Predict Tumor Response Research Articles

Abstract 275: Deciphering biphasic responses to Sonic Hedgehog pathway inhibition in breast cancer: Insights from a tumor-fibroblast spheroid model and PDXs

Abstract A significant subset (30-40%) of triple-negative breast cancer (TNBC) cases exhibit hyperactivation of the sonic hedgehog (SHH) pathway, correlating with poor clinical outcomes. However, the therapeutic efficacy of SHH inhibitors in TNBC has yielded inconsistent results, showcasing biphasic tumor responses going from complete remission in some patients to faster disease progression in others. Such tumor response discrepancies underscore the need for more relevant culture models to elucidate how stromal cells respond to SHH signals and impact tumor cell reprogramming.We have developed a tumor-fibroblast spheroid model of robust paracrine SHH signaling to examine alterations in aggressive tumor cell phenotypes resulting from altered SHH pathway activity levels to understand better how SHH therapy leads to biphasic effects in tumor tissues. Specifically, tumor stemness alterations were examined as a function of SHH signal strength altered by tumor-fibroblast proximity, and findings were confirmed in two PDX models of TNBC of divergent sensitivity to pharmacological SHH pathway inhibition. In vitro, results show that tumor stemness potency is enriched by tumor-fibroblast proximity and inversely correlates with SHH pathway activity levels. Tumor stemness potency was determined via a mammosphere forming assay and resistance to chemotherapy using docetaxel as treatment. CD44+ sorted tumor cells derived from adjacent fibroblast cultures showed higher mammosphere forming efficiency and docetaxel sensitivity than those from mixed cultures. These effects correlated with differences in SHH pathway activity strengths and were reverted by pharmacological inhibition of SHH confirming pathway activity involvement. In two PDX models, both exhibiting high SHH pathway activity and similar tumor vascularization, we observed variable response to pharmacological SHH inhibition. PDX2 displayed favorable responses with minimal alpha-smooth muscle actin-positive (SMA+) fibroblast infiltration, while PDX1 exhibited no benefit from SHH therapy, accompanied by a high level of SMA+ fibroblasts. Spatial transcriptomic analysis confirmed stemness enrichments in the PDX1 model treated with SHH inhibitor- a scenario our mixed co-culture model resembled. Stemness-enriched tumor regions were positive for the Ki67 proliferation marker and confined to areas of high SMA+ cell abundance. Plotting Ki67 vs SMA+ cell levels revealed a positive correlation, suggesting that SMA levels may predict tumor response to SHH pathway inhibition.In summary, our studies demonstrate that pharmacological SHH inhibition can induce altered tumor plasticity by favoring stemness phenotypes. Strategies targeting tumor stemness may mitigate biphasic effects in response to SHH inhibitors, offering insights for optimizing TNBC therapeutic approaches. Citation Format: Heizel M. Rosado-Galindo, Miosotis Acevedo-Esquillin, Wandaliz Torres-García, Ana M. Reyes-Ramos, Gabriela Ortiz-Soto, Michelle M. Martínez-Montemayor, Maribella Domenech. Deciphering biphasic responses to Sonic Hedgehog pathway inhibition in breast cancer: Insights from a tumor-fibroblast spheroid model and PDXs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 275.

Abstract 5115: Designing targeted approaches for recurrent medulloblastoma

Abstract Designing targeted therapies for recurrent medulloblastomaPediatric brain tumors are the leading cause of cancer-related death in children, with medulloblastoma (MB) being the most common type. Despite significant progress in the field, approximately 30% of children with MB will relapse. Recurrent MB is commonly metastatic and virtually none of these patients will live beyond the one-year hallmark. These sobering statistics highlight the significant unmet need for effective therapies for recurrent MB. The likely underlying cause of the constant failure of our current clinical approaches, which are based on data obtained from disease models recapitulating primary tumors, is the disparity in genomic and transcriptomic data between primary and relapsed disease. Because of these disparities, we hypothesize that by conducting mechanistic studies and drug screens in relapse disease models, we can improve the outcomes for children with recurrent MB. Our data, obtained through a bioinformatics mining approach to predict tumor response, enabled us to identify a clinically relevant candidate drug for the treatment of recurrent MB: Minnelide. This compound acted on MYC to reduce tumor growth and the metastatic dissemination of tumors with the genetic background often found in relapsed MB patients. Additionally, to further support the translational relevance of our data, Minnelide increased the efficacy of adjuvant therapeutics used in the clinical management of MB. Our findings not only highlight the potential for repurposing Minnelide to treat children with recurrent MB, but also the potential of our research approaches aimed at identifying novel therapeutics for relapsed cancers. Citation Format: Jezabel Rodriguez Blanco. Designing targeted approaches for recurrent medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5115.

Abstract 5166: A multiplexed immunofluorescence assay to assess Rb and phospho-Rb as predictive biomarkers for CDK4/6 inhibitors in HR+/HER2- breast cancer

Abstract Introduction: Cyclin-dependent kinases 4/6 inhibitors (CDK4/6i) are used as the first-line treatment of advanced/metastatic or high-risk HR+/HER2- breast cancer (BC) that make up about 60-70% of all cases. However, nearly 50% of patients exhibit drug resistance. Therefore, biomarkers that predict CDK4/6i response are needed to spare patients from toxicities and high costs. Resistance to CDK4/6i [palbociclib, ribociclib, and abemaciclib] is associated with the aberrant or loss of Retinoblastoma (Rb). A decline in phospho-Rb (pRb) levels on therapy is also associated with CDK4/6i response. We aimed to develop a multiplex immunofluorescence (IF) assay to assess Rb and pRb levels that can be used on circulating tumor cells (CTCs) to predict tumor response to CDK4/6i. Here, we report the selection of internal controls for Rb and pRb, assay repeatability and reproducibility, as well as compatibility of the CTC isolation protocol with the assay. Methods: Rb and pRb expression was evaluated by western blotting (WB) and IF in parental (P), estrogen deprivation-resistant (EDR), palbociclib-resistant (PalboR), and EDR/PalboR derivatives of two HR+/HER2- cell lines (MCF7 and T47D), Rb1 KO cells of MCF7 and T47D, as well as triple-negative cell lines, BT549 and MDA-MB-468. IF-stained cells were imaged using Leica STED SP8 confocal microscope and Zeiss Axioscan 7. The concordance between IF and WB results was assessed using a Bland-Altman plot. Selectivity and specificity of the assay as well as repeatability and reproducibility between investigators were also assessed. Blood from healthy subjects was used to test the compatibility of the ScreenCell® filtration system to isolate CTC with the IF assay. Results: Our initial approach utilized indirect IF staining for Rb and pRb using the same primary antibodies as WB. On the Bland-Altman plot, most data points were relatively close to the bias line, suggesting that the difference between the two methods was acceptable. The analytical range for mean Rb and pRb staining intensity was 0.744 - 46.779 and 1.001 - 52.919, respectively. Based on WB and IF data, we nominated T47D PalboR and MDA-MB-468 cells as negative controls for Rb and pRb expression. The selectivity and specificity were 100% and 70%, respectively, for the Rb expression and 99% and 61% for pRb, respectively. The IF assay was repeatable and reproducible between two investigators. The ScreenCell® CTC isolation method was not compatible with the assay, as Rb and pRb expression was either not detected or limited when processed using FC2 or PBTFC buffer, irrespective of the antigen retrieval. Conclusion: We have selected internal cell line controls for Rb and pRb and are in the process of optimizing signal-to-noise ratio and specificity using conjugated antibodies. We are also testing the compatibility of other CTC isolation methods with the IF assay. Citation Format: Mantasha Tabassum, Shivaani Suresh Kanna, Wangjia Cao, Mothaffar Rimawi, George E Miles, Meghana V Trivedi. A multiplexed immunofluorescence assay to assess Rb and phospho-Rb as predictive biomarkers for CDK4/6 inhibitors in HR+/HER2- breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5166.

Noninvasively Deciphering the Immunosuppressive Tumor Microenvironment Using Galectin-1 PET to Inform Immunotherapy Responses.

Immune checkpoint blockade (ICB) has achieved groundbreaking results in clinical cancer therapy; however, only a subset of patients experience durable benefits. The aim of this study was to explore strategies for predicting tumor responses to optimize the intervention approach using ICB therapy. Methods: We used a bilateral mouse model for proteomics analysis to identify new imaging biomarkers for tumor responses to ICB therapy. A PET radiotracer was synthesized by radiolabeling the identified biomarker-targeting antibody with 124I. The radiotracer was then tested for PET prediction of tumor responses to ICB therapy. Results: We identified galectin-1 (Gal-1), a member of the carbohydrate-binding lectin family, as a potential negative biomarker for ICB efficacy. We established that Gal-1 inhibition promotes a sensitive immune phenotype within the tumor microenvironment (TME) for ICB therapy. To assess the pre-ICB treatment status of the TME, a Gal-1-targeted PET radiotracer, 124I-αGal-1, was developed. PET imaging with 124I-αGal-1 showed the pretreatment immunosuppressive status of the TME before the initiation of therapy, thus enabling the prediction of ICB resistance in advance. Moreover, the use of hydrogel scaffolds loaded with a Gal-1 inhibitor, thiodigalactoside, demonstrated that a single dose of thiodigalactoside-hydrogel significantly potentiated ICB and adoptive cell transfer immunotherapies by remodeling the immunosuppressive TME. Conclusion: Our study underscores the potential of Gal-1-targeted PET imaging as a valuable strategy for early-stage monitoring of tumor responses to ICB therapy. Additionally, Gal-1 inhibition effectively counteracts the immunosuppressive TME, resulting in enhanced immunotherapy efficacy.

Platelet-to-lymphocyte ratio predicts tumor response and survival of patients with hepatocellular carcinoma undergoing immunotherapies

BackgroundLymphocyte-related factors were associated with survival outcome of different types of cancers. Nevertheless, the association between lymphocytes-related factors and tumor response of immunotherapy remains unclear. MethodsThis is a retrospective study. Eligible participants included patients with unresectable or advanced hepatocellular carcinoma (HCC) who underwent immunotherapy as their first-line treatment. Radiological assessment of tumor response adhered to RECIST 1.1 and HCC-specific modified RECIST (mRECIST) criteria. Univariate and multivariate logistic analyses were employed to analyze clinical factors associated with tumor response. Kaplan-Meier survivial analysis were employed to compare progression‐free survival (PFS) and overall survival (OS) across different clinical factors. Furthermore, patients who received treatment with either a combination of bevacizumab and anti-PD-1(L1) antibody (Beva group) or tyrosine-kinase inhibitor (TKI) and anti-PD-1 antibody (TKI group) were examined to explore the relation between clinical factors and tumor response. ResultsA total of 208 patients were enrolled in this study. The median PFS and OS were 9.84 months and 24.44 months,respectively. An independent factor associated with a more favorable tumor response to immunotherapy was identified when PLR<100. Patients with PLR<100 had longer PFS than other patients, while OS showed no significant difference. Further analysis revealed that PLR exhibited superior prognostic value in patients of the Beva group as compared to those in the TKI group. ConclusionsThere exisits an association between PLR and tumor response as well as survival outcomes in patients receiving immunotherapy, particularly those treated with the combination of bevacizumab and anti-PD-1.

Soluble PD-L1 predicts tumor response and immune-related adverse events in patients with advanced melanoma treated with anti-PD-1 antibodies.

Immune checkpoint inhibitors (ICIs) bring prognostic benefits to patients with malignancies. However, there is a substantial number of patients whose lesions are not improved by ICIs. In addition, ICIs may cause immune-related adverse events (irAEs), which could lead to an unfavorable prognosis with fatal consequences. Therefore, we conducted a retrospective study to evaluate the utility of circulating sPD-L1 (soluble programmed cell death 1 ligand 1) as a biomarker in patients with advanced melanoma treated with anti-PD-1 (programmed cell death 1 protein) antibodies. Sera from 31 consecutive patients were prospectively collected before and after anti-PD-1 antibody treatment and the serum level of sPD-L1 was evaluated. We found that high sPD-L1 levels before treatment were associated with better prognosis, and this association was observed only in patients with a low tumor burden. We also found that sPD-L1 levels were elevated in patients who developed severe irAEs after treatment, and the patients with severe irAEs had significantly higher fluctuations in sPD-L1 (delta sPD-L1) than those without severe irAEs. Our study suggests that serum sPD-L1 level is a useful biomarker to predict tumor response and irAE development in patients with advanced melanoma treated with anti-PD-1 antibodies.

Multi-task reconstruction network for synthetic diffusion kurtosis imaging: Predicting neoadjuvant chemoradiotherapy response in locally advanced rectal cancer

PurposeTo assess the feasibility and clinical value of synthetic diffusion kurtosis imaging (DKI) generated from diffusion weighted imaging (DWI) through multi-task reconstruction network (MTR-Net) for tumor response prediction in patients with locally advanced rectal cancer (LARC). MethodsIn this retrospective study, 120 eligible patients with LARC were enrolled and randomly divided into training and testing datasets with a 7:3 ratio. The MTR-Net was developed for reconstructing Dapp and Kapp images from apparent diffusion coefficient (ADC) images. Tumor regions were manually segmented on both true and synthetic DKI images. The synthetic image quality and manual segmentation agreement were quantitatively assessed. The support vector machine (SVM) classifier was used to construct radiomics models based on the true and synthetic DKI images for pathological complete response (pCR) prediction. The prediction performance for the models was evaluated by the receiver operating characteristic (ROC) curve analysis. ResultsThe mean squared error (MSE), peak signal-to-noise ratio (PSNR), and structural similarity index measure (SSIM) for tumor regions were 0.212, 24.278, and 0.853, respectively, for the synthetic Dapp images and 0.516, 24.883, and 0.804, respectively, for the synthetic Kapp images. The Dice similarity coefficient (DSC), positive predictive value (PPV), sensitivity (SEN), and Hausdorff distance (HD) for the manually segmented tumor regions were 0.786, 0.844, 0.755, and 0.582, respectively. For predicting pCR, the true and synthetic DKI-based radiomics models achieved area under the curve (AUC) values of 0.825 and 0.807 in the testing datasets, respectively. ConclusionsGenerating synthetic DKI images from DWI images using MTR-Net is feasible, and the efficiency of synthetic DKI images in predicting pCR is comparable to that of true DKI images.

Baseline and early response 2-[18F]FDG-PET/MRI for prediction of radiotherapy outcome in uterine cervical squamous cell carcinoma: a prospective single-center observational cohort study

BackgroundShould early response imaging predict tumor response to therapy, personalized treatment adaptations could be feasible to improve outcome or reduce the risk of adverse events. This prospective single-center observational study on 2-fluorine-18-fluoro-deoxy-glucose (2-[18F]FDG) positron-emission tomography/magnetic resonance imaging (PET/MRI) features aims to investigate the association between semantic 2-[18F]FDG-PET/MRI imaging parameters and outcome prediction in uterine cervical squamous cell carcinoma (CSCC) treated with radiotherapy.ResultsEleven study participants with previously untreated CSCC were examined with 2-[18F]FDG-PET/MRI at baseline and approximately one week after start of curative radiotherapy. All study participants had at least 24 months clinical follow-up. Two patients relapsed during the follow-up period. Reduced tumor size according to visual assessment was present in 9/11 participants (median change in sum of largest diameters (SLD) − 10.4%; range − 2.5 to − 24.6%). The size reduction was less pronounced in the relapse group compared to the no relapse group, with median change in SLD − 4.9%, versus − 10.4%. None of the reductions qualified as significantly reduced or increased in size according to RECIST 1.1., hence all participants were at this stage classified as non-responders/stable disease. Median baseline functional tumor volume (FTV) for the relapse group was 126 cm3, while for the no relapse group 9.3 cm3. Median delta FTV in the relapse group was 50.7 cm3, representing an actual increase in metabolically active volume, while median delta FTV in the no relapse group was − 2.0 cm3. Median delta apparent diffusion coefficient (ADC) was lower in the relapse group versus the no relapse group (− 3.5 mm2/s vs. 71 mm2/s).ConclusionsEarly response assessment with 2-[18F]FDG-PET/MRI identified potentially predictive functional imaging biomarkers for prediction of radiotherapy outcome in CSCC, that could not be recognized with tumor measurements according to RECIST 1.1. These biomarkers (delta FTV and delta ADC) should be further evaluated.Trial registration Clinical Trials, NCT02379039. Registered 4 March 2015—Retrospectively registered, https://classic.clinicaltrials.gov/ct2/show/study/NCT02379039.

QUANTITATIVE ANALYSIS OF PET IMAGING VIA THE FOUR-COMPARTMENT MODEL FOR LUNG CANCER ASSESSMENT

Lung cancer is a life-threatening disease that requires early detection for effective treatment. Positron emission tomography (PET) imaging has been instrumental in diagnosing and monitoring lung cancer, but it has some limitations. To overcome these limitations, the four-compartment model has been developed, which provides a more accurate representation of the cancer's metabolic activity. This model incorporates the vascular volume and tracer delivery rate into the traditional two-compartment model, resulting in improved diagnostic accuracy and treatment planning. Recent studies have shown that the four-compartment model outperforms conventional PET scans in predicting tumor response to treatment and differentiating between active and inactive cancer cells. The four-compartment model holds great promise in revolutionizing the diagnosis and monitoring of lung cancer, offering improved outcomes and renewed hope for patients worldwide. Keywords: Lung cancer, PET imaging, four-compartment model, metabolic activity, diagnosis, monitoring, limitations, vascular volume, tracer delivery rate, accuracy, treatment planning, tumor response, active cancer cells.

Peripheral blood lymphocyte subsets predict the efficacy of TACE with or without PD-1 inhibitors in patients with hepatocellular carcinoma: a prospective clinical study.

Although peripheral blood lymphocyte subsets, particularly PD-1+ T cells, are promising prognostic indicators for patients with cancer. However, their clinical significance remains unclear. We prospectively enrolled 157 patients with hepatocellular carcinoma (HCC) treated with transcatheter arterial chemoembolization combined with or without PD-1 inhibitors. Twenty peripheral lymphocyte subsets and cytokines were analyzed. We analyzed the differences in PD-1+ T cells between patients treated with and without PD-1 inhibitors and their associations with tumor response, survival prognosis, and clinical features. We found that the baseline CD8+PD-1+ and CD4+PD-1+ T-cell frequencies in patients who had received PD-1 inhibitors were lower than those in patients who had not received PD-1 inhibitors (p < 0.001). In the former patients, there were no differences in PD-1+ T-cell frequencies between the responder and non-responder subgroups (p > 0.05), whereas in the latter patients, the levels of CD8+PD-1+ T cells, CD4+PD-1+ T cells, and CD8+PD-1+/CD4+PD-1+ ratio did not predict tumor response, progression-free survival (PFS), or overall survival (OS) (p>0.05). Furthermore, in multivariate analysis of patients treated with or without PD-1 inhibitors revealed that the levels of CD8+CD38+ T cells (OR = 2.806, p = 0.006) were associated with tumor response, whereas those of CD8+CD28+ T cells (p = 0.038, p = 0.001) and natural killer (NK) cells (p = 0.001, p = 0.027) were associated with PFS and OS. Although, these independent prognostic factors were associated with progressive tumor characteristics (p<0.05), with the exception of CD8+CD28+ T cells, changes in these factors before and after treatment were unassociated with tumor response (p > 0.05). Circulating CD8+CD38+ T cells, CD8+CD28+ T cells, and NK cells were identified as potential prognostic factors for tumor response and survival in patients with HCC. Contrastingly, although PD-1 inhibitors can effectively block the T cell PD-1 receptor, the baseline PD-1+ T-cell frequencies and changes in the frequency of these cells have limited prognostic value.

Drug-resistant profiles of extracellular vesicles predict therapeutic response in TNBC patients receiving neoadjuvant chemotherapy

BackgroundPredicting tumor responses to neoadjuvant chemotherapy (NAC) is critical for evaluating prognosis and designing treatment strategies for patients with breast cancer; however, there are no reliable biomarkers that can effectively assess tumor responses. Therefore, we aimed to evaluate the clinical feasibility of using extracellular vesicles (EVs) to predict tumor response after NAC.MethodsDrug-resistant triple-negative breast cancer (TNBC) cell lines were successfully established, which developed specific morphologies and rapidly growing features. To detect resistance to chemotherapeutic drugs, EVs were isolated from cultured cells and plasma samples collected post-NAC from 36 patients with breast cancer.ResultsAmong the differentially expressed gene profiles between parental and drug-resistant cell lines, drug efflux transporters such as MDR1, MRP1, and BCRP were highly expressed in resistant cell lines. Drug efflux transporters have been identified not only in cell lines but also in EVs released from parental cells using immunoaffinity-based EV isolation. The expression of drug resistance markers in EVs was relatively high in patients with residual disease compared to those with a pathological complete response.ConclusionsThe optimal combination of drug-resistant EV markers was significantly efficient in predicting resistance to NAC with 81.82% sensitivity and 92.86% specificity.

Survival outcomes in patients with resectable gastric cancer treated with total neoadjuvant therapy.

338 Background: Perioperative chemotherapy is the standard of care for patients diagnosed with advanced gastric cancer. However, the use of total neoadjuvant therapy (TNT), which includes both chemotherapy and chemoradiation, is increasing in other malignancies. The purpose of this study is to determine overall survival (OS) in a contemporary cohort of gastric cancer patients treated with TNT and surgical resection. Methods: Patients diagnosed with microsatellite-stable clinical T2+ or N+ gastric adenocarcinoma (January 2012 to June 2022) were identified from a prospectively maintained institutional database. Those who underwent staging laparoscopy and received neoadjuvant chemotherapy and chemoradiation therapy, followed by gastrectomy, were included in the study. OS and variables associated with OS were determined using standard statistical methods. Results: Of 203 study patients, the median (interquartile range) age was 61 (50-69.5) years and 50 (24.6%) had tumor involving the gastroesophageal junction. The most common TNT sequence was chemotherapy followed by chemoradiation, which was utilized in 173 (85.2%) patients. The chemotherapy regimen typically given was fluorouracil and oxaliplatin in 149 (73.4%) patients. The most common radiation dose was 45 Gy in 25 fractions (169 [83.3%] patients), with 18 (8.9%) patients receiving 30 Gy in 10 fractions. One hundred ninety-seven (97.0%) patients completed all their planned neoadjuvant therapy. Surgical resection included total gastrectomy in 108 (53.2%), adjacent organ resection in 24 (11.8%), and extended (D1+/D2) lymphadenectomy in 193 (95.1%) patients. Pathologic complete response was achieved (pCR) in 32 (15.8%) patients. The median OS was 8.4 (95% confidence interval [CI] 6.5-not reached) years, and the 5-year OS rate was 65.2% (95% CI 57.8-73.5%). Patients with pCR had a 5-year OS rate of 89.1% (95% CI 78.1-100.0%). On multivariable analysis, D1+/D2 lymphadenectomy (HR 0.21 [95% CI 0.088-0.51]), post-treatment pathologic (yp) T (ypT3 vs ypT0, HR 3.11 [95% CI 1.09-8.82]; ypT4 vs ypT0, HR 5.51 [95% CI 1.64-18.5]) and N stages (ypN1 vs ypN0, HR 2.41 [95% CI 1.13-5.13]; ypN2 vs ypN0, HR 2.43 [95% CI 1.14-5.20]; ypN3 vs ypN0, HR 4.70 [95% CI 2.09-10.6]), incidental distant metastasis at time of resection (HR 3.75 [95% CI 1.50-9.37]), and postoperative complications (HR 2.06 [95% CI 1.21-3.52]) were associated with OS. Conclusions: TNT is associated with a high rate of treatment completion and promising long-term OS for patients with resectable gastric cancer. Comparative studies with perioperative treatment and predictors of tumor response will be important in identifying patients suitable for TNT.

KRAS mutation status in the prediction of pancreatic tumor response after neoadjuvant systemic therapy and magnetic resonance-guided SBRT.

709 Background: Stereotactic body radiotherapy (SBRT) has been incorporated into multi-modality treatment of locally advanced and borderline resectable pancreatic ductal adenocarcinoma (PDAC). For non-metastatic inoperable PDAC patients (pts) who receive magnetic resonance-guided SBRT (MRgSBRT), baseline features that predict for treatment response remain unsettled. In localized PDAC, multiple studies have investigated the KRAS oncogene as a prognostic factor with mixed findings. In this single institution retrospective study of PDAC pts treated with MRgSBRT, we hypothesized that KRAS mutation status would be predictive of meaningful clinical outcomes. Methods: From an IRB approved dataset of PDAC pts treated with MRgSBRT between 2016 and 2022, 39 pts with non-metastatic inoperable pancreatic cancer, known KRAS mutation status, ≥ 3 months of neoadjuvant systemic therapy (NST), and at least 3 months post-RT follow up were extracted for analysis. Baseline demographics, tumor and treatment characteristics, and clinical endpoints including conversion to resectability, best imaging response per RECIST v1.1, pathologic response (PR) per TRG-CAP, and overall survival (OS) after MRgSBRT were collected. Objective response (ORR) on both imaging and pathology was defined as complete response (CR) + partial response (PR); disease control (DC) was defined as CR + PR + stable disease (SD). Logistic regression was used to assess correlation between baseline variables and ORR. Cox proportional hazard models were utilized to determine association with OS. Results: Out of 39 pts, 21 (53%) were KRAS-mutated (KRAS-mt) and 18 (47%) were KRAS wild-type (KRAS-wt). Median age was 62, 54% were male, only 1 pt had ECOG &gt; 1, and CA 19-9 at diagnosis was 197. Median duration of NST was 9 cycles, and common agents included Gemcitabine and Abraxane (21%); FOLFIRINOX (28%); a combination of the two regimens (41%); or other NSTs (10%). Median MRgSBRT dose fractionation was 50 Gy (range 35 – 50) in 5 fractions; all fractions underwent adaptive optimization. Thirty pts (77%) experienced DC on imaging, 16 (43%) had ORR, and 12 (31%) were converted to resectable following MRgSBRT. Cohort median OS was 12.3 months, and pts who had surgery had a non-significant median OS advantage (18 vs 12 months; p=0.19). KRAS-mt was associated with worse ORR (p=0.04; AUC=0.73) and decreased OS (HR: 2.15; p=0.03). In a clinical model incorporating baseline characteristics (age, ECOG, radiographic staging, CA 19-9 level, and KRAS), only KRAS predicted OS (HR: 3.02 for KRAS-mt; p=0.01). KRAS-mt status was also predictive of OS among pts who underwent surgery (HR: 5.24 for KRAS-mt; p=0.04). Conclusions: For localized PDAC pts inoperable at diagnosis who received NST followed by MRgSBRT, KRAS was the only significant predictor of ORR and OS, highlighting the need for further treatment intensification in KRAS-mt pts.

Bioinspired Tumor Calcification-Guided Early Diagnosis and Eradication of Hepatocellular Carcinoma.

Tumor calcification is found to be associated with the benign prognostic, and which shows considerable promise as a somewhat predictive index of the tumor response clinically. However, calcification is still a missing area in clinical cancer treatment. A specific strategy is proposed for inducing tumor calcification through the synergy of calcium peroxide (CaO2)-based microspheres and transcatheter arterial embolization for the treatment of hepatocellular carcinoma (HCC). The persistent calcium stress in situ specifically leads to powerful tumor calcioptosis, resulting in diffuse calcification and a high-density shadow on computed tomography that enables clear localization of the in vivo tumor site and partial delineation of tumormargins in an orthotopic HCC rabbit model. This osmotic calcification can facilitate tumor clinical diagnosis, which is of great significance in differentiating tumor response during early follow-up periods. Proteome and phosphoproteome analysis identify that calreticulin (CALR) is a crucial target protein involved in tumor calcioptosis. Further fluorescence molecular imaging analysis also indicates that CALR can be used as a prodromal marker of calcification to predict tumor response at an earlier stage in different preclinical rodent models. These findings suggest that upregulated CALR in association with tumor calcification, which may be broadly useful for quick visualization of tumor response.

Value of blood oxygenation level-dependent magnetic resonance imaging in early evaluation of the response and prognosis of esophageal squamous cell carcinoma treated with definitive chemoradiotherapy: a preliminary study

BackgroundTo find a useful hypoxia non-invasive biomarker for evaluating early treatment response and prognosis to definitive chemoradiotherapy (dCRT) in patients with esophageal squamous cell carcinoma (ESCC), using blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI).MethodsThe R2* values were obtained pre- and 2–3 weeks post-dCRT in 28 patients with ESCC using BOLD MRI. Independent samples t-test (normality) or Mann-Whitney U test (non-normality) was used to compare the differences of R2*-related parameters between the complete response (CR) and the non-CR groups. Diagnostic performance of parameters in predicting response was tested with receiver operating characteristic (ROC) curve analysis. The 3-year overall survival (OS) was evaluated using Kaplan Meier curve, log rank test, and Cox proportional hazards regression analysis.ResultsThe post-R2*, ∆R2*, and ∆%R2* in the CR group were significantly higher than those in the non-CR group (P = 0.002, 0.003, and 0.006, respectively). The R2*-related parameters showed good prediction of tumor response, with AUC ranging from 0.813 to 0.829. The 3-year OS rate in patients with ∆R2* >-7.54 s− 1 or CR were significantly longer than those with ∆R2* ≤ -7.54 s− 1 (72.37% vs. 0.00%; Hazard ratio, HR = 0.196; 95% confidence interval, 95% CI = 0.047–0.807; P = 0.024) or non-CR (76.47% vs. 29.27%; HR = 0.238, 95% CI = 0.059–0.963; P = 0.044).ConclusionsThe preliminary results demonstrated that the R2* value might be a useful hypoxia non-invasive biomarker for assessing response and prognosis of ESCC treated with dCRT. BOLD MRI might be used as a potential tool for evaluating tumor oxygenation metabolism, which is routinely applied in clinical practice and beneficial to clinical decision-making. A large sample size was needed for further follow-up studies to confirm the findings.

The GRAPHS-CRAFITY score: a novel efficacy predictive tool for unresectable hepatocellular carcinoma treated with immunotherapy.

To investigate MR features associated with prognosis of unresectable HCC receiving immunotherapy and establish a MR feature-based scoring system to predict efficacy of immunotherapy. This retrospective study included patients with unresectable HCC who received immunotherapy at 2 hospitals between August 2018 and February 2022. The last follow-up was October 2022. Clinical variables and MR features were assessed using univariate and multivariate Cox regression analyses. A new scoring system was constructed based on independent risk factors and the CRAFITY score consisting of AFP (≥ 100ng/ml) and CRP (≥ 1mg/dl). And the predictive performance of CRAFITY core and new score were compared by receiver-operating-characteristics curves (ROCs), area under ROCs (AUCs), and calibration curves. A total of 166 patients (55.6 ± 10.4years) were included in training cohort and 77 patients (55.4 ± 10.7years) were included in validation cohort. There were significant differences in BCLC stage, max size, macrovascular invasion, intratumoral artery, and enhancing capsule between the 2 groups. Based on independent risk factors (gross GRowtH type, intratumoral fAt, enhancing tumor caPsule, Sex and CRAFITY score), a novel efficacy predictive tool named the GRAPHS-CRAFITY score was developed to predict OS. The OS was significantly different among the 3 groups according to GRAPHS-CRAFITY score (p value < 0.001). The GRAPHS-CRAFITY score could predict tumor response and disease control (p value < 0.001, p value < 0.001). The GRAPHS-CRAFITY score is a reliable and easily applicable tool to predict the efficacy of unresectable HCC receiving immunotherapy.

68Ga-FAPI PET imaging monitors response to combined TGF-βR inhibition and immunotherapy in metastatic colorectal cancer.

BACKGROUNDImproving and predicting tumor response to immunotherapy remains challenging. Combination therapy with a transforming growth factor-β receptor (TGF-βR) inhibitor that targets cancer-associated fibroblasts (CAFs) is promising for the enhancement of efficacy of immunotherapies. However, the effect of this approach in clinical trials is limited, requiring in vivo methods to better assess tumor responses to combination therapy.METHODSWe measured CAFs in vivo using the 68Ga-labeled fibroblast activation protein inhibitor-04 (68Ga-FAPI-04) for PET/CT imaging to guide the combination of TGF-β inhibition and immunotherapy. One hundred thirty-one patients with metastatic colorectal cancer (CRC) underwent 68Ga-FAPI and 18F-fluorodeoxyglucose (18F-FDG) PET/CT imaging. The relationship between uptake of 68Ga-FAPI and tumor immunity was analyzed in patients. Mouse cohorts of metastatic CRC were treated with the TGF-βR inhibitor combined with KN046, which blocks programmed death ligand 1 (PD-L1) and CTLA-4, followed by 68Ga-FAPI and 18F-FDG micro-PET/CT imaging to assess tumor responses.RESULTSPatients with metastatic CRC demonstrated high uptake rates of 68Ga-FAPI, along with suppressive tumor immunity and poor prognosis. The TGF-βR inhibitor enhanced tumor-infiltrating T cells and significantly sensitized metastatic CRC to KN046. 68Ga-FAPI PET/CT imaging accurately monitored the dynamic changes of CAFs and tumor response to combined the TGF-βR inhibitor with immunotherapy.CONCLUSION68Ga-FAPI PET/CT imaging is powerful in assessing tumor immunity and the response to immunotherapy in metastatic CRC. This study supports future clinical application of 68Ga-FAPI PET/CT to guide precise TGF-β inhibition plus immunotherapy in CRC patients, recommending 68Ga-FAPI and 18F-FDG dual PET/CT for CRC management.TRIAL REGISTRATIONCFFSTS Trial, ChiCTR2100053984, Chinese Clinical Trial Registry.FUNDINGNational Natural Science Foundation of China (82072695, 32270767, 82272035, 81972260).

Prostate Cancer Organoids for Tumor Modeling and Drug Screening.

Prostate cancer (PCa) is the second most common malignancy and the fifth leading cause of cancer death in men worldwide. Despite its prevalence, the highly heterogenic PCa has shown difficulty to establish representative cell lines that reflect the diverse phenotypes and different stages of the disease in vitro and hence hard to model in preclinical research. The patient-derived organoid (PDO) technique has emerged as a groundbreaking three-dimensional (3D) tumor modeling platform in cancer research. This versatile assay relies on the unique ability of cancer stem cells (CSCs) to self-organize and differentiate into organ-like mini structures. The PDO culture system allows for the long-term maintenance of cancer cells derived from patient tumor tissues. Moreover, it recapitulates the parental tumor features and serves as a superior preclinical model for in vitro tumor representation and personalized drug screening. Henceforth, PDOs hold great promise in precision medicine for cancer. Herein, we describe the detailed protocol to establish and propagate organoids derived from isolated cell suspensions of PCa patient tissues or cell lines using the 3D semisolid Matrigel™-based hanging-drop method. In addition, we highlight the relevance of PDOs as a tool for evaluating drug efficacy and predicting tumor response in PCa patients.

Evaluation of Neoadjuvant Chemoradiotherapy Response in Rectal Cancer Using MR Images and Deep Learning Neural Networks.

The aim of the study was to develop deep-learning neural networks to guide treatment decisions and for the accurate evaluation of tumor response to neoadjuvant chemoradiotherapy (nCRT) in rectal cancer using magnetic resonance (MR) images. Fifty-nine tumors with stage 2 or 3 rectal cancer that received nCRT were retrospectively evaluated. Pathological tumor regression grading was carried out using the Dworak (Dw-TRG) guidelines and served as the ground truth for response predictions. Imaging-based tumor regression grading was performed according to the MERCURY group guidelines from pre-treatment and post-treatment para-axial T2-weighted MR images (MR-TRG). Tumor signal intensity signatures were extracted by segmenting the tumors volumetrically on the images. Normalized histograms of the signatures were used as input to a deep neural network (DNN) housing long short-term memory (LSTM) units. The output of the network was the tumor regression grading prediction, DNN-TRG. In predicting complete or good response, DNN-TRG demonstrated modest agreement with Dw-TRG (Cohen's kappa= 0.79) and achieved 84.6% sensitivity, 93.9% specificity, and 89.8% accuracy. MR-TRG revealed 46.2% sensitivity, 100% specificity, and 76.3% accuracy. In predicting a complete response, DNN-TRG showed slight agreement with Dw-TRG (Cohen's kappa= 0.75) with 71.4% sensitivity, 97.8% specificity, and 91.5% accuracy. MR-TRG provided 42.9% sensitivity, 100% specificity, and 86.4% accuracy. DNN-TRG benefited from higher sensitivity but lower specificity, leading to higher accuracy than MR-TRG in predicting tumor response. The use of deep LSTM neural networks is a promising approach for evaluating the tumor response to nCRT in rectal cancer.</P>.

Hematological predictors of tumor response to neoadjuvant chemotherapy in patients with triple-negative breast cancer

Hematological predictors of tumor response to neoadjuvant chemotherapy in patients with triple-negative breast cancer