Breast tissue imaging atlas using ultra-fast confocal microscopy to identify cancer lesions

New generation ultra-fast fluorescence confocal microscopy (UFCM) allows to image histological architecture of fresh breast tissue and may be used for ex vivo intraoperative analysis for margin status. The criteria to identify breast tumoral and non-tumoral tissues in UFCM images are still objects of investigation. The objective of the study was to create an atlas of ex vivo UFCM images of breast tissues and breast carcinomas based on the first extensive collection of large field-of-view UFCM breast images. One hundred sixty patients who underwent conserving surgery for breast cancer were included. Their fresh surgical specimens were sliced, stained with acridine orange, and imaged at high resolution with large-field-of-view UFCM. The resulting images were digitally false colored to resemble frozen sections. Each UFCM image was correlated with the corresponding definitive histology. Representative images of normal tissue, inflammation, benign lesions, invasive carcinoma (IC), and ductal carcinoma in situ (DCIS) were collected. A total of 320 large-field images were recorded from 58 IC of no special type, 44 invasive lobular carcinomas, 1 invasive mucinous carcinoma, 47 DCIS, 2 lobular carcinomas in situ, and 8 specimens without cancer. Representative images of the main components of the normal breast and the main types of ICs and DCIS were annotated to establish an UFCM atlas. UFCM enables the imaging of the fresh breast tissue sections. Main morphological criteria defined in traditional histopathology such as tissue architecture and cell features can be applied to describe UFCM images content. The generated atlas of the main normal or tumoral tissue features will support the adoption of this optical technology for the intraoperative examination of breast specimens in clinical practice as it can be used to train physicians on UFCM images and develop artificial intelligence algorithms. Further studies are needed to document rare breast lesions.

Accuracy of World Health Organisation-grade parameters (necrosis and mitotic activity) and foci of vascular invasion in predicting prognosis of papillary thyroid carcinoma. A case-control validation study

AIMS

Tumour necrosis and/or increased mitoses define high-grade papillary thyroid carcinoma (PTC). It is unclear whether angioinvasion is prognostic for PTC. Cut-offs at five or more mitoses/2 mm2 and four or more angioinvasive foci have been empirically defined based upon data from all forms of aggressive non-anaplastic thyroid carcinomas. Performance of tumour necrosis, mitoses and vascular invasion in predicting distant metastases when specifically applied to PTC is undefined.

METHODS

We analysed 50 consecutive PTC cases with distant metastases (DM-PTC): 16 synchronous and 34 metachronous. A total of 108 non-metastatic PTC (N-DM-PTC, 15.0-year median follow-up) were used as controls. Invasive encapsulated follicular variant PTC was excluded. Necrosis, mitoses and angioinvasion were quantified. Receiver operating characteristics (ROC) and area under the curve (AUC) analyses determined best sensitivity and specificity cut-offs predictive of distant metastases.

RESULTS

Metastases correlated with necrosis (any extent = 43.8% all DM-PTC, 53.1% metachronous DM-PTC versus 5% N-DM-PTC; P < 0.001), mitoses (P < 0.001) and angioinvasion (P < 0.001). Mitoses at five or more per 2 mm2 was the best cut-off correlating with distant metastases: sensitivity/specificity 42.9%/97.2% all DM-PTC (AUC = 0.78), 18.8%/97.2% synchronous DM-PTC (AUC = 0.63), 54.6%/97.2% metachronous DM-PTC (AUC = 0.85). Angioinvasive foci at five or more was the best cut-off correlating with distant metastases: sensitivity/specificity 36.2%/91.7% all DM-PTC (AUC = 0.75), 25%/91.7% synchronous DM-PTC (AUC = 0.79) and 41.9%/91.7% metachronous DM-PTC (AUC = 0.73). Positive/negative predictive values (PPV/NPV) were: necrosis 22.6%/98.2%; five or more mitoses 32.3%/98.2%; five or more angioinvasive foci 11.8%/97.9%. After multivariable analysis, only necrosis and mitotic activity remained associated with DM-PTC.

CONCLUSION

Our data strongly support PTC grading, statistically validating World Health Organisation (WHO) criteria to identify poor prognosis PTC. Angioinvasion is not an independent predictor of DM-PTC.

Comparing accuracy of tomosynthesis plus digital mammography or synthetic 2D mammography in breast cancer screening: baseline results of the MAITA RCT consortium

AIM

The analyses here reported aim to compare the screening performance of digital tomosynthesis (DBT) versus mammography (DM).

METHODS

MAITA is a consortium of four Italian trials, REtomo, Proteus, Impeto, and MAITA trial. The trials adopted a two-arm randomised design comparing DBT plus DM (REtomo and Proteus) or synthetic-2D (Impeto and MAITA trial) versus DM; multiple vendors were included. Women aged 45 to 69 years were individually randomised to one round of DBT or DM.

FINDINGS

From March 2014 to February 2022, 50,856 and 63,295 women were randomised to the DBT and DM arm, respectively. In the DBT arm, 6656 women were screened with DBT plus synthetic-2D. Recall was higher in the DBT arm (5·84% versus 4·96%), with differences between centres. With DBT, 0·8/1000 (95% CI 0·3 to 1·3) more women received surgical treatment for a benign lesion. The detection rate was 51% higher with DBT, ie. 2·6/1000 (95% CI 1·7 to 3·6) more cancers detected, with a similar relative increase for invasive cancers and ductal carcinoma in situ. The results were similar below and over the age of 50, at first and subsequent rounds, and with DBT plus DM and DBT plus synthetic-2D. No learning curve was appreciable. Detection of cancers >= 20 mm, with 2 or more positive lymph nodes, grade III, HER2-positive, or triple-negative was similar in the two arms.

INTERPRETATION

Results from MAITA confirm that DBT is superior to DM for the detection of cancers, with a possible increase in recall rate. DBT performance in screening should be assessed locally while waiting for long-term follow-up results on the impact of advanced cancer incidence.

Spatial Distribution of Immune Cells Drives Resistance to Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer

Neoadjuvant chemotherapy (NAC) alone or combined with target therapies represents the standard of care for localized triple-negative breast cancer (TNBC). However, only a fraction of patients have a response, necessitating better understanding of the complex elements in the TNBC ecosystem that establish continuous and multidimensional interactions. Resolving such complexity requires new spatially-defined approaches. Here, we used spatial transcriptomics to investigate the multidimensional organization of TNBC at diagnosis and explore the contribution of each cell component to response to NAC. Starting from a consecutive retrospective series of TNBC cases, we designed a case-control study including 24 patients with TNBC of which 12 experienced a pathologic complete response (pCR) and 12 no-response or progression (pNR) after NAC. Over 200 regions of interest (ROI) were profiled. Our computational approaches described a model that recapitulates clinical response to therapy. The data were validated in an independent cohort of patients. Differences in the transcriptional program were detected in the tumor, stroma, and immune infiltrate comparing patients with a pCR with those with pNR. In pCR, spatial contamination between the tumor mass and the infiltrating lymphocytes was observed, sustained by a massive activation of IFN-signaling. Conversely, pNR lesions displayed increased pro-angiogenetic signaling and oxygen-based metabolism. Only modest differences were observed in the stroma, revealing a topology-based functional heterogeneity of the immune infiltrate. Thus, spatial transcriptomics provides fundamental information on the multidimensionality of TNBC and allows an effective prediction of tumor behavior. These results open new perspectives for the improvement and personalization of therapeutic approaches to TNBCs.

A Prognostic Model Based on Residual Cancer Burden and Tumor-Infiltrating Lymphocytes on Residual Disease after Neoadjuvant Therapy in HER2+ Breast Cancer

PURPOSE

We aim to evaluate the prognostic significance of tumor-infiltrating lymphocyte on residual disease (RD-TIL) in HER2+ patients with breast cancer who failed to achieve pathologic complete response (pCR) after anti-HER2+ chemotherapy (CT)-based neoadjuvant treatment (NAT). We assessed the feasibility of combining the prognostic information provided by residual cancer burden (RCB) and RD-TILs into a composite score (RCB+TIL).

EXPERIMENTAL DESIGN

HER2+ patients with breast cancer treated with CT+anti-HER2-based NAT at three institutions were retrospectively included. RCB and TIL levels were evaluated on hematoxylin and eosin-stained slides from surgical samples according to available recommendations. Overall survival (OS) was used as an outcome measure.

RESULTS

A total of 295 patients were included, of whom 195 had RD. RCB was significantly associated with OS. Higher RD-TILs were significantly associated with poorer OS as compared with lower RD-TILs (15% cutoff). In multivariate analysis, both RCB and RD-TIL maintained their independent prognostic value. A combined score, RCB+TIL, was calculated from the estimated coefficient of RD-TILs and the RCB index in a bivariate logistic model for OS. The RCB+TIL score was significantly associated with OS. The C-index for OS of the RCB+TIL score was numerically higher than that of RCB and significantly higher than that of RD-TILs.

CONCLUSIONS

We have reported an independent prognostic impact of RD-TILs after anti-HER2+CT NAT, which might underlie an imbalance of the RD microenvironment towards immunosuppressive features. We provided a new composite prognostic score based on RCB+TIL, which was significantly associated with OS and proved to be more informative than the isolated evaluation of RCB and RD-TILs.

Medullary Thyroid Carcinomas Classified According to the International Medullary Carcinoma Grading System and a Surveillance, Epidemiology, and End Results-Based Metastatic Risk Score: A Correlation With Genetic Profile and Angioinvasion

Due to the lack of a standardized tool for risk-based stratification, the International Medullary Carcinoma Grading System (IMTCGS) has been proposed for medullary thyroid carcinomas (MTCs) based on necrosis, mitosis, and Ki67. Similarly, a risk stratification study using the Surveillance, Epidemiology, and End Results (SEER) database highlighted significant differences in MTCs in terms of clinical-pathological variables. We aimed to validate both the IMTCGS and SEER-based risk table on 66 MTC cases, with special attention to angioinvasion and the genetic profile. We found a significant association between the IMTCGS and survival because patients classified as high-grade had a lower event-free survival probability. Angioinvasion was also found to be significantly correlated with metastasis and death. Applying the SEER-based risk table, patients classified either as intermediate- or high-risk had a lower survival rate than low-risk patients. In addition, high-grade IMTCGS cases had a higher average SEER-based risk score than low-grade cases. Moreover, when we explored angioinvasion in correlation with the SEER-based risk table, patients with angioinvasion had a higher average SEER-based score than patients without angioinvasion. Deep sequencing analysis found that 10 out of 20 genes frequently mutated in MTCs belonged to a specific functional class, namely chromatin organization, and function, which may be responsible for the MTC heterogeneity. In addition, the genetic signature identified 3 main clusters; cases belonging to cluster II displayed a significantly higher number of mutations and higher tumor mutational burden, suggesting increased genetic instability, but cluster I was associated with the highest number of negative events. In conclusion, we confirmed the prognostic performance of the IMTCGS and SEER-based risk score, showing that patients classified as high-grade had a lower event-free survival probability. We also underline that angioinvasion has a significant prognostic role, which has not been incorporated in previous risk scores.

Breast carcinoma detection in ex vivo fresh human breast surgical specimens using a fast slide-free confocal microscopy scanner: HIBISCUSS project

BACKGROUND

New generation ultra-fast fluorescence confocal microscopy allows the ex vivo intraoperative analysis of fresh tissue. The High resolution Imaging for Breast carcInoma detection in ex vivo Specimens after breast Conserving sUrgery by hiStolog Scanner (HIBISCUSS) project aimed to develop an online learning program to recognize the main breast tissue features on ultra-fast fluorescence confocal microscopy images and to evaluate the performance of surgeons and pathologists in diagnosing cancerous and non-cancerous breast tissue in ultra-fast fluorescence confocal microscopy images.

METHODS

Patients who underwent conservative surgery or mastectomy for breast carcinoma (invasive or in situ lesions) were included. The fresh specimens were stained with a fluorescent dye and imaged using a large field-of-view (20 cm2) ultra-fast fluorescence confocal microscope.

RESULTS

One hundred and eighty-one patients were included. The images from 55 patients were annotated to generate learning sheets and images from 126 patients were blindly interpreted by seven surgeons and two pathologists. The time for tissue processing and ultra-fast fluorescence confocal microscopy imaging was between 8 and 10 min. The training program was composed of 110 images divided into nine learning sessions. The final database for blind performance assessment comprised 300 images. The mean duration for one training session and one performance round was 17 and 27 min respectively. The performance of pathologists was almost perfect with 99.6 per cent (standard deviation (s.d.) 5.4 per cent) accuracy. Surgeons' accuracy significantly increased (P = 0.001) from 83 per cent (s.d. 8.4 per cent) in round 1 to 98 per cent (s.d. 4.1 per cent) in round 7 as well as the sensitivity (P = 0.004). Specificity increased without significance from 84 per cent (s.d. 16.7 per cent) in round 1 to 87 per cent (s.d. 16.4 per cent) in round 7 (P = 0.060).

CONCLUSION

Pathologists and surgeons showed a short learning curve in differentiating breast cancer from non-cancerous tissue in ultra-fast fluorescence confocal microscopy images. Performance assessment for both specialties supports ultra-fast fluorescence confocal microscopy evaluation for intraoperative management.

REGISTRATION NUMBER

NCT04976556 (http://www.clinicaltrials.gov).

Imaging of lumpectomy surface with large field-of-view confocal laser scanning microscopy 'Histolog® scanner' for breast margin assessment in comparison with conventional specimen radiography

PURPOSE

The Histolog® Scanner (SamanTree Medical SA, Lausanne, Switzerland) is a large field-of-view confocal laser scanning microscope designed to allow intraoperative margin assessment by the production of histological images ready for assessment in the operating room. We evaluated the feasibility and the performance of the Histolog® Scanner (HS) to correctly identify infiltrated margins in clinical practice of lumpectomy specimens. It was extrapolated if the utilization of the HS has the potential to reduce infiltrated margins and therefore reduce re-operation rates in patients undergoing breast conserving surgery (BCS) due to a primarily diagnosed breast cancer including ductal carcinoma in situ.

METHODS

This is a single-center, prospective, non-interventional, diagnostic pilot study including 50 consecutive patients receiving BCS. The complete surface of the specimen was scanned using the HS intraoperatively. The surgery and the intraoperative margin assessment of the specimen was performed according to the clinical routine consisting of conventional specimen radiography as well as the clinical impression of the surgeon. Three surgeons and an experienced pathologist assessed the scans produced by the HS for cancer cells on the surface. The potential of the HS to correctly identify involved margins was compared to the results of the conventional specimen radiography alone as well as the clinical routine. The histopathological report served as the gold standard.

RESULTS

50 specimens corresponding to 300 surfaces were scanned by the HS. The mean sensitivity of the surgeons to identify involved margins with the HS was 37.5% ± 5.6%, the specificity was 75.2% ± 13.0%. The assessment of resection margins by the pathologist resulted in a sensitivity of 37.5% and a specificity of 81.0%, while the local clinical routine resulted in a sensitivity of 37.5% and a specificity of 78.2%.

CONCLUSION

Acquisition of high-resolution histological images using the HS was feasible in clinical practice. Sensitivity and specificity were comparable to clinical routine. With more specific training and experience on image interpretation and acquisition, the HS may have the potential to enable more accuracy in the margin assessment of BCS specimens.

Adding pieces to the puzzle of differentiated-to-anaplastic thyroid cancer evolution: the oncogene E2F7

Anaplastic Thyroid Cancer (ATC) is the most aggressive and de-differentiated subtype of thyroid cancer. Many studies hypothesized that ATC derives from Differentiated Thyroid Carcinoma (DTC) through a de-differentiation process triggered by specific molecular events still largely unknown. E2F7 is an atypical member of the E2F family. Known as cell cycle inhibitor and keeper of genomic stability, in specific contexts its function is oncogenic, guiding cancer progression. We performed a meta-analysis on 279 gene expression profiles, from 8 Gene Expression Omnibus patient samples datasets, to explore the causal relationship between DTC and ATC. We defined 3 specific gene signatures describing the evolution from normal thyroid tissue to DTC and ATC and validated them in a cohort of human surgically resected ATCs collected in our Institution. We identified E2F7 as a key player in the DTC-ATC transition and showed in vitro that its down-regulation reduced ATC cells' aggressiveness features. RNA-seq and ChIP-seq profiling allowed the identification of the E2F7 specific gene program, which is mainly related to cell cycle progression and DNA repair ability. Overall, this study identified a signature describing DTC de-differentiation toward ATC subtype and unveiled an E2F7-dependent transcriptional program supporting this process.

Abstract A22: Deciphering natural killer transcriptional activation in triple-negative breast cancer: A novel opportunity for adoptive cell therapies?

Triple-Negative Breast Cancer (TNBC) patients that do not respond to neoadjuvant chemotherapy account for 60-70% of all cases and are orphans of therapeutic alternatives after chemotherapy failure. Despite the great progress that has been made in the application of immune-based strategies, clinical opportunities for TNBC patients are still lacking. We aimed to investigate the molecular mechanisms leading to the activation of the TNBC immunological microenvironment, thus providing novel clues for the design and development of immune-based therapeutic approaches and adoptive immune cell therapies for TNBC patients. We analyzed consecutive TNBC cases treated at AUSL-IRCCS Hospital of Reggio Emilia from 2011 to 2017. 24 Tru-Cut biopsies were selected, comparing 12 patients with pathological complete response (pCR) after neoadjuvant treatment and 12 patients with cancer progression. Then, we performed a morphology-guided transcriptome profiling of the immune infiltrate using our GeoMx-Digital spatial profiler (DSP) to investigate which immune populations were associated with a more favorable outcome. The immune infiltrate of patients showing pCR was significantly enriched for activated Natural Killer (NK) cells, compared to patients with disease progression. Intriguingly, both T-helper CD4- and CD8-T lymphocytes did not reach statistical significance, suggesting a secondary involvement in predicting neoadjuvant efficacy in TNBC patients. We confirmed that NK cells can significantly impair TNBC cell proliferation and viability in vitro and improved the efficacy of chemotherapeutic drugs (paclitaxel, docetaxel). To increase our knowledge of the molecular mechanisms governing NK effector functions toward TNBC, we decided to investigate the specific transcriptional landscape that triggers NK cell activation. We profiled the transcriptome of activated NK cells by RNA-sequencing, identifying several de-regulated pathways involved in NK innate anti-tumor response, including the down-regulation of Immune checkpoint (IC) molecules (CTLA4, CEACAM3, PD1, KIR2DL4, KIR3DX1, KIR3DL3, TIGIT, TIM3, LAG3, etc) and the up-regulation of vesicle-trafficking and autophagy-related proteins (STX5, STX7, BNIP3L, SNAP29, GABARAPL1, RAB4B, etc). To predict upstream transcription regulators, promoters of de-regulated genes were in silico scanned for common binding motifs with the FIMO algorithm, thus identifying a list of candidate Transcription Factors (TFs). Among top-scoring TFs, we identified PAX5 which has been already involved in NK differentiation and cytotoxicity. Other top-scoring TFs are currently under investigation as potential NK Master Regulators of their effector functions, including SMAD3, VEZF1, and MAZ. Overall, our results point out the relevance of NK cells in predicting neoadjuvant treatment response in TNBC patients. Moreover, the modulation of the NK transcriptional program may be a novel tool to potentiate their anti-tumor potential, thus proving novel clues to optimize their application in adoptive cell therapies and in the treatment of TNBC patients.

Citation Format: Francesca Reggiani, Benedetta Donati, Moira Ragazzi, Veronica Manicardi, Federica Torricelli, Elisabetta Sauta, Elisa Gasparini, Simonetta Piana, Valentina Sancisi, Alessia Ciarrocchi. Deciphering natural killer transcriptional activation in triple-negative breast cancer: A novel opportunity for adoptive cell therapies? [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr A22.

Imaging of lumpectomy surface with large field-of-view confocal laser scanning microscope for intraoperative margin assessment - POLARHIS study

INTRODUCTION

Breast-conserving surgery (BCS) in case of breast cancer and/or in-situ-carcinoma lesions (DCIS) intends to completely remove breast cancer while saving healthy tissue as much as possible to achieve better aesthetic and psychological outcomes for the patient. Such modality should result in postoperative tumor-free margins of the surgical resection in order to carry on with the next therapeutical steps of the patient care. However, 10-40% of patients undergo more than one procedure to achieve acceptable cancer-negative margins. A 2nd operation or further operation (re-operation) has physical, psychological, and economic consequences. It also delays the administration of adjuvant therapy, and has been associated with an elevated risk of local and distant disease relapse. In addition, a high re-operation rate can have significant economic effects - both for the service provider and for the payer. A more efficient intraoperative assessment of the margin may address these issues. Recently, a large field-of-view confocal laser scanning microscope designed to allow real-time intraoperative margin assessment has arrived on the market - the Histolog Scanner. In this paper, we present the first evaluation of lumpectomy margins assessment with this new device.

MATERIALS AND METHODS

40 consecutive patients undergoing BCS with invasive and/or DCIS were included. The whole surface of the surgical specimens was imaged right after the operation using the Histolog Scanner (HLS). The assessment of all the specimen margins was performed intraoperatively according to the standard-of-care of the center which consists of combined ultrasound (IOUS) and/or conventional specimen radiography (CSR), and gross surgical inspection. Margin assessment on HLS images was blindly performed after the surgery by 5 surgeons and one pathologist. The capabilities to correctly determine margin status in HLS images was compared to the final histopathological assessment. Furthermore, the potential reduction of positive-margin and re-operation rates by utilization of the HLS were extrapolated.

RESULTS

The study population included 7/40 patients with DCIS (17.5%), 17/40 patients with DCIS and invasive ductal cancer (IDC NST) (42.5%), 10/40 patients with IDC NST (25%), 4/40 with invasive lobular cancer (ILC) (10%), and 1/40 patients with a mix of IDC NST, DCIS, and ILC. Clinical routine resulted in 13 patients with positive margins identified by final histopathological assessment, resulting in 12 re-operations (30% re-operation rate). Amongst these 12 patients, 10 had DCIS components involved in their margin, confirming the importance of improving the detection accuracy of this specific lesion. Surgeons, who were given a short familiarization on HLS images, and a pathologist were able to detect positive margins in 4/12 and 7/12 patients (33% and 58%), respectively, that were missed by the intraoperative standard of care. In addition, a retrospective analysis of the HLS images revealed that cancer lesions can be identified in 9/12 (75%) patients with positive margins.

CONCLUSION

The present study presents that breast cancer can be detected by surgeons and pathologists in HLS images of lumpectomy margins leading to a potential reduction of 30% and 75% of the re-operations. The Histolog Scanner is easily inserted into the clinical workflow and has the potential to improve the intraoperative standard-of-care for the assessment of breast conserving treatments. In addition, it has the potential to increase oncological safety and cosmetics by avoiding subsequent resections and can also have a significant positive economic effect for service providers and cost bearers. The data presented in this study will have to be further confirmed in a prospective phase-III-trial.

Comparative Analysis of PRAME Expression in 127 Acral and Nail Melanocytic Lesions

PRAME (PReferentially expressed Antigen in MElanoma), a cancer testis antigen expressed in low levels in gonadal, endometrial, and adrenal gland tissues, has been recently considered a valuable tool in the differential diagnosis between benign and malignant melanocytic lesions. The aim of the current study is to perform PRAME immunostaining on a large series of benign and malignant acral lesions to evaluate the reproducibility of data reported in the literature and to validate PRAME as an affordable tool in the differential diagnosis between benign and malignant acral melanocytic tumors. Immunohistochemical analysis for PRAME was performed in 127 benign and malignant acral and nail melanocytic lesions. To better correlate PRAME expression with the nature (benign vs. malignant) of the lesions, we categorized PRAME tumor cells percentage positivity and intensity in a cumulative score obtained by adding the quartile of positive tumor cells (0, 1+, 2+, 3+, 4+) to PRAME expression intensity in tumor cells (0, 1+, 2+, 3+). Adopting an arbitrary PRAME expression score of < 5 versus ≥5 resulted in a correct identification of 82.5% of benign and 87.1% of malignant lesions. PRAME immunohistochemistry demonstrated good sensitivity and specificity in the diagnosis of acral melanocytic lesions, however, in line with the previous literature, we identified a subset of challenging cases such as acral Spitz nevi, in situ melanomas, and small, thin, invasive melanomas in which PRAME did not correlate with morphologic features. This suggests that PRAME can be a valid tool to be incorporated in a diagnostic clinicopathologic algorithm, subject to morphologic characteristics.

A Randomized Trial Comparing Breast Cancer Incidence and Interval Cancers after Tomosynthesis Plus Mammography versus Mammography Alone

Background Adding digital breast tomosynthesis (DBT) to digital mammography (DM) improves breast cancer screening sensitivity, but how this impacts mortality and other end points is unknown. Purpose To compare interval and overall breast cancer incidence after screening with DBT plus DM versus DM alone. Materials and Methods In this prospective trial (RETomo), women attending screening were randomized to one round of DBT plus DM (experimental arm) or to DM (control arm). All were then rescreened with DM after 12 months (women aged 45-49 years) or after 24 months (50-69 years). The primary outcome was interval cancer incidence. Cumulative incidence up to the subsequent screening round plus 9 months (21- and 33-month follow-up for women aged 45-49 and 50-69, respectively) was also reported. Ductal carcinomas in situ are included. Subgroup analyses by age and breast density were conducted; 95% CIs computed according to binomial distribution are reported. Results Baseline cancer detection was higher in the DBT plu DM arm than DM arm (101 of 13 356 women vs 61 of 13 521 women; relative detection, 1.7 [95% CI: 1.2, 2.3]). The mean age ± standard deviation for the women in both arms was 55 years ± 7. Interval cancer incidence was similar in the two arms (21 vs 22 cancers; relative incidence, 0.97 [95% CI: 0.53, 1.8]). Cumulative incidence remained higher in the DBT plus DM arm in women over 50 (153 vs 124 cancers; relative incidence, 1.2 [95% CI: 0.99, 1.6]), while it was similar in the two arms in women aged 45-49 (36 vs 41 cancers; relative incidence, 0.89 [95% CI: 0.57, 1.4]). Conclusion In women younger than 50 years, the benefit of early diagnosis seemed to be appreciable, while for women over age 50, the higher sensitivity of tomosynthesis plus mammography was not matched by a subsequent reduction in cancers at the next screening examination or in the intervening interval. Clinical trial registration no. NCT02698202 © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Lee and Ray in this issue.

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review (Part 6): Correlation of PD-L1 Expression with the Status of Mismatch Repair System, BRCA, PTEN, and Other Genes

Pembrolizumab (anti-PD-1) is allowed in selected metastatic castration-resistant prostate cancer (PC) patients showing microsatellite instability/mismatch repair system deficiency (MSI-H/dMMR). BRCA1/2 loss-of-function is linked to hereditary PCs and homologous recombination DNA-repair system deficiency: poly-ADP-ribose-polymerase inhibitors can be administered to BRCA-mutated PC patients. Recently, docetaxel-refractory metastatic castration-resistant PC patients with BRCA1/2 or ATM somatic mutations had higher response rates to pembrolizumab. PTEN regulates cell cycle/proliferation/apoptosis through pathways including the AKT/mTOR, which upregulates PD-L1 expression in PC. Our systematic literature review (PRISMA guidelines) investigated the potential correlations between PD-L1 and MMR/MSI/BRCA/PTEN statuses in PC, discussing few other relevant genes. Excluding selection biases, 74/677 (11%) PCs showed dMMR/MSI; 8/67 (12%) of dMMR/MSI cases were PD-L1+. dMMR-PCs included ductal (3%) and acinar (14%) PCs (all cases tested for MSI were acinar-PCs). In total, 15/39 (39%) PCs harbored BRCA1/2 aberrations: limited data are available for PD-L1 expression in these patients. 13/137 (10%) PTEN- PCs were PD-L1+; 10/29 (35%) PD-L1+ PCs showed PTEN negativity. SPOP mutations may increase PD-L1 levels, while the potential correlation between PD-L1 and ERG expression in PC should be clarified. Further research should verify how the efficacy of PD-1 inhibitors in metastatic castration-resistant PCs is related to dMMR/MSI, DNA-damage repair genes defects, or PD-L1 expression.

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 7: PD-L1 Expression in Liquid Biopsy

Liquid biopsy is an accessible, non-invasive diagnostic tool for advanced prostate cancer (PC) patients, potentially representing a real-time monitoring test for tumor evolution and response to treatment through the analysis of circulating tumor cells (CTCs) and exosomes. We performed a systematic literature review (PRISMA guidelines) to describe the current knowledge about PD-L1 expression in liquid biopsies of PC patients: 101/159 (64%) cases revealed a variable number of PD-L1+ CTCs. Outcome correlations should be investigated in larger series. Nuclear PD-L1 expression by CTCs was occasionally associated with worse prognosis. Treatment (abiraterone, enzalutamide, radiotherapy, checkpoint-inhibitors) influenced PD-L1+ CTC levels. Discordance in PD-L1 status was detected between primary vs. metastatic PC tissue biopsies and CTCs vs. corresponding tumor tissues. PD-L1 is also released by PC cells through soluble exosomes, which could inhibit the T cell function, causing immune evasion. PD-L1+ PC-CTC monitoring and genomic profiling may better characterize the ongoing aggressive PC forms compared to PD-L1 evaluation on primary tumor biopsies/prostatectomy specimens (sometimes sampled a long time before recurrence/progression). Myeloid-derived suppressor cells and dendritic cells (DCs), which may have immune-suppressive effects in tumor microenvironment, have been found in PC patients circulation, sometimes expressing PD-L1. Occasionally, their levels correlated to clinical outcome. Enzalutamide-progressing castration-resistant PC patients revealed increased PD-1+ T cells and circulating PD-L1/2+ DCs.

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 5: Epigenetic Regulation of PD-L1

Epigenetic alterations (including DNA methylation or miRNAs) influence oncogene/oncosuppressor gene expression without changing the DNA sequence. Prostate cancer (PC) displays a complex genetic and epigenetic regulation of cell-growth pathways and tumor progression. We performed a systematic literature review (following PRISMA guidelines) focused on the epigenetic regulation of PD-L1 expression in PC. In PC cell lines, CpG island methylation of the CD274 promoter negatively regulated PD-L1 expression. Histone modifiers also influence the PD-L1 transcription rate: the deletion or silencing of the histone modifiers MLL3/MML1 can positively regulate PD-L1 expression. Epigenetic drugs (EDs) may be promising in reprogramming tumor cells, reversing epigenetic modifications, and cancer immune evasion. EDs promoting a chromatin-inactive transcriptional state (such as bromodomain or p300/CBP inhibitors) downregulated PD-L1, while EDs favoring a chromatin-active state (i.e., histone deacetylase inhibitors) increased PD-L1 expression. miRNAs can regulate PD-L1 at a post-transcriptional level. miR-195/miR-16 were negatively associated with PD-L1 expression and positively correlated to longer biochemical recurrence-free survival; they also enhanced the radiotherapy efficacy in PC cell lines. miR-197 and miR-200a-c positively correlated to PD-L1 mRNA levels and inversely correlated to the methylation of PD-L1 promoter in a large series. miR-570, miR-34a and miR-513 may also be involved in epigenetic regulation.

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 3: PD-L1, Intracellular Signaling Pathways and Tumor Microenvironment

The tumor microenvironment (TME) includes immune (T, B, NK, dendritic), stromal, mesenchymal, endothelial, adipocytic cells, extracellular matrix, and cytokines/chemokines/soluble factors regulating various intracellular signaling pathways (ISP) in tumor cells. TME influences the survival/progression of prostate cancer (PC), enabling tumor cell immune-evasion also through the activation of the PD-1/PD-L1 axis. We have performed a systematic literature review according to the PRISMA guidelines, to investigate how the PD-1/PD-L1 pathway is influenced by TME and ISPs. Tumor immune-escape mechanisms include suppression/exhaustion of tumor infiltrating cytotoxic T lymphocytes, inhibition of tumor suppressive NK cells, increase in immune-suppressive immune cells (regulatory T, M2 macrophagic, myeloid-derived suppressor, dendritic, stromal, and adipocytic cells). IFN-γ (the most investigated factor), TGF-β, TNF-α, IL-6, IL-17, IL-15, IL-27, complement factor C5a, and other soluble molecules secreted by TME components (and sometimes increased in patients' serum), as well as and hypoxia, influenced the regulation of PD-L1. Experimental studies using human and mouse PC cell lines (derived from either androgen-sensitive or androgen-resistant tumors) revealed that the intracellular ERK/MEK, Akt-mTOR, NF-kB, WNT and JAK/STAT pathways were involved in PD-L1 upregulation in PC. Blocking the PD-1/PD-L1 signaling by using immunotherapy drugs can prevent tumor immune-escape, increasing the anti-tumor activity of immune cells.

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 1: Focus on Immunohistochemical Results with Discussion of Pre-Analytical and Interpretation Variables

Immunotherapy targeting the PD-1-PD-L1 axis yielded good results in treating different immunologically ''hot'' tumors. A phase II study revealed good therapeutic activity of pembrolizumab in selected prostatic carcinoma (PC)-patients. We performed a systematic literature review (PRISMA guidelines), which analyzes the immunohistochemical expression of PD-L1 in human PC samples and highlights the pre-analytical and interpretation variables. Interestingly, 29% acinar PCs, 7% ductal PCs, and 46% neuroendocrine carcinomas/tumors were PD-L1+ on immunohistochemistry. Different scoring methods or cut-off criteria were applied on variable specimen-types, evaluating tumors showing different clinic-pathologic features. The positivity rate of different PD-L1 antibody clones in tumor cells ranged from 3% (SP142) to 50% (ABM4E54), excluding the single case tested for RM-320. The most tested clone was E1L3N, followed by 22C3 (most used for pembrolizumab eligibility), SP263, SP142, and 28-8, which gave the positivity rates of 35%, 11-41% (depending on different scoring systems), 6%, 3%, and 15%, respectively. Other clones were tested in <200 cases. The PD-L1 positivity rate was usually higher in tumors than benign tissues. It was higher in non-tissue microarray specimens (41-50% vs. 15%), as PC cells frequently showed heterogenous or focal PD-L1-staining. PD-L1 was expressed by immune or stromal cells in 12% and 69% cases, respectively. Tumor heterogeneity, inter-institutional preanalytics, and inter-observer interpretation variability may account for result biases.

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 4: Experimental Treatments in Pre-Clinical Studies (Cell Lines and Mouse Models)

In prostate cancer (PC), the PD-1/PD-L1 axis regulates various signaling pathways and it is influenced by extracellular factors. Pre-clinical experimental studies investigating the effects of various treatments (alone or combined) may discover how to overcome the immunotherapy-resistance in PC-patients. We performed a systematic literature review (PRISMA guidelines) to delineate the landscape of pre-clinical studies (including cell lines and mouse models) that tested treatments with effects on PD-L1 signaling in PC. NF-kB, MEK, JAK, or STAT inhibitors on human/mouse, primary/metastatic PC-cell lines variably down-modulated PD-L1-expression, reducing chemoresistance and tumor cell migration. If PC-cells were co-cultured with NK, CD8+ T-cells or CAR-T cells, the immune cell cytotoxicity increased when PD-L1 was downregulated (opposite effects for PD-L1 upregulation). In mouse models, radiotherapy, CDK4/6-inhibitors, and RB deletion induced PD-L1-upregulation, causing PC-immune-evasion. Epigenetic drugs may reduce PD-L1 expression. In some PC experimental models, blocking only the PD-1/PD-L1 pathway had limited efficacy in reducing the tumor growth. Anti-tumor effects could be increased by combining the PD-1/PD-L1 blockade with other approaches (inhibitors of tyrosine kinase, PI3K/mTOR or JAK/STAT3 pathways, p300/CBP; anti-RANKL and/or anti-CTLA-4 antibodies; cytokines; nitroxoline; DNA/cell vaccines; radiotherapy/Radium-223).

What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 2: Clinic-Pathologic Correlations

Many studies have investigated the potential prognostic and predictive role of PD-L1 in prostatic carcinoma (PC). We performed a systematic literature review (PRISMA guidelines) to critically evaluate human tissue-based studies (immunohistochemistry, molecular analysis, etc.), experimental research (cell lines, mouse models), and clinical trials. Despite some controversial results and study limitations, PD-L1 expression by tumor cells may be related to clinic-pathologic features of adverse outcome, including advanced tumor stage (high pT, presence of lymph node, and distant metastases), positivity of surgical margins, high Grade Group, and castration resistance. Different PD-L1 positivity rates may be observed in matched primary PCs and various metastatic sites of the same patients. Over-fixation, type/duration of decalcification, and PD-L1 antibody clone may influence the immunohistochemical analysis of PD-L1 on bone metastases. PD-L1 seemed expressed more frequently by castration-resistant PCs (49%) as compared to hormone-sensitive PCs (17%). Some series found that PD-L1 positivity was associated with decreased time to castration resistance. Treatment with ipilimumab, cyclophosphamide/GVAX/degarelix, or degarelix alone may increase PD-L1 expression. Correlation of PD-L1 positivity with overall survival and outcomes related to tumor recurrence were rarely investigated; the few analyzed series produced conflicting results and sometimes showed limitations. Further studies are required. The testing and scoring of PD-L1 should be standardized.

Assessment of estrogen receptor low positive status in breast cancer: Implications for pathologists and oncologists

Estrogen receptor (ER) status assessment by immunohistochemistry (IHC) is the gold standard test for the identification of patients with breast cancer who may benefit from endocrine therapy (ET). Whilst most ER+ breast cancers have a high IHC score, about 3% of cases display a low positivity, with 1% to 10% of cells being weakly stained. These tumors are generally classified within the luminal-like category; however, their risk profile seems to be more similar to that of ER-negative breast cancers. The decision on ET for patients with a diagnosis of ER-low breast cancer should be carefully considered in light of the risks and possible benefits of the treatment. Potential pitfalls hinder pathologists and oncologists from establishing an appropriate threshold for "low positivity". Furthermore, several pre-analytical and analytical variables might trouble the pathological identification of these clinically challenging cases. In this review, we sought to discuss the adversities that can be accounted for the pathological identification of ER-low breast cancers in real-world clinical practice, and to provide practical suggestions for the perfect ER testing in light of the most updated recommendations and guidelines.

Next-Generation Sequencing Panel for 1p/19q Codeletion and IDH1-IDH2 Mutational Analysis Uncovers Mistaken Overdiagnoses of 1p/19q Codeletion by FISH

The 1p/19q codeletion is the result of a translocation between chromosome 1 (Chr1p) and chromosome 19 (Chr19q) with the loss of derivative (1;19)(p10;q10) chromosome. The 1p/19q codeletion has predictive and prognostic significance, and it is essential for the classification of gliomas. In routine practice, the fluorescence in situ hybridization (FISH) diagnosis of 1p/19q codeletion is sometimes unexpected. This study aimed to develop a next-generation sequencing panel for the concurrent definition of the 1p/19q codeletion and IDH1/IDH2 mutation status to resolve these equivocal cases. A total of 65 glioma samples were investigated using a 1p/19q-single-nucleotide polymorphism (SNP)-IDH panel. The panel consists of 192 amplicons, including SNPs mapping to Chr1 and Chr19 and amplicons for IDH1/IDH2 analysis. The 1p/19q SNP-IDH panel consistently identified IDH1/IDH2 mutations. In 49 of 60 cases (81.7%), it provided the same 1p/19q results obtained by FISH. In the remaining 11 cases, the 1p/19q SNP-IDH panel uncovered partial chromosome imbalances as a result of interstitial amplification or deletion of the regions where the FISH probes map, leading to a mistaken overdiagnosis of 1p/19q codeletion by FISH. The 1p/19q SNP-IDH next-generation sequencing panel allows reliable analysis of the 1p/19q codeletion and IDH1/IDH2 mutation at the same time. The panel not only allows resolution of difficult cases but also represents a cost-effective alternative to standard molecular diagnostics procedures.

Imbalance of Mg Homeostasis as a Potential Biomarker in Colon Cancer

BACKGROUND

Increasing evidences support a correlation between magnesium (Mg) homeostasis and colorectal cancer (CRC). Nevertheless, the role of Mg and its transporters as diagnostic markers in CRC is still a matter of debate. In this study we combined X-ray Fluorescence Microscopy and databases information to investigate the possible correlation between Mg imbalance and CRC.

METHODS

CRC tissue samples and their non-tumoural counterpart from four patients were collected and analysed for total Mg level and distribution by X-Ray Fluorescence Microscopy. We also reviewed the scientific literature and the main tissue expression databases to collect data on Mg transporters expression in CRC.

RESULTS

We found a significantly higher content of total Mg in CRC samples when compared to non-tumoural tissues. Mg distribution was also impaired in CRC. Conversely, we evidenced an uncertain correlation between Mg transporters expression and colon malignancies.

DISCUSSION

Although further studies are necessary to determine the correlation between different cancer types and stages, this is the first report proposing the measurement of Mg tissue localisation as a marker in CRC. This study represents thus a proof-of-concept that paves the way for the design of a larger prospective investigation of Mg in CRC.

Accuracy and Reproducibility of Contrast-Enhanced Mammography in the Assessment of Response to Neoadjuvant Chemotherapy in Breast Cancer Patients with Calcifications in the Tumor Bed

This study aimed to evaluate contrast-enhanced mammography (CEM) accuracy and reproducibility in the detection and measurement of residual tumor after neoadjuvant chemotherapy (NAC) in breast cancer (BC) patients with calcifications, using surgical specimen pathology as the reference. Pre- and post-NAC CEM images of 36 consecutive BC patients receiving NAC in 2012–2020, with calcifications in the tumor bed at diagnosis, were retrospectively reviewed by two radiologists; described were absence/presence and size of residual disease based on contrast enhancement (CE) only and CE plus calcifications. Twenty-eight patients (77.8%) had invasive and 5 (13.9%) in situ-only residual disease at surgical specimen pathology. Considering CE plus calcifications instead of CE only, CEM sensitivity for invasive residual tumor increased from 85.7% (95% CI = 67.3–96%) to 96.4% (95% CI = 81.7–99.9%) and specificity decreased from 5/8 (62.5%; 95% CI = 24.5–91.5%) to 1/8 (14.3%; 95% CI = 0.4–57.9%). For in situ-only residual disease, false negatives decreased from 3 to 0 and false positives increased from 1 to 2. CEM pathology concordance in residual disease measurement increased (R squared from 0.38 to 0.45); inter-reader concordance decreased (R squared from 0.79 to 0.66). Considering CE plus calcifications to evaluate NAC response in BC patients increases sensitivity in detection and accuracy in measurement of residual disease but increases false positives.

An international 3-center training and reading study to assess basal cell carcinoma surgical margins with ex vivo fluorescence confocal microscopy

BACKGROUND

Novel solutions are needed for expediting margin assessment to guide basal cell carcinoma (BCC) surgeries. Ex vivo fluorescence confocal microscopy (FCM) is starting to be used in freshly excised surgical specimens to examine BCC margins in real time. Training and educational process are needed for this novel technology to be implemented into clinic.

OBJECTIVE

To test a training and reading process, and measure diagnostic accuracy of clinicians with varying expertise level in reading ex vivo FCM images.

METHODS

An international three-center study was designed for training and reading to assess BCC surgical margins and residual subtypes. Each center included a lead dermatologic/Mohs surgeon (clinical developer of FCM) and three additional readers (dermatologist, dermatopathologist, dermatologic/Mohs surgeon), who use confocal in clinical practice. Testing was conducted on 30 samples.

RESULTS

Overall, the readers achieved 90% average sensitivity, 78% average specificity in detecting residual BCC margins, showing high and consistent diagnostic reading accuracy. Those with expertise in dermatologic surgery and dermatopathology showed the strongest potential for learning to assess FCM images.

LIMITATIONS

Small dataset, variability in mosaic quality between centers.

CONCLUSION

Suggested process is feasible and effective. This process is proposed for wider implementation to facilitate wider adoption of FCM to potentially expedite BCC margin assessment to guide surgery in real time.

How Can We Treat Vulvar Carcinoma in Pregnancy? A Systematic Review of the Literature

According to our systematic literature review (PRISMA guidelines), only 37 vulvar squamous cell carcinomas (VSCCs) were diagnosed during pregnancy (age range: 17-41 years). The tumor size range was 0.3-15 cm. The treatment was performed after (14/37, 38%), before (10/37, 27%), or before-and-after delivery (11/37, 30%). We found that 21/37 (57%) cases were stage I, 2 II (5%), 11 III (30%), and 3 IVB (8%). HPV-related features (condylomas/warts; HPV infection; high-grade squamous intraepithelial lesion) were reported in 11/37 (30%) cases. We also found that 9/37 (24%) patients had inflammatory conditions (lichen sclerosus/planus, psoriasis, chronic dermatitis). The time-to-recurrence/progression (12/37, 32%) ranged from 0 to 36 (mean 9) months. Eight women died of disease (22%) 2.5-48 months after diagnosis, 2 (5%) were alive with disease, and 23 (62%) were disease-free at the end of follow-up. Pregnant patients must be followed-up. Even if they are small, newly arising vulvar lesions should be biopsied, especially in women with risk factors (HPV, dermatosis, etc.). The treatment of VSCCs diagnosed in late third trimester might be delayed until postpartum. Elective cesarean section may prevent vulvar wound dehiscence. In the few reported cases, pregnancy/fetal outcomes seemed to not be affected by invasive treatments during pregnancy. However, clinicians must be careful; larger cohorts should define the best treatment. Definite guidelines are lacking, so a multidisciplinary approach and discussion with patients are mandatory.

Coexisting well-differentiated and anaplastic thyroid carcinoma in the same primary resection specimen: immunophenotypic and genetic comparison of the two components in a consecutive series of 13 cases and a review of the literature

Anaplastic carcinoma (AC) is a rare but highly aggressive form of thyroid cancer. It mostly arises on a background of pre-existing well-differentiated cancer (WDC); however, whether it evolves directly from a WDC or originates as a second independent neoplasm is still to be defined. To obtain further insights into these mechanisms, we performed morphological, immunohistochemical, and next-generation sequencing analyses to compare AC and its associated WDC in a subset of 13 surgically resected specimens. Histologically, most WDC were of aggressive subtypes. Papillary carcinomas (8 cases; 62%) were tall cell (4/8), columnar (1/8), classic with hobnail features (1/8), classic and follicular variant in the remaining 2 cases; Hürthle cell and follicular carcinomas were present in 5 (38%) and in 1 (8%) patient, respectively. One patient harbored both a PTC, follicular variant, and a Hürthle cell carcinoma. We did not find any correlation between a histotype of WDC and a specific anaplastic growth pattern. Immunohistochemically, ACs retained pankeratin/PAX8 expression but with significantly lower levels than WDCs, and they tended to lose TTF1 expression, as can be expected within a dedifferentiation process. In addition, AC showed a more frequent expression of p63 and/or SMA, a mutated pattern of p53, and an abnormal expression of p16. Genetic analysis showed that the number of mutations was higher in AC than in the associated WDC, confirming a role of the progressive accumulation of genetic damage in this transition. We observed that mutations found in the WDCs were consistently identified in the anaplastic counterparts, further supporting the hypothesis of a developmental link.

Periostin, tenascin, osteopontin isoforms in long- and non-long survival patients with pancreatic cancer: a pilot study

Pancreatic adenocarcinoma (PDAC) is the most frequent histological type of malignancy in the pancreas. Extracellular matrix (ECM), plays a critical role during the process of human carcinogenesis and the possible diversity in matricellular proteins composition of ECM may have a significant impact on the clinical course of PDAC. Aim of this paper was to evaluate the expression of three matricellular proteins, including Periostin (POSTN), Tenascin (TNS) and Osteopontin (OPN), in PDAC from long-survival (LS) and non-long survival (NLS) patients. A total of 30 PDAC were analyzed, 15 from patients that survived more than 60 months after surgery (LS) and 15 that died from the disease within 24 (NLS). RNA was extracted and OPN, TNS and POSTN mRNA levels were evaluated by qRT-PCR. LS and NLS samples showed the same type of POSTN and TN isoforms. On the contrary, OPN seems to be preferentially expressed in NLS PDAC. Moreover, OPNb and OPNc isoforms were expressed exclusively in NLS samples. In conclusion, Our data led to hypothesize a possible relationship between the expression of different isoforms of each of these proteins and the clinical outcome of patients with PDAC.

A Humanized Bone Niche Model Reveals Bone Tissue Preservation Upon Targeting Mitochondrial Complex I in Pseudo-Orthotopic Osteosarcoma

A cogent issue in cancer research is how to account for the effects of tumor microenvironment (TME) on the response to therapy, warranting the need to adopt adequate in vitro and in vivo models. This is particularly relevant in the development of strategies targeting cancer metabolism, as they will inevitably have systemic effects. For example, inhibition of mitochondrial complex I (CI), despite showing promising results as an anticancer approach, triggers TME-mediated survival mechanisms in subcutaneous osteosarcoma xenografts, a response that may vary according to whether the tumors are induced via subcutaneous injection or by intrabone orthotopic transplantation. Thus, with the aim to characterize the TME of CI-deficient tumors in a model that more faithfully represents osteosarcoma development, we set up a humanized bone niche ectopic graft. A prominent involvement of TME was revealed in CI-deficient tumors, characterized by the abundance of cancer associated fibroblasts, tumor associated macrophages and preservation of osteocytes and osteoblasts in the mineralized bone matrix. The pseudo-orthotopic approach allowed investigation of osteosarcoma progression in a bone-like microenvironment setting, without being invasive as the intrabone cell transplantation. Additionally, establishing osteosarcomas in a humanized bone niche model identified a peculiar association between targeting CI and bone tissue preservation.

Concordance, intra- and inter-observer agreements between light microscopy and whole slide imaging for samples acquired by EUS in pancreatic solid lesions

BACKGROUND

No study has compared the performance of light microscopy (LM) and whole slide imaging (WSI) for endoscopic ultrasound (EUS) histological acquired tissue samples from pancreatic solid lesions (PSLs). We evaluated the concordance between LM and WSI and the inter- and intra-observer agreements among pathologists on PSLs EUS acquired samples.

METHODS

LM and WSI from 60 patients with PSLs were evaluated by five expert pathologists to define: diagnostic classification, presence of a core, number and percentage of lesional cells. Washout period between evaluations was 3 months. Time of the procedures was also assessed.

RESULTS

Forty-eight cell-block and 12 biopsy samples were evaluated. A high concordance between LM and WSI was found. Inter- and intra-observer agreements for diagnostic classification were substantial and complete, respectively. For all the other parameters, the inter-observer agreement was usually higher for LM. For the intra-observer, a substantial agreement was reached regarding the presence of tissue core and the number and the percentage of malignant cells. Median time for performing LM was significantly shorter than for WSI (p < 0.0001).

CONCLUSIONS

LM and WSI of cell-block and biopsy samples acquired by EUS in PSLs were highly concordant, with a substantial inter-observer and a complete intra-observer agreements regarding diagnostic classification.

High levels of Notch intracellular cleaved domain are associated with stemness and reduced bevacizumab efficacy in patients with advanced colon cancer

δ‑like ligand 4 (DLL4)‑Notch signaling is associated with tumor resistance to anti‑vascular endothelial growth factor (VEGF) therapy. Furthermore, Notch signaling is critical for the maintenance of colon cancer stem cells (CSCs), which are relevant in drug resistance and tumor angiogenesis. CD44 is a transmembrane glycoprotein and is considered a putative marker of CSCs. To assess the association of Notch intracellular cleaved domain (NICD), DLL4 and CD44 expression with the efficacy of anti‑angiogenic drugs, a series of samples derived from patients with advanced colon cancer enrolled in prospective clinical trials were analyzed. Histological samples from 51 primary tumors that originated from patients treated with bevacizumab‑based first‑line chemotherapy were analyzed by immunohistochemistry for NICD, DLL4 and CD44 expression, and CD31 for microvessel count. The expression levels of genes relevant for angiogenesis [angiopoietin (ANGPT)1, ANGPT2, fibroblast growth factor (FGF)1, FGF2, epidermal growth factor, placental growth factor, VEGFA and DLL4] were detected by reverse transcription‑quantitative PCR using RNA extracted from the frozen tissues of four tumors with low and four tumors with high NICD expression. Strong NICD levels were observed in 12/51 (24%) of the patients, whereas 16/51 (31%) of the colon cancer subjects exhibited high CD44 expression. Strong CD44 staining was associated with high NICD levels compared with the CD44 expression levels noted in samples with low NICD levels (67 vs. 20%, P=0.005). No association was observed with regards to the expression levels of NICD, CD44 and the other aforementioned biomarkers. High expression levels of NICD and CD44 predicted reduced progression‑free survival (P<0.001) and overall survival (P=0.002). No significant differences in the expression of angiogenesis‑related genes were detected between low and high NICD‑expressing tumors. In conclusion, NICD and CD44 tissue levels exhibited an association and may be related to a reduced survival rate in patients with advanced colon cancer treated with bevacizumab.

Expression of NOTCH1 in thyroid cancer is mostly restricted to papillary carcinoma

The NOTCH signaling is an evolutionarily conserved signaling pathway that regulates cell-cell interactions. NOTCH family members play a fundamental role in a variety of processes during development in particular in cell fate decisions. As other crucial factors during embryogenesis, NOTCH signaling is aberrantly reactivated in cancer where it has been linked to context-dependent effects. In thyroid cancer, NOTCH1 expression has been associated to aggressive features even if its in vivo expression within the entire spectrum of thyroid tumors has not definitively established. A series of 106 thyroid specimens including non-neoplastic lesions, benign and malignant tumors of common and rare histotypes, were investigated by immunohistochemistry to assess NOTCH1 expression. Extent of positivity and protein localization were investigated and correlated with clinical and morphological parameters. NOTCH1 positivity was predominantly associated with papillary carcinomas and only occasionally found in follicular carcinomas. Poorly differentiated and undifferentiated thyroid carcinomas showed only a partial positivity. NOTCH1 expression pattern also seemed differently distributed according to histotype. Our data confirm a role of NOTCH1 in thyroid cancer and highlight for the first time the specific involvement of this pathway in papillary carcinomas. Our data also indicate that other thyroid malignancies do not rely on NOTCH1 signaling for development and progression.

Angiosarcoma and anaplastic carcinoma of the thyroid are two distinct entities: a morphologic, immunohistochemical, and genetic study

Angiosarcoma and anaplastic carcinoma are the most lethal neoplasms of the thyroid worldwide and share some similarities, which have led to a longstanding controversy on their etiopathological relationship. Thyroid angiosarcomas are characterized by vessel formation and an immunophenotype common to endothelial cells, while anaplastic carcinomas are partially or wholly composed of mesenchymal-like cells that have lost the morphologic and functional features of normal thyroid follicular cells. To investigate whether angiosarcomas represent the endothelial extreme of the differentiation spectrum of carcinomas or they are bona fide vascular neoplasms, we studied the clinico-morphologic and genetic characteristics of a series of 10 angiosarcomas and 22 anaplastic carcinomas. Immunohistochemically, among the endothelial markers, CD31 and ERG were the most consistently expressed in angiosarcomas. Among the markers of thyroid origin, PAX8 was the most reliable in anaplastic carcinomas, while TTF-1 reactivity was found in only 5% of anaplastic carcinomas and thyroglobulin was always negative. Pankeratin reacted with most angiosarcomas and anaplastic carcinomas and is therefore not useful in the differential diagnosis. Interestingly a mutated pattern of p53 immunostaining prompted a diagnosis of anaplastic carcinoma. To compare the genetic profile, we used the NGS approach to sequence hotspot regions within a panel of 57 genes. As a result, only a few mutations were found in angiosarcomas and all of them were single events (no TP53 or TERT mutation). On the other hand, anaplastic carcinomas were characterized by a higher number of mutations, and TP53 and TERT promoter mutations were the most frequent genetic alterations. The lack in angiosarcomas of the common mutations identified in anaplastic carcinomas supports a different genetic origin and strongly suggests that, in spite of a shared sarcomatous morphology and a similar clinical aggressiveness, angiosarcomas and anaplastic carcinomas rely on a completely different set of genetic alterations during their evolution.

Inducing cancer indolence by targeting mitochondrial Complex I is potentiated by blocking macrophage-mediated adaptive responses

Converting carcinomas in benign oncocytomas has been suggested as a potential anti-cancer strategy. One of the oncocytoma hallmarks is the lack of respiratory complex I (CI). Here we use genetic ablation of this enzyme to induce indolence in two cancer types, and show this is reversed by allowing the stabilization of Hypoxia Inducible Factor-1 alpha (HIF-1α). We further show that on the long run CI-deficient tumors re-adapt to their inability to respond to hypoxia, concordantly with the persistence of human oncocytomas. We demonstrate that CI-deficient tumors survive and carry out angiogenesis, despite their inability to stabilize HIF-1α. Such adaptive response is mediated by tumor associated macrophages, whose blockage improves the effect of CI ablation. Additionally, the simultaneous pharmacological inhibition of CI function through metformin and macrophage infiltration through PLX-3397 impairs tumor growth in vivo in a synergistic manner, setting the basis for an efficient combinatorial adjuvant therapy in clinical trials.

Diagnostic accuracy of ex vivo fluorescence confocal microscopy in Mohs surgery of basal cell carcinomas: a prospective study on 753 margins

BACKGROUND

Frozen histological sections are used for intraoperative margin assessment during Mohs surgery. Fluorescence confocal microscopy (FCM) is a new tool that offers a promising and faster alternative to frozen histology.

OBJECTIVES

To evaluate prospectively in a clinical setting the accuracy of FCM vs. frozen sections in margin assessment of basal cell carcinoma (BCC).

METHODS

Patients with BCC scheduled for Mohs surgery were prospectively enrolled. Freshly excised surgical specimens were examined by FCM and then frozen sections were evaluated. Permanent sections were obtained, in order to validate the sample technique. A blind re-evaluation was also performed for discordant cases. Sensitivity and specificity levels, as well as positive and negative predictive values (PPV and NPV, respectively), were calculated and receiver-operating characteristic curves generated.

RESULTS

We enrolled 127 BCCs in as many patients (40·2% females). Seven hundred and fifty-three sections were examined. All BCCs were located in the head and neck area. In evaluating the performance of FCM vs. frozen sections, sensitivity was 79·8%, specificity was 95·8%, PPV was 80·5% and NPV was 95·7% [area under the curve 0·88, 95% confidence interval 0·84-0·92 (P < 0·001)]. Forty-nine discordant cases were re-evaluated; 24 were false positive and 25 false negative. The performance of FCM and frozen sections was also evaluated according to the final histopathological assessment.

CONCLUSIONS

We found high levels of accuracy for FCM vs. frozen section evaluation in intraoperative BCC margin assessment during Mohs surgery. Some technical issues prevent the wide use of this technique, but new devices promise to overcome these limitations.

Abstract P3-10-24: Not presented

This abstract was not presented at the conference.

Citation Format: Gasparini E, Bisagni A, Di Cicilia R, Kuhn E, Falco G, Ferrari G, Foroni M, Tamagnini I, Bassano C, Ragazzi M, Gardini G, Cecchi F, Hembrough T, Bisagni G. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-10-24.

Comparing two visualization protocols for tomosynthesis in screening: specificity and sensitivity of slabs versus planes plus slabs

OBJECTIVES

Tomosynthesis (DBT) has proven to be more sensitive than digital mammography, but it requires longer reading time. We retrospectively compared accuracy and reading times of a simplified protocol with 1-cm-thick slabs versus a standard protocol of slabs + 1-mm-spaced planes, both integrated with synthetic 2D.

METHODS

We randomly selected 894 DBTs (including 12 cancers) from the experimental arm of the RETomo trial. DBTs were read by two radiologists to estimate specificity. A second set of 24 cancers (8 also present in the first set) mixed within 276 negative DBTs was read by two radiologists. In total, 28 cancers with 64 readings were used to estimate sensitivity. Radiologists read with both protocols separated by a 3-month washout. Only women that were positive at the screening reading were assessed. Variance was estimated taking into account repeated measures.

RESULTS

Sensitivity was 82.8% (53/64, 95% confidence interval (95% CI) 67.2-92.2) and 90.6% (95% CI 80.2-95.8) with simplified and standard protocols, respectively. In the random screening setting, specificity was 97.9% (1727/1764, 95% CI 97.1-98.5) and 96.3% (95% CI 95.3-97.1), respectively. Inter-reader agreement was 0.68 and 0.54 with simplified and standard protocols, respectively. Median reading times with simplified protocol were 20% to 30% shorter than with standard protocol.

CONCLUSIONS

A simplified protocol reduced reading time and false positives but may have a negative impact on sensitivity.

KEY POINTS

• The adoption of digital breast tomosynthesis (DBT) in screening, more sensitive than mammography, could be limited by its potential effect on the radiologists' workload, i.e., increased reading time and fatigue. • A DBT simplified protocol with slab only, compared to a standard protocol (slab plus planes) both integrated with synthetic 2D, reduced time and false positives but had a negative impact on sensitivity.

Not the same thing: metastatic PTCs have a different background than ATCs

Anaplastic thyroid cancer (ATC) is a rare but highly aggressive form of thyroid cancer. By contrast, differentiated papillary thyroid cancer (PTC) only rarely behave aggressively and develop distant metastasis. Whether distantly metastatic PTC (DM-PTC) and ATC share a common genetic background is still to be defined. We used next-generation sequencing (NGS) to explore the genetic background of a cohort of ATC and DM-PTC and a group of well-differentiated PTCs that did not developed distant metastasis as control (ctrl-PTC). A panel of 128 amplicons within 21 thyroid cancer-related genes was analyzed in a set of 151 thyroid cancer samples including 66 ATCs and DM-PTCs. We showed that the ATC/DM-PTC group had an overall mutational load higher than ctrl-PTCs and that ATCs and DM-PTCs are characterized by a different genetic background, with the exception of mutations in the TERT promoter that were overrepresented in both ATCs (61.1%) and DM-PTCs (48.2%) vs non-aggressive ctrl-PTCs (7.6%). In ATCs, TERT promoter mutations were frequently associated with TP53 mutations, while in the DM-PTCs no significant co-occurrence was observed. No significant association of MED12 mutations with aggressiveness of thyroid cancer was observed in our analysis. Finally, correlation analysis showed that increasing number of mutations negatively impact on patient overall survival also within the ATC and DM-PTC group. In conclusions, overall our analysis further highlights the relevance of TERT promoter mutations in driving aggressiveness and provides new pieces of information in the definition of aggressiveness evolution of thyroid cancer lesions.

Abstract P1-13-02: Withdrawn

This abstract was withdrawn by the authors.

Long-term survivors of pancreatic adenocarcinoma show low rates of genetic alterations in KRAS, TP53 and SMAD4

BACKGROUND

Pancreatic adenocarcinoma (PDAC) is one of the deadliest human malignancies. Although surgery is currently the only effective treatment for PDAC, most patients survive less than 20 months after tumor resection.

OBJECTIVE

The primary goal was to investigate alterations in KRAS, TP53, SMAD4 and CDKN2A/p16 in tumors from patients with exceptionally long survival after surgery.

METHODS

Tumors from 15 patients with PDAC that survived more than 55 months after surgery ("LS") were analyzed for KRAS, TP53, IDH1, NRAS and BRAF using next-generation sequencing. SMAD4 and CDKN2A/p16 was tested using immunohistochemistry. MGMT promoter methylation was investigated.

RESULTS

Tumors from "LS" have a lower prevalence of KRAS and TP53 mutations and had more frequently SMAD4 retained expression, if compared with that of patients died within 24 months from surgery. The survival of patients with wild-type KRAS and TP53 tumors was more than twice longer than that of patients bearing KRAS and TP53 mutations (90.2 vs. 41.1 months). Patients with KRAS wild-type tumors and that retained SMAD4 expression had a survival twice longer than cases with alterations in both genes (83.8 vs. 36.7 months). Eleven tumors (39.3%) showed MGMT methylation.

CONCLUSIONS

Our data indicate that absence of KRAS, TP53 and SMAD4 genetic alterations may identify a subset of pancreatic carcinomas with better outcome.

Genome-wide profiling identifies the THYT1 signature as a distinctive feature of widely metastatic Papillary Thyroid Carcinomas

BACKGROUND

Papillary Thyroid Carcinomas (PTCs) are generally indolent tumors. However, a small but significant percentage of PTCs behaves aggressively, progressing to a diffuse metastatic spreading and leading to patient's death. The lack of reliable markers for predicting the metastatic behavior of these tumors prevents a correct risk based stratification of the disease, thus contributing to the issue of patients' overtreatment. In this study we aimed at identifying genetic features associated with the development of distant metastasis in PTCs.

RESULTS

We showed that DM PTCs are characterized by a moderate degree of copy number alterations but display low level of microsatellite instability and a low mutational burden. We identified duplication of Chr1q, duplication of Chr5p harboring the TERT genomic locus and mutations of TERT promoter as distinctive features of DM PTCs. These three genetic variables defined a signature (THYT1) that was significantly associated with a metastatic behavior and a shortened survival. We analyzed the THYT1 signature in PTCs fine needle aspirate biopsies (FNAB) and we demonstrating the applicability of this signature as a molecular marker in the pre-operative diagnostic setting of PTCs.

MATERIALS AND METHODS

A consecutive series of 2,937 thyroid malignancies, diagnosed at the Arcispedale S. Maria Nuova - IRCCS, Italy between 1978 and 2015 were searched to retrieve those who developed distant metastasis (DM, n = 50). We performed a deep profiling to explore the genomic landscape of these tumors.

CONCLUSIONS

Overall our data identify the first genetic signature that independently predicts metastasis and negative outcome of PTCs, and lay the basis for the possible application of the THYT1 as prognostic marker to improve risk-based stratification and management of PTC patients.

Breast granulomatosis with polyangiitis mimicking breast cancer

Inflammatory lesions of the breast encompass primary reactive processes and local manifestation of systemic diseases. They are very rare and they are generally treated without resort to biopsy. Nevertheless they could be clinically challenge mimicking malignant process and needing surgery to reach a correct diagnosis. Here we describe a rare case of breast granulomatosis with polyangiitis, which presented with radiological and clinical alarming features that immediately raised the suspicious of malignancy leading to breast-conserving surgery.