Genetic and immune landscape evolution in MMR-deficient colorectal cancer.

Mismatch repair-deficient (MMRd) colorectal cancers (CRCs) have high mutation burdens, which make these tumours immunogenic and many respond to immune checkpoint inhibitors. The MMRd hypermutator phenotype may also promote intratumour heterogeneity (ITH) and cancer evolution. We applied multiregion sequencing and CD8 and programmed death ligand 1 (PD-L1) immunostaining to systematically investigate ITH and how genetic and immune landscapes coevolve. All cases had high truncal mutation burdens. Despite pervasive ITH, driver aberrations showed a clear hierarchy. Those in WNT/ß-catenin, mitogen-activated protein kinase, and TGF-ß receptor family genes were almost always truncal. Immune evasion (IE) drivers, such as inactivation of genes involved in antigen presentation or IFN-γ signalling, were predominantly subclonal and showed parallel evolution. These IE drivers have been implicated in immune checkpoint inhibitor resistance or sensitivity. Clonality assessments are therefore important for the development of predictive immunotherapy biomarkers in MMRd CRCs. Phylogenetic analysis identified three distinct patterns of IE driver evolution: pan-tumour evolution, subclonal evolution, and evolutionary stasis. These, but neither mutation burdens nor heterogeneity metrics, significantly correlated with T-cell densities, which were used as a surrogate marker of tumour immunogenicity. Furthermore, this revealed that genetic and T-cell infiltrates coevolve in MMRd CRCs. Low T-cell densities in the subgroup without any known IE drivers may indicate an, as yet unknown, IE mechanism. PD-L1 was expressed in the tumour microenvironment in most samples and correlated with T-cell densities. However, PD-L1 expression in cancer cells was independent of T-cell densities but strongly associated with loss of the intestinal homeobox transcription factor CDX2. This explains infrequent PD-L1 expression by cancer cells and may contribute to a higher recurrence risk of MMRd CRCs with impaired CDX2 expression. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Bile Microbiome Signatures Associated with Pancreatic Ductal Adenocarcinoma Compared to Benign Disease: A UK Pilot Study.

Pancreatic ductal adenocarcinoma (PDAC) has a very poor survival. The intra-tumoural microbiome can influence pancreatic tumourigenesis and chemoresistance and, therefore, patient survival. The role played by bile microbiota in PDAC is unknown. We aimed to define bile microbiome signatures that can effectively distinguish malignant from benign tumours in patients presenting with obstructive jaundice caused by benign and malignant pancreaticobiliary disease. Prospective bile samples were obtained from 31 patients who underwent either Endoscopic Retrograde Cholangiopancreatography (ERCP) or Percutaneous Transhepatic Cholangiogram (PTC). Variable regions (V3-V4) of the 16S rRNA genes of microorganisms present in the samples were amplified by Polymerase Chain Reaction (PCR) and sequenced. The cohort consisted of 12 PDAC, 10 choledocholithiasis, seven gallstone pancreatitis and two primary sclerosing cholangitis patients. Using the 16S rRNA method, we identified a total of 135 genera from 29 individuals (12 PDAC and 17 benign). The bile microbial beta diversity significantly differed between patients with PDAC vs. benign disease (Permanova p = 0.0173). The separation of PDAC from benign samples is clearly seen through unsupervised clustering of Aitchison distance. We found three genera to be of significantly lower abundance among PDAC samples vs. benign, adjusting for false discovery rate (FDR). These were Escherichia (FDR = 0.002) and two unclassified genera, one from Proteobacteria (FDR = 0.002) and one from Enterobacteriaceae (FDR = 0.011). In the same samples, the genus Streptococcus (FDR = 0.033) was found to be of increased abundance in the PDAC group. We show that patients with obstructive jaundice caused by PDAC have an altered microbiome composition in the bile compared to those with benign disease. These bile-based microbes could be developed into potential diagnostic and prognostic biomarkers for PDAC and warrant further investigation.

A Comprehensive Review of the Current and Future Role of the Microbiome in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is expected to become the second most common cause of cancer death in the USA by 2030, yet progress continues to lag behind that of other cancers, with only 9% of patients surviving beyond 5 years. Long-term survivorship of PDAC and improving survival has, until recently, escaped our understanding. One recent frontier in the cancer field is the microbiome. The microbiome collectively refers to the extensive community of bacteria and fungi that colonise us. It is estimated that there is one to ten prokaryotic cells for each human somatic cell, yet, the significance of this community in health and disease has, until recently, been overlooked. This review examines the role of the microbiome in PDAC and how it may alter survival outcomes. We evaluate the possibility of employing microbiomic signatures as biomarkers of PDAC. Ultimately this review analyses whether the microbiome may be amenable to targeting and consequently altering the natural history of PDAC.

PRIME-HCC: phase Ib study of neoadjuvant ipilimumab and nivolumab prior to liver resection for hepatocellular carcinoma.

BACKGROUND: After liver resection (LR), patients with hepatocellular cancer (HCC) are at high risk of recurrence. There are no approved anti-cancer therapies known to affect such risk, highlighting the acute need for novel systemic therapies to control the probability of disease relapse. Immunotherapy is expanding as a novel treatment option for HCC. Emerging data from cohort 4 of the CA209-040 study, which investigated the safety and preliminary efficacy of nivolumab/ipilimumab co-administration in advanced HCC, suggest that the combination can be delivered safely with an acceptable proportion of reversible grade 3-4 toxicities (27.1%) and a low discontinuation rate (2%) in patients with HCC. Here, we describe the design and rationale of PRIME-HCC, a two-part, multi-centre, phase Ib study to assess safety and bioactivity of the nivolumab/ipilimumab combination prior to LR in early-stage HCC. METHODS: The study involves an initial safety run-in phase (Part 1) to allow for preliminary safety characterisation within the first 6 patients enrolled and a subsequent expansion (Part 2). Ipilimumab will be administered once only on Day 1. Nivolumab will be administered on Day 1 and Day 22 (± 3 days) for a total of two 21-day cycles (i.e. 6 weeks of treatment). The primary objective of the study is to determine the safety and tolerability of the nivolumab/ipilimumab combination prior to LR. The secondary objective is to preliminarily characterize the efficacy of the combination prior to LR, including objective response rate (ORR) and pathologic response rates. Additional exploratory objectives include preliminary evidence of long-term disease control and to identify predictive correlates of response to the nivolumab/ipilimumab combination in HCC. DISCUSSION: The results of this study will help define the positioning of neoadjuvant nivolumab/ipilimumab combination in the perioperative management of HCC, with potential to improve survival outcomes in this patient population. TRIAL REGISTRATION: EudraCT Number: 2018-000987-27 Clinical trial registry & ID: ClinicalTrials.gov : NCT03682276 .

Rationale and design of the POLEM trial: avelumab plus fluoropyrimidine-based chemotherapy as adjuvant treatment for stage III mismatch repair deficient or POLE exonuclease domain mutant colon cancer: a phase III randomised study.

BACKGROUND: 10%-15% of early-stage colon cancers harbour either deficient mismatch repair (dMMR), microsatellite instability high (MSI-H) or POLE exonuclease domain mutations, and are characterised by high tumour mutational burden and increased lymphocytic infiltrate. Metastatic dMMR colon cancers are highly sensitive to immune checkpoint inhibition, and recent data show POLE-mutant tumours are similarly responsive. We are conducting a phase III randomised trial to determine if the addition of the anti-PD-L1 antibody avelumab following adjuvant chemotherapy improves disease-free survival (DFS) in patients with stage III dMMR/MSI-H or POLE mutant colon cancer and is a cost-effective approach for the UK National Health Service (NHS). METHODS: We are recruiting patients with completely resected, stage III colon cancer confirmed to have dMMR/MSI-H, locally or POLE exonuclease domain mutation on central testing. Eligible patients are randomised in a 1:1 ratio to standard fluoropyrimidine-based chemotherapy (capecitabine, oxaliplatin for 12 weeks or capecitabine for 24 weeks) or chemotherapy, followed by avelumab (10 mg/kg, 2 weekly for 24 weeks). Stratification is by chemotherapy received and MMR/MSI-H status. The primary endpoint is DFS. Secondary endpoints include overall survival, toxicity, quality of life and health resource use. The 3-year DFS rate in the control arm is expected to be ~75%. Avelumab is expected to improve the 3-year DFS rate by 12% (ie, 87%). Target accrual is 402 patients, which provides 80% power to detect an HR of 0.48 for DFS at a two-sided alpha of 0.05. This national, multicentre phase III trial is sponsored by the Royal Marsden NHS Foundation Trust and it is anticipated that approximately 40 centres in the UK will participate. This study opened to recruitment in August 2018. TRIAL REGISTRATION NUMBER: NCT03827044.

Percutaneous irreversible electroporation with systemic treatment for locally advanced pancreatic adenocarcinoma.

BACKGROUND: The prognosis for unresectable locally advanced pancreatic adenocarcinoma (LAPC) remains poor. There is increasing interest in modern ablative techniques to improve outcomes. We report on the potential value of integrating percutaneous irreversible electroporation (IRE) in patients undergoing systemic chemotherapy. METHODS: Seventy-five patients with unresectable pancreatic carcinoma underwent percutaneous IRE after chemotherapy using computerised tomography guidance under general anaesthesia. Postoperative immediate and 30-day morbidity and mortality, progression-free (PFS) and overall survival (OS) were evaluated. RESULTS: Post-procedural immediate and 30-day mortality rates were both zero. All-grade adverse events were 25%. Median in-patient stay was 1 day (range, 1-5 days). Median OS and PFS post-IRE for LAPC were 27 and 15 months respectively. Four patients with LAPC down-staged post-IRE ablation to be surgically resectable, with R0 resections in 3 cases. CONCLUSIONS: These results suggest that percutaneous IRE ablation of unresectable LAPC is safe to integrate with standard-of-care chemotherapy and may improve survival, which provides a template for further evaluation in prospective randomized clinical trials.

Overexpression of the mammalian target of rapamycin: a novel biomarker for poor survival in resected early stage non-small cell lung cancer.

INTRODUCTION: The best hope of cure for patients with non-small cell lung cancer (NSCLC) is surgical resection. However, even in stage IA patients, 30% die within 5 years. Further improvements in survival require a biomarker(s), which defines the subset of these patients destined to do badly so that they could be targeted for additional therapies. Here, we investigate whether the immunohistochemical expression of a key kinase implicated in lung cancer biology, the mammalian target of rapamycin (mTOR) can predict survival outcome in patients with early stage resected NSCLC. MATERIALS AND METHODS: One hundred thirty-four patients with resected early stage (IA-IIB) NSCLC were pathologically reviewed centrally before staining for mTOR. Multiple variables including age, sex, stage, angioinvasion, lymph node status, and mTOR staining were assessed by univariate and multivariate analyses. RESULTS: Stage (p = 0.044), lymph node status (p = 0.049), angioinvasion (p = 0.017), and mTOR staining (p = 0.007) were significant univariate predictors of poor survival. However, only angioinvasion (p = 0.016) and mTOR staining (p = 0.046) remained significant after multivariate analysis. Moreover, mTOR staining was the only variable to predict poor outcome in patients who either had negative lymph nodes (p = 0.016) or were stage IA (p = 0.0016). CONCLUSIONS: The mTOR staining provides a new biomarker for poor outcome in early stage NSCLC and could enable resected stage IA patients to be selected for novel therapies possibly with an mTOR inhibitor.

AKT/mTOR pathway activation and BCL-2 family proteins modulate the sensitivity of human small cell lung cancer cells to RAD001.

PURPOSE: The Akt/mammalian target of rapamycin (mTOR) pathway is frequently activated in human cancers and plays an important role in small cell lung cancer (SCLC) biology. We investigated the potential of targeting mTOR signaling as a novel antitumor approach in SCLC. EXPERIMENTAL DESIGN: The expression of mTOR in patient specimens and in a panel of SCLC cell lines was analyzed. The effects on SCLC cell survival and downstream signaling were determined following mTOR inhibition by the rapamycin derivative RAD001 (Everolimus) or down-regulation by small interfering RNA. RESULTS: We found elevated expression of mTOR in patient specimens and SCLC cell lines, compared with normal lung tissue and normal lung epithelial cells. RAD001 treatment impaired basal and growth factor-stimulated cell growth in a panel of SCLC cell lines. Cells with increased Akt pathway activation were more sensitive to RAD001. Accordingly, a constitutive activation of the Akt/mTOR pathway was sufficient to sensitize resistant SCLC cells to the cytotoxic effect of RAD001. In the sensitive cells, RAD001 showed a strong additive effect to the proapoptotic action of the chemotherapeutic agent etoposide. Intriguingly, we observed low Bcl-2 family proteins levels in the SCLC cells with a constitutive Akt pathway activation, whereas an increased expression was detected in the RAD001-resistant SCLC cells. An antisense construct targeting Bcl-2 or a Bcl-2-specific inhibitor was able to sensitize resistant SCLC cells to RAD001. Moreover, SCLC tumor growth in vivo was significantly inhibited by RAD001. CONCLUSION: Together, our data show that inhibiting mTOR signaling with RAD001 potently disrupts growth and survival signaling in human SCLC cells.

Management and outcome of healthy women with a persistently elevated beta-hCG.

PURPOSE: Raised serum beta human chorionic gonadotrophin (beta-hCG) not due to pregnancy can occur as a consequence of (1) gestational trophoblastic neoplasia (GTN), (2) non-gestational trophoblastic tumours, (3) a false-positive beta-hCG, (4) the menopause or (5) a high normal level. Accurate differentiation between these causes is vital to avoid potentially inappropriate investigations and therapies, which may induce infertility or other serious adverse events. Here we report the United Kingdom experience of patients with an elevated beta-hCG of initial uncertain cause and provide a clinical algorithm for the management of such cases. METHOD: The Charing Cross and Weston Park Hospital GTN databases were screened to identify patients referred with an elevated beta-hCG who were not pregnant and had no previous diagnosis of GTN. RESULTS: Between 1981 and 2004 fourteen women presented with persistently raised serum beta-hCG resulting in diagnostic problems. False-positive beta-hCG was excluded in all. Three patients developed gestational choriocarcinoma after 9-29 months. However, in 11 women no cause for the persistently elevated beta-hCG was found. One of these achieved chemotherapy-induced normalisation of serum beta-hCG, but the remaining 10 underwent surgery and/or chemotherapy without benefit. Thus, 71% (10/14) of patients remain well with unexplained elevated beta-hCG levels. CONCLUSION: Elevated serum and urinary beta-hCG levels in healthy women should be investigated systematically to exclude an underlying malignant process and to avoid inappropriate surgical and medical intervention. Long-term follow-up is required as tumours may not become apparent for many months or years.

Value of whole body 18FDG-PET to identify the active site of gestational trophoblastic neoplasia.

OBJECTIVE: To evaluate the usefulness of positron emission tomography with 18-fluorodeoxyglucose (18FDG-PET) in locating residual or relapsed gestational trophoblastic neoplasia (GTN). STUDY DESIGN: The Charing Cross GTN database was screened, and 11 patients who had undergone 18FDG-PET were identified. A retrospective analysis was conducted to determine the value of this investigation as compared with other imaging modalities in clinical care. RESULTS: All patients had elevated beta-human chorionic gonadotropin (beta-hCG) at the time of the investigation; none were false positive. In 7 patients the 18FDG-PET scans correctly confirmed the presence (4 of 7 cases) or absence (3 of 7 cases) of disease sites defined by other imaging investigations. In 2 patients positive PET-guided appropriate surgical resection of lung lesions that appeared of equivocal significance on computed tomography (CT) resulted in -hCG normalization. One patient had a pulmonary metastasis on CT not considered positive on 18FDG-PET (false negative). One patient with enlarged mediastinal lymph nodes on CT that were 18FDG-PET positive also had a vascular uterus on magnetic resonance imaging/Dopper ultrasound that was negative on PET (false negative). Hysterectomy led to hCG normalization and cure. The mediastinal lymph nodes were positive on CT and PET due to sarcoidosis (false positive). Patients with serum hCG levels <10 IU/L could have positive PET scans; that can contribute to patient care. CONCLUSION: 18FDG-PET can aid in identifying residual disease sites in women relapsing from previously treated GTN. However, careful evaluation in combination with other imaging modalities is required to reduce the risk of false positive and negative results.

AIDS-related malignancies: changing epidemiology and the impact of highly active antiretroviral therapy.

PURPOSE OF REVIEW: Three cancers in people with HIV denote an AIDS diagnosis: Kaposi's sarcoma, high-grade B-cell non-Hodgkin's lymphoma and invasive cervical cancer. In addition a number of other cancers occur at increased frequency in this population group but are not AIDS-defining illnesses. This review discusses the impact of highly active antiretroviral therapy on the epidemiology and outcome of AIDS-defining cancers. RECENT FINDINGS: The incidence of both Kaposi's sarcoma and non-Hodgkin's lymphoma has declined in the era of highly active antiretroviral therapy and the outcome of both tumours has improved. Moreover, highly active antiretroviral therapy alone produces a response in a majority of antiretroviral-naïve patients with Kaposi's sarcoma. In contrast, highly active antiretroviral therapy has had little impact on the incidence of human papilloma virus-associated tumours (cervical and anal cancer) in people with HIV, although it may improve survival by reducing opportunistic infection deaths. As people with HIV live longer with highly active antiretroviral therapy, an increased incidence of other non AIDS-defining cancers that have no known association with oncogenic infections is becoming apparent. SUMMARY: For those with access to highly active antiretroviral therapy, the good news from the AIDS-defining cancers - particularly Kaposi's sarcoma and non-Hodgkin's lymphoma - may be balanced by the increasing numbers of non AIDS-defining cancers.

A prognostic index for systemic AIDS-related non-Hodgkin lymphoma treated in the era of highly active antiretroviral therapy.

BACKGROUND: The established International Prognostic Index for lymphomas has not included patients with systemic AIDS-related non-Hodgkin lymphoma. OBJECTIVE: To establish the most appropriate prognostic index for use in patients with systemic AIDS-related non-Hodgkin lymphoma. DESIGN: A prospective study involving univariate and multivariable analyses of patients with AIDS-related non-Hodgkin lymphoma whose data were used to examine standard and new criteria for survival after diagnosis. SETTING: The Chelsea and Westminster cohort of HIV-1-infected persons. PATIENTS: 9621 HIV-positive patients, 111 in whom AIDS-related non-Hodgkin lymphoma was treated after 1996, in the era of highly active antiretroviral therapy (HAART). INTERVENTION: Cox proportional hazards regression analysis to determine the prognostic significance of multiple clinicopathologic variables. RESULTS: Survival of patients with AIDS-related non-Hodgkin lymphoma has increased in the HAART era (log-rank chi-square, 9.23; P = 0.002). Univariate analyses using the established International Prognostic Index factors of age, tumor stage, lactate dehydrogenase level, Eastern Cooperative Oncology Group performance status, and number of extranodal sites were confirmed to be significant variables. Regression modeling for patients in whom disease was diagnosed after 1996 revealed only 2 independent predictors of death: International Prognostic Index risk group and CD4 cell count. These predictors yielded 4 internally validated risk strata with predicted 1-year survival rates of 82%, 47%, 20%, and 15% (P < 0.001). Prognostic risk scores in the highest quartile yielded a likelihood ratio for death of 7.90 (hazard ratio, 1.0), whereas a prognostic score less than 1.0 yielded a likelihood ratio of 0.23 (hazard ratio, 0.15 [95% CI, 0.06 to 0.33]). LIMITATIONS: The sample was small, and different HAART regimens were used. CONCLUSIONS: For patients with AIDS-related non-Hodgkin lymphoma that was diagnosed in the era of HAART, application of the International Prognostic Index remains useful. The addition of CD4 cell count provides further independent prognostic information. Patients who present with AIDS-related non-Hodgkin lymphoma and a low CD4 cell count have a poor prognosis; this information can be used to guide therapeutic options.

Paclitaxel for AIDS-associated Kaposi's sarcoma.

Treatment options are limited for patients with advanced acquired immunodeficiency syndrome-related Kaposi's sarcoma (AIDS-KS). The management of early stage cutaneous AIDS-KS has been revolutionized by the introduction of highly active antiretroviral therapy and for most patients highly active antiretroviral therapy alone will control early stage AIDS-KS. However, patients with advanced stage Kaposi's sarcoma with visceral disease, tumor-associated edema or extensive oral disease require systemic chemotherapy in addition to antiretrovirals. The standard first-line therapy for these affected individuals is a liposomal anthracycline, and response rates of around 70% are usually achieved. For patients with refractory or recurrent AIDS-KS, treatment algorithms are less well defined. The use of paclitaxel in these circumstances is reviewed.

Increased gestational age at evacuation of a complete hydatidiform mole: does it correlate with increased risk of requiring chemotherapy?

OBJECTIVE: To assess whether a complete hydatidiform mole (CHM) carries an increased risk of later requiring chemotherapy in pregnancies continued to term. STUDY DESIGN: The Charing Cross gestational trophoblastic neoplasia (GTN) database was screened between 1973 and 2002 to identify registered singleton CHMs with a known gestational age at the time of evacuation. Of the 8,313 cases 2,800 were centrally histopathologically reviewed by us and confirmed as CHM. The proportion of patients requiring chemotherapyfor both total registered and centrally reviewed patients was analyzed by trimester of evacuation (< 13, 13-24, > 24 weeks). Statistical significance was assessed by the chi2 test. RESULTS: For the total population, including non-centrally reviewed patients, evacuation occurring in the first, second or third trimester was associated with a treatment rate of 13.9% (601 of 4,333), 10.8% (412 of 3,803) and 5.1% (9 of 177), respectively. In patientsfor whom a central pathologic review had been performed to confirm the diagnosis, the treatment rates were 27.7% (525 of 1,897), 27% (241 of 893) and 20% (2 of 10). The higher apparent treatment rates reflect an error in the denominator as we do not review all nontreated cases. In the total population, evacuation in the third trimester correlated with a reduction in risk of subsequent treatment (P<.001). Most of these late deliveries were induced (before adequate ultrasound), whereas the earlier pregnancies were mostly terminated via suction dilatation and curettage. CONCLUSION: There is no evidence that delayed evacuation/delivery of singleton CHM increases the risk of subsequently requiring chemotherapy.