Expression levels of ROS1/ALK/c-MET and therapeutic efficacy of cetuximab plus chemotherapy in advanced biliary tract cancer

Precision immunotherapy for cholangiocarcinoma: Pioneering the use of human-derived anti-cMET single chain variable fragment in anti-cMET chimeric antigen receptor (CAR) NK cells

Cholangiocarcinoma (CCA) presents a significant clinical challenge which is often identified in advanced stages, therby restricting the effectiveness of surgical interventions for most patients. The high incidence of cancer recurrence and resistance to chemotherapy further contribute to a bleak prognosis and low survival rates. To address this pressing need for effective therapeutic strategies, our study focuses on the development of an innovative cellular immunotherapy, specifically utilizing chimeric antigen receptor (CAR)-engineered natural killer (NK) cells designed to target the cMET receptor tyrosine kinase. In this investigation, we initiated the screening of a phage library displaying human single-chain variable fragment (ScFv) to identify novel ScFv molecules with specificity for cMET. Remarkably, ScFv11, ScFv72, and ScFv114 demonstrated exceptional binding affinity, confirmed by molecular docking analysis. These selected ScFvs, in addition to the well-established anti-cMET ScFvA, were integrated into a CAR cassette harboring CD28 transmembrane region-41BB-CD3ζ domains. The resulting anti-cMET CAR constructs were transduced into NK-92 cells, generating potent anti-cMET CAR-NK-92 cells. To assess the specificity and efficacy of these engineered cells, we employed KKU213A cells with high cMET expression and KKU055 cells with low cMET levels. Notably, co-culture of anti-cMET CAR-NK-92 cells with KKU213A cells resulted in significantly increased cell death, whereas no such effect was observed with KKU055 cells. In summary, our study identified cMET as a promising therapeutic target for CCA. The NK-92 cells, armed with the anti-cMET CAR molecule, have shown strong ability to kill cancer cells specifically, indicating their potential as a promising treatment for CCA in the future.

Emerging targeted therapies and strategies to overcome resistance in biliary tract cancers

In the last decade, targeted therapies have shown rapid advancement in biliary tract cancer (BTC). Today, many targeted agents are available and under investigation for patients with BTC. More recently, immune checkpoint inhibitors (ICI) such as durvalumab and pembrolizumab in combination with gemcitabine plus cisplatin (gem/cis) have resulted in improved overall survival and progression-free survival in the first-line setting. However, the efficacy benefit of these novel therapeutics is often short-lived, with literature outlining concerns about both primary and secondary resistance to these agents. Investigators also need to consider toxicity profiles that can emerge using this strategy. There have been efforts to reduce evolving resistance through combinatory approaches, both pre-clinically and in early clinical settings. This review summarizes the emerging targeted therapies in BTC, evolving biomarkers of resistance, strategies to overcome them, and an analysis of ongoing clinical trials of patients with advanced BTC.

Therapeutic Implications of Ceritinib in Cholangiocarcinoma beyond ALK Expression and Mutation

Cholangiocarcinoma (CCA) is a difficult-to-treat cancer, with limited therapeutic options and surgery being the only curative treatment. Standard chemotherapy involves gemcitabine-based therapies combined with cisplatin, oxaliplatin, capecitabine, or 5-FU with a dismal prognosis for most patients. Receptor tyrosine kinases (RTKs) are aberrantly expressed in CCAs encompassing potential therapeutic opportunity. Hence, 112 RTK inhibitors were screened in KKU-M213 cells, and ceritinib, an approved targeted therapy for ALK-fusion gene driven cancers, was the most potent candidate. Ceritinib's cytotoxicity in CCA was assessed using MTT and clonogenic assays, along with immunofluorescence, western blot, and qRT-PCR techniques to analyze gene expression and signaling changes. Furthermore, the drug interaction relationship between ceritinib and cisplatin was determined using a ZIP synergy score. Additionally, spheroid and xenograft models were employed to investigate the efficacy of ceritinib in vivo. Our study revealed that ceritinib effectively killed CCA cells at clinically relevant plasma concentrations, irrespective of ALK expression or mutation status. Ceritinib modulated multiple signaling pathways leading to the inhibition of the PI3K/Akt/mTOR pathway and activated both apoptosis and autophagy. Additionally, ceritinib and cisplatin synergistically reduced CCA cell viability. Our data show ceritinib as an effective treatment of CCA, which could be potentially explored in the other cancer types without ALK mutations.

Preclinical evidence for anaplastic lymphoma kinase inhibitors as novel therapeutic treatments for cholangiocarcinoma

Introduction

Bile duct cancer (cholangiocarcinoma, CCA) has a poor prognosis for patients, and despite recent advances in targeted therapies for other cancer types, it is still treated with standard chemotherapy. Anaplastic lymphoma kinase (ALK) has been shown to be a primary driver of disease progression in lung cancer, and ALK inhibitors are effective therapeutics in aberrant ALK-expressing tumors. Aberrant ALK expression has been documented in CCA, but the use of ALK inhibitors has not been investigated. Using CCA cell lines and close-to-patient primary cholangiocarcinoma cells, we investigated the potential for ALK inhibitors in CCA.

Methods

ALK, cMET, and ROS1 expression was determined in CCA patient tissue by immunohistochemistry and digital droplet polymerase chain reaction, and that in cell lines was determined by immunoblot and immunofluorescence. The effect on cell viability and mechanism of action of ALK, cMet, and ROS1 inhibitors was determined in CCA cell lines. To determine whether ceritinib could affect primary CCA cells, tissue was taken from four patients with biliary tract cancer, without ALK rearrangement, mutation, or overexpression, and grown in three-dimensional tumor growth assays in the presence or absence of humanized mesenchymal cells.

Results

ALK and cMet but not ROS were both upregulated in CCA tissues and cell lines. Cell survival was inhibited by crizotinib, a c-met/ALK/ROS inhibitor. To determine the mechanism of this effect, we tested c-Met-specific and ALK/ROS-specific inhibitors, capmatinib and ceritinib, respectively. Whereas capmatinib did not affect cell survival, ceritinib dose-dependently inhibited survival in all cell lines, with IC50 ranging from 1 to 9 µM and co-treatments with gemcitabine and cisplatin further sensitized cells, with IC50 ranging from IC50 0.60 to 2.32 µM. Ceritinib did not inhibit cMet phosphorylation but did inhibit ALK phosphorylation. ALK was not mutated in any of these cell lines. Only ceritinib inhibited 3D growth of all four patient samples below mean peak serum concentration, in the presence and absence of mesenchymal cells, whereas crizotinib and capmatinib failed to do this. Ceritinib appeared to exert its effect more through autophagy than apoptosis.

Discussion

These results indicate that ceritinib or other ALK/ROS inhibitors could be therapeutically useful in cholangiocarcinoma even in the absence of aberrant ALK/ROS1 expression.

An unresectable and metastatic intrahepatic cholangiocarcinoma with EML4-ALK rearrangement achieving partial response after first-line treatment with ensartinib: a case report

Systemic chemotherapies are the primary treatment options for patients with unresectable and metastatic intrahepatic cholangiocarcinoma (ICC), but the effectiveness of current systemic therapies is limited. The development of targeted-therapy has changed the treatment landscape of ICC, and comprehensive genome sequencing of advanced cholangiocarcinoma patients could be beneficial to identify potential targets to guide individualized treatment. Herein, we reported an unresectable and metastatic ICC patient who detected EML4-ALK rearrangement in peripheral blood, which was later confirmed on tissue-based testing, and achieved partial response (PR) after first-line treatment with ensartinib. This case suggests that the liquid biopsy is of clinical value for unresectable or metastatic ICC, and the discovery of rare molecular targets provides new therapeutically approaches for advanced ICC patients.

Combination Therapies for Advanced Biliary Tract Cancer

Biliary tract cancers (BTCs) are a group of malignant neoplasms that have recently increased in incidence and have a poor prognosis. Surgery is the only curative therapy. However, most patients are only indicated for palliative therapy because of advanced-stage disease at diagnosis and rapid progression. The current first-line treatment for advanced BTC is gemcitabine and cisplatin chemotherapy. Nonetheless, many patients develop resistance to this regimen. Over the years, few chemotherapy regimens have managed to improve the overall survival of patients. Accordingly, novel therapies such as targeted therapy have been introduced to treat this patient population. Extensive research on tumorigenesis and the genetic profiling of BTC have revealed the heterogenicity and potential target pathways, such as EGFR, VEGF, MEK/ERK, PI3K and mTOR. Moreover, mutational analysis has documented the presence of IDH1, FGFR2, HER2, PRKACA, PRKACB, BRAF, and KRAS gene aberrations. The emergence of immunotherapy in recent years has expanded the treatment landscape for this group of malignancies. Cancer vaccines, adoptive cell transfer, and immune checkpoint inhibitors have been extensively investigated in trials of BTC. Therefore, patient stratification and a combination of various therapies have become a reasonable and important clinical strategy to improve patient outcomes. This review elaborates the literature on combined treatment strategies for advanced BTC from the past few years and ongoing clinical trials to provide new inspiration for the treatment of advanced BTC.

The Molecular Pathogenesis and Targeted Therapies for Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a group of malignancies of the bile ducts with high mortality rates and limited treatment options. In the past decades, remarkable efforts have been dedicated toward elucidating the specific molecular signaling pathways and oncogenic loops driving cholangiocarcinogenesis to ultimately develop more effective therapies. Despite some recent advances, an extensive intra- and inter-tumor heterogeneity together with a poorly understood immunosuppressive microenvironment significantly compromises the efficacy of available treatments. Here, we provide a concise review of the latest advances and current knowledge of the molecular pathogenesis of CCA focusing on clinically relevant aberrations as well as future research avenues.

A review of molecularly targeted therapy in biliary tract carcinoma: what is the next step?

Patients with unresectable biliary tract carcinomas (BTCs) have a poor prognosis with a median overall survival of fewer than 12 months following systemic chemotherapy. In recent years, the identification of distinct molecular alterations with corresponding targeted therapies is modifying this therapeutic algorithm. The aim of this review is to present an overview of targeted therapy for BTCs, describing published available data and potential future challenges in ongoing trials. From clinicaltrials.gov online database all ongoing trials for BTCs (any stage) was examinated in July 2021, and data regarding study design, disease characteristics and type of treatments were registered. Oncogenic-driven therapy (targeted therapy) was investigated in 67 trials. According to research, 15 ongoing trials (22.4%) are investigating fibroblast growth factor (FGF) receptor (FGFR)-inhibitors in BTCs. Three (18.7%) are open-label randomized multicenter phase 3 trials, 8 (50%) are single-arm phase two trials, and 4 (25%) are phase one studies. Twelve (17.9%) clinical trials dealt with isocitrate dehydrogenase (IDH) 1/2 targeting therapy either in combination with cisplatin (Cis) and gemcitabine (Gem) as first-line treatment for BTCs or in monotherapy in patients with IDH1 mutant advanced malignancies, including cholangiocarcinoma (CCA). Nine (13.4%) clinical trials tested human epidermal growth factor receptor (HER) 2 targeting therapy. Four (44.4%) studies are phase I trials, two (22.2%) are phase I/II trials, and three (33.3%) phase II trials. Rare molecular alterations in BTCs, such as anaplastic lymphoma kinase (ALK), c-ros oncogene1 receptor tyrosine kinase (ROS1), and v-RAF murine sarcoma viral oncogene homologue B1 (BRAF), are also under investigation in a few trials. Forty-four clinical trials (17.2%) are investigating not oncogenic-driven multitarget therapy like multireceptor tyrosin kinase inhibitors and antiangiogenetic agents. In conclusion, this review shows that BTCs management is experiencing important innovations, especially in biomarker-based patient selection and in the new emerging therapeutic approach. Many ongoing trials could answer questions regarding the role of molecular inhibitors leading to new therapeutic frontiers for molecular subcategories of BTCs.

Emerging Therapies for Advanced Cholangiocarcinoma: An Updated Literature Review

Cholangiocarcinoma is a group of malignancies with poor prognosis. Treatments for the management of advanced-stage cholangiocarcinoma are limited, and the 5-year survival rate is estimated to be approximately 5-15%, considering all tumor stages. There is a significant unmet need for effective new treatment approaches. The present review is provided with the aim of summarizing the current evidence and future perspectives concerning new therapeutic strategies for cholangiocarcinoma. The role of targeted therapies and immunotherapies is currently investigational in cholangiocarcinoma. These therapeutic options might improve survival outcomes, as shown by the promising results of several clinical trials illustrated in the present review. The co-presence of driver mutations and markers of susceptibility to immunotherapy may lead to rational combination strategies and clinical trial development. A better understanding of immunologically based therapeutic weapons is needed, which will lead to a form of a precision medicine strategy capable of alleviating the clinical aggressiveness and to improve the prognosis of cholangiocarcinoma.

RRM1 Expression as a Prognostic Biomarker for Unresectable or Recurrent Biliary Tract Cancer Treated with Gemcitabine plus Cisplatin

The combination of gemcitabine plus cisplatin (GP) is regarded as a first-line treatment for patients with unresectable or recurrent biliary tract cancer (BTC). Several proteins including human equilibrative nucleoside transporter-1 (hENT1), deoxycytidine kinase (DCK), cytidine deaminase (CDA), and ribonucleotide reductase subunit 1 (RRM1) are known to be involved in gemcitabine uptake and metabolism. This study was aimed to identify the predictive and prognostic values of these biomarkers in patients who treated with GP for advanced BTC. Tumor samples were obtained from 34 patients with unresectable or recurrent BTC who were treated with GP between August 2015 and February 2018. Intratumoral expression of hENT1, DCK, CDA and RRM1 was determined by immunohistochemistry and analyzed for association with chemotherapy response, progression-free survival (PFS) and overall survival (OS). Median OS was significantly longer in the RRM1-negative group than in the RRM1-positive (9.9 months vs. 5.9 months, p = 0.037). Multivariate adjustment analyses also demonstrated RRM1 expression as an independent prognostic factor for OS in patients treated with GP chemotherapy. Increased intratumoral expression of RRM1 on immunohistochemical staining may be a biomarker predicting poor survival in patients with GP chemotherapy for advanced BTC. Large-scale well-predefined prospective research is needed to validate the utility of biomarkers in clinical practice.

A phase I study of the anaplastic lymphoma kinase inhibitor ceritinib in combination with gemcitabine-based chemotherapy in patients with advanced solid tumors

In this phase I, dose-escalation study, we sought to determine the maximum tolerated dose (MTD) of the anaplastic lymphoma kinase/c-ROS oncogene 1 receptor (ALK/ROS1) inhibitor ceritinib in combination with gemcitabine-based chemotherapy in patients with advanced solid tumors. Secondary objectives were characterization of the safety profile, pharmacokinetics and preliminary efficacy of these combinations, and identification of potential biomarkers of efficacy. Ceritinib was combined with gemcitabine (Arm 1), gemcitabine/nab-paclitaxel (Arm 2) or gemcitabine/cisplatin (Arm 3). Drug concentrations in plasma were measured by tandem mass spectrometric detection (LC-MS/MS). We analyzed archival tumor tissue for ALK, ROS1, hepatocyte growth factor receptor (c-MET) and c-Jun N-terminal kinase (JNK) expression by immunohistochemistry. Arm 2 closed early secondary to toxicity. Twenty-one patients were evaluable for dose-limiting toxicity (DLT). There was one DLT in Arm 1 (grade 3 ALT increase) and three DLTs in Arm 3 (grade 3 acute renal failure, grade 3 thrombocytopenia, grade 3 dyspnea). The MTD of ceritinib was determined to be 600 mg (Arm 1) and 450 mg orally daily (Arm 3). Main toxicities were hematologic, constitutional and gastrointestinal as expected by the chemotherapy backbone. The apparent clearance for ceritinib decreased substantially after repeated dosing; cisplatin did not significantly affect the pharmacokinetics of ceritinib. The overall response rate was 20%; the median progression-free survival was 4.8 months. Three out of five response-evaluable cholangiocarcinoma patients had clinical benefit. Increased expression of c-MET was associated with a lack of clinical benefit. Ceritinib in combination with gemcitabine and gemcitabine/cisplatin has a manageable toxicity profile. Further development of this strategy in tumors with ALK or ROS1 fusions is warranted.

Will advanced cholangiocarcinoma become a targetable malignancy?

Cholangiocarcinoma and biliary tract cancers are rare but aggressive tumors that are characterized by an heterogenous molecular and genetic footprint. Genetic aberrations such as FGFR2 fusion and ErBb2 amplification are common in those cancers. Recent studies aimed at exploring the efficacy and benefit of targeted therapy in the treatment of advanced cholangiocarcinoma. Many promising drugs exist and warrant additional investigations. This review will summarize available results and highlight therapeutic strategies incorporated in clinical trials.

Inhibition of MEIS3 Generates Cetuximab Resistance through c-Met and Akt

INTRODUCTION

Although cetuximab has been widely used in the treatment of colon cancer, a large number of patients eventually develop drug resistance. Therefore, it is essential to clarify the mechanism of drug resistance.

METHODS

In this study, we combined in silico analysis and a single guide RNA (sgRNA) library to locate cetuximab-sensitive genes. Cell proliferation, apoptosis, and cell cycle were assessed to validate the change in cetuximab sensitivity. Finally, western blotting was performed to detect changes in epidermal growth factor (EGFR) upstream and downstream genes.

RESULTS

Using in silico analysis and the sgRNA library, MEIS3 was confirmed as the cetuximab-sensitive gene. Further experiments indicated that the expression of MEIS3 could determine the level of cetuximab. Meanwhile, MEIS3-inhibited cells were sensitive to mesenchymal epithelial transition factor (c-Met) and protein kinase B (Akt) inhibitors, which is related to the change in phosphorylation of c-Met and degradation of Akt.

CONCLUSION

MEIS3 modified the sensitivity to cetuximab through c-Met and Akt.

Novel AMBRA1-ALK fusion identified by next-generation sequencing in advanced gallbladder cancer responds to crizotinib: a case report

Gallbladder cancer (GBC) is the most aggressive malignancy of the biliary tract with poor prognosis. Several targetable genetic alterations have been identified in GBC; however, responses to targeted therapy are disappointing. We report a case of a 58-year-old Chinese woman with GBC who was detected with a novel ALK genomic rearrangement and received crizotinib after progression from first-line chemotherapy. The patient was diagnosed with stage IV adenocarcinoma of the neck of the gallbladder and received oxaliplatin combined with capecitabine as first-line therapy. After four cycles of this chemotherapy regimen, the patient started to show obstructive jaundice, and progressive disease was evaluated. Biliary drainage surgery was performed to alleviate the symptoms of obstructive jaundice. Upon referral to our department, her archived tissue samples were submitted for next-generation sequencing (Burning Rock Biotech) and immunohistochemistry, which identified the presence of a novel AMBRA1-ALK rearrangement and ALK overexpression, respectively. Oral crizotinib was administered achieving partial response within two cycles of treatment, which lasted for 7 months. AMBRA1-ALK has not been previously reported in any solid tumors and its sensitivity to crizotinib is not well characterized. Moreover, ALK alterations have been rarely reported for GBC. This case suggests that a subset of GBC might be driven by aberrant ALK signaling, which could potentially be explored as a biomarker of therapeutic response to ALK inhibitors in GBC. Moreover, our case report contributes an incremental step in understanding the genetic heterogeneity in GBC and provides clinical evidence of the utility of next-generation sequencing in exploring actionable mutations to expand treatment choices in rare solid tumors including GBC.

ErBb Family Proteins in Cholangiocarcinoma and Clinical Implications

The erythroblastic leukemia viral oncogene homolog (ErBb) family consists of the receptor tyrosine kinases (RTK) epidermal growth factor receptor (EGFR; also called ERBB1), ERBB2, ERBB3, and ERBB4. This family is closely associated with the progression of cholangiocarcinoma (CC) through the regulation of cellular networks, which are enhanced during tumorigenesis, metastasis, and chemoresistance. Additionally, the constitutive activation of cellular signaling by the overexpression and somatic mutation-mediated alterations conferred by the ErBb family on cholangiocarcinoma and other cancers enhances tumor aggressiveness and chemoresistance by contributing to the tumor microenvironment. This review summarizes the recent findings on the molecular functions of the ErBb family and their mutations during the progression of cholangiocarcinoma. It also discusses the developments and applications of various devising strategies for targeting the ErBb family through different inhibitors in various stages of clinical trials, which are essential for improving targeted clinical therapies.

Testing for ROS1, ALK, MET, and HER2 rearrangements and amplifications in a large series of biliary tract adenocarcinomas

Biliary tract carcinomas are divided into intrahepatic, perihilar, distal extrahepatic cholangiocarcinomas, and gallbladder adenocarcinomas. Therapies targeting ROS1, ALK, MET, and HER2 alterations are currently evaluated in clinical trials. We assessed ROS1 and ALK translocations/amplifications as well as MET and HER2 amplifications for each tumor subtype by fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC) in 73 intrahepatic, 40 perihilar bile duct, 36 distal extrahepatic cholangiocarcinomas, and 45 gallbladder adenocarcinomas (n = 194). By FISH, we detected targetable alterations in 5.2% of cases (n = 10): HER2 and MET amplifications were found in 4.1% (n = 8) and 1.0% (n = 2), respectively. The HER2-amplified cases were mostly gallbladder adenocarcinomas (n = 5). The MET- and HER2-amplified cases were all positive by IHC. Fourteen cases without MET amplification were positive by IHC, whereas HER2 over-expression was detected by IHC only in HER2-amplified cases. We detected no ALK or ROS1 translocation or amplification. Several alterations were consistent with aneuploidy: 24 cases showed only one copy of ROS1 gene, 4 cases displayed a profile of chromosomal instability, and an over-representation of centromeric alpha-satellite sequences was found in five cases. We confirm a relatively high rate of HER2 amplifications in gallbladder adenocarcinomas and the efficacy of IHC to screen these cases. Our results also suggest the value of IHC to screen MET amplification. Contrary to initial publications, ROS1 rearrangements seem to be very rare in biliary tract adenocarcinomas. We confirm a relatively high frequency of aneuploidy and chromosomal instability and reveal the over-representation of centromeric alpha-satellite sequences in intrahepatic cholangiocarcinomas.

Off-label use of common predictive biomarkers in gastrointestinal malignancies: a critical appraisal

The use of immunohistochemistry (IHC) as a companion diagnostic is an increasingly important part of the case workup by pathologists and is often central to clinical decision making. New predictive molecular markers are constantly sought for to improve treatment stratification parallel to drug development. Unfortunately, official biomarker guidelines lag behind, and pathologists are often left hesitating when medical oncologists request off-labelled biomarker testing. We performed a literature review of five commonly requested off-label IHC predictive biomarkers in gastrointestinal tract (GIT) malignancies: HER2, mismatch repair (MMR), PD-L1, BRAF V600E and ROS1. We found that HER2 amplification is rare and poorly associated to IHC overexpression in extracolonic and extragastric GIT cancers; however in KRAS wild type colorectal cancers, which fail conventional treatment, HER2 IHC may be useful and should be considered. For MMR testing, more evidence is needed to recommend reflex testing in GIT cancers for treatment purposes. MMR testing should not be discouraged in patients considered for second line checkpoint inhibitor therapy. With the exception of gastric tumors, PD-L1 IHC is a weak predictor of checkpoint inhibitor response in the GIT and should be replaced by MMR in this context. BRAF inhibitors showed activity in BRAF V600E mutated cholangiocarcinomas and pancreatic carcinomas in non-first line settings. ROS1 translocation is extremely rare and poorly correlated to ROS1 IHC expression in the GIT; currently there is no role for ROS1 IHC testing in GIT cancers. Overall, the predictive biomarker literature has grown exponentially, and official guidelines need to be updated more regularly to support pathologists’ testing decisions.

Comparative molecular profiling of HPV-induced squamous cell carcinomas

Approximately 5% of all cancer incidences result from human papillomavirus (HPV) infection. HPV infection most commonly leads to cancers of the anogenital region or oropharynx. It is unknown whether different HPV-mediated cancers collectively share a molecular signature and it is important to determine if there are targetable alterations common to different types of HPV-positive tumors. We analyzed 743 p53 wild-type samples of anal, cervical, oropharyngeal, and vulvar squamous cell carcinomas which underwent multiplatform testing at a commercial molecular profiling service. Expression of 24 proteins was measured by immunohistochemistry (IHC), mutation of 48 genes was determined by next-generation and Sanger sequencing, and copy number alteration for six genes was determined by in situ hybridization. The four cohorts had remarkably similar molecular profiles. No gene had a statistically significant difference in mutation frequency or copy number change between the four different types of squamous cell carcinomas. The only significant differences between cohorts were frequency of ERCC1 and SPARC loss as determined by IHC. In all four cancer types, oncogene mutation and PD-L1 expression was relatively infrequent. The most commonly mutated gene was PIK3CA, with mutations most often affecting the helical domain of the protein and accompanied by concurrent lack of PTEN expression. Loss of MGMT and RRM1 was common among the four cohorts and may be predictive of response to cytotoxic therapies not currently being used to treat these cancer types. The similar molecular profiles of the four cohorts indicate that treatment strategies may be similarly efficacious across HPV-positive cancers.