In recent years, several studies have presented evidence suggesting a potential role for metformin in anti-cancer therapy. Preclinical studies have demonstrated several anticancer molecular mechanisms of metformin including mTOR inhibition, cytotoxic effects, and immunomodulation. Epidemiologic data have demonstrated decreased cancer incidence and mortality in patients taking metformin. Several clinical trials, focused on evaluation of metformin as an anti-cancer agent are presently underway. Data published from a small number of completed trials has put forth intriguing results. Clinical trials in pre-surgical endometrial cancer patients exhibited a significant decrease in Ki67 with metformin monotherapy. Another interesting observation was made in patients with breast cancer, wherein a trend towards improvement in cancer proliferation markers was noted in patients without insulin resistance. Data on survival outcomes with the use of metformin as an anti-cancer agent is awaited. This manuscript will critically review the role of metformin as a potential cancer treatment.

The fibroblast growth factor/fibroblast growth factor receptor (FGF/FGFR) is a tyrosine kinase signaling pathway that has a fundamental role in many biologic processes including embryonic development, tissue regeneration, and angiogenesis. Increasing evidence indicates that this pathway plays a critical role in oncogenesis via gene amplification, activating mutations, or translocation in tumors of various histologies. With multiplex sequencing technology, the detection of FGFR aberrations has become more common and is tied to cancer cell proliferation, resistance to anticancer therapies, and neoangiogenesis. Inhibition of FGFR signaling appears promising in preclinical studies, suggesting a pathway of clinical interest in the development of targeted therapy. Phase I trials have demonstrated a manageable toxicity profile. Currently, there are multiple FGFR inhibitors under study with many non-selective (multi-kinase) inhibitors demonstrating limited clinical responses. As we progress from the first generation of non-selective drugs to the second generation of selective FGFR inhibitors, it is clear that FGFR aberrations do not behave uniformly across cancer types; thus, a deeper understanding of biomarker strategies is undoubtedly warranted. This review aims to consolidate data from recent clinical trials with a focus on selective FGFR inhibitors. As Phase II clinical trials emerge, concentration on patient selection as it pertains to predicting response to therapy, feasible methods for overcoming toxicity, and the likelihood of combination therapies should be utilized. We will also discuss qualities that may be desirable in future generations of FGFR inhibitors, with the hope that overcoming these current barriers will expedite the availability of this novel class of medications.

DNA repair genes are frequently mutated in cancer, yet limited data exist regarding the overall genomic landscape and functional implications of these alterations in their entirety.  We created comprehensive lists of DNA repair genes and indirect caretakers.  Mutation, copy number variation (CNV), and expression frequencies of these genes were analyzed in COSMIC. Mutation co-occurrence, clinical outcomes, and mutation burden were analyzed in TCGA. We report the 20 genes most frequently with mutations (n > 19,689 tumor samples for each gene), CNVs (n > 1,556), or up- or down-regulated (n = 7,998).  Mutual exclusivity was observed as no genes displayed both high CNV gain and loss or high up- and down-regulation, and CNV gain and loss positively correlated with up- and down-regulation, respectively. Co-occurrence of mutations differed between cancers, and mutations in many DNA repair genes were associated with higher total mutation burden. Mutation and CNV frequencies offer insights into which genes may play tumor suppressive or oncogenic roles, such as NEIL2 and RRM2B, respectively.  Mutual exclusivities within CNV and expression frequencies, and correlations between CNV and expression, support the functionality of these genomic alterations. This study provides comprehensive lists of candidate genes as potential biomarkers for genomic instability, novel therapeutic targets, or predictors of immunotherapy efficacy.

Despite significant advances in standard of care therapies, the 5-year survival rate for metastatic colorectal cancer (CRC) remains around 12%. Immunotherapy has not provided the stellar advances in colorectal cancer that has been seen in other malignancies. Immunotherapy appears to play a pivotal role in microsatellite unstable CRC tumors where the response rates are profound. These results have led to FDA approval of pembrolizumab for MSI-H CRC tumors. Additional research into several new immune agents including IDO inhibitors, vaccine therapy and combinatorial agents are being evaluated for CRC. This review will provide an overview of the approaches currently being investigated.

Fibroblast growth factor receptors (FGFR) are transmembrane kinase proteins with growing importance in cancer biology given the frequency of molecular alterations and vast interface with multiple other signaling pathways. Furthermore, numerous FGFR inhibitors in clinical development demonstrate the expanding therapeutic relevance of this pathway. Indeed, results from early phase clinical trials already indicate that a subset of patients with advanced tumors derive benefit from FGFR targeted therapies. FGFR gene aberrations and FGFR gene rearrangements are relatively rare in solid malignancies. The recently described FGFR3-TACC3 fusion protein has a constitutively active tyrosine kinase domain and promotes aneuploidy. We summarize the prevalence data on FGFR3-TACC3 fusions among different histological tumor types and the preliminary evidence that this rearrangement represents a targetable molecular aberration in some patients with solid tumors.

Biliary tract cancer, or cholangiocarcinoma, arises from the biliary epithelium of the small ducts in the periphery of the liver (intrahepatic) and the main ducts of the hilum (extrahepatic), extending into the gallbladder. The incidence and epidemiology of biliary tract cancer are fluid and complex. It is shown that intrahepatic cholangiocarcinoma is on the rise in the Western world, and gallbladder cancer is on the decline. Radiation therapy has emerged as an important component of adjuvant therapy for resected disease and definitive therapy for locally advanced disease. The emerging sophisticated techniques of imaging tumors and conformal dose delivery are expanding the indications for radiotherapy in the management of bile duct tumors. As we understand more about the molecular pathways driving biliary tract cancers, targeted therapies are at the forefront of new therapeutic combinations. Understanding the gene expression profile and mutational burden in biliary tract cancer allows us to better discern the pathogenesis and identify promising new developmental therapeutic targets.

Background. Pancreatic ductal adenocarcinoma (PDAC) remains resistant to chemotherapy and immunotherapy individually because of its desmoplastic stroma and immunosuppressive tumor microenvironment. Synergizing cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) immune checkpoint blockade with chemotherapy could overcome these barriers. Here we present results of a phase Ib trial combining ipilimumab and gemcitabine in advanced PDAC. Materials and Methods. This was a single-institution study with a 3 + 3 dose-escalation design. The primary objective was to determine the maximum tolerated dose (MTD). Secondary objectives included determining the toxicity profile, objective response rate (ORR), median progression-free survival (PFS), and overall survival (OS).Results. Twenty-one patients were enrolled, 13 during dose escalation and 8 at the MTD. The median age was 66 years, 62% were female, 95% had stage IV disease, and 67% had received at least one prior line of therapy. The primary objective to establish the MTD was achieved at doses of ipilimumab 3 mg/kg and gemcitabine 1,000 mg/m 2 . The most common grade 3 or 4 adverse events were anemia (48%), leukopenia (48%), and neutropenia (43%). The ORR was 14% (3/21), and seven patients had stable disease. Median response duration for the three responders was 11 months, with one response duration of 19.8 months. Median PFS was 2.78 months (95% confidence interval [CI], 1.61-4.83 months), and median OS was 6.90 months (95% CI, 2.63-9.57 months). Conclusion. Gemcitabine and ipilimumab is a safe and tolerable regimen for PDAC with a similar response rate to gemcitabine alone. As in other immunotherapy trials, responses were relatively durable in this study. The Oncologist 2020;25:e808-e815 Implications for Practice: Gemcitabine and ipilimumab is a safe and feasible regimen for treating advanced pancreatic cancer. Although one patient in this study had a relatively durable response of nearly 20 months, adding ipilimumab to gemcitabine does not appear to be more effective than gemcitabine alone in advanced pancreatic cancer.

Genomic analysis of tumor tissue is the standard technique for identifying DNA alterations in malignancies. Genomic analysis of circulating tumor cell-free DNA (cfDNA) represents a relatively non-invasive method of assessing genomic alterations using peripheral blood. We compared the concordance of genomic alterations between cfDNA and tissue biopsies in this retrospective study. Twenty-eight patients with advanced solid tumors with paired next-generation sequencing tissue and cfDNA biopsies were identified. Sixty-five genes were common to both assays. Concordance was defined as the presence or absence of the identical genomic alteration(s) in a single gene on both molecular platforms. Including all aberrations, the average number of alterations per patient for tissue and cfDNA analysis was 4.82 and 2.96, respectively. When eliminating alterations not detectable in the cfDNA assay, mean number of alterations for tissue and cfDNA was 3.21 and 2.96, respectively. Overall, concordance was 91.9–93.9%. However, the concordance rate decreased to 11.8–17.1% when considering only genes with reported genomic alterations in either assay. Over 50% of mutations detected in either technique were not detected using the other biopsy technique, indicating a potential complementary role of each assay. Across 5 genes (TP53, EGFR, KRAS, APC, CDKN2A), sensitivity and specificity were 59.1% and 94.8%, respectively. Potential explanations for the lack of concordance include differences in assay platform, spatial and temporal factors, tumor heterogeneity, interval treatment, subclones, and potential germline DNA contamination. These results highlight the importance of prospective studies to evaluate concordance of genomic findings between distinct platforms that ultimately may inform treatment decisions.