Summary Background Squamous cell carcinoma of the anal canal (SCCA) is a rare malignancy associated with infection by human papillomavirus (HPV). No consensus treatment approach exists for the ...treatment of metastatic disease. Because intratumoral HPV oncoproteins upregulate immune checkpoint proteins such as PD-1 to evade immune-mediated cytotoxicity, we did a trial of the anti-PD-1 antibody nivolumab for patients with metastatic SCCA. Methods We did this single-arm, multicentre, phase 2 trial at ten academic centres in the USA. We enrolled patients with treatment-refractory metastatic SCCA, who were given nivolumab every 2 weeks (3 mg/kg). The primary endpoint was response according to Response Evaluation Criteria in Solid Tumors, version 1.1, in the intention-to-treat population. At the time of data cutoff, the study was ongoing, with patients continuing to receive treatment. The study is registered with ClinicalTrials.gov , number NCT02314169. Results We screened 39 patients, of whom 37 were enrolled and received at least one dose of nivolumab. Among the 37 patients, nine (24% 95% CI 15–33) had responses. There were two complete responses and seven partial responses. Grade 3 adverse events were anaemia (n=2), fatigue (n=1), rash (n=1), and hypothyroidism (n=1). No serious adverse events were reported. Interpretation To our knowledge, this is the first completed phase 2 trial of immunotherapy for SCCA. Nivolumab is well tolerated and effective as a monotherapy for patients with metastatic SCCA. Immune checkpoint blockade appears to be a promising approach for patients with this orphan disease. Funding National Cancer Institute/Cancer Therapy Evaluation Program, the HPV and Anal Cancer Foundation, the E B Anal Cancer Fund, The University of Texas MD Anderson Moon Shots Program, and an anonymous philanthropic donor.
Summary Phosphatase and tensin homolog (PTEN) is a tumor suppressor in the AKT/mTOR pathway. Animal model studies have shown that loss of PTEN function is involved in the progression of pancreatic ...cancer. However, the prognostic significance of loss of PTEN expression in pancreatic cancer is unclear. PTEN expression was evaluated by immunohistochemistry on tissue microarrays consisting of multiple cores of 133 resected stage II pancreatic ductal adenocarcinomas. A PTEN expression score was calculated as the product of the percentage of positive tumor cells and the intensity of PTEN staining. We categorized PTEN expression for each tumor as retained (PTEN score >5) or lost (PTEN score ≤5). Thirty-four (25.6%) patients had tumors with loss of PTEN expression, and 99 (74.4%) had tumors with retained PTEN expression. Recurrence/Metastasis was observed in 88.2% (30/34) of patients whose tumors showed loss of PTEN compared with 68.7% (68/99) of patients whose tumors showed retained PTEN ( P = .03). Patients whose tumors showed loss of PTEN had a shorter overall survival (median, 19.9 ± 3.6 months) than did patients whose tumors had retained PTEN (32.7 ± 5.0 months, P = .03). In a multivariate analysis, loss of PTEN expression was an independent prognostic factor for poor overall survival in patients with stage II pancreatic ductal adenocarcinoma. No significant correlations between loss of PTEN expression and other clinicopathologic parameters were observed ( P > .05). Assessment of PTEN expression may be used as a prognostic marker for patients with resected pancreatic ductal adenocarcinoma.
Immune checkpoint blockade (ICB) has revolutionized cancer treatment, yet quality of life and continuation of therapy can be constrained by immune-related adverse events (irAEs). Limited ...understanding of irAE mechanisms hampers development of approaches to mitigate their damage. To address this, we examined whether mice gained sensitivity to anti-CTLA-4 (αCTLA-4)-mediated toxicity upon disruption of gut homeostatic immunity. We found αCTLA-4 drove increased inflammation and colonic tissue damage in mice with genetic predisposition to intestinal inflammation, acute gastrointestinal infection, transplantation with a dysbiotic fecal microbiome, or dextran sodium sulfate administration. We identified an immune signature of αCTLA-4-mediated irAEs, including colonic neutrophil accumulation and systemic interleukin-6 (IL-6) release. IL-6 blockade combined with antibiotic treatment reduced intestinal damage and improved αCTLA-4 therapeutic efficacy in inflammation-prone mice. Intestinal immune signatures were validated in biopsies from patients with ICB colitis. Our work provides new preclinical models of αCTLA-4 intestinal irAEs, mechanistic insights into irAE development, and potential approaches to enhance ICB efficacy while mitigating irAEs.
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