Weijing Sun

Programmed Death-Ligand 1 Expression Is Common in Gastric Cancer Associated With Epstein-Barr Virus or Microsatellite Instability.

Blockade of the programmed death 1 (PD-1) pathway has emerged as a novel therapy for cancer. Therefore, development of biomarkers for response prediction, such as PD-ligand 1 (PD-L1) expression by immunohistochemistry, may help to stratify patients. Solid tumors with CD8 T-cell rich tumor microenvironment have been implicated to be associated with increased PD-L1 expression. We hypothesized that gastric cancers associated with Epstein-Barr virus infection (EBV+) or microsatellite instability (MSI), both of which are known to harbor such tumor microenvironment, are associated with increased PD-L1 expression. Forty-four resected gastric cancers including 7 EBV+, 16 MSI, and 21 microsatellite stable cancers without EBV (EBV−/MSS) were studied for PD-L1 expression and T-cell subpopulations by immunohistochemistry. Positive PD-L1 expression (PD-L1+), defined as membranous staining in either tumor cells or tumor immune infiltrates, was seen in 32 (72%) gastric cancers. EBV+ or MSI cancers showed significantly higher rates of PD-L1+ compared with EBV−/MSS cancers (7/7, 100%; 14/16, 87%; 11/21, 52%; P=0.013). PD-L1+/EBV+ and PD-L1+/MSI cancers had significantly more CD8 T cells at tumor invasive front than PD-L1+/EBV−/MSS cancers (P<0.001). PD-L1+ was not associated with the depth of invasion or nodal metastasis (P=0.534, 0.288). Multivariate analysis showed PD-L1+ was not an independent predictor of disease-free survival while MSI was (P=0.548, 0.043). In summary, EBV+ or MSI gastric cancers are more likely to express PD-L1 and have increased CD8 T cells at tumor invasive front than EBV−/MSS cancers. Our results suggest EBV infection and MSI should be investigated for predicting response to PD-1 blockade.

Lapatinib and gemcitabine for metastatic pancreatic cancer. A phase II study.

Purpose: To determine the overall survival for patients with metastatic pancreatic cancer treated with lapatinib and gemcitabine. Materials and Methods: Patients with metastatic pancreatic cancer received lapatinib, 1,500 mg/d, and Gemcitabine, 1 g/m2/wk for 3 weeks followed by 1 week off, until disease progression. This multicenter phase II study was planned to enter 125 patients to evaluate whether the treatment regimen could achieve a 1-year survival of 30% and a median survival of 7 months. An additional subset of 20 patients were to receive 2 months of single agent lapatinib followed by lapatinib and gemcitabine. Results: At a planned 6 month analysis, the Brown University Oncology Group Data Safety Monitoring Board terminated accrual after 29 patients because of futility analysis. The median survival was 4 months (95% confidence interval, 3.0–5.0 months). Three of the 29 (10%) patients had a partial response. The 4 patients who received single agent lapatinib all progressed at 1 month. Conclusion: Lapatinib is not effective in pancreatic cancer. Evaluation of HER2 inhibitors in pancreatic cancer is not warranted.

Colorectal poorly differentiated neuroendocrine carcinomas frequently exhibit BRAF mutations and are associated with poor overall survival.

The molecular alterations in colorectal poorly differentiated neuroendocrine carcinoma remain incompletely characterized, particularly with respect to mutations in BRAF and KRAS. We analyzed 32 colorectal poorly differentiated neuroendocrine carcinomas and 40 colorectal poorly differentiated conventional adenocarcinomas for mutations in KRAS and BRAF and for DNA mismatch repair protein abnormalities to correlate histopathology with molecular alterations and survival. Compared with poorly differentiated conventional adenocarcinoma, poorly differentiated neuroendocrine carcinoma frequently harbored BRAF mutations (59% versus 5%; P < .001) and less frequently demonstrated KRAS codon 12 or 13 mutations (17% versus 43%; P = .03). BRAF mutations were identified in both pure poorly differentiated neuroendocrine carcinoma (60%) and poorly differentiated neuroendocrine carcinoma associated with a signet ring cell adenocarcinoma component (82%). Most (93%) poorly differentiated neuroendocrine carcinomas demonstrated proficient DNA mismatch repair by either microsatellite instability polymerase chain reaction or DNA mismatch repair immunohistochemistry. Patients with poorly differentiated neuroendocrine carcinoma had a significantly worse overall survival compared with patients with poorly differentiated conventional adenocarcinoma (P < .001). There was no significant difference in overall survival between patients with pure poorly differentiated neuroendocrine carcinoma and patients with both poorly differentiated neuroendocrine carcinoma and adenocarcinoma components (P = .5). In conclusion, colorectal poorly differentiated neuroendocrine carcinomas frequently harbor BRAF mutations and are associated with poor overall survival.

Isocitrate dehydrogenase-1 is mutated in inflammatory bowel disease-associated intestinal adenocarcinoma with low-grade tubuloglandular histology but not in sporadic intestinal adenocarcinoma.

The underlying molecular alterations in chronic idiopathic inflammatory bowel disease–associated intestinal adenocarcinoma remain largely unknown. Somatic IDH mutations are often seen in gliomas and myeloid leukemia but have also been recently reported in a subset of other neoplasms. We analyzed a series of intestinal adenocarcinomas with (n=23) and without (n=39) associated chronic idiopathic inflammatory bowel disease treated at our institution for IDH1 and IDH2 mutations and correlated the clinicopathologic findings with mutation status. Compared with intestinal adenocarcinomas not associated with inflammatory bowel disease, adenocarcinomas associated with inflammatory bowel disease more frequently demonstrated IDH mutations (13% vs. 0%, P=0.047). All IDH mutations were identified in IDH1 and resulted in substitution of arginine by cysteine at position 132 (p.R132C, c.394C>T). IDH1 mutations were frequently (66%) associated with concurrent KRAS mutations (p.G12D, c.35G>A). IDH1-mutated intestinal adenocarcinomas were seen in the setting of both Crohn disease and ulcerative colitis and were located in both the ileum and colon. Compared with IDH1-negative inflammatory bowel disease–associated adenocarcinoma, IDH1-positive adenocarcinomas more frequently demonstrated tubuloglandular histology (100% vs. 25%, P=0.032) and were more frequently associated with precursor lesions exhibiting serrated morphology (66% vs. 6%, P=0.034). IDH1 mutations were also identified in the precursor dysplastic lesions associated with IDH1-positive adenocarcinomas. In conclusion, we demonstrate that IDH1 mutations are occasionally identified in inflammatory bowel disease–associated intestinal adenocarcinoma but not in intestinal adenocarcinoma not associated with inflammatory bowel disease. In addition, IDH1-mutated intestinal adenocarcinoma is associated with a characteristic low-grade tubuloglandular histology and often harbors concurrent KRAS mutations. Identification of patients with IDH1-mutated intestinal adenocarcinoma may become clinically important as new therapies emerge that target tumors that harbor IDH mutations.

Smad4 loss in esophageal adenocarcinoma is associated with an increased propensity for disease recurrence and poor survival.

Previously regarded as a rare neoplasm, the incidence of esophageal adenocarcinoma has risen rapidly in recent decades. It is often discovered late in the disease process and has a dismal prognosis. Current prognostic markers including clinical, radiographic, and histopathologic findings have limited utility and do not consider the biology of this deadly disease. Genome-wide analyses have identified SMAD4 inactivation in a subset of tumors. Although Smad4 has been extensively studied in other gastrointestinal malignancies, its role in esophageal adenocarcinoma remains to be defined. Herein, we show, in a large cohort of esophageal adenocarcinomas, Smad4 loss by immunohistochemistry in 21 of 205 (10%) tumors and that Smad4 loss correlated with increased postoperative recurrence (P=0.040). Further, patients whose tumors lacked Smad4 had shorter time to recurrence (TTR) (P=0.007) and poor overall survival (OS) (P=0.011). The median TTR and OS of patients with Smad4-negative tumors was 13 and 16 months, respectively, as compared with 23 and 22 months, respectively, among patients with Smad4-positive tumors. In multivariate analyses, Smad4 loss was a prognostic factor for both TTR and OS, independent of histologic grade, lymphovascular invasion, perineural invasion, tumor stage, and lymph node status. Considering Smad4 loss correlated with postoperative locoregional and/or distant metastases, Smad4 was also assessed in a separate cohort of 5 locoregional recurrences and 43 metastatic esophageal adenocarcinomas. In contrast to primary tumors, a higher prevalence of Smad4 loss was observed in metastatic disease (44% vs. 10%). In summary, loss of Smad4 protein expression is an independent prognostic factor for TTR and OS that correlates with increased propensity for disease recurrence and poor survival in patients with esophageal adenocarcinoma after surgical resection.

Gemcitabine/nab-paclitaxel as second-line therapy following FOLFIRINOX in metastatic/advanced pancreatic cancer—retrospective analysis of response

BACKGROUNDnGiven the tolerability of nPG in first-line therapy, we desired to evaluate the response and toxicity profiles of second-line gemcitabine with nab-paclitaxel (nPG) following FOLFIRINOX. Methods: We retrospectively identified 30 patients who received first-line FOLFIRINOX for unresectable or metastatic pancreatic adenocarcinoma followed by second-line nPG. Response was evaluated by RECIST criteria and carbohydrate antigen 19-9 (CA19-9) change.nnnRESULTSnMedian age was 63 years with 77% percent having metastatic disease. Nineteen patients (63%) achieved PR based on CA19-9. Median overall survival (OS) with nPG was 12.4 months (mo) and median progression-free survival (PFS) was 3.7 mo. Median PFS and OS for patients with at least stable CA19-9 were 4.7 and 13.9 mo since initiation of nPG. Patients with an increased CA19-9 level during nPG had a shorter median PFS (1.4 mo) and OS (5.3 mo). A significant PFS difference was demonstrated in patients with at least stable disease as the best RECIST response versus in those with progressive disease (5.4 vs. 1.9 mo, P<0.001). Grade 3/4 adverse events include thrombocytopenia (33%), anemia (23%), nausea (17%), lymphopenia (7%), infectious complications (6%), diarrhea (3%), and neuropathy (3%).nnnCONCLUSIONSnThis study demonstrates a clinical benefit of second-line nPG. The study also suggests a possible use of CA19-9 to predict response to therapy.

Hepatocellular Carcinoma: Past and Future of Molecular Target Therapy

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer related mortality worldwide. The incidence of HCC has been increasing annually. Viral infection, alcohol usage, and other causes of cirrhosis have been identified as major risk factors for HCC development. The underlying pathogenesis has not been as well defined. There have been multiple hypotheses to the specific mechanisms of hepatocarcinogenesis and they share the common theme of chronic inflammation, increase oxidative stress, and genomic alteration. Therapeutic options of HCC have been primarily local and/or regional including transplantation, resection, and radial frequency ablation, chemoembolization or radio-embolization. For unresectable or metastatic disease, the options are limited. Conventional chemotherapeutic options have been noted to have limited benefit. Sorafenib has been the one and only systemic therapy which has demonstrated modest overall survival benefit. This has led to more extensive research with focus on targeted therapy. Numerous pre-clinical and early phase clinical studies have been noted but failed to show efficacy in later phase clinical trials. In an effort to identify new potential therapeutic options, new understanding of underlying pathways to hepatocarcinogenesis should be one of the main focuses. This leads to development of more molecularly targeted agents to specific pathways, and immunotherapy. This article provides a review of major studies of molecular targeted agents which attempts to target these specific pathways in HCC.

Extreme chromosome 17 copy number instability is a prognostic factor in patients with gastroesophageal adenocarcinoma: A retrospective cohort study

Gastric and esophageal cancers frequently show genomic instability and aneuploidy. Chromosomal copy number instability (CIN) is a form of genomic instability that exerts pleiotropic effects on cellular biology and is a source of genetic heterogeneity in a population of cells. CIN results in cell‐to‐cell variation in chromosome copy number which can be detected and quantified by fluorescence in situ hybridization (FISH). CIN is a biomarker associated with differential response to a number of chemotherapy compounds. We quantified chromosome 17 copy number instability (CIN‐17) in 348 gastroesophageal adenocarcinomas by centromeric FISH in cases that were tested for HER2 amplification. We evaluated the association between CIN‐17 and clinical outcome after surgical and nonsurgical treatment. CIN‐17 was detected in 45.4% (158/348) and extreme CIN‐17 in 28.4% (99/348). Extreme CIN‐17 had no association with outcome in surgically treated patients. However, in patients treated with conventional radiation and/or chemotherapy, extreme CIN‐17 was associated with 55% reduction in overall mortality (hazard ratio, 0.448; 95% confidence interval, 0.263–0.763) after adjusting for age and clinical stage at diagnosis. Extreme CIN‐17 is detected in over a quarter of gastroesophageal adenocarcinomas and is a favorable prognostic marker in patients treated nonoperatively.