Fluorine-18 Prostate-Specific Membrane Antigen-1007 PET/CT vs Multiparametric MRI for Locoregional Staging of Prostate Cancer.

Importance: Prostate-specific membrane antigen (PSMA) demonstrates overexpression in prostate cancer and correlates with tumor aggressiveness. PSMA positron emission tomography (PET) is superior to conventional imaging for the metastatic staging of prostate cancer per current research but studies of second-generation PSMA PET radioligands for locoregional staging are limited. Objective: To determine the accuracy of fluorine-18 PSMA-1007 PET/computed tomography (18F-PSMA-1007 PET/CT) compared to multiparametric magnetic resonance imaging (MRI) in the primary locoregional staging of intermediate-risk and high-risk prostate cancers. Design, Setting, and Participants: The Next Generation Trial was a phase 2 prospective validating paired cohort study assessing the accuracy of 18F-PSMA-1007 PET/CT and MRI for locoregional staging of prostate cancer, with results of histopathologic examination as the reference standard comparator. Radiologists, nuclear medicine physicians, and pathologists were blinded to preoperative clinical, pathology, and imaging data. Patients underwent all imaging studies and radical prostatectomies at 2 tertiary care hospitals in Alberta, Canada. Eligible participants included men with intermediate-risk or high-risk prostate cancer who consented to radical prostatectomy. Participants who underwent radical prostatectomy were included in the final analysis. Patients were recruited between March 2022 and June 2023, and data analysis occurred between July 2023 and December 2023. Exposures: All participants underwent both 18F-PSMA-1007 PET/CT and MRI within 2 weeks of one another and before radical prostatectomy. Main Outcomes and Measures: The primary outcome was the correct identification of the prostate cancer tumor stage by each imaging test. The secondary outcomes were correct identification of the dominant nodule, laterality, extracapsular extension, and seminal vesical invasion. Results: Of 150 eligible men with prostate cancer, 134 patients ultimately underwent radical prostatectomy (mean [SD] age at prostatectomy, 62.0 [5.7] years). PSMA PET was superior to MRI for the accurate identification of the final pathological tumor stage (61 [45%] vs 38 [28%]; P = .003). PSMA PET was also superior to MRI for the correct identification of the dominant nodule (126 [94%] vs 112 [83%]; P = .01), laterality (86 [64%] vs 60 [44%]; P = .001), and extracapsular extension (100 [75%] vs 84 [63%]; P = .01), but not for seminal vesicle invasion (122 [91%] vs 115 [85%]; P = .07). Conclusions and Relevance: In this phase 2 prospective validating paired cohort study, 18F-PSMA-1007 PET/CT was superior to MRI for the locoregional staging of prostate cancer. These findings support PSMA PET in the preoperative workflow of intermediate-risk and high-risk tumors.

Exploring The Prognostic Significance of SET-Domain Containing 2 (SETD2) Expression in Advanced and Castrate-Resistant Prostate Cancer.

SET-domain containing 2 (SETD2) is a histone methyltransferase and an epigenetic modifier with oncogenic functionality. In the current study, we investigated the potential prognostic role of SETD2 in prostate cancer. A cohort of 202 patients' samples was assembled on tissue microarrays (TMAs) containing incidental, advanced, and castrate-resistant CRPCa cases. Our data showed significant elevated SETD2 expression in advanced and castrate-resistant disease (CRPCa) compared to incidental cases (2.53 ± 0.58 and 2.21 ± 0.63 vs. 1.9 ± 0.68; p < 0.001, respectively). Interestingly, the mean intensity of SETD2 expression in deceased vs. alive patients was also significantly different (2.31 ± 0.66 vs. 2 ± 0.68; p = 0.003, respectively). Overall, high SETD2 expression was found to be considered high risk and was significantly associated with poor prognosis and worse overall survival (OS) (HR 1.80; 95% CI: 1.28-2.53, p = 0.001) and lower cause specific survival (CSS) (HR 3.14; 95% CI: 1.94-5.08, p < 0.0001). Moreover, combining high-intensity SETD2 with PTEN loss resulted in lower OS (HR 2.12; 95% CI: 1.22-3.69, p = 0.008) and unfavorable CSS (HR 3.74; 95% CI: 1.67-8.34, p = 0.001). Additionally, high SETD2 intensity with ERG positive expression showed worse prognosis for both OS (HR 1.99, 95% CI 0.87-4.59; p = 0.015) and CSS (HR 2.14, 95% CI 0.98-4.68, p = 0.058). We also investigated the protein expression database TCPA, and our results showed that high SETD2 expression is associated with a poor prognosis. Finally, we performed TCGA PRAD gene set enrichment analysis (GSEA) data for SETD2 overexpression, and our data revealed a potential association with pathways involved in tumor progression such as the AMPK signaling pathway, the cAMP signaling pathway, and the PI3K-Akt signaling pathway, which are potentially associated with tumor progression, chemoresistance, and a poor prognosis.

An international multicenter study to evaluate reproducibility of automated scoring for assessment of Ki67 in breast cancer.

The nuclear proliferation biomarker Ki67 has potential prognostic, predictive, and monitoring roles in breast cancer. Unacceptable between-laboratory variability has limited its clinical value. The International Ki67 in Breast Cancer Working Group investigated whether Ki67 immunohistochemistry can be analytically validated and standardized across laboratories using automated machine-based scoring. Sets of pre-stained core-cut biopsy sections of 30 breast tumors were circulated to 14 laboratories for scanning and automated assessment of the average and maximum percentage of tumor cells positive for Ki67. Seven unique scanners and 10 software platforms were involved in this study. Pre-specified analyses included evaluation of reproducibility between all laboratories (primary) as well as among those using scanners from a single vendor (secondary). The primary reproducibility metric was intraclass correlation coefficient between laboratories, with success considered to be intraclass correlation coefficient >0.80. Intraclass correlation coefficient for automated average scores across 16 operators was 0.83 (95% credible interval: 0.73-0.91) and intraclass correlation coefficient for maximum scores across 10 operators was 0.63 (95% credible interval: 0.44-0.80). For the laboratories using scanners from a single vendor (8 score sets), intraclass correlation coefficient for average automated scores was 0.89 (95% credible interval: 0.81-0.96), which was similar to the intraclass correlation coefficient of 0.87 (95% credible interval: 0.81-0.93) achieved using these same slides in a prior visual-reading reproducibility study. Automated machine assessment of average Ki67 has the potential to achieve between-laboratory reproducibility similar to that for a rigorously standardized pathologist-based visual assessment of Ki67. The observed intraclass correlation coefficient was worse for maximum compared to average scoring methods, suggesting that maximum score methods may be suboptimal for consistent measurement of proliferation. Automated average scoring methods show promise for assessment of Ki67 scoring, but requires further standardization and subsequent clinical validation.

EMT in Breast Carcinoma-A Review.

The epithelial to mesenchymal transition (EMT) is a cellular program that is involved in embryonic development; wound healing, but also in tumorigenesis. Breast carcinoma (BC) is the most common cancer in women worldwide, and the majority of deaths (90%) are caused by invasion and metastasis. The EMT plays an important role in invasion and subsequent metastasis. Several distinct biological events integrate a cascade that leads not only to a change from an epithelial to mesenchymal phenotype, but allows for detachment, migration, invasion and ultimately, colonization of a second site. Understanding the biological intricacies of the EMT may provide important insights that lead to the development of therapeutic targets in pre-invasive and invasive breast cancer, and could be used as biomarkers identifying tumor subsets with greater chances of recurrence, metastasis and therapeutic resistance leading to death.

Prognostic Value of ADAMTS Proteases and Their Substrates in Epithelial Ovarian Cancer.

BACKGROUND: ADAMTS are metalloproteases with disintegrin and thrombospondin motifs. They are secreted proteases playing a role in biological processes such as inflammation, angiogenesis, and urogenital development. ADAMTS have specific substrates, such as the proteoglycans (PG) versican, aggrecan, and brevican. Despite data indicating a role of ADAMTS in tumor invasion and metastases, effects played by these molecules in cancer progression are still controversial. In ovarian cancer, the importance of ADAMTS gene mutations was recently described and related to chemotherapy outcome. OBJECTIVE: To analyze protein levels of ADAMTS-1, -4, and -5, and TIMP-3 in human ovarian cancer classified as benign, borderline, or malignant. We also assessed the expression of the ADAMTS substrates aggrecan, brevican, and versican in these neoplasms. Correlations between overall survival and protein expression were performed. METHODS: Tumors were classified according to the WHO Classification of Tumors of Female Reproductive Organs. Protein and PG expression was studied by immunohistochemistry. Differences in labeling were analyzed by percent measurements of stained areas. RESULTS: ADAMTS-1, ADAMTS-5, and its tissue inhibitor TIMP-3 are increased in borderline and malignant tumors compared to benign neoplasms. Aggrecan and versican levels were increased in malignant subtypes compared to benign ovarian cancer. Higher ADAMTS-1, TIMP-3, and versican expression was associated with a shorter overall survival. CONCLUSIONS: Comparison of protease, TIMP-3, and substrate expression showed that in malignant tumors all ADAMTS and TIMP-3 expression levels were significantly raised compared to the substrates studied.

Integrated Genomic Analysis of Pancreatic Ductal Adenocarcinomas Reveals Genomic Rearrangement Events as Significant Drivers of Disease.

Many somatic mutations have been detected in pancreatic ductal adenocarcinoma (PDAC), leading to the identification of some key drivers of disease progression, but the involvement of large genomic rearrangements has often been overlooked. In this study, we performed mate pair sequencing (MPseq) on genomic DNA from 24 PDAC tumors, including 15 laser-captured microdissected PDAC and 9 patient-derived xenografts, to identify genome-wide rearrangements. Large genomic rearrangements with intragenic breakpoints altering key regulatory genes involved in PDAC progression were detected in all tumors. SMAD4, ZNF521, and FHIT were among the most frequently hit genes. Conversely, commonly reported genes with copy number gains, including MYC and GATA6, were frequently observed in the absence of direct intragenic breakpoints, suggesting a requirement for sustaining oncogenic function during PDAC progression. Integration of data from MPseq, exome sequencing, and transcriptome analysis of primary PDAC cases identified limited overlap in genes affected by both rearrangements and point mutations. However, significant overlap was observed in major PDAC-associated signaling pathways, with all PDAC exhibiting reduced SMAD4 expression, reduced SMAD-dependent TGFß signaling, and increased WNT and Hedgehog signaling. The frequent loss of SMAD4 and FHIT due to genomic rearrangements strongly implicates these genes as key drivers of PDAC, thus highlighting the strengths of an integrated genomic and transcriptomic approach for identifying mechanisms underlying disease initiation and progression.

Transcriptomic and Immunohistochemical Profiling of SLC6A14 in Pancreatic Ductal Adenocarcinoma.

We used a target-centric strategy to identify transporter proteins upregulated in pancreatic ductal adenocarcinoma (PDAC) as potential targets for a functional imaging probe to complement existing anatomical imaging approaches. We performed transcriptomic profiling (microarray and RNASeq) on histologically confirmed primary PDAC tumors and normal pancreas tissue from 33 patients, including five patients whose tumors were not visible on computed tomography. Target expression was confirmed with immunohistochemistry on tissue microarrays from 94 PDAC patients. The best imaging target identified was SLC6A14 (a neutral and basic amino acid transporter). SLC6A14 was overexpressed at the transcriptional level in all patients and expressed at the protein level in 95% of PDAC tumors. Very little is known about the role of SLC6A14 in PDAC and our results demonstrate that this target merits further investigation as a candidate transporter for functional imaging of PDAC.

Characterization of precursor lesions in the endometrium and fallopian tube epithelium of early-stage uterine serous carcinoma.

To determine if selected cases of uterine serous carcinoma (USC) arise from tubal rather than endometrial epithelium. Bilateral fallopian tubes from 38 women with pure USC were entirely submitted for histopathologic examination using the protocol Sectioning and Extensively Examining the FIMbria (SEE-FIM). Non-neoplastic endometrium was extensively sampled. Immunohistochemistry for p53 was performed on all paraffin blocks of fallopian tube and non-neoplastic endometrium. Endometrial intraepithelial carcinoma (EIC) was present in 22 cases (58%). Endometrial p53 foci were identified in 3 patients. There were 11 cases (29%) with fallopian tube involvement; 9 of 11 had tubal wall invasion or lymphatic involvement without serous tubal intraepithelial carcinoma (STIC) and were, therefore, classified as metastatic from the endometrium. STIC was identified in 3 patients (8%). There were 3 cases with tubal p53 foci in non-neoplastic epithelium. EIC was present in 58% of patients, further supporting EIC as a precursor lesion to USC. STIC was present in 8%, suggesting that the fallopian tube may in fact represent the primary lesion in a minority of patients with USC. This finding may account for the early multifocal disease distribution observed in these patients.

Genomic rearrangements define lineage relationships between adjacent lepidic and invasive components in lung adenocarcinoma.

The development of adenocarcinoma of the lung is believed to proceed from in situ disease (adenocarcinoma in situ, AIS) to minimally invasive disease with prominent lepidic growth (minimally invasive adenocarcinoma, MIA), then to fully invasive adenocarcinoma (AD), but direct evidence for this model has been lacking. Because some lung adenocarcinomas show prominent lepidic growth (AD-L), we designed a study to address the lineage relationship between the lepidic (noninvasive) component (L) and the adjacent nonlepidic growth component representing invasive disease within individual tumors. Lineage relationships were evaluated by next-generation DNA sequencing to define large genomic rearrangements in microdissected tissue specimens collected by laser capture. We found a strong lineage relationship between the majority of adjacent lepidic and invasive components, supporting a putative AIS-AD transition. Notably, many rearrangements were detected in the less aggressive lepidic component, although the invasive component exhibited an overall higher rate of genomic rearrangement. Furthermore, a significant number of genomic rearrangements were present in histologically normal lung adjacent to tumor, but not in host germline DNA, suggesting field defects restricted to zonal regions near a tumor. Our results offer a perspective on the genetic pathogenesis underlying adenocarcinoma development and its clinical management.

Genetic alterations associated with progression from pancreatic intraepithelial neoplasia to invasive pancreatic tumor.

BACKGROUND & AIMS: Increasing grade of pancreatic intraepithelial neoplasia (PanIN) has been associated with progression to pancreatic ductal adenocarcinoma (PDAC). However, the mechanisms that control progression from PanINs to PDAC are not well understood. We investigated the genetic alterations involved in this process. METHODS: Genomic DNA samples from laser-capture microdissected PDACs and adjacent PanIN2 and PanIN3 lesions from 10 patients with pancreatic cancer were analyzed by exome sequencing. RESULTS: Similar numbers of somatic mutations were identified in PanINs and tumors, but the mutational load varied greatly among cases. Ten of the 15 isolated PanINs shared more than 50% of somatic mutations with associated tumors. Mutations common to tumors and clonally related PanIN2 and PanIN3 lesions were identified as genes that could promote carcinogenesis. KRAS and TP53 frequently were altered in PanINs and tumors, but few other recurrently modified genes were detected. Mutations in DNA damage response genes were prevalent in all samples. Genes that encode proteins involved in gap junctions, the actin cytoskeleton, the mitogen-activated protein kinase signaling pathway, axon guidance, and cell-cycle regulation were among the earliest targets of mutagenesis in PanINs that progressed to PDAC. CONCLUSIONS: Early stage PanIN2 lesions appear to contain many of the somatic gene alterations required for PDAC development.

FOXL2 mutations in granulosa cell tumors occurring in males.

CONTEXT: Granulosa cell tumors comprise less than 5% of ovarian tumors in women and are much rarer in men, with only about 20 cases reported, to our knowledge. Recently, a somatic mutation of FOXL2 was reported in virtually all adult-type granulosa cell tumors in women. OBJECTIVE: To investigate FOXL2 mutations in granulosa cell tumors occurring in males. DESIGN: Five cases of an adult-type granulosa cell tumor from males were selected from the files of the Mayo Clinic. Nine other testicular tumors (1 juvenile granulosa cell tumor, 5 Leydig cell tumors, and 3 Sertoli-Leydig cell tumors) were evaluated for comparison. Inhibin immunostain was performed in all cases. DNA was extracted from formalin-fixed, paraffin-embedded tissue, followed by polymerase chain reaction and direct sequencing of FOXL2. RESULTS: All 5 cases had classic histopathologic features of the adult-type granulosa cell tumor. Inhibin was diffusely positive in all cases. FOXL2 402C→G (C134W) was identified in 40% (2 of 5) of the male, adult-type granulosa cell tumors. Of the 2 tumors positive for the mutation, 1 occurred in the testis of a man, and the other one affected the abdominal ovaries of a phenotypically male patient. All other testicular tumors were negative for the mutation. CONCLUSIONS: The FOXL2 402C→G (C134W) mutation is also present in adult-type granulosa cell tumors occurring in men, although in a smaller proportion when compared with the rates reported in women. FOXL2 mutational analysis can be a helpful in the diagnosis of granulosa cell tumors of the testis.

HMGA gene rearrangement is a recurrent somatic alteration in polypoid endometriosis.

The pathogenesis of endometriosis is unclear, and several genetic, endocrine, immune, and environmental agents have been evaluated with no putative causative factors identified. Here, we show somatic genetic alterations involving HMGA1 (6p21) and HMGA2 (12q15) in 3 cases of polypoid endometriosis. The lesions involved the small bowel mesentery and perirectal soft tissue in 1 case and the posterior vaginal fornix and sigmoid colon serosa in 2 other cases, respectively. All had a polypoid configuration with cystically dilated irregular glands and fibrotic stroma, containing thick-walled vessels. Conventional cytogenetic analysis of 1 case showed 46,XX,t(5;12)(q13;q15) in all metaphases. Fluorescence in situ hybridization studies confirmed the balanced rearrangement of HMGA2. HMGA1 rearrangements were present in 2 additional cases. Rearrangements were exclusively found in the stromal component but not in the glandular component. These findings suggest that HMGA rearrangements likely contribute to the pathogenesis of endometriosis. However, additional studies are needed to better define the biologic role of this genetic alteration.

The impact of tissue block sampling on the detection of p53 signatures in fallopian tubes from women with BRCA 1 or 2 mutations (BRCA+) and controls.

The tubal p53 signature is a putative precursor to pelvic serous carcinoma, but its frequencies in women with inherited mutations in the BRCA1 or BRCA2 genes (BRCA+) and controls has been controversial. An initial section and two levels (100-200 µm) from every block in BRCA+ (24) and control tubes (40) were stained for p53. The frequency of p53 signatures was computed between the populations and across the three levels from each block, and analyzed by Fisher exact test. A total of 17 (71%) BRCA+ and 20 (50%) control tubes were p53 signature positive (P=0.12); 21 and 16% of all tissue blocks sectioned harbored signatures (P=0.29), and 76 and 67% were found in the fimbria. In 49 and 32% of p53 signature positive cases in the two groups, the p53 signatures were not discovered until the second or third round of sectioning. In all, 38 and 40% of BRCA+ and control subjects harbored p53 signatures in more than one focus in a single block. In one case (BRCA+), a highly atypical proliferation was identified in one serial section. The p53 signatures are more common than previously reported and the frequency of detection increases as a function of sectioning through the tissue block, both in absolute frequency and in numbers of p53 signatures detected in a given block. There is a trend for a higher absolute frequency of p53 signatures (71 vs 50%; P=0.12) in BRCA+ subjects, but this is not reflected in a greater average number of p53 signatures or positive blocks per case. This study underscores the importance of systematic immunohistochemical examination of fallopian tubes when conducting epidemiological studies that compare the frequency of p53 signatures in different populations. Attention to this detail is critical when exploring risk factors germane to early serous carcinogenesis.