 1, 2013, to November 30, 2022, for additional biomolecular testing. Testing rates were reported by index year and molecular marker. Multivariate logistic regression analyses were conducted to identify characteristics associated with testing.

RESULTS

The full data set included 2,982 patients, of whom 53% were age 65 years and older; most were non-Hispanic White (56%) and received care in a community setting (73%). The advEndo Spotlight subsample (n = 509) had similar characteristics. From 2013 to 2021, testing for any biomarker increased from 53% to 89% (MMR/MSI, 17% to 81%; ER/PR, 45% to 62%; HER2, 15% to 43%). Patients who received care at an academic versus community facility, had commercial/other insurance versus Medicare/Medicaid, had primary advanced versus recurrent EC, had endometrioid versus nonendometrioid carcinoma, or had no previous surgery as part of primary treatment were more likely to receive testing.

CONCLUSION

Molecular testing rates in pA/rEC have increased over time, likely due in part to incorporation of biomarker testing into treatment guidelines. This highlights an unmet need to ensure universal access to testing in patients with pA/rEC. Understanding these factors can inform approaches to increase access to molecular testing and increase testing rates.

Melanoma Cell Adhesion Molecule Plays a Pivotal Role in Proliferation, Migration, Tumor Immune Microenvironment, and Immunotherapy in Colorectal Cancer

INTRODUCTION

MCAM, alternatively referred to as CD146, is an integral membrane glycoprotein belonging to the immunoglobulin superfamily. However, its importance in the tumorigenesis of colorectal cancer is still partially understood. Therefore, this study was designed to investigate the significance of MCAM in colorectal cancer.

METHODS

MCAM expression was analyzed by TCGA and GEO databases. qRT-PCR and IHC analysis were conducted to validate MCAM expression in patient tissues. The tumor-inhibiting ability of MCAM was further assessed by CCK-8 assay, colony formation assay, and wound-healing assay. qRT-PCR and WB analysis were conducted to evaluate the expression of EMT markers and MMP2/9. qRT-PCR analysis was utilized to detect the polarization status of macrophages. Kaplan-Meier curve, univariate, and multivariate cox analyses were employed to verify the ability of MCAM in prognosis prediction. TIDE scores were used to assess the impact of MCAM on immunotherapy.

RESULTS

The expression of MCAM was significantly downregulated in CRC, and low MCAM expression revealed poor prognosis in CRC patients. Moreover, MCAM overexpression inhibited the proliferation, migration, and invasive ability of CRC cells. Additionally, MCAM overexpression suppressed N-cadherin and MMP2/9 expression. Furthermore, MCAM impacted M1 macrophage polarization. MCAM is an independent predictor of CRC patient prognosis through Cox regression analysis. Lastly, TIDE score analysis indicated that elevated expression of MCAM increased immunotherapy efficacy.

CONCLUSION

The findings of this research suggest that MCAM impacts M1 macrophage polarization and enhances immunotherapy efficacy, underscoring its potential as a therapeutic target for colorectal cancer.

Analytical and Clinical Validation of Solo-Test Driver: A Targeted Amplicon-Based NGS Test-System for FFPE and cfDNA Analysis in Clinical Oncology Setting

BACKGROUND

Next-generation sequencing (NGS) is increasingly integrated into cancer patient management, necessitating cost-effective, reliable tests for companion diagnostics. We present the validation of the Solo-test Driver panel, a custom NGS amplicon-based tool for DNA analysis of 34 oncogenes, addressing key clinical needs.

METHODS

The panel's performance was validated for detecting SNVs, CNVs, and MSI. Analytical validation used 182 samples, while clinical validation involved 130 samples, both encompassing diverse tumor types and specimen formats.

RESULTS

The Solo-test Driver panel has the potential to identify an additional 18.3%, 16.5%, and 8.7% of RAS+ colorectal, PIK3CA+ breast, and EGFR+ lung cancer patients, respectively, when compared to FDA-approved PCR tests. Analytical validation demonstrated high intra-lab robustness (coefficient of variation of coverage uniformity 6.4%) and high inter-lab robustness (PCC of per-amplicon coverage 0.82, 0.84, 0.9 for three different labs). Estimated in silico sensitivity was 100% for detecting clinically actionable SNVs at 250x, corresponding to only 60,000 read pairs per sample. In vitro mixing experiments determined LoD starting from 3.3% VAF. Estimated in silico LoD ranged from 0.5% to 5% at 1000× (1% to 5% at 650x). Clinical validation demonstrated PPA/NPA of 100%/80%, 95%/100%, and 100%/100% for detecting MSI, SNVs, and CNVs, respectively.

CONCLUSIONS

The Solo-test Driver panel offers a reliable, cost-effective solution for detecting somatic alterations and genomic signatures, making it suitable for routine companion diagnostics in solid tumors.

Microsatellite instability-high status as a pan-cancer biomarker for immunotherapy efficacy

BACKGROUND

Microsatellite instability-high (MSI-H) cancers are linked to exceptional benefit from immune checkpoint inhibitors (ICIs), but studies on their efficacy across various MSI-H cancer types are limited.

METHODS

Randomized clinical trials (RCTs) comparing ICIs to chemotherapy in advanced MSI-H/dMMR cancers were systematically reviewed. Eligible studies included 13 RCTs with 1633 MSI-H patients across colorectal, gastric, and endometrial cancers. Data were analyzed using hazard ratios for progression-free survival (PFS) and overall survival (OS), with subgroup analyses by tumor type. Statistical heterogeneity was assessed using Cochrane's Q and I2.

RESULTS

Immunotherapy significantly improved PFS and OS in MSI-H patients, with an HR for OS of 0.35 (95% CI 0.27-0.46; p < 0.00001) versus 0.81 for MSS patients. PFS showed a 64% reduced risk of progression (HR = 0.36, 95% CI 0.28-0.46; p < 0.0001). Subgroup analyses highlighted PFS benefits across tumor types: colorectal (HR = 0.28, 95% CI 0.11-0.73), gastric (HR = 0.43, 95% CI 0.27-0.68), and endometrial cancers (HR = 0.34, 95% CI 0.27-0.42).

CONCLUSIONS

This meta-analysis establishes MSI-H as a predictive biomarker for ICIs, supporting its role in therapy selection and underscoring the need for MSI-H/dMMR-focused clinical trials.

Mismatch repair (MMR) and microsatellite instability (MSI) phenotypes across solid tumors: A comprehensive cBioPortal study on prevalence and prognostic impact

Mismatch repair deficiency (MMR-d) and microsatellite instability (MSI) are prognostic and predictive biomarkers in oncology. Current testing for MMR/MSI relies on immunohistochemistry (IHC) for MMR proteins and molecular assays for MSI detection. This combined diagnostic strategy, however, lacks tumor specificity and does not account for gene variants. This study provides an in-depth analysis of MMR mutations frequency, spectrum, and distribution in solid tumors. Data from 23,893 patients across 11 tumor types, using 66 publicly available studies, were analyzed. MMR-mutated (MMR-m) status was defined by alterations in MLH1, PMS2, MSH2, and/or MSH6; MSI was assessed by MSIsensor. Cases with indeterminate labelling were excluded. Survival was analyzed using the Kaplan-Meier method. Among 19,353 tumors, 949 MMR variants were identified, comprising 432 pathogenic and 517 variants of unknown significance (VUS), as defined by OncoKB. MSH6 mutations were the most frequent (n = 279, 29.4 %), followed by MSH2 (n = 198, 20.9 %), MLH1 (n = 187, 19.7 %), and PMS2 (n = 161, 16.9 %). MMR-m cases were more frequent in endometrial (EC, 20.5 %), colorectal (CRC, 8.2 %), bladder (BLCA, 8.7 %), and gastroesophageal cancers (GEC, 5.4 %). Pathogenic mutations were more common than non-pathogenic in EC, CRC, and GEC (p < 0.001, p = 0.01, p = 0.32, respectively). MMR-m status was not associated with MSI in 247 (48.9 %) cases, including 67 (13.2 %) with pathogenic mutations. The highest concordance between MMR-m and MSI was observed in CRC (65.7 %), EC (91.2 %), and GEC (69.6 %), while the lowest in pancreatic (0.2 %) and lung cancers (0.1 %). MMR-m GECs showed improved overall survival compared to MMR-wt (p = 0.009), a relationship not observed in other tumor types. This study demonstrates that the MMR spectrum is extremely hetoerogeneous in solid tumors, highliting the need for comprehensive and tumor-specific testing strategies.

Dynamics of blood microsatellite instability (bMSI) burden predicts outcome of a patient treated with immune checkpoint inhibitors: a case report of hyperprogressive disease

Microsatellite instability (MSI) is a widely studied molecular signature, which is associated with long-term benefit in patients treated with immune checkpoint inhibitor therapy. This approach has been proven to be effective in the treatment of patients with MSI-positive colorectal cancer (CRC). Analysis of serial liquid biopsy samples allows to detect changes in the tumor in response to therapy. Typically, somatic mutations are used for tracing the dynamics of the tumor, and the assessment of DNA signatures such as MSI is not currently used for these purposes. Here, we describe a case of a MSI-positive CRC, who received nivolumab monotherapy. Sequential sampling of the patient's plasma demonstrated an increase in MSI burden (bMSI), which was found to correlate with the increase of driver mutation burden one month after starting nivolumab, and hyperprogressive disease. Thus, analysis of bMSI in liquid biopsy via NGS may be a promising method for timely assessment of the treatment effectiveness received by patients with MSI-positive CRC.

Deep visual proteomics reveals DNA replication stress as a hallmark of signet ring cell carcinoma

Signet Ring Cell Carcinoma (SRCC) is a rare and highly malignant form of adenocarcinoma with increasing incidence and poor prognosis due to late diagnosis and limited treatment options. We employed Deep Visual Proteomics (DVP), which combines AI-directed cell segmentation and classification with laser microdissection and ultra-high sensitivity mass spectrometry, for cell-type-specific proteomic analysis of SRCC across the bladder, prostate, seminal vesicle, and a lymph node of a single patient. DVP identified significant alterations in DNA damage response (DDR) proteins, particularly within the ATR and mismatch repair (MMR) pathways, indicating replication stress as a crucial factor in SRCC mutagenicity. Additionally, we observed substantial enrichment of immune-related proteins, reflecting high levels of cytotoxic T lymphocyte infiltration and elevated PD-1 expression. These findings suggest that pembrolizumab immunotherapy may be more effective than conventional chemotherapy for this patient. Our results provide novel insights into the proteomic landscape of SRCC, identify potential targets, and open up for personalized therapeutic strategies in managing SRCC.

Deep learning-assisted colonoscopy images for prediction of mismatch repair deficiency in colorectal cancer

BACKGROUND

Deficient mismatch repair or microsatellite instability is a major predictive biomarker for the efficacy of immune checkpoint inhibitors of colorectal cancer. However, routine testing has not been uniformly implemented due to cost and resource constraints.

METHODS

We developed and validated a deep learning-based classifiers to detect mismatch repair-deficient status from routine colonoscopy images. We obtained the colonoscopy images from the imaging database at Endoscopic Center of the Sixth Affiliated Hospital, Sun Yat-sen University. Colonoscopy images from a prospective trial (Neoadjuvant PD-1 blockade by toripalimab with or without celecoxib in mismatch repair-deficient or microsatellite instability-high locally advanced colorectal cancer) were used to test the model.

RESULTS

A total of 5226 eligible images from 892 tumors from the consecutive patients were utilized to develop and validate the deep learning model. 2105 colorectal cancer images from 306 tumors were randomly selected to form model development dataset with a class-balanced approach. 3121 images of 488 proficient mismatch repair tumors and 98 deficient mismatch repair tumors were used to form the independent dataset. The model achieved an AUROC of 0.948 (95% CI 0.919-0.977) on the test dataset. On the independent validation dataset, the AUROC was 0.807 (0.760-0.854), and the NPV in was 94.2% (95% CI 0.918-0.967). On the prospective trial dataset, the model identified 29 tumors among the 33 deficient mismatch repair tumors (87.88%).

CONCLUSIONS

The model achieved a high NPV in detecting deficient mismatch repair colorectal cancers. This model might serve as an automatic screening tool.

Comprehensive Analyses of PANoptosome with Potential Implications in Cancer Prognosis and Immunotherapy

Cell death resistance significantly contributes to poor therapeutic outcomes in various cancers. PANoptosis, a unique inflammatory programmed cell death (PCD) pathway activated by specific triggers and regulated by the PANoptosome, possesses key features of apoptosis, pyroptosis, and necroptosis, but these cannot be accounted for by any of the three PCD pathways alone. While existing studies on PANoptosis have predominantly centered on infectious and inflammatory diseases, its role in cancer malignancy has been understudied. In this comprehensive investigation, we conducted pan-cancer analyses of PANoptosome component genes across 33 cancer types. We characterized the genetic, epigenetic, and transcriptomic landscapes, and introduced a PANoptosome-related potential index (PANo-RPI) for evaluating the intrinsic PANoptosome assembly potential in cancers. Our findings unveil PANo-RPI as a prognostic factor in numerous cancers, including KIRC, LGG, and PAAD. Crucially, we established a significant correlation between PANo-RPI and tumor immune responses, as well as the infiltration of diverse lymphoid and myeloid cell subsets across nearly all cancer types. Moreover, a high PANo-RPI was consistently associated with improved immunotherapy response and efficacy, as evidenced by re-analysis of multiple immunotherapy cohorts. In conclusion, our study suggests that targeting PANoptosome components and modulating PANoptosis may hold tremendous therapeutic potential in the context of cancer.

Evaluating Tumour Mutational Burden as a Key Biomarker in Personalized Cancer Immunotherapy: A Pan-Cancer Systematic Review

BACKGROUND

Tumour mutational burden (TMB) is an emerging biomarker for predicting the efficacy of immune checkpoint inhibitors (ICIs) in cancer therapy. While its role is well established in lung cancer and melanoma, its predictive value for breast and prostate cancers remains unclear.

OBJECTIVE

This systematic review aimed to assess the predictive value of TMB for ICI therapy across four major cancer types-lung, melanoma, breast, and prostate-and to explore factors contributing to the variability in its effectiveness as a biomarker.

METHODS

A systematic search and a review of the literature were conducted in accordance with PRISMA guidelines. Studies examining the relationship between TMB levels and clinical outcomes following ICI therapy in the specified cancers were analyzed. The data were synthesized to evaluate TMB's predictive value and identify gaps in the current research.

RESULTS

High TMB consistently correlated with improved outcomes in lung cancer and melanoma, confirming its predictive utility in these cancers. Conversely, the findings for breast and prostate cancers were inconclusive. The variability in TMB's predictive value for these cancers suggests the need for complementary biomarkers or refined criteria to enhance its reliability. Methodological inconsistencies in TMB evaluation were also noted as a significant limitation.

CONCLUSIONS

TMB serves as a robust biomarker for predicting ICI response in lung cancer and melanoma, but demonstrates limited predictive utility in breast and prostate cancers. Future research should prioritize standardizing TMB assessment protocols and investigating additional biomarkers to improve treatment personalization for these cancer types.

Study of Microsatellite Instability by Immunohistochemistry in a Cohort of Patients With Melanoma

BACKGROUND

Microsatellite instability (MSI) has prognostic value and impacts therapy strategies in several malignancies. Data regarding MSI in melanoma are scarce. The aim of this study was to assess MSI through the analysis of MMR protein expression in patients with melanoma.

METHODS

An observational retrospective single-center study was designed based on patients with primary melanoma. We assessed MSI through immunohistochemical staining with anti-MLH1, anti-MSH2, anti-MSH6, and anti-PMS2 on full-thickness excision tissue.

RESULTS

Ninety-three patients were included in this study. The complete absence of nuclear staining in tumoral cells was extremely rare, with only one melanoma not expressing MSH6. Most melanomas showed an expression index for MLH1 (77.7%), MSH2 (87.2%), and PMS2 (78.6%) ≥ 75%. Most melanomas (57.8%) exhibited an MSH6 expression index in the range of 1%-74%. A low MSH6 expression index and a reduced combined MMR protein expression index (MMR-e) were significantly associated with higher melanoma-specific survival. A mild PMS2 staining intensity was significantly associated with a higher melanoma-specific survival. The patients with high MMR-e who received immunotherapy progressed and died more frequently than those with reduced MMR-e (75% vs. 33.3%).

CONCLUSION

More studies are needed to further define the role of MSI in melanoma prognosis and response to immunotherapy.