Histological and Somatic Mutational Profiles of Mismatch Repair Deficient Endometrial Tumours of Different Aetiologies

SIMPLE SUMMARY: Endometrial cancers can arise due to an error in DNA mending known as mismatch repair. This can happen because of an error in the cancer itself (somatic) or due to an inherited error (Lynch syndrome). Treatment trials have considered endometrial cancers caused by either of these errors as identical. As it is easier to recruit people with Lynch syndrome, they may be overrepresented in this group despite being less numerous in clinical practice. This would not be an issue if somatic and Lynch syndrome-related endometrial cancers were similar at a molecular level. The data presented herein, however, indicates that these two routes to mismatch repair, although sharing many similarities, lead to endometrial cancers with distinct molecular and pathological features. This may explain the range of outcomes observed in clinical trials of endometrial cancers with mismatch repair errors. ABSTRACT: Background: Mismatch repair deficient (MMRd) tumours may arise from somatic events acquired during carcinogenesis or in the context of Lynch syndrome (LS), an inherited cancer predisposition condition caused by germline MMR pathogenic variants. Our aim was to explore whether sporadic and hereditary MMRd endometrial cancers (EC) display distinctive tumour biology. Methods: Clinically annotated LS-EC were collected. Histological slide review was performed centrally by two specialist gynaecological pathologists. Mutational analysis was by a bespoke 75- gene next-generation sequencing panel. Comparisons were made with sporadic MMRd EC. Multiple correspondence analysis was used to explore similarities and differences between the cohorts. Results: After exclusions, 135 LS-EC underwent independent histological review, and 64 underwent mutational analysis. Comparisons were made with 59 sporadic MMRd EC. Most tumours were of endometrioid histological subtype (92% LS-EC and 100% sporadic MMRd EC, respectively, p = NS). Sporadic MMRd tumours had significantly fewer tumour infiltrating lymphocytes (p ≤ 0.0001) and showed more squamous/mucinous differentiation than LS-EC (p = 0.04/p = 0.05). PTEN mutations were found in 88% sporadic MMRd and 61% LS-EC, respectively (p < 0.001). Sporadic MMRd tumours had significantly more mutations in PDGFRA, ALK, IDH1, CARD11, CIC, MED12, CCND1, PTPN11, RB1 and KRAS, while LS-EC showed more mutations affecting SMAD4 and ARAF. LS-EC showed a propensity for TGF-β signalling disruption. Cluster analysis found that wild type PTEN associates predominantly with LS-EC, whilst co-occurring mutations in PTEN, PIK3CA and KRAS predict sporadic MMRd EC. Conclusions: Whilst MMRd EC of hereditary and sporadic aetiology may be difficult to distinguish by histology alone, differences in infiltrating immune cell counts and mutational profile may predict heterogenous responses to novel targeted therapies and warrant further study

Histological and Somatic Mutational Profiles of Mismatch Repair Deficient Endometrial Tumours of Different Aetiologies

From MDPI via Jisc Publications RouterHistory: accepted 2021-09-06, pub-electronic 2021-09-10Publication status: PublishedFunder: Medical Research Council; Grant(s): MR/M018431/1Background: Mismatch repair deficient (MMRd) tumours may arise from somatic events acquired during carcinogenesis or in the context of Lynch syndrome (LS), an inherited cancer predisposition condition caused by germline MMR pathogenic variants. Our aim was to explore whether sporadic and hereditary MMRd endometrial cancers (EC) display distinctive tumour biology. Methods: Clinically annotated LS-EC were collected. Histological slide review was performed centrally by two specialist gynaecological pathologists. Mutational analysis was by a bespoke 75- gene next-generation sequencing panel. Comparisons were made with sporadic MMRd EC. Multiple correspondence analysis was used to explore similarities and differences between the cohorts. Results: After exclusions, 135 LS-EC underwent independent histological review, and 64 underwent mutational analysis. Comparisons were made with 59 sporadic MMRd EC. Most tumours were of endometrioid histological subtype (92% LS-EC and 100% sporadic MMRd EC, respectively, p = NS). Sporadic MMRd tumours had significantly fewer tumour infiltrating lymphocytes (p ≤ 0.0001) and showed more squamous/mucinous differentiation than LS-EC (p = 0.04/p = 0.05). PTEN mutations were found in 88% sporadic MMRd and 61% LS-EC, respectively (p 0.001). Sporadic MMRd tumours had significantly more mutations in PDGFRA, ALK, IDH1, CARD11, CIC, MED12, CCND1, PTPN11, RB1 and KRAS, while LS-EC showed more mutations affecting SMAD4 and ARAF. LS-EC showed a propensity for TGF-β signalling disruption. Cluster analysis found that wild type PTEN associates predominantly with LS-EC, whilst co-occurring mutations in PTEN, PIK3CA and KRAS predict sporadic MMRd EC. Conclusions: Whilst MMRd EC of hereditary and sporadic aetiology may be difficult to distinguish by histology alone, differences in infiltrating immune cell counts and mutational profile may predict heterogenous responses to novel targeted therapies and warrant further study

A transcriptionally distinct CXCL13+CD103+CD8+ T-cell population is associated with B-cell recruitment and neoantigen load in human cancer

The chemokine CXCL13 mediates recruitment of B cells to tumors and is essential for the formation of tertiary lymphoid structures (TLSs). TLSs are thought to support antitumor immunity and are associated with improved prognosis. However, it remains unknown whether TLSs are formed in response to the general inflammatory character of the tumor microenvironment, or rather, are induced by (neo)antigen-specific adaptive immunity. We here report on the finding that the transforming growth factor beta (TGFβ)-dependent CD103+CD8+ tumor-infiltrating T-cell (TIL) subpopulation expressed and produced CXCL13. Accordingly, CD8+ T cells from peripheral blood activated in the presence of TGFβ upregulated CD103 and secreted CXCL13. Conversely, inhibition of TGFβ receptor signaling abrogated CXCL13 production. CXCL13+CD103+CD8+ TILs correlated with B-cell recruitment, TLSs, and neoantigen burden in six cohorts of human tumors. Altogether, our findings indicated that TGFβ plays a non-canonical role in coordinating immune responses against human tumors and suggest a potential role for CXCL13+CD103+CD8+ TILs in mediating B-cell recruitment and TLS formation in human tumors

Gremlin 1 identifies a skeletal stem cell with bone, cartilage, and reticular stromal potential

The stem cells that maintain and repair the postnatal skeleton remain undefined. One model suggests that perisinusoidal mesenchymal stem cells (MSCs) give rise to osteoblasts, chondrocytes, marrow stromal cells, and adipocytes, although the existence of these cells has not been proven through fate-mapping experiments. We demonstrate here that expression of the bone morphogenetic protein (BMP) antagonist gremlin 1 defines a population of osteochondroreticular (OCR) stem cells in the bone marrow. OCR stem cells self-renew and generate osteoblasts, chondrocytes, and reticular marrow stromal cells, but not adipocytes. OCR stem cells are concentrated within the metaphysis of long bones not in the perisinusoidal space and are needed for bone development, bone remodeling, and fracture repair. Grem1 expression also identifies intestinal reticular stem cells (iRSCs) that are cells of origin for the periepithelial intestinal mesenchymal sheath. Grem1 expression identifies distinct connective tissue stem cells in both the bone (OCR stem cells) and the intestine (iRSCs)

Multiplex analysis of intratumoural immune infiltrate and prognosis in patients with stage II–III colorectal cancer from the SCOT and QUASAR 2 trials: A retrospective analysis

Background Tumour-infiltrating CD8+ cytotoxic T cells confer favourable prognosis in colorectal cancer. The added prognostic value of other infiltrating immune cells is unclear and so we sought to investigate their prognostic value in two large clinical trial cohorts. Methods We used multiplex immunofluorescent staining of tissue microarrays to assess the densities of CD8+, CD20+, FoxP3+, and CD68+ cells in the intraepithelial and intrastromal compartments from tumour samples of patients with stage II–III colorectal cancer from the SCOT trial (ISRCTN59757862), which examined 3 months versus 6 months of adjuvant oxaliplatin-based chemotherapy, and from the QUASAR 2 trial (ISRCTN45133151), which compared adjuvant capecitabine with or without bevacizumab. Both trials included patients aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0–1. Immune marker predictors were analysed by multiple regression, and the prognostic and predictive values of markers for colorectal cancer recurrence-free interval by Cox regression were assessed using the SCOT cohort for discovery and QUASAR 2 cohort for validation. Findings After exclusion of cases without tissue microarrays and with technical failures, and following quality control, we included 2340 cases from the SCOT trial and 1069 from the QUASAR 2 trial in our analysis. Univariable analysis of associations with recurrence-free interval in cases from the SCOT trial showed a strong prognostic value of intraepithelial CD8 (CD8IE) as a continuous variable (hazard ratio [HR] for 75th vs 25th percentile [75vs25] 0·73 [95% CI 0·68–0·79], p=2·5 × 10−16), and of intrastromal FoxP3 (FoxP3IS; 0·71 [0·64–0·78], p=1·5 × 10−13) but not as strongly in the epithelium (FoxP3IE; 0·89 [0·84–0·96], p=1·5 × 10−4). Associations of other markers with recurrence-free interval were moderate. CD8IE and FoxP3IS retained independent prognostic value in bivariable and multivariable analysis, and, compared with either marker alone, a composite marker including both markers (CD8IE-FoxP3IS) was superior when assessed as a continuous variable (adjusted [a]HR75 vs 25 0·70 [95% CI 0·63–0·78], p=5·1 × 10−11) and when categorised into low, intermediate, and high density groups using previously published cutpoints (aHR for intermediate vs high 1·68 [95% CI 1·29–2·20], p=1·3 × 10−4; low vs high 2·58 [1·91–3·49], p=7·9 × 10−10), with performance similar to the gold-standard Immunoscore. The prognostic value of CD8IE-FoxP3IS was confirmed in cases from the QUASAR 2 trial, both as a continuous variable (aHR75 vs 25 0·84 [95% CI 0·73–0·96], p=0·012) and as a categorical variable for low versus high density (aHR 1·80 [95% CI 1·17–2·75], p=0·0071) but not for intermediate versus high (1·30 [0·89–1·88], p=0·17). Interpretation Combined evaluation of CD8IE and FoxP3IS could help to refine risk stratification in colorectal cancer. Investigation of FoxP3IS cells as an immunotherapy target in colorectal cancer might be merited

Tumour-infiltrating CD8+ lymphocytes and colorectal cancer recurrence by tumour and nodal stage

Background Intratumoural T-cell infiltrate intensity cortes wrelaith clinical outcome in stage II/III colorectal cancer (CRC). We aimed to determine whether this association varies across this heterogeneous group. Methods We performed a pooled analysis of 1804 CRCs from the QUASAR2 and VICTOR trials. Intratumoural CD8+ and CD3+ densities were quantified by immunohistochemistry in tissue microarray (TMA) cores, and their association with clinical outcome analysed by Cox regression. We validated our results using publicly available gene expression data in a pooled analysis of 1375 CRCs from seven independent series. Results In QUASAR2, intratumoural CD8+ was a stronger predictor of CRC recurrence than CD3+ and showed similar discriminative ability to both markers in combination. Pooled multivariable analysis of both trials showed increasing CD8+ density was associated with reduced recurrence risk independent of confounders including DNA mismatch repair deficiency, POLE mutation and chromosomal instability (multivariable hazard ratio [HR] for each two-fold increase = 0.92, 95%CI = 0.87–0.97, P = 3.6 × 10−3). This association was not uniform across risk strata defined by tumour and nodal stage: absent in low-risk (pT3,N0) cases (HR = 1.03, 95%CI = 0.87–1.21, P = 0.75), modest in intermediate-risk (pT4,N0 or pT1-3,N1-2) cases (HR = 0.92, 95%CI = 0.86–1.0, P = 0.046) and strong in high-risk (pT4,N1-2) cases (HR = 0.87, 95%CI = 0.79–0.97, P = 9.4 × 10−3); PINTERACTION = 0.090. Analysis of tumour CD8A expression in the independent validation cohort revealed similar variation in prognostic value across risk strata (PINTERACTION = 0.048). Conclusions The prognostic value of intratumoural CD8+ cell infiltration in stage II/III CRC varies across tumour and nodal risk strata. </p

Correlative and functional analysis of genomic instability and immune response in colorectal and endometrial cancer

Cancer is a common disease, which results in considerable amounts of morbidity and mortality worldwide. It is now recognised that the tumour immune response is essential in determining cancer biology. However, anti-tumour immunity varies considerably between cancers, and even within the same cancer type. In part, it is determined by the tumour mutational landscape. But much remains to be understood about how the interaction with the cancer genome shapes the tumour immune microenvironment, and influences clinical outcomes. In this research, I demonstrated that tumour CD8+cell infiltrate is significantly associated with reduced recurrence risk and improved overall survival in stage II/III colorectal cancer (CRC). Importantly, this relationship was independent of key confounding factors, including genomic instabilities that have been shown to influence both anti-tumour immunity and clinical outcomes. Furthermore, this relationship was not consistent across all stage II/III CRCs, but rather varied according to tumour and nodal status. Mismatch repair deficiency (MMRd) is a form of genomic instability that contributes to the development of both CRC and endometrial cancer (EC). I showed that MMRd is associated with improved outcomes in CRC, but not EC. This might be a reflection of differences in the immune landscape between MMRd CRC and EC: MMRd CRCs had much greater levels of infiltrate T lymphocytes. Furthermore, MMRd ECs showed an enrichment for loss of function JAK1 mutations, which was associated with abrogated IFNγ signalling activation. Finally, this research demonstrated a murine model to allow functional investigation of MMR loss and its impact on the tumour microenvironment. Conditional, inducible Mlh1 loss resulted in a specific phenotype, with the development of intestinal polyps. In contrast to human disease, these polyps showed CD8+ T cell exclusion, which may be a secondary to Beta-2 Microglobulin loss. In summary, this work constitutes a correlative and functional study of the associated between the immune response and clinical outcome, and how the this is influenced by tumour genomic instability

The prevalence of Lynch syndrome in women with endometrial cancer: a systematic review protocol

Abstract Background Lynch syndrome is the most common inherited cancer syndrome, which predisposes individuals to a number of different cancers, principally colorectal and endometrial cancer. The early diagnosis of Lynch syndrome enables colorectal surveillance, which has been shown to save lives through the detection and removal of premalignant polyps and earlier detection of invasive disease. Endometrial cancer, which is often the sentinel cancer in women, provides an opportunity to diagnose Lynch syndrome and thus enable colorectal surveillance as well as the cascade testing for Lynch syndrome in other family members. These potential benefits have led to a call for the universal screening of women with endometrial cancer for Lynch syndrome, a practice that is now commonplace in colorectal cancer. Healthcare providers and clinicians are however restricted by insufficient knowledge about the prevalence of Lynch syndrome in women with endometrial cancer, with estimates varying as widely as 1–10%. The aim of this study is to perform a systematic review with a meta-analysis of the current literature base in order to estimate the prevalence of Lynch syndrome among women with endometrial cancer to inform this discussion. Methods Medline, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Methodology Register, NHS Health and Technology Assessment Database and the Web of Science will be systematically searched for relevant studies via the Ovid platform. Two authors will review the titles and abstracts independently, with discrepancy settled by a third author. Data extraction will be completed to record demographic, pathological and clinical data, as well as the diagnostic methods used for estimating the prevalence of Lynch syndrome in women with endometrial cancer. Bias will be assessed and recorded using the Newcastle-Ottawa Scale and that of the International Cochrane Collaboration. Dependent on the heterogeneity of the data, we aim to produce a cumulative incidence in addition to subgroup analyses as to investigate secondary outcomes. Discussion The aim of this systematic review is to provide a robust estimate of the prevalence of Lynch syndrome in women with endometrial cancer. This will enable resource allocation and decision-making regarding the appropriateness of screening all women, or certain women, with endometrial cancer for Lynch syndrome. Such a policy could enable the earlier diagnosis of Lynch syndrome in women and, through the application of colorectal cancer surveillance, improve their survival outcomes. Systematic review registration This systematic review has been registered on PROSPERO (ref CRD42017081707)