A comprehensive AI model development framework for consistent Gleason grading

BACKGROUND

Artificial Intelligence(AI)-based solutions for Gleason grading hold promise for pathologists, while image quality inconsistency, continuous data integration needs, and limited generalizability hinder their adoption and scalability.

METHODS

We present a comprehensive digital pathology workflow for AI-assisted Gleason grading. It incorporates A!MagQC (image quality control), A!HistoClouds (cloud-based annotation), Pathologist-AI Interaction (PAI) for continuous model improvement, Trained on Akoya-scanned images only, the model utilizes color augmentation and image appearance migration to address scanner variations. We evaluate it on Whole Slide Images (WSI) from another five scanners and conduct validations with pathologists to assess AI efficacy and PAI.

RESULTS

Our model achieves an average F1 score of 0.80 on annotations and 0.71 Quadratic Weighted Kappa on WSIs for Akoya-scanned images. Applying our generalization solution increases the average F1 score for Gleason pattern detection from 0.73 to 0.88 on images from other scanners. The model accelerates Gleason scoring time by 43% while maintaining accuracy. Additionally, PAI improve annotation efficiency by 2.5 times and led to further improvements in model performance.

CONCLUSIONS

This pipeline represents a notable advancement in AI-assisted Gleason grading for improved consistency, accuracy, and efficiency. Unlike previous methods limited by scanner specificity, our model achieves outstanding performance across diverse scanners. This improvement paves the way for its seamless integration into clinical workflows.

Diagnostic efficacy and interobserver agreement among readers with variable experience of the Prostate Imaging for Recurrence Reporting system with whole-mount histology after androgen deprivation therapy as a reference

Background

The Prostate Imaging for Recurrence Reporting (PI-RR) system was recently proposed to assess the local recurrence of prostate cancer (PCa), but its exact performance for the prostate after radiotherapy or radical prostatectomy is difficult to determine. We aimed to evaluate the diagnostic performance and interreader agreement of this system using whole-mount histology of the prostate after androgen deprivation therapy (ADT) as the standard of reference.

Methods

In total, 119 patients with PCa post-ADT underwent multiparametric magnetic resonance imaging (mp-MRI) before prostatectomy. Three radiologists analyzed the MRI images independently, scoring imaging findings according to PI-RR. Spearman correlation was performed to assess the relationship between the percentage of sectors with residual cancer and PI-RR score. The diagnostic performance for detection of residual cancer was assessed on a per-sector basis. The chi-squared test was used to compare the cancer detection rate (CDR) among readers. Overall and pairwise interreader agreement in assigning PI-RR categories and residual cancer sectors with a score ≥3 or ≥4 were evaluated with the Cohen kappa coefficient.

Results

Histology revealed 209 sectors with residual cancer. The percentage of pathologically positive sectors increased with the increase in PI-RR score for all readers. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) at a cutoff of score 3 ranged from 74.2% to 83.7%, 86.4% to 92.7%, 51.3% to 64.3%, and 95.4% to 96.9%, respectively, and at a cutoff of score 4, they ranged from 47.4% to 56.5%, 97.9% to 98.6%, 82.5% to 85.3%, and 91.6% to 92.9%, respectively. There was no significant difference among the CDR of readers. In PI-RR categories and detection of residual cancer sectors, overall interreader agreement was moderate for all readers, but agreement was higher between the more experienced readers (moderate to substantial) than between the more and less experienced readers (fair to moderate).

Conclusions

MRI scoring with the PI-RR assessment provided accurate evaluation of PCa after ADT, but readers' experience influenced interreader agreement and cancer diagnosis.

Intra-Abdominal Epithelioid Neoplasm With EWSR1::CREB Fusions Involving the Kidney: A Clinicopathologic and Molecular Characterization With an Emphasis on Differential Diagnosis

Soft tissue neoplasms, harboring fusions between EWSR1 and FUS with genes encoding CREB transcription factors family (ATF1, CREB1, and CREM), are an emerging heterogeneous group of mesenchymal tumors that differ significantly in morphology, immunophenotypes, and behavior. Recently, EWSR1/FUS::CREB fusions have been recognized to define a group of aggressive neoplasms of epithelioid morphology with multiple growth patterns and a striking predilection for mesothelial-lined cavities. These neoplasms presenting as a primary neoplasm of intra-abdominal visceral organs are rare, which could elicit a wide range of differential diagnoses because of their diverse morphologies and immunohistochemical profiles. We report 3 cases of intra-abdominal epithelioid neoplasms with EWSR1::CREB fusions involving the kidney. This study included 2 female patients and 1 male patient, with age at presentation ranging from 17 to 61 years (mean: 32 years). All the patients underwent radical nephrectomy without adjunctive therapies. Grossly, the tumors were large, and all were solitary masses with sizes ranging from 5.6 to 30.0 cm (mean: 14.5 cm). Histologically, the neoplasms showed infiltrating and indistinct borders and were composed predominantly of monomorphic round-to-epithelioid cells with variable amounts of pale-to-clear cytoplasm, arranged in cords, nests, and sheets and embedded in a sclerotic hyalinized stroma with variable lymphoid cuffing either intermixed or at the periphery. Notably, a hemangiopericytomatous growth pattern was commonly seen. Nuclear atypia was mild, and mitotic activity was scarce. Immunohistochemically, all 3 cases were at least focally positive for epithelial membrane antigen and keratin AE1/AE3, with 2 tumors showing focal MUC4 expression and 1 case displaying diffuse CD34 and focal CAIX positivity. Targeted RNA sequencing identified EWSR1::CREM fusion in 2 cases and EWSR1::ATF1 fusion in 1 case. Subsequent fluorescence in situ hybridization analysis confirmed the RNA sequencing results. On follow-up, 1 patient developed multiple spinal bone metastases 5 months after the surgery while the other 2 patients were free of disease 9 and 120 months after diagnosis, respectively. Our findings demonstrate that intra-abdominal epithelioid neoplasms with EWSR1::CREB fusions may rarely occur primarily in the kidney and should be included in the differential diagnosis of primary renal epithelioid mesenchymal neoplasms.

Nomogram to predict the presence of PSMA-negative but FDG-positive lesion in castration-resistant prostate cancer: a multicenter cohort study

Background

PSMA-negative but FDG-positive (PSMA-/FDG+) lesion in dual-tracer (68Ga-PSMA and 18F-FDG) positron emission tomography/computed tomography (PET/CT) is associated with an unfavorable response to Lutetium-177 (177Lu)-PSMA-617. This study sought to develop both radiomics and clinical models for the precise prediction of the presence of PSMA-/FDG+ lesions in patients with castration-resistant prostate cancer (CPRC).

Methods

A cohort of 298 patients who underwent dual-tracer PET/CT with a less than 5-day interval was included. The evaluation of the prognostic performance of the radiomics model drew upon the survival data derived from 40 patients with CRPC treated with 177Lu-PSMA-617 in an external cohort. Two endpoints were evaluated: (a) prostate-specific antigen (PSA) response rate, defined as a reduction exceeding 50% from baseline and (b) overall survival (OS), measured from the initiation of 177Lu-PSMA-617 to death from any cause.

Results

PSMA-/FDG+ lesions were identified in 56 (18.8%) CRPC patients. Both radiomics (area under the curve [AUC], 0.83) and clinical models (AUC, 0.78) demonstrated robust performance in PSMA-/FDG+ lesion prediction. Decision curve analysis revealed that the radiomics model yielded a net benefit over the 'screen all' strategy at a threshold probability of ⩾4%. At a 5% probability threshold, the radiomics model facilitated a 21% reduction in 18F-FDG PET/CT scans while only missing 2% of PSMA-/FDG+ cases. Patients with a low estimated score exhibited significantly prolonged OS (hazard ratio = 0.49, p = 0.029) and a higher PSA response rate (75% versus 35%, p = 0.011) compared to those with a high estimated score.

Conclusion

This study successfully developed two models with accurate estimations of the risk associated with PSMA-/FDG+ lesions in CRPC patients. These models held potential utility in aiding the selection of candidates for 177Lu-PSMA-617 treatment and guiding 68Ga-PSMA PET/CT-directed radiotherapy.

Association of Pathological Features and Multiparametric MRI-Based Radiomics With TP53-Mutated Prostate Cancer

BACKGROUND

TP53 mutations are associated with prostate cancer (PCa) prognosis and therapy.

PURPOSE

To develop TP53 mutation classification models for PCa using MRI radiomics and clinicopathological features.

STUDY TYPE

Retrospective.

POPULATION

388 patients with PCa from two centers (Center 1: 281 patients; Center 2: 107 patients). Cases from Center 1 were randomly divided into training and internal validation sets (7:3). Cases from Center 2 were used for external validation.

FIELD STRENGTH/SEQUENCE

3.0T/T2-weighted imaging, dynamic contrast-enhanced imaging, diffusion-weighted imaging.

ASSESSMENT

Each patient's index tumor lesion was manually delineated on the above MRI images. Five clinicopathological and 428 radiomics features were obtained from each lesion. Radiomics features were selected by least absolute shrinkage and selection operator and binary logistic regression (LR) analysis, while clinicopathological features were selected using Mann-Whitney U test. Radiomics models were constructed using LR, support vector machine (SVM), and random forest (RF) classifiers. Clinicopathological-radiomics combined models were constructed using the selected radiomics and clinicopathological features with the aforementioned classifiers.

STATISTICAL TESTS

Mann-Whitney U test. Receiver operating characteristic (ROC) curve analysis and area under the curve (AUC). P value <0.05 indicates statistically significant.

RESULTS

In the internal validation set, the radiomics model had an AUC of 0.74 with the RF classifier, which was significantly higher than LR (AUC = 0.61), but similar to SVM (AUC = 0.69; P = 0.422). For the combined model, the AUC of RF model was 0.84, which was significantly higher than LR (0.64), but similar to SVM (0.80; P = 0.548). Both the combined RF and combined SVM models showed significantly higher AUCs than the radiomics models. In the external validation set, the combined RF and combined SVM models showed AUCs of 0.83 and 0.82.

DATA CONCLUSION

Pathological-radiomics combined models with RF, SVM show the association of TP53 mutations and pathological-radiomics features of PCa.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

[Clinicopathological features of adult Wilms tumor with BRAF V600E mutation]

Objective: To identify BRAF V600E mutations in adult Wilms tumor (WT) with overlapping histologic features of metanephric adenoma (MA) and to investigate the clinicopathological features of adult WT. Methods: The clinical features of adult WT diagnosed at the Fudan University Shanghai Cancer Center, Shanghai, China from 2012 to 2021 were reviewed. HE-stained slides of all cases were reviewed by 2 expert pathologists. Representative tissues were selected for BRAF V600E immunohistochemical (IHC) staining and gene sequencing. Results: In adult WT with MA-like areas (cohort Ⅰ, n=6), 5 of the 6 cases were composed of epithelial-predominant and were positive for WT-1 and CD56, respectively, and all were positive for CD57. All 6 cases revealed highly variable Ki-67 indices, ranging from 1% in some areas to 60% in others. 5 of the 6 cases harbored a BRAF V600E mutation. All cases in cohort I were followed up for 23 to 71 months, and all survived. In classical adult WT without MA-like areas cohort (cohort Ⅱ, n=13), all 7 cases with available material were negative for BRAF by IHC and none of them had any BRAF mutation. Conclusions: BRAF V600E mutations are frequently present in adult WT with overlapping morphologically features of MA, but not in those without. More importantly, adult WTs with overlapping histologic features of MA may be an intermediate entity between typical MA and WT that may have a favorable prognosis and possible therapeutic targets.

Prospective clinical sequencing of 1016 Chinese prostate cancer patients: uncovering genomic characterization and race disparity

Although there is a well-known disparity in prostate cancer (PC) incidence and mortality between Chinese and Western patients, the underlying genomic differences have been investigated only sparsely. This clinicogenomic study was conducted to reveal the genomic mutations contributing to the PC disparity across ethnicities and investigate the mutational profile of Chinese PC patients. A total of 1016 Chinese PC patients were prospectively enrolled and subjected to targeted sequencing, resulting in usable sequencing data for 41 genes from 859 patients. Genomic data retrieved from The Cancer Genome Atlas (TCGA; locoregional PC), Memorial Sloan Kettering Cancer Center [MSKCC; metastatic castration-sensitive PC (mCSPC)], and Stand Up To Cancer [SU2C; metastatic castration-resistant PC (mCRPC)] cohorts were used as comparators representing Western men. Genomic mutations were analyzed using an integrated bioinformatic strategy. A comparison of the disease stages revealed that mutations in tumor protein 53 (TP53), androgen receptor (AR), forkhead box A1 (FOXA1), and genes involved in the cell cycle pathway were enriched in mCRPC. Mutations in adenomatous polyposis coli (APC) gene were found to be more prevalent in patients with visceral metastasis. Genomic differences between Western and Chinese men were mainly observed in castration-sensitive PC, with tumors from Chinese men having more FOXA1 (11.4% vs. 4.2%) but fewer TP53 (4.8% vs. 13%) mutations in locoregional PC and harboring fewer TP53 (11% vs. 29.2%), phosphatase and tensin homolog (PTEN; 2.5% vs. 10.3%), and APC (1.7% vs. 7.4%) mutations in the mCSPC stage than those of Western men. Patients of both ethnicities with mCRPC had similar mutational spectra. Furthermore, FOXA1 class-2 was less common than FOXA1 class-1 and showed no enrichment in metastasis, contrary to the findings in the Western cohort. Our study provides a valuable resource for a better understanding of PC in China and reveals the genomic alterations associated with PC disparity across races.

Plasma proteomic profiling discovers molecular features associated with upper tract urothelial carcinoma

Upper tract urothelial carcinoma (UTUC) is often diagnosed late and exhibits poor prognosis. Limited data are available on potential non-invasive biomarkers for disease monitoring. Here, we investigate the proteomic profile of plasma in 362 UTUC patients and 239 healthy controls. We present an integrated tissue-plasma proteomic approach to infer the signature proteins for identifying patients with muscle-invasive UTUC. We discover a protein panel that reflects lymph node metastasis, which is of interest in identifying UTUC patients with high risk and poor prognosis. We also identify a ten-protein classifier and establish a progression clock predicting progression-free survival of UTUC patients. Finally, we further validate the signature proteins by parallel reaction monitoring assay in an independent cohort. Collectively, this study portrays the plasma proteomic landscape of a UTUC cohort and provides a valuable resource for further biological and diagnostic research in UTUC.

TERT accelerates BRAF mutant-induced thyroid cancer dedifferentiation and progression by regulating ribosome biogenesis

TERT reactivation occurs frequently in human malignancies, especially advanced cancers. However, in vivo functions of TERT reactivation in cancer progression and the underlying mechanism are not fully understood. In this study, we expressed TERT and/or active BRAF (BRAF V600E) specifically in mouse thyroid epithelium. While BRAF V600E alone induced papillary thyroid cancer (PTC), coexpression of BRAF V600E and TERT resulted in poorly differentiated thyroid carcinoma (PDTC). Spatial transcriptome analysis revealed that tumors from mice coexpressing BRAF V600E and TERT were highly heterogeneous, and cell dedifferentiation was positively correlated with ribosomal biogenesis. Mechanistically, TERT boosted ribosomal RNA (rRNA) expression and protein synthesis by interacting with multiple proteins involved in ribosomal biogenesis. Furthermore, we found that CX-5461, an rRNA transcription inhibitor, effectively blocked proliferation and induced redifferentiation of thyroid cancer. Thus, TERT promotes thyroid cancer progression by inducing cancer cell dedifferentiation, and ribosome inhibition represents a potential strategy to treat TERT-reactivated cancers.

Heterogeneity of [68Ga]Ga-PSMA-11 PET/CT in metastatic castration-resistant prostate cancer: genomic characteristics and association with abiraterone response

PURPOSE

The aim of this study was to evaluate the impact of the spatial heterogeneity of prostate-specific membrane antigen (PSMA) uptake on circulating tumor DNA (ctDNA) characteristics and the response rate to new hormonal agent (NHA) treatment.

METHODS

This retrospective study included 153 patients with metastatic castration-resistant prostate cancer (mCRPC) who underwent gallium-68 [68 Ga]Ga-PSMA-11 positron emission tomography/computed tomography (PET/CT) and ctDNA sequencing with a less than 2-week interval. SUVhetero was defined as the variance of SUVmean for each PSMA-positive lesion. SUVmax-mean was obtained by subtracting the SUVmax by the SUVmean. Patients receiving abiraterone treatment after [68 Ga]Ga-PSMA-11 PET/CT and ctDNA sequencing and with complete follow-up record were included into prostate-specific antigen (PSA) response rate analysis. PSA response was defined as a reduction of greater than 50% from baseline.

RESULTS

The ctDNA detection rate was 65% (100/153). Higher SUVhetero value contributed to higher ctDNA% (Spearman's rho = 0.278, p < 0.002). A total of 60 patients were included in PSA response rate analysis. The median follow-up was 19.3 (IQR 16.2-23.2) months. Compare to patients with higher SUVhetero value, patients with NA SUVhetero had a higher PSA response rate (52% vs. 90%, p = 0.036). A higher SUVmax-mean value was strongly correlated with higher SUVhetero (Spearman's rho = 0.833, p < 0.0001). Patients with higher SUVmax-mean value also had a higher PSA response rate compared to patients with lower SUVmax-mean value (83.3% vs. 53.3%, p = 0.024). An external cohort confirmed baseline SUVmax-mean value was associated with enzalutamide treatment response rate. Patients with alterations in AR, DNA damage repair pathway, TP53, AR-associated pathway, cell cycle pathway, or WNT pathway had higher SUVmax-mean value compared to those without (p < 0.05).

CONCLUSION

Spatial heterogeneity of the PSMA uptake was associated with ctDNA characteristics and response rate to NHA treatment.

Inherited mutations in Chinese patients with upper tract urothelial carcinoma

Upper tract urothelial carcinoma (UTUC) accounts for 10% of urothelial carcinomas (UCs) and has a substantial hereditary component. However, the majority of our knowledge of germline spectrum comes from bladder cancer (BCa) data in White populations. Here, we sequence 309 Chinese UTUC cases and identify 71 germline pathogenic/likely pathogenic (P/LP) mutations in 62 patients (20.1%). Compared with White cases, we observe disparities and similarities in inherited mutational profiles. Association analysis reveals that germline P/LP mutations in MSH2, BRCA2, BRCA1, and BRIP1 significantly increase UTUC risk in Chinese populations. Furthermore, germline P/LP mutation in homologous recombination genes indicates poor prognosis for non-metastatic UTUC. Finally, we perform paired sequencing and observe significant correlations between germline mutation patterns and tumor subtypes. This study highlights the importance of genetic testing in patients with UTUC and calls for germline data from various ethnicities to better understand this disease.

The prevalence and prognosis of next-generation therapeutic targets in metastatic castration-resistant prostate cancer

The success of the PROfound, IPATential150, and TheraP trials promoted the transition from sequential treatment to therapeutic targets (TTs)-guided precision treatment in metastatic castration-resistant prostate cancer (mCRPC). The objective of this study was to evaluate the prevalence and prognostic value of TTs from these three trials. All included Chinese mCRPC patients underwent circulating tumor DNA (ctDNA) sequencing, PTEN status assessment, and dual-tracer [⁶⁸ Ga-prostate-specific membrane antigen (PSMA) and ¹⁸ F-fluorodexyglucose (FDG)] positron emission tomography/computed tomography (PET/CT). Previous treatment with cabazitaxel, Lu-PSMA or olaparib was unallowed. Patients with known significant sarcomatoid or spindle cell or neuroendocrine small cell components were also excluded. TTs were defined as positive as follows: (a) high PSMA and no PSMA-/FDG+ disease on dual-tracer PET/CT scans; (b) defects in homologous recombination repair (HRR) genes in ctDNA; and (c) loss of PTEN immunohistochemistry staining in tumor tissue. The prevalence and prognostic value on progression-free survival (PFS) of TTs were evaluated. A total of 106 consecutive mCRPC patients were included. The prevalence of positive PET/CT, HRR defect, and PTEN loss was 30%, 29% and 16%, respectively. Sixty-three patients had at least one TT. Metastatic volume (odds ratio = 5.0; P = 0.017) was the only independent factor of positive TT in multivariate analysis. Seventy-four patients received abiraterone after TT screening. Patients with positive PET/CT (P = 0.011) and HRR defect (P = 0.002) had a significantly shorter PFS after receiving abiraterone than patients with negative TTs. However, PTEN status was unrelated to PFS, which may be due to a less number of patients with PTEN loss (P = 0.952). Overall, patients with any positive TTs had a significantly shorter PFS after abiraterone than patients with negative TTs (P = 0.009). Nearly 60% of Chinese patients with mCRPC who had a poor prognosis on abiraterone were candidates for precision treatments based on the specific criteria of TTs.

Stereotactic Radiotherapy for Lesions Detected via 68Ga-Prostate-specific Membrane Antigen and 18F-Fluorodexyglucose Positron Emission Tomography/Computed Tomography in Patients with Nonmetastatic Prostate Cancer with Early Prostate-specific Antigen Progression on Androgen Deprivation Therapy: A Prospective Single-center Study

BACKGROUND

Dual-tracer positron emission tomography/computed tomography (PET/CT) with a ⁶⁸Ga-labelled prostate-specific membrane antigen (PSMA) ligand and ¹⁸F-fluorodeoxyglucose (FDG) improves detection of metastatic heterogeneity and burden in patients with nonmetastatic prostate cancer (nmPCa). However, there is limited prospective evidence regarding its impact on the efficacy of stereotactic body radiotherapy (SBRT).

OBJECTIVE

To evaluate metastasis-free survival (MFS) and toxicity after SBRT to dual-tracer PET/CT-detected metastases in patients with nmPCa and early prostate-specific antigen (PSA) progression on androgen deprivation therapy (ADT; PSA ≤2 ng/ml).

DESIGN, SETTING, AND PARTICIPANTS

Patients were prospectively screened using dual-tracer PET/CT between April 2019 and October 2020. SBRT was recommended for patients with five or fewer nonvisceral metastases (SBRT group). Patients without detectable metastases (N-/M- group) and those who refused SBRT (ADT group) continued to receive ADT. Patients were followed with conventional imaging.

INTERVENTION

SBRT to each PET/CT-detected metastasis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Kaplan-Meier methods were used to determine MFS. Toxicity was evaluated using Common Terminology Criteria for Adverse Event v4.0.

RESULTS AND LIMITATIONS

Seventy-four consecutive patients were screened. The median PSA and PSA doubling time were 0.59 ng/ml and 4.56 mo, respectively. Overall, 54 patients had metastases and 17 had PSMA-/FDG+ disease. Seven patients were excluded from the MFS analysis, including two with a history of abiraterone treatment and five with more than five metastases. The median follow-up was 21.4 mo. The ADT group had shorter MFS than the SBRT group (11.0 mo vs not reached; hazard ratio [HR] 4.69, 95% confidence interval [CI] 2.92-25.0; p < 0.001) and the N-/M- group (11.0 mo vs not reached; HR 8.78, 95% CI 4.04-40.30; p < 0.001). There was no significant difference in median MFS between the SBRT group and the N-/M- group (p = 0.261). A PSA response >90% was achieved by 86% of patients in the SBRT group. There were no grade ≥3 adverse events after SBRT. The nonrandomized design is the major study limitation.

CONCLUSIONS

Dual-tracer PET/CT-guided SBRT delivered superior local control rates in comparison to ADT alone and had minimal toxicity.

PATIENT SUMMARY

We investigated metastasis-targeted radiotherapy for patients with up to five prostate cancer metastases detected with two different radioisotope scans. Our results show that this approach yields promising metastasis-free survival and low toxicity.

Single-cell transcriptomic analysis of the tumor ecosystems underlying initiation and progression of papillary thyroid carcinoma

The tumor ecosystem of papillary thyroid carcinoma (PTC) is poorly characterized. Using single-cell RNA sequencing, we profile transcriptomes of 158,577 cells from 11 patients’ paratumors, localized/advanced tumors, initially-treated/recurrent lymph nodes and radioactive iodine (RAI)-refractory distant metastases, covering comprehensive clinical courses of PTC. Our data identifies a “cancer-primed” premalignant thyrocyte population with normal morphology but altered transcriptomes. Along the developmental trajectory, we also discover three phenotypes of malignant thyrocytes (follicular-like, partial-epithelial-mesenchymal-transition-like, dedifferentiation-like), whose composition shapes bulk molecular subtypes, tumor characteristics and RAI responses. Furthermore, we uncover a distinct BRAF-like-B subtype with predominant dedifferentiation-like thyrocytes, enriched cancer-associated fibroblasts, worse prognosis and promising prospect of immunotherapy. Moreover, potential vascular-immune crosstalk in PTC provides theoretical basis for combined anti-angiogenic and immunotherapy. Together, our findings provide insight into the PTC ecosystem that suggests potential prognostic and therapeutic implications.

The characterisation of the papillary thyroid carcinoma (PTC) tumour microenvironment remains crucial. Here, the authors perform single-cell RNA sequencing in 11 patients and identify potential opportunities for the use of immunotherapy and its combination with anti-angiogenic therapy in PTC.

Inherited Mutations in Chinese Men With Prostate Cancer

BACKGROUND

Although China accounts for 7.8% of worldwide new prostate cancer (PCa) cases and 14.5% of new deaths according to GLOBOCAN 2020, the risk of PCa associated with germline mutations is poorly defined, hampered in part by lack of nationwide evidence. Here, we sequenced 19 PCa predisposition genes in 1,836 Chinese patients with PCa and estimated disease risk associated with inherited mutations.

PATIENTS AND METHODS

Patients were recruited from 4 tertiary cancer centers (n=1,160) and a commercial laboratory (n=676). Germline DNA was sequenced using a multigene panel, and pathogenic/likely pathogenic (P/LP) mutation frequencies in patients with PCa were compared with populations from the gnomAD (Genome Aggregation Database) and ChinaMAP (China Metabolic Analytics Project) databases. Clinical characteristics and progression-free survival were assessed by mutation status.

RESULTS

Of 1,160 patients from hospitals, 89.7% had Gleason scores ≥8, and 65.6% had metastases. P/LP mutations were identified in 8.49% of Chinese patients with PCa. Association with PCa risk was significant for mutations in ATM (odds ratio [OR], 5.9; 95% CI, 3.1-11.1), BRCA2 (OR, 15.3; 95% CI, 10.0-23.2), MSH2 (OR, 15.8; 95% CI, 4.2-59.6), and PALB2 (OR, 5.9; 95% CI, 2.7-13.2). Compared with those without mutations, patients with mutations in ATM, BRCA2, MSH2, or PALB2 showed a poor outcome with treatment using androgen deprivation therapy and abiraterone (hazard ratio, 2.19 [95% CI, 1.34-3.58] and 2.47 [95% CI, 1.23-4.96], respectively) but similar benefit from docetaxel.

CONCLUSIONS

The present multicenter study confirmed that a significant proportion of Chinese patients with PCa had inherited mutations and identified predisposition genes in this underreported ethnicity. These data provide empirical evidence for precision prevention and prognostic estimation in Chinese patients with PCa.

[Pathological features of primary extragonadal germ cell tumor of the prostate with small round blue cell morphology]

Objective: To investigate the clinicopathological features and clinical management of primary extragonadal germ cell tumor of the prostate. Methods: Two cases of primary extragonadal germ cell tumor in the prostate were collected at Fudan University Shanghai Cancer Center, in January and September 2016, respectively. Their pathological features, clinical treatments and follow-up were retrospectively analyzed. Results: The two patients were 41 and 32 years old, respectively, and both presented with obstructive symptoms of the lower urinary tract. Histologically, both cases showed small round blue cells and an invasive growth pattern. The immunohistochemistry (IHC) stains of SALL4, OCT3/4, CD117 and PLAP were all positive, while those of PSA, AR and syn were negative. Moreover, case 1 demonstrated perinuclear dot-like staining for CKpan, which might be a diagnostic pitfall. There was no evidence of disease in other areas via physical examination or radiographic studies. Based on these IHC findings and the morphology, the two cases were diagnosed as primary seminoma of the prostate, which were consequently treated with six cycles of bleomycin, etoposide and cisplatin-based chemotherapy. A complete response was achieved in case 1. Case 2 was followed up and showed tumor recurrence, and progression with elevated tumor marker AFP. The subsequent radical removed specimens of case 2 were finally diagnosed as mixed germ cell tumor of the prostate. Conclusion: As a rare neoplastic entity, primary germ cell tumor of the prostate can show small blue round cell morphology. Pathologically, the morphology of small round blue cells combined with a perinuclear dot-like pattern of CKpan IHC staining may be a diagnostic pitfall. The clinical treatment strategy should be evaluated with consideration of the pathological diagnosis and comprehensive evaluation of the tumor markers.

Prognostic Value of Local Treatment in Prostate Cancer Patients With Different Metastatic Sites: A Population Based Retrospective Study

Purpose

Our study aims to examine the impact of definitive local therapy in prostate cancer patients with different metastatic sites.

Methods

Totally, 5,849 patients diagnosed with metastatic prostate carcinoma from 2010 to 2014 were selected from Surveillance, Epidemiology, and End Results (SEER). Log-rank analyses, multivariable regression analysis, and Kaplan-Meier methods were used to assess prognostic impact of local treatment in patients with different metastatic sites. Survival curves and forest plots were also plotted to describe the prognostic value of definitive local therapy.

Results

In our study, 159 patients received radical prostatectomy, and 62 received brachytherapy, while 5,628 did not receive local definitive local therapy. Survival analysis revealed that patients who received definitive local therapy had a better 5-year overall survival (OS) (P = 0.011) and cancer-specific survival (CSS) (P = 0.012). Multivariate regression analyses demonstrated that type of treatment was an independent prognostic indicator for OS (P = 0.011) and CSS (P = 0.012), along with age at diagnosis, chemotherapy, PSA level, and Gleason score. According to subgroup analysis, patients with bone metastasis or distant lymph node (LN) metastasis were significantly more likely to benefit from definitive local therapy. In addition, forest plots demonstrated that RP group had significant favorable OS and CSS in subgroups of younger age at diagnosis, T2-3 stage, N0-1 stage, Gleason score =7 or ≥8, bone metastasis, and distant LN metastasis.

Conclusions

Our study suggested that local therapy improved survival in prostate cancer patients with bone or distant LN metastasis. Furthermore, patients who were at T2-3 stage or Gleason score ≥7 also significantly benefit from definitive local therapy.

Identification of a methylation panel aid in risk stratification in node-positive penile squamous cell carcinoma

Molecular prognostic factors for individualized treatment of squamous cell carcinoma (SCC) are poorly defined. Our study developed and validated a novel molecular tools aid in preinguinal and postinguinal lymphadenectomy risk stratification in node-positive penile SCC. Patients with node-positive penile SCC who underwent inguinal or ilioinguinal lymphadenectomy were divided into three cohorts: a discovery set, a development set and a validation set. The local ethics committee approved the study. The primary endpoint was cancer-specific survival (CSS). At the discovery stage, 17 CpG sites were significantly associated with CSS. In the development set, we constructed a 3-CpG-based prognostic score for survival prediction. The hazard ratio (HR) of the panel (dichotomized using the optimal cutoff) was 5.8 in the multivariate analyses (P < .001). The addition of the methylation score significantly improved the pN-stage C-index from 0.70 to 0.79 (incremental C = 0.09, P < .001). In the validation set, the methylation panel showed a HR of 9.9 in the multivariate analyses. The addition of the molecular marker improved the pN-stage C-index from 0.69 to 0.78 (incremental C = 0.09, P < .001). The methylation score remarkably separated survival curves in different pN stages, which indicate that the tool can be applied to tailor the treatment in both preinguinal and postinguinal lymphadenectomy settings. We developed and validated a prognostic methylation panel for node-positive penile SCC. The tool may aid in the risk stratification of the population with heterogeneous outcomes and needs prospective validation. Patients in high-risk group may benefit from more aggressive therapy or clinical trials.

Prevalence of comprehensive DNA damage repair gene germline mutations in Chinese prostate cancer patients

Germline DNA damage repair (DDR) deficiency has been associated with increased cancer risk, poor prognosis and therapeutic opportunity for prostate cancer (PCa) patients. However, the landscape of germline mutations in PCa covering comprehensive DDR genes has not been reported. We performed whole-exome sequencing in 246 patients who meet the National Cancer Center Network guidelines for genetic testing and analyzed variants in 276 DDR genes, which was from the Cancer Genome Atlas. A total of 79 deleterious germline alterations in 60 DDR genes were identified in 31% (76/246) patients. Mutations were found in nine DDR pathways, including 11.8% men in homologous recombination repair (HR) pathways, 2.4% men in mismatch repair (MMR) pathway and 16.7% (41/246) patients in non-HR/MMR pathways. In HRR and MMR pathways, mutations were mostly identified in BRCA2 (5.3%), HFM1 (0.8%), ZSWIM7 (0.8%), MSH2 (0.8%) and MSH3 (0.8%). When compared with the cancer-free cohort, POLN and POLG conferred high risk to PCa with odds ratio 6.9 and 20.5, respectively. We provided a comprehensive view of germline DDR gene mutations in PCa patients. We also identified two potential PCa predisposition genes: POLN and POLG, which have not been reported in the Western population, confirming the necessity of customizing a multigene panel for Chinese PCa patients.

A Prospective Trial of 68Ga-PSMA and 18F-FDG PET/CT in Nonmetastatic Prostate Cancer Patients with an Early PSA Progression During Castration

PURPOSE

Tumor heterogeneity and burden, which impact treatment outcome in prostate cancer, are rarely evaluated using next-generation imaging.

EXPERIMENTAL DESIGN

The trial prospectively included 37 patients who had an early PSA progression (≤2 ng/mL) during castration and high-risk (PSA doubling time ≤10 months) nonmetastatic disease by conventional imaging. All patients underwent both ⁶⁸Ga-PSMA and ¹⁸F-FDG PET/CT. Lesions were classified into PSMA+FDG± lesions and PSMA-FDG+ lesions. The primary endpoint was the prevalence of PSMA-FDG+ disease. Tumor burden, predictors for positive imaging, and suitability for oligometastases-directed therapy (OMDT) were also evaluated.

RESULTS

All patients were treated with RP and the median duration of castration was 23 months. The median PSA at imaging was 0.57 ng/mL. Overall, 114 lesions were detected in 29 of the 37 patients. A high prevalence (73%) of N+/M+ disease was observed. Of the 114 lesions, 81 were PSMA+FDG± and 33 were PSMA-FDG+. Per patient level, 9 men (24%; 95% confidence interval: 10%-39%) showed at least one new PSMA-FDG+ lesions. A short PSA doubling time (P = 0.009, OR = 8.000) was associated with PSMA+FDG± disease, while a high Gleason grade group (P = 0.022, OR = 13.091) with PSMA-FDG+ disease. Nineteen patients (51%) with 51 lesions, including 10 PSMA-FDG+ lesions, could be enrolled for OMDT. Among different disease stages, PSMA-FDG+ disease was rarely detected in the hormone-sensitive cohort, but frequently found in the castration-resistant cohort.

CONCLUSIONS

Using ⁶⁸Ga-PSMA and ¹⁸F-FDG PET, we observed a high prevalence of N+/M+ disease and a significant proportion of PSMA-FDG+ disease in patients with an early PSA progression during castration (ChiCTR1900022634).

A prospective trial of 68Ga-PSMA and 18F-FDG PET/CT in nonmetastatic prostate cancer patients with an early PSA progression during castration

e17579

Background: To evaluate tumor heterogeneity and burden in nonmetastatic prostate cancer patients with an early PSA progression during castration by 68Ga-PSMA and 18F-FDG PET/CT. Methods: The trial prospectively included 37 patients who had an early PSA progression (≤2ng/ml) during castration, and high-risk (PSADT ≤10 months) nonmetastatic disease by conventional imaging. All patients underwent both 68Ga-PSMA and 18F-FDG PET/CT. Lesions were classified into PSMA-dominant lesions (PSMA+/FDG- and PSMA+/FDG+) and PSMA-/FDG+ lesions according to the tracer uptake status. The primary endpoint was the prevalence of PSMA-/FDG+ disease. Results: All patients were treated with RP (median duration of castration = 23 months). The median PSA at imaging was 0.57ng/ml. Overall, 114 lesions were detected in 29 of the 37 patients. A high prevalence (73%) of N+/M+ disease was observed. Of the 114 lesions, 81 were PSMA-dominant and 33 were PSMA-/FDG+. Per patient level, 9 men (24%, 95%CI: 10%-39%) showed at least one new PSMA-/FDG+ lesions. A short PSADT ( P= 0.009, OR = 8.000) were associated with PSMA-dominant disease, while a high Gleason grade group ( P= 0.022, OR = 13.091) with PSMA-/FDG+ disease. 19 patients (51%) with 51 lesions could be enrolled for oligometastases-directed therapy including 10 PSMA-/FDG+ lesions. Among different disease stages, PSMA-/FDG+ disease was rarely detected in the hormone-sensitive cohort, but frequently found in the castration-resistant cohort. Conclusions: Using 68Ga-PSMA and 18F-FDG PET, we observed a high prevalence of N+/M+ disease and a significant proportion of PSMA-/FDG+ disease in patients with an early PSA progression during castration. (ChiCTR 1900022634). Clinical trial information: 1900022634 . [Table: see text]

Prognostic Value of Germline DNA Repair Gene Mutations in De Novo Metastatic and Castration-Sensitive Prostate Cancer

BACKGROUND

Germline DNA damage repair gene mutations (gDDRm) have been found in approximately 12% of patients with metastatic prostate cancer (mPCa). Previous studies of the clinical impact of gDDRm have mainly been in the setting of metastatic castration-resistant prostate cancer (mCRPC). This study aimed to determine the prognostic value of gDDRm in de novo metastatic and castration-sensitive prostate cancer (mCSPC).

MATERIALS AND METHODS

We retrospectively collected the records of 139 consecutive men with de novo mCSPC who initially received systemic therapies following guidelines. This included 128 patients who underwent genetic testing at our center and 11 patients referred to our center after being identified as gDDRm carriers. Time to mCRPC was collected. Kaplan-Meier and log-rank analysis were used to analyze the association between gDDRm and clinical outcomes. Survival outcomes were adjusted using multivariable Cox regression models.

RESULTS

Of the 139 patients with de novo mCSPC, 28 gDDRm carriers were identified. Median time progressing to mCRPC was significantly shorter in patients carrying gDDRm than in those without mutations (8.3 vs 13.2 months; hazard ratio [HR], 2.37; p < .001). Moreover, median progression time was almost halved in BRCA2 carriers (6.3 vs. 13.2 months; HR, 3.73; p < .001). Subgroup analysis revealed that the presence of gDDRm indicated poor therapy response regardless of disease volume and prostate-specific antigen nadir within the first 7 months. Presence of gDDRm remained independently associated with increased risk of progression to mCRPC in multivariate analysis (adjusted HR, 1.98; p = .006).

CONCLUSION

Our study suggested that positive gDDRm status predicted rapid progression to castration resistance in patients with de novo mCSPC. We propose identifying gDDRm status at the time of diagnosis for mCSPC patients, considering it is the first step of tailoring individualized treatment. In addition, DNA repair genes were a good therapeutic target for poly (ADP-ribose) polymerase inhibitors, and our results call for more frontline targeted therapy trials in gDDRm carriers to prolong the progression time.

IMPLICATIONS FOR PRACTICE

Results of this study suggested that positive germline DNA damage repair gene mutation (gDDRm) status predicted earlier progression to castration resistance in patients with de novo metastatic and castration-sensitive prostate cancer (mCSPC). These findings indicated the importance of intense therapy for some subgroups of mCSPC, especially for mCSPC harboring gDDRm with low-volume disease. Moreover, gDDRm was a good therapeutic target for poly (ADP-ribose) polymerase inhibitors, and these findings call for more molecular marker driven trials moving to the mTNPC setting.

Comparison of different lymph node staging schemes in prostate cancer patients with lymph node metastasis

PURPOSE

In addition to standard TNM N staging, lymph node ratio (LNR) and log odds of metastatic lymph node (LODDS) staging methods have been developed for cancer staging. We compared the prognostic performance of the total number of lymph nodes examined (TNLE), number of metastatic lymph node (NMLN), LNR, and LODDS in prostate cancer.

METHODS

Data from 1400 patients diagnosed with prostate cancer between 2004 and 2009 who underwent lymphadenectomy were extracted from the Surveillance Epidemiology and End Results database. Kaplan-Meier methods and multivariable Cox regression analysis were used to evaluate the prognostic value of different lymph node staging schemes in patients with lymph node metastasis.

RESULTS

Univariate analysis showed that age, T stage, radiotherapy history, Gleason score, LNR classification, LODDS classification, and NMLN except TNLE classification were significant prognostic factors for overall survival. In multivariate analysis, LNR classification, LODDS classification, and NMLN but TNLE classification remained significant prognostic factors for overall survival. LNR classification had the highest C-index (0.672; 95% confidence interval [CI]: 0.609-0.734) and the lowest Akaike information criterion (AIC) (4057.018), indicating the best prognostic performance. Scatter plots showed that LODDS increased with increasing LNR, exhibiting a strong overall correlation between these two lymph node staging methods (r² = 0.9072). LNR and LODDS generally increased with increasing NMLN, although the correlation was relatively low.

CONCLUSION

Our results indicate that LNR and LODDS may be better predictors of overall survival than the AJCC/UICC N category in patients undergoing curative surgery for prostate cancer.

Germline DNA Repair Gene Mutation Landscape in Chinese Prostate Cancer Patients

Genetic testing for prostate cancer (PCa) patients is in constant development. Specific genetic alterations indicate personalized managing strategies, requiring clinicians to refer appropriate patients for genetic testing. However, our understanding of genetic epidemiology of PCa is mainly based on data from Caucasian populations. In addition, there is evidence that alterations in DNA repair genes (DRGs) may be ethnic specific in other cancers such as breast cancer. Thus, whether Caucasian-based genetic information can be used to guide clinical practice in Chinese population remains unknown. Aiming to clarify the landscape of germline DRG mutation in Chinese patients with PCa, we sequenced 316 patients for 18 DRGs. Among all cases, 9.8% (31/316, 95% confidence interval [CI]: 6.5-13%) carried pathogenic mutations in 18 PCa-related DRGs: 6.3% in BRCA2, 0.63% in BRCA1, 0.63% in ATM, and 2.5% in 15 other genes. Overall, we observed similar germline DRG mutation frequencies, although there is large disparity in the risk of PCa between China and the West. Our study called for a comprehensive analysis in detailed mutation spectra to refine management strategies further, given the ethnic diversity. PATIENT SUMMARY: We sequenced germline pathogenic mutations in 18 DNA repair genes in 316 patients and elucidated the mutation landscape of Chinese prostate cancer (PCa) patients. Our study confirmed the necessity of genetic testing in Chinese PCa and called for a comprehensive analysis in detailed mutation spectra to refine management strategies further, given the ethnic diversity.

Germline mutations of renal cancer predisposition genes and clinical relevance in Chinese patients with sporadic, early-onset disease

BACKGROUND

An inherited susceptibility to renal cancers is associated with multiple predisposing genes, but most screening tests are limited to patients with a family history. Next-generation sequencing (NGS)-based multigene panels provide an efficient and adaptable tool for investigating pathogenic germline mutations on a larger scale. This study investigated the frequency of pathogenic germline mutations in renal cancer predisposition genes in patients with sporadic, early-onset disease.

METHODS

An NGS-based panel of 23 known and potential renal cancer predisposition genes was used to analyze germline mutations in 190 unrelated Chinese patients under the age of 45 years who presented with renal tumors. The detected variants were filtered for pathogenicity, and then their frequencies were calculated and correlated with clinical features. Germline variants of the fumarate hydratase (FH) and BRCA1-associated protein 1 (BAP1) genes were comprehensively analyzed because of their aggressive potential.

RESULTS

In total, 18 patients (9.5%) had germline mutations in 10 genes. Twelve of these 18 patients had alterations in renal cancer predisposition genes (6.3%), and 6 patients had mutations in potential predisposition genes such as BRCA1/2. Notably, pathogenic mutation carriers had a significant family history in second-degree relatives in comparison with those without pathogenic mutations (P < .001). Variants of unknown clinical significance in FH and BAP1 demonstrated evidence of additional somatic loss in tumors.

CONCLUSIONS

In patients with early-onset disease, a multigene panel identified a high pathogenic germline mutation rate in renal cancer predisposition genes. This study emphasizes the importance of screening patients with early-onset disease for mutations in cancer predisposition genes. Germline screening should be encouraged in early-onset patients to provide personalized medicine and improve patient outcomes.

Author Correction: The Oncogenic Role of COL23A1 in Clear Cell Renal Cell Carcinoma

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Identification and validation of a 44-gene expression signature for the classification of renal cell carcinomas

BACKGROUND

Renal cancers account for more than 3% of all adult malignancies and cause more than 23,400 deaths per year in China alone. The four most common types of kidney tumours include clear cell, papillary, chromophobe and benign oncocytoma. These histological subtypes vary in their clinical course and prognosis, and different clinical strategies have been developed for their management. Some kidney tumours can be very difficult to distinguish based on the pathological assessment of morphology and immunohistochemistry.

METHODS

Six renal cell carcinoma microarray data sets, including 106 clear cell, 66 papillary, 42 chromophobe, 46 oncocytoma and 35 adjacent normal tissue samples, were subjected to integrative analysis. These data were combined and used as a training set for candidate gene expression signature identification. In addition, two independent cohorts of 1020 RNA-Seq samples from The Cancer Genome Atlas database and 129 qRT-PCR samples from Fudan University Shanghai Cancer Center (FUSCC) were analysed to validate the selected gene expression signature.

RESULTS

A 44-gene expression signature derived from microarray analysis was strongly associated with the histological differentiation of renal tumours and could be used for tumour subtype classification. The signature performance was further validated in 1020 RNA-Seq samples and 129 qRT-PCR samples with overall accuracies of 93.4 and 93.0%, respectively.

CONCLUSIONS

A 44-gene expression signature that could accurately discriminate renal tumour subtypes was identified in this study. Our results may prompt further development of this gene expression signature into a molecular assay amenable to routine clinical practice.

Expression of ARID1B Is Associated With Poor Outcomes and Predicts the Benefit from Adjuvant Chemotherapy in Bladder Urothelial Carcinoma

Background ARID1B, which exists as a mutually exclusive isoform with ARID1A in the SWI/SNF chromatin remodeling complex, has been recently identified as a major mutant gene in a wide variety of cancers. The present study aimed to determine the association between ARID1B expression and outcomes, as well as the benefit from adjuvant chemotherapy in patients with bladder cancer. Methods Tissue microarrays of 143 consecutively recruited patients with bladder cancer from our center were created. Immunohistochemistry was performed to assess the expression of ARID1B and its association with outcomes. Clinicopathological factors were also evaluated. Results ARID1B expression was significantly associated with tumor size (P=0.015), T stage (P=0.027), lymph node status (P=0.030), TNM stage (P=0.040), overall survival (P<0.001), and progression-free survival (P=0.043). Furthermore, high expression of ARID1B was an independent indicator of poor OS (P=0.022). The prognostic model containing ARID1B showed a better predictive accuracy than the bench models. Most importantly, the benefit of adjuvant chemotherapy observed in patients with low ARID1B expression was superior to that observed in patients with high ARID1B expression. Conclusions Our study suggests that ARID1B can serve as a prognostic biomarker of bladder urothelial carcinoma. Additionally, ARID1B might be a predictive marker for selecting patients for adjuvant chemotherapy in the high-risk subgroup.

The Oncogenic Role of COL23A1 in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common adult renal neoplasm and its incidence continues to increase. Collagen is the most abundant extracellular matrix protein in stroma, and contributes to the development and progression of ccRCC. We examined the human collagen type XXIII α1 chain (COL23A1) expression in ccRCC and the relationship between COL23A1 and patients' survival. We found COL23A1 mRNA was elevated in tumor compared with adjacent normal tissues, which was further validated by TCGA cohort. IHC results from 151 ccRCC cases suggested that high COL23A1 expression correlated with larger tumor size (P = 0.017) and advanced T stage (P = 0.011). The overall survival (OS) was shorter for ccRCC patients with high COL23A1 expression (P = 0.002). In multivariate analysis, high COL23A1 expression was an independent prognostic factor of OS (HR: 3.024, P = 0.017). Furthermore, COL23A1 knockdown repressed proliferation of ccRCC cell lines by blocking cell cycle progression. Cell adhesion and migration capacity was also downregulated by knockdown of COL23A1. Our data indicate that COL23A1 may be a novel prognostic indicator in ccRCC and might be a specific and accessible biomarker as well as a potential new target for clinical diagnosis of ccRCC.

PD-L1 expression in Xp11.2 translocation renal cell carcinoma: Indicator of tumor aggressiveness

Programmed death ligand-1 (PD-L1), a promising antitumor target, has proven clinical value against many malignancies. However, the PD-L1 content of Xp11.2 translocation renal cell carcinoma (Xp11.2 RCC) and its correlation with clinical outcomes remain unclear. This study aimed to investigate PD-L1 expression in Xp11.2 RCC and to assess its prognostic value. Formalin-fixed paraffin-embedded specimens from 36 adult patients that were histologically confirmed (by fluorescence in situ hybridization) were subjected to immunohistochemical analysis. Of the 36 Xp11.2 RCC patients, 9 (25.0%) had tumors with positive PD-L1 expression and 27 (75.0%) had tumors with negative PD-L1 expression. Positive PD-L1 expression correlated with advanced tumor stage (P = 0.001), regional lymph node metastasis (P < 0.001), and distant metastasis (P < 0.001). A multivariate analysis identified positive PD-L1 expression was an independent adverse prognostic factor for both progression free survival (hazard ratio: 3.7, P = 0.018) and overall survival (hazard ratio: 4.5, P = 0.034). The median PFS and OS for the whole cohort were 13.0 months (95% confidence interval [CI], 9.4-16.6 months) and 36.0 months (95% CI, 23.9-48.1 months), respectively. Our findings suggest that positive PD-L1 expression is indicative of worse clinical outcome in Xp11.2 RCC. Further studies are needed to explore the potential efficacy of targeting PD-L1 in Xp11.2 RCC.

Prognostic value of pathological features of primary lesion in metastatic renal cell carcinoma treated with sorafenib

AIM

This study aimed to investigate whether the pathological features of primary lesions show additional prognostic value in patients with metastatic renal cell carcinoma who are treated with sorafenib.

PATIENTS & METHODS

A consecutive cohort of 284 patients was included from Fudan University Shanghai Cancer Center between 2007 and 2013. The association between survival and pathological features of primary tumors was assessed using the Cox proportional hazards model. The incremental value of prognostication was evaluated.

RESULTS

We found that the pathological features of primary lesions provided added prognostic value over the Memorial Sloan-Kettering Cancer Center model in patients with metastatic renal cell carcinoma who were treated with sorafenib.

CONCLUSION

Addition of a pathological score in the clinical setting could better identify patients at risk of poor survival.

[Clear cell papillary renal cell carcinoma: a distinct low-grade renal tumour]

OBJECTIVE

To study the clinicopathologic features of clear cell papillary renal cell carcinoma (CCPRCC).

METHODS

The clinical, morphologic and immunohistochemical characteristics of 6 cases of CCPRCC were reviewed, with analysis of follow-up data.

RESULTS

There were altogether 3 men and 3 women. The mean age of patients was 56 years. The size of tumors ranged from 1.0 to 4.5 cm in greatest dimension. They had solid or solid-cystic cut surface. Histologically, the tumors were encapsulated and showed several morphologic patterns, with tubules, papillae, acini, interconnecting ribbons and macro/microcysts lined by single layer of cells with clear or small amount of eosinophilic cytoplasm and low-grade nuclei (corresponding to Fuhrman grade 1 or 2). Mitotic figures were rarely seen. Characteristically, there was linear arrangement of the nuclei away from the basement membrane, conferring an appearance similar to that of endometrial glands in early secretory phase. Tubules and cysts contained serosanguineous fluid or colloid-like secretion were identified. No foamy histiocytes, psammomatous calcifications or hemosiderin was present in the papillary areas. Two of the tumors showed focal or extensive angioleiomyoma/leiomyoma-like components. No coagulative necrosis, sarcomatoid dedifferentiation, nor microscopic vascular invasion was observed. Immunohistochemically, all tumors showed strong co-expression of CK7 and CA9 (with characteristic "goblet" staining pattern). The staining for EMA, CK (AE1/AE3), vimentin, CK8, CK18, CK19 and PAX-8 were also positive in all cases. Ki-67 was expressed in less than or about 5% of the tumor cell nuclei. The staining for CD10, P504S, CD117, TFE3 and TFEB was negative. Follow-up data were available in all patients, with mean duration of 14 months (range = 7 to 27 months). All of the patients were disease-free after operation.

CONCLUSION

CCPRCC is a special type of low-grade renal neoplasm with characteristic histopathologic and immunohistochemical features. It needs to be distinguished from clear cell renal cell carcinoma or papillary renal cell carcinoma.

[Expression of neonatal Fc receptor on human nephritis and rat nephritis models]

OBJECTIVE

To study the expression of neonatal Fc receptor in podocytes in human nephritis and immune-induced rat nephritis models: anti-Thy1.1 nephritis and Heymann nephritis.

METHODS

Thirty-nine cases of renal biopsies were enrolled from September 2009 to February 2010, including 8 cases of minimal change disease, 4 cases of focal segmental glomerulosclerosis, 9 cases of membranous nephropathy, 12 cases of IgA nephropathy and 6 cases of lupus nephritis. Five normal kidney tissue samples adjacent to renal clear-cell carcinoma were served as normal controls. Laser capture microdissection and real-time RT-PCR were used to assess the expression level of FcRn mRNA in glomeruli of various glomerulonephritides, and immunohistochemistry (IHC) of FcRn by SuperVision method was performed. In addition, rat models of mesangial proliferative nephritis (anti-Thy1.1 nephritis) and passive membranous nephropathy (Heymann nephritis) were established and FcRn was examined in renal tissues by IHC.

RESULTS

The FcRn mRNA level in lupus nephritis was statistically higher than that of normal controls (P < 0.05). FcRn protein expression by IHC was seen in lupus nephritis (6/6), membranous nephropathy (6/9) and IgA nephropathy (7/12), significantly higher than that of normal controls (0/5), P < 0.05. Minimal change disease and focal segmental glomerular sclerosis showed minimal or none expression of FcRn (1/8, 0/4 respectively) and not statistically difference from that of normal controls. Furthermore, FcRn expression in podocytes was detected in rat anti-Thy1.1 (3/5) and Heymann nephritis models (2/7) but was not detected in normal controls.

CONCLUSIONS

Expression of FcRn in podocytes was up-regulated in immune-induced human nephritis and rat nephritis models of anti-Thy1.1 nephritis and Heymann nephritis. FcRn may play a role in the development of immune-induced glomerulonephritis.

Role of cross-talk between the Smad2 and MAPK pathways in TGF-beta1-induced collagen IV expression in mesangial cells

Transforming growth factor beta1 (TGF-beta1) can promote sclerosis in many kidney diseases by enhancing the synthesis of collagens. However, the mechanisms of down-stream intracellular signal transduction in TGF-beta1-induced collagen synthesis is not fully understood. The purpose of this study was to further investigate the mechanisms and the cross-talk between the MAPK and Smad2 pathways. We found that U0126, a specific inhibitor of ERK1/2, and SB203580, a specific inhibitor of p38, down-regulated the TGF-beta1-induced phosphorylation of Smad2 at both linker and C-terminal sites in rat mesangial cells. Whereas, SP600125, a specific inhibitor of JNK, only down-regulated the phosphorylation of Smad2 at the C-terminal sites, but had little effect on the phosphorylation of Smad2 at linker sites. However, all three MAPK inhibitors reduced collagen IV synthesis induced by TGF-beta1. Furthermore, TGF-beta1 induced the phosphorylation of Smad2 at both the linker and C-terminal sites. Transient transfection of a dominant negative Smad2 construct significantly decreased TGF-beta1-induced phosphorylation of ERK1/2, JNK and expression of collagen IV, but did not decrease the phosphorylation of p38. These findings demonstrate that there is cross-talk between the MAPK (ERK1/2, JNK, p38) and Smad2 pathways, and that the cross-talk interacts mutually to enhance the synthesis of collagen IV in rat mesangial cells.