Novel combinatorial autophagy inhibition therapy for triple negative breast cancers.

BACKGROUND: Triple negative breast cancer (TNBC) has the worst prognosis among breast cancer subtypes. It is characterized by lack of estrogen, progesterone and human epidermal growth factor 2 receptors, and thus, have limited therapeutic options. Autophagy has been found to be correlated with poor prognosis and aggressive behaviour in TNBC. This study aimed to target autophagy in TNBC via a novel approach to inhibit TNBC progression. METHODS: Immunoblotting and confocal microscopy were carried out to examine the effect of tumor microenvironmental stressors on autophagy. Cellular proliferation and migration assays were used to test the effect of different autophagy inhibitors and standard chemotherapy alone or in combination. In vivo xenograft mouse model was utilized to assess the effect of autophagy inhibitors alone or in combination with Paclitaxel. High resolution mass spectrometry based proteomic analysis was performed to explore the mechanisms behind chemoresistance in TNBC. Lastly, immunohistochemistry was done to assess the correlation between autophagy related proteins and clinical characteristics in TNBC tissue specimens. RESULTS: Metabolic stressors were found to induce autophagy in TNBC cell lines. Autophagy initiation inhibitors, SAR405 and MRT68921, showed marked synergy in their anti-proliferative activity in both chemosensitive and chemoresistant TNBC cell models. Paradoxically, positive expression of autophagosome marker LC3 was shown to be associated with better overall survival of TNBC patients. CONCLUSION: In this study, a novel combination between different autophagy inhibitors was identified which inhibited tumor cell proliferation in both chemosensitive and chemoresistant TNBC cells and could result in development of a novel treatment modality against TNBC.

Adjuvant chemotherapy for adenocarcinoma arising from intraductal papillary mucinous neoplasia: multicentre ADENO-IPMN study.

BACKGROUND: The clinical impact of adjuvant chemotherapy after resection for adenocarcinoma arising from intraductal papillary mucinous neoplasia is unclear. The aim of this study was to identify factors related to receipt of adjuvant chemotherapy and its impact on recurrence and survival. METHODS: This was a multicentre retrospective study of patients undergoing pancreatic resection for adenocarcinoma arising from intraductal papillary mucinous neoplasia between January 2010 and December 2020 at 18 centres. Recurrence and survival outcomes for patients who did and did not receive adjuvant chemotherapy were compared using propensity score matching. RESULTS: Of 459 patients who underwent pancreatic resection, 275 (59.9%) received adjuvant chemotherapy (gemcitabine 51.3%, gemcitabine-capecitabine 21.8%, FOLFIRINOX 8.0%, other 18.9%). Median follow-up was 78 months. The overall recurrence rate was 45.5% and the median time to recurrence was 33 months. In univariable analysis in the matched cohort, adjuvant chemotherapy was not associated with reduced overall (P = 0.713), locoregional (P = 0.283) or systemic (P = 0.592) recurrence, disease-free survival (P = 0.284) or overall survival (P = 0.455). Adjuvant chemotherapy was not associated with reduced site-specific recurrence. In multivariable analysis, there was no association between adjuvant chemotherapy and overall recurrence (HR 0.89, 95% c.i. 0.57 to 1.40), disease-free survival (HR 0.86, 0.59 to 1.30) or overall survival (HR 0.77, 0.50 to 1.20). Adjuvant chemotherapy was not associated with reduced recurrence in any high-risk subgroup (for example, lymph node-positive, higher AJCC stage, poor differentiation). No particular chemotherapy regimen resulted in superior outcomes. CONCLUSION: Chemotherapy following resection of adenocarcinoma arising from intraductal papillary mucinous neoplasia does not appear to influence recurrence rates, recurrence patterns or survival.

Long-term Outcomes following Resection of Adenocarcinoma Arising from Intraductal Papillary Mucinous Neoplasm (A-IPMN) versus Pancreatic Ductal Adenocarcinoma (PDAC): A Propensity-score Matched Analysis.

OBJECTIVE: The aim of the present study was to compare long-term post-resection oncological outcomes between A-IPMN and PDAC. SUMMARY BACKGROUND DATA: Knowledge of long term oncological outcomes (e.g recurrence and survival data) comparing between adenocarcinoma arising from intraductal papillary mucinous neoplasms (A-IPMN) and pancreatic ductal adenocarcinoma (PDAC) is scarce. METHODS: Patients undergoing pancreatic resection (2010-2020) for A-IPMN were identified retrospectively from 18 academic pancreatic centres and compared with PDAC patients from the same time-period. Propensity-score matching (PSM) was performed and survival and recurrence were compared between A-IPMN and PDAC. RESULTS: 459 A-IPMN patients (median age,70; M:F,250:209) were compared with 476 PDAC patients (median age,69; M:F,262:214). A-IPMN patients had lower T-stage, lymphovascular invasion (51.4%vs. 75.6%), perineural invasion (55.8%vs. 71.2%), lymph node positivity (47.3vs. 72.3%) and R1 resection (38.6%vs. 56.3%) compared to PDAC(P<0.001). The median survival and time-to-recurrence for A-IPMN versus PDAC were 39.0 versus19.5months (P<0.001) and 33.1 versus 14.8months (P<0.001), respectively (median follow-up,78 vs.73 months). Ten-year overall survival for A-IPMN was 34.6%(27/78) and PDAC was 9%(6/67). A-IPMN had higher rates of peritoneal (23.0 vs. 9.1%, P<0.001) and lung recurrence (27.8% vs. 15.6%, P<0.001) but lower rates of locoregional recurrence (39.7% vs. 57.8%; P<0.001). Matched analysis demonstrated inferior overall survival (P=0.005), inferior disease-free survival (P=0.003) and higher locoregional recurrence (P<0.001) in PDAC compared to A-IPMN but no significant difference in systemic recurrence rates (P=0.695). CONCLUSIONS: PDACs have inferior survival and higher recurrence rates compared to A-IPMN in matched cohorts. Locoregional recurrence is higher in PDAC but systemic recurrence rates are comparable and constituted by their own distinctive site-specific recurrence patterns.

Novel prognostic nomogram for predicting recurrence-free survival in medullary thyroid carcinoma.

AIMS: Recently, there have been attempts to improve prognostication and therefore better guide treatment for patients with medullary thyroid carcinoma (MTC). In 2022, the International MTC Grading System (IMTCGS) was developed and validated using a multi-institutional cohort of 327 patients. The aim of the current study was to build upon the findings of the IMTCGS to develop and validate a prognostic nomogram to predict recurrence-free survival (RFS) in MTC. METHODS AND RESULTS: Data from 300 patients with MTC from five centres across the USA, Europe, and Australia were used to develop a prognostic nomogram that included the following variables: age, sex, AJCC stage, tumour size, mitotic count, necrosis, Ki67 index, lymphovascular invasion, microscopic extrathyroidal extension, and margin status. A process of 10-fold cross-validation was used to optimize the model's performance. To assess discrimination and calibration, the area-under-the-curve (AUC) of a receiver operating characteristic (ROC) curve, concordance-index (C-index), and dissimilarity index (D-index) were calculated. Finally, the model was externally validated using a separate cohort of 87 MTC patients. The model demonstrated very strong performance, with an AUC of 0.94, a C-index of 0.876, and a D-index of 19.06. When applied to the external validation cohort, the model had an AUC of 0.9. CONCLUSIONS: Using well-established clinicopathological prognostic variables, we developed and externally validated a robust multivariate prediction model for RFS in patients with resected MTC. The model demonstrates excellent predictive capability and may help guide decisions on patient management. The nomogram is freely available online at https://nomograms.shinyapps.io/MTC_ML_DFS/.

Inhibition of autophagy initiation: A novel strategy for oral squamous cell carcinomas.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is one of the most common forms of oral cancer and is known to have poor prognostic outcomes. Autophagy is known to be associated with aggressive tumor biology of OSCC. Hence, this study aimed to develop a novel therapeutic strategy against OSCC by targeting the autophagic pathway. METHODS: Immunoblotting, and confocal microscopy were used to examine the effect of tumor microenvironmental stressors on the autophagy activity. Cellular proliferation and migration assays were performed to assess the anti-cancer activity of standard chemotherapy and autophagy initiation inhibitors, either alone or in combination. High resolution mass-spectrometry based proteomic analysis was utilized to understand the mechanisms behind chemoresistance in OSCC models. Finally, immunohistochemistry was performed to determine associations between autophagy markers and clinicopathological characteristics. RESULTS: Tumor microenvironmental stressors were shown to induce autophagy activity in OSCC cell lines. Novel combinations of chemotherapy and autophagy inhibitors as well as different classes of autophagy inhibitors were identified. Combination of MRT68921 and SAR405 demonstrated marked synergy in their anti-proliferative activity and also showed synergy with chemotherapy in chemoresistant OSCC cell models. Autophagy was identified as one of the key pathways involved in mediating chemoresistance in OSCC. Furthermore, TGM2 was identified as a key upstream regulator of chemoresistance in OSCC models. Finally, positive staining for autophagosome marker LC3 was shown to be associated with low histological grade OSCC. CONCLUSION: In conclusion, this study identified a combination of novel autophagy inhibitors which can potently inhibit proliferation of both chemosensitive as well as chemoresistant OSCC cells and could be developed as a novel therapy against advanced OSCC tumors.

Risk of Recurrence after Surgical Resection for Adenocarcinoma Arising from Intraductal Papillary Mucinous Neoplasia (IPMN) with Patterns of Distribution and Treatment: An International, Multicentre, Observational Study.

OBJECTIVE: This international multicentre cohort study aims to identify recurrence patterns and treatment of first and second recurrence in a large cohort of patients after pancreatic resection for adenocarcinoma arising from IPMN. SUMMARY BACKGROUND DATA: Recurrence patterns and treatment of recurrence post resection of adenocarcinoma arising from IPMN are poorly explored. METHOD: Patients undergoing pancreatic resection for adenocarcinoma from IPMN between January 2010 to December 2020 at 18 pancreatic centres were identified. Survival analysis was performed by the Kaplan-Meier log rank test and multivariable logistic regression by Cox-Proportional Hazards modelling. Endpoints were recurrence (time-to, location, and pattern of recurrence) and survival (overall survival and adjusted for treatment provided). RESULTS: Four hundred and fifty-nine patients were included (median, 70 y; IQR, 64-76; male, 54 percent) with a median follow-up of 26.3 months (IQR, 13.0-48.1 mo). Recurrence occurred in 209 patients (45.5 percent; median time to recurrence, 32.8 months, early recurrence [within 1 y], 23.2 percent). Eighty-three (18.1 percent) patients experienced a local regional recurrence and 164 (35.7 percent) patients experienced distant recurrence. Adjuvant chemotherapy was not associated with reduction in recurrence (HR 1.09;P=0.669) One hundred and twenty patients with recurrence received further treatment. The median survival with and without additional treatment was 27.0 and 14.6 months (P<0.001), with no significant difference between treatment modalities. There was no significant difference in survival between location of recurrence (P=0.401). CONCLUSION: Recurrence after pancreatic resection for adenocarcinoma arising from IPMN is frequent with a quarter of patients recurring within 12 months. Treatment of recurrence is associated with improved overall survival and should be considered.

A Critical Assessment of Diagnostic Criteria for the Tall Cell Subtype of Papillary Thyroid Carcinoma-How Much? How Tall? And When Is It Relevant?

Tall cell papillary thyroid carcinoma (TC-PTC) is considered adverse histology. However, previous studies are confounded by inconsistent criteria and strong associations with other adverse features. It is therefore still unclear if TC-PTC represents an independent prognostic factor in multivariate analysis and, if it does, what criteria should be employed for the diagnosis. We retrospectively reviewed 487 PTCs from our institution (where we have historically avoided the prospective diagnosis of TC-PTC) for both the height of tall cells (that is if the cells were two, or three, times as tall as wide) and the percentage of tall cells. On univariate analysis, there was significantly better disease free survival (DFS) in PTCs with no significant tall cell component (< 30%) compared to PTCs with cells two times tall as wide (p = 0.005). The proportion of tall cells (30-50% and > 50%) was significantly associated with DFS (p = 0.012). In a multivariate model including age, size, vascular space invasion, and lymph node metastasis, the current WHO tall cell criteria, met by 7.8% of PTCs, lacked statistical significance for DFS (p = 0.519). However, in the subset of tumours otherwise similar to the American Thyroid Association (ATA) guidelines low-risk category, WHO TC-PTC demonstrated a highly significant reduction in DFS (p = 0.004). In contrast, in intermediate to high-risk tumours, TC-PTC by WHO criteria lacked statistical significance (p = 0.384). We conclude that it may be simplistic to think of tall cell features as being present or absent, as both the height of the cells (two times versus three times) and the percentage of cells that are tall have different clinical significances in different contexts. Most importantly, the primary clinical significance of TC-PTC is restricted to PTCs that are otherwise low risk by ATA guidelines.

A Detailed Histologic and Molecular Assessment of the Diffuse Sclerosing Variant of Papillary Thyroid Carcinoma.

Diffuse sclerosing variant papillary thyroid carcinoma (DS-PTC) is characterized clinically by a predilection for children and young adults, bulky neck nodes, and pulmonary metastases. Previous studies have suggested infrequent BRAFV600E mutation but common RET gene rearrangements. Using strict criteria, we studied 43 DS-PTCs (1.9% of unselected PTCs in our unit). Seventy-nine percent harbored pathogenic gene rearrangements involving RET, NTRK3, NTRK1, ALK, or BRAF; with the remainder driven by BRAFV600E mutations. All 10 pediatric cases were all gene rearranged (P = .02). Compared with BRAFV600E-mutated tumors, gene rearrangement was characterized by psammoma bodies involving the entire lobe (P = .038), follicular predominant or mixed follicular architecture (P = .003), pulmonary metastases (24% vs none, P = .04), and absent classical, so-called "BRAF-like" atypia (P = .014). There was no correlation between the presence of gene rearrangement and recurrence-free survival. Features associated with persistent/recurrent disease included pediatric population (P = .030), gene-rearranged tumors (P = .020), microscopic extrathyroidal extension (P = .009), metastases at presentation (P = .007), and stage II disease (P = .015). We conclude that DS-PTC represents 1.9% of papillary thyroid carcinomas and that actionable gene rearrangements are extremely common in DS-PTC. DS-PTC can be divided into 2 distinct molecular subtypes and all BRAFV600E-negative tumors (1.5% of papillary thyroid carcinomas) are driven by potentially actionable oncogenic fusions.

A novel prognostic nomogram for predicting survival in diffuse pleural mesothelioma.

Recent advances in the management of diffuse pleural mesothelioma (DPM) have increased interest in prognostication and risk stratification on the basis that maximum benefit of combination immunotherapy appears to be seen in patients who otherwise would have the worst prognosis. Various grading schemes have been proposed, including the recently published Mesothelioma Weighted Grading Scheme (MWGS). However, predictive modelling using deep learning algorithms is increasingly regarded as the gold standard in prognostication. We therefore sought to develop and validate a prognostic nomogram for DPM. Data from 369 consecutive patients with DPM were used as independent training and validation cohorts to develop a prognostic tool that included the following variables: age, sex, histological type, nuclear atypia, mitotic count, necrosis, and BAP1 immunohistochemistry. Patients were stratified into four risk groups to assess model discrimination and calibration. To assess discrimination, the area-under-the-curve (AUC) of a receiver-operator-curve (ROC), concordance-index (C-index), and dissimilarity index (D-index) were calculated. Based on the 5-year ROC analysis, the AUC for our model was 0.75. Our model had a C-index of 0.67 (95% CI 0.53-0.79) and a D-index of 2.40 (95% CI 1.69-3.43). Our prognostic nomogram for DPM is the first of its kind, incorporates well established prognostic markers, and demonstrates excellent predictive capability. As these factors are routinely assessed in most pathology laboratories, it is hoped that this model will help inform prognostication and difficult management decisions, such as patient selection for novel therapies. This nomogram is now freely available online at: https://nomograms.shinyapps.io/Meso_Cox_ML/.

The Presence of Typical "BRAFV600E-Like" Atypia in Papillary Thyroid Carcinoma is Highly Specific for the Presence of the BRAFV600E Mutation.

Papillary thyroid carcinomas (PTCs) are driven by a variety of molecular abnormalities including BRAF, RAS, ALK, RET, and NTRK alterations. PTCs driven by the BRAFV600E mutation, or tumours which demonstrate a similar gene expression profile to PTCs driven by this mutation, have been reported to demonstrate specific morphological features sometimes termed "BRAFV600E-like" atypia. BRAFV600E-like atypia is characterised by a well-developed papillary architecture, infiltrative growth, marked nuclear clearing, prominent intranuclear pseudoinclusions, abundant eosinophilic cytoplasm, and scattered psammoma bodies. We sought to investigate the sensitivity and specificity of these morphological features for the presence of BRAFV600E mutation in PTCs as determined by mutation specific immunohistochemistry. An unselected cohort of 495 PTCs was reviewed by a single pathologist and categorised into three groups: typical BRAFV600E-like atypia (145 cases, 29%), possible BRAFV600E-like atypia (166 cases, 33%) and little/no BRAFV600E-like atypia (184 cases, 37%). The specificity and sensitivity of typical BRAFV600E-like atypia for the BRAFV600E mutation was 97.2% and 44.3%, respectively. When typical and possible BRAFV600E-like atypia were analysed together, the specificity was 70.6% and the sensitivity was 81.7%. In the morphologically little/no BRAFV600E-like atypia group, 58 cases (31.5%) had a BRAFV600E mutation. We conclude that typical BRAFV600E-like atypia is highly specific for the presence of the BRAFV600E mutation; however, the absence of BRAFV600E-like atypia does not exclude this mutation.

A Clinicopathologic and Molecular Analysis of Fumarate Hydratase-deficient Pheochromocytoma and Paraganglioma.

Up to 40% of pheochromocytomas (PCCs) and paragangliomas (PGLs) are hereditary. Germline mutations/deletions in fumarate hydratase ( FH ) cause hereditary leiomyomatosis and renal cell carcinoma syndrome which manifests predominantly with FH-deficient uterine/cutaneous leiomyomas and renal cell carcinomas (RCCs)-tumors characterized by loss of immunohistochemical (IHC) expression of FH and/or positive staining for S-(2-succino)-cysteine. Occasional patients develop PCC/PGL. We investigated the incidence, morphologic, and clinical features of FH-deficient PCC/PGL. We identified 589 patients with PCC/PGLs that underwent IHC screening for FH and/or S-(2-succino)-cysteine. Eight (1.4%) PCC/PGLs were FH deficient (1.1% in an unselected population). The median age for FH-deficient cases was 55 (range: 30 to 77 y) with 50% arising in the adrenal. All 4 with biochemical data were noradrenergic. Two (25%) metastasized, 1 dying of disease after 174 months. Germline testing was performed on 7 patients, 6 of whom had FH missense mutations. None were known to have a significant family history before presentation or developed cutaneous leiomyomas, or FH-deficient RCC at extended follow-up. The patient wild-type for FH on germline testing was demonstrated to have somatic FH mutation and loss of heterozygosity corresponding to areas of subclonal FH deficiency in her tumor. One patient did not undergo germline testing, but FH mutation was demonstrated in his tumor. We conclude that FH-deficient PCC/PGL are underrecognized but can be identified by IHC. FH-deficient PCC/PGL are strongly associated with germline missense mutations but are infrequently associated with leiomyoma or RCC, suggesting there may be a genotype-phenotype correlation. FH-deficient PCC/PGL may have a higher metastatic risk.

What are the problems with the current staging of discontinuous tumour nodules (DTNs) in colorectal carcinoma? Is there a better way?

Discontinuous extramural tumour nodules (DTNs) are deposits of metastatic carcinoma in soft tissue not associated with lymph nodes. Although they are established as an adverse prognostic factor in colorectal carcinoma (CRC), under the AJCC eighth edition staging system their presence does not upstage patients who also have lymph node metastases. Counterintuitively, in some situations the presence of lymph node metastases may in effect downstage a patient with DTNs from pN1c to pN1a/b. Therefore, we sought to critically assess the significance of DTNs in a large unselected single institution cohort of patients undergoing surgical resection for CRC. Of 3822 CRC patients undergoing surgical resection from 2005 to 2021, DTNs were present in 686 (18.0%). In univariate (HR=2.687, 95CI 2.355-3.065; p<0.001) and multivariate analysis (HR=1.805, 95CI 1.529-2.132; p<0.001) in a model including age, gender, stage, grade, location, lymph node ratio and apical lymph node status, DTNs were associated with worse overall survival (OS). N1c patients (DTN present but no nodal metastasis) demonstrated worse OS compared to the current pN1a group (p<0.001) and were least different to the current pN2a group (p=0.571). Within the current N1a (p=0.013), N1b (p=0.004) and N2a (p=0.002) groups, patients who also had DTNs had worse OS. DTNs were associated with worse OS for all stage III CRCs combined (p<0.001), and for stage IIIB (p<0.001) and stage IIIC (p=0.007) individually. We conclude that DTNs are an independent adverse prognostic factor that should be considered in the staging system in a way that is additional to (rather than integrated with) the number of involved lymph nodes. We then assess a simple suggestion for how this could be achieved by increasing the overall stage by one group in the presence of DTNs (requiring the creation of a new stage IIID).

Necrosis is an independent predictor of disease-free and overall survival in pancreatic well-differentiated neuroendocrine tumours (NETs): a proposal to include it in grading systems.

Pancreatic neuroendocrine tumours (NETs) are currently graded using the World Health Organization (WHO) 2019 system, which is based solely on mitotic count and Ki-67 proliferative index. Although necrosis is a well recognised adverse prognostic feature that is included in the grading systems of NETs of certain types such as pulmonary carcinoid and medullary thyroid carcinoma, there is currently insufficient evidence to support its inclusion in the grading of pancreatic NETs. Therefore, we sought to investigate the prognostic significance of tumour necrosis in our cohort of resected pancreatic NETs, with a view to providing evidence to support its incorporation into the WHO grading scheme. Under our proposal, pancreatic NETs without necrosis would continue to be graded based solely on mitotic count and Ki-67 index using the established WHO cut-offs, while NETs with tumour necrosis would be classified as grade 3, irrespective of proliferative activity. Using this system in our cohort of 110 resected pancreatic NETs, overall survival (OS) was 250, 198, and 151 months (p=0.039) and disease-free survival (DFS) was 180 months, 117 months, and 38 months (p<0.0001) for grades 1, 2, and 3, respectively. In contrast, there was no significant difference in OS (p=0.231) or DFS (p=0.058) between low grade (grade 1) and intermediate-high grade (grade 2/3) tumours using the current WHO system which does not consider necrosis. Interobserver concordance for assessment of necrosis was excellent. In conclusion, necrosis is an independent predictor of OS and DFS for pancreatic NETs, and our findings strongly support its addition to the grading scheme for this tumour.

A Critical Assessment of Current Grading Schemes for Diffuse Pleural Mesothelioma With a Proposal for a Novel Mesothelioma Weighted Grading Scheme (MWGS).

Although there is early support for schemes based on nuclear grade, necrosis and mitotic rate, there is currently no widely implemented grading system for diffuse pleural mesothelioma (DPM). We investigated current systems and propose a novel Mesothelioma Weighted Grading Scheme (MWGS). The MWGS assigns weighted scores from 0 to 10 based on age (≤74, >74 yrs: 0,1); histologic type (epithelioid, biphasic, sarcomatoid: 0,1,2); necrosis (absent, present: 0,2); mitotic count per 2 mm2 (≤1, 2 to 4, ≥5: 0,1,2); nuclear atypia (mild, moderate, severe: 0,1,2); and BRCA1-associated protein 1 (BAP1) expression (lost, retained: 0,1). A score of 0 to 3 is low grade, 4 to 6 intermediate grade, and 7 to 10 high grade. In 369 consecutive DPMs, median survival was 17.1, 10.1, and 4.1 months for low, intermediate, and high grades (P<0.0001). A progressive increase in score correlated with worsening overall survival (P<0.0001). Interobserver concordance was substantial (κ=0.588), with assessment of nuclear grade being the most subjective parameter (κ=0.195). We compared the MWGS to the 2-tiered system discussed in the World Health Organization (WHO) fifth edition. The WHO system predicted median survival in epithelioid (median 18.0 vs. 11.3 mo, P=0.003) and biphasic (16.2 vs. 4.2 mo, P=0.002), but not sarcomatoid DPM (5.4 vs. 4.7 mo, P=0.407). Interestingly, the WHO grading system was prognostic in cases with BAP1 loss (median survival 18.7 vs. 10.4 mo, P<0.0001), but not retained BAP1 expression (8.9 vs. 6.2 mo, P=0.061). In conclusion, the WHO scheme has merit in epithelioid/biphasic and BAP1-deficient DPM, however, the MWGS can be used for risk stratification of all DPMs, regardless of histologic subtype and BAP1 status.

Switch/sucrose-non-fermentable (SWI/SNF) complex (SMARCA4, SMARCA2, INI1/SMARCB1)-deficient colorectal carcinomas are strongly associated with microsatellite instability: an incidence study in 4508 colorectal carcinomas.

AIMS: Loss of expression of mammalian switch/sucrose-non-fermentable (SWI/SNF) [BRG1/BRM-associated factor (BAF)] complex subunits, including SMARCA4, SMARCA2 and INI1/SMARCB1 (termed SWI/SNF complex deficiency), has been reported in colorectal carcinomas (CRCs) but its frequency and clinical significance are uncertain. METHODS AND RESULTS: We performed immunohistochemistry for SMARCA4, SMARCA2 and SMARCB1 on 4508 consecutive resected CRCs. Loss of SMARCA4 expression was found in 13 cases (0.3%), loss of SMARCA2 expression was found in 59 cases (1.3%), and loss of SMARCB1 expression was found in 21 cases (0.4%). Some CRCs showed loss of expression of more than one subunit, so that 84 CRCs (1.7%) were deficient for at least one component. SWI/SNF complex deficiency was associated with higher grade, a right-sided location, mismatch repair deficiency, and BRAF V600E mutation (P < 0.05); 5.8% of mismatch repair-deficient (MMRd) cases and 5.4% of BRAF V600E-mutant cases were SWI/SNF complex-deficient, as compared with 0.9% and 0.4% of mismatch repair-proficient and BRAF-wild-type cases (P < 0.001). Any loss of SMARCB1 expression and global loss of SMARCA2 expression were associated with statistically significant worse overall survival, whereas SMARCA4-deficient cases showed a trend only towards poor overall survival (P = 0.121). In multivariate analysis, any loss of SMARCA4 expression and global loss of SMARCA2 expression were associated with worse survival [odds ratio (OR) 3.33, P = 0.019; and OR 3.39, P < 0.001]. Of particular note, among the subgroup of cases that were MMRd and BRAF V600E-mutated (otherwise considered to be a good prognostic group), loss of SMARCA4 expression was associated with much worse median survival (10.5 months versus 110.9 months; P = 0.003). CONCLUSIONS: SWI/SNF complex deficiency is rare in CRC but is enriched in MMRd cases. Identifying these cases has morphological associations and prognostic significance, and in the future may have potential therapeutic implications.

Predicting survival in colorectal carcinoma after curative resection: a new prognostic nomogram.

Several prognostic nomograms designed to predict survival after curative resection for colorectal cancer (CRC) have been proposed. Recently, routine pathological assessment has evolved with subtle changes to the AJCC staging system, and routine screening for mismatch repair deficiency (MMRd). Therefore we sought to develop and validate a new prognostic nomogram. All cause survival data from 4517 consecutive patients with primary CRC were used as independent training and validation cohorts to develop a final model including only: age, sex, tumour stage, nodal status, number of lymph nodes resected, apical node status, distant metastases, thin-walled vascular invasion, and MMR status. Patients were stratified into four risk groups to assess model discrimination and calibration. To assess discrimination, the area-under-the-curve (AUC) of a receiver-operator-curve (ROC), concordance-index (C-index), and D-index were calculated. The model was compared to the Memorial Sloan Kettering Cancer Center (MSKCC) CRC nomogram and the AJCC TNM staging. Based on the 5-year ROC analysis, the AUC for our model was 0.81 (0.79 and 0.74 for MSKCC and AJCC, respectively). Moreover, our model demonstrated a concordance index of 0.77 (95% CI 0.70-0.82) compared to 0.75 (95% CI 0.68-0.81) for MSKCC and 0.73 (95% CI 0.65-0.79) for AJCC. In conclusion, our new prognostic nomogram incorporates a larger number of clinically relevant prognostic markers, including MMR status, and therefore demonstrates improved predictive capability. As these factors are routinely assessed, it is hoped that this model will inform prognostication and difficult management decisions, such as patient selection for adjuvant therapy.

PD-L1 Is Preferentially Expressed in PIT-1 Positive Pituitary Neuroendocrine Tumours.

Pituitary neuroendocrine tumours (PitNETs) cause lifelong morbidity, some requiring extensive surgical intervention, radiotherapy, or chemotherapy. A small percentage still cause debilitating disease, resistant to standard treatments, and may benefit from novel therapies. We assessed PD-L1 expression in a large cohort of PitNETs to investigate whether immunotherapy could represent a rational therapeutic choice. Unselected PitNETs undergoing surgical resection were reclassified according to the WHO 2017 system and underwent PD-L1 immunohistochemistry (clone SP263) in tissue microarray format. Membranous expression was scored as 0 (no expression), 1+ (< 50% expression) and 2+ (> 50% expression). A total of 265 PitNETs underwent PD-L1 immunohistochemistry. Prominent non-specific cytoplasmic staining was noted making assessment of true membrane expression difficult. Allowing for this, 40 of 264 (15%) PitNETs demonstrated strong staining (> 50% of neoplastic cells positive). These included 5/10 (50%) somatotrophs, 7/17 (41%) lactotrophs, 2/5 (40%) mammosomatotrophs, 4/8 (50%) mixed somatotroph-lactotrophs, 3/5 (60%) PIT-1 positive plurihormonal tumours with TSH expression, 10/28 (36%) of PIT-1 positive plurihormonal tumours, and 4/10 (40%) of PIT-1 positive tumours with no hormonal expression. Only 2/32 (6%) transcription factor triple negative, hormone negative tumours, 5/113 (4%) of gonadotrophs, and 0/6 thyrotrophs or 0/30 corticotrophs showed significant staining. We conclude that PD-L1 expression is common in somatotrophs, lactotrophs, and PIT-1 positive plurihormonal PitNETs but rare in transcription factor negative, hormone negative PitNETs, gonadotrophs, and corticotrophs. If the therapeutic role of immunotherapy is to be explored in PitNETs, it may be that it is of most benefit in the PD-L1 high subgroup.