A Retrospective, Observational Analysis of Tumor Infiltrating Lymphocytes and Tumor Regression in Melanoma.

BACKGROUND: Tumor infiltrating lymphocytes (TILs) and regression are thought to be distinct markers of the immune response to melanoma. OBJECTIVE: This study sought to analyze the relationship of TIL grade and presence of regression to each other and to other prognostic histopathologic and clinical values in melanoma. MATERIALS AND METHODS: A retrospective analysis was conducted using patients diagnosed with melanoma between 2013 and 2019 whose complete histopathologic reports were available. RESULTS: Regression was seen in 48.9%, 30.1% and 37.9% of patients with brisk, non-brisk, and absent TILs respectively (P=0.019). Melanoma tumors with brisk TILs were found to have a lower Breslow thickness than those with non-brisk or absent (P= 0.001). Tumors with regression were also found to have lower Breslow thickness (P<0.001). Neither TIL grade nor regression were protective of nodal metastasis or associated with improved survival. CONCLUSION: Brisk TILs have a positive association with thinner tumors and the presence of tumor regression relative to non-brisk or absent TILs. This may suggest a more robust immune response in tumors with brisk TILs. Further exploration of the interplay between TIL grade, lymphocyte cell subtype and lymphocyte density may help explain this finding.

Predicting positive peritoneal cytology in pancreatic cancer.

INTRODUCTION: Positive cytology from peritoneal washings obtained prior to potential resection of pancreatic cancer is associated with grim prognosis, equivalent to M1 disease. We examine our experience with pancreatic cancer patients who underwent pre-resection lavage in an attempt to predict who would have malignant cells on peritoneal cytology. METHODS: We conducted a retrospective review of patients undergoing pancreatectomy for pancreatic adenocarcinoma at a tertiary care institution from 1995 to 2019 and had pre-resection lavage performed. Demographic and clinicopathologic data were collected. Logistic regression models were used to identify predictors of positive cytology. RESULTS: Three hundred ninety-nine patients underwent pancreatic resection and had lavage performed. Forty-three (10.8%) had positive peritoneal cytology. Those with positive cytology had higher median Ca19-9 value than those with negative cytology at diagnosis (368.5 vs 200 U/mL, p = 0.007) and after neoadjuvant therapy (100.3 vs 43 U/mL, p = 0.013). After controlling for preoperative therapy received, an initial Ca19-9 greater than 1220 U/mL (OR 2.72, 95% CI 1.07-6.89, p = 0.035), locally advanced disease (OR 4.86, 95% CI 1.31-18.09, p = 0.018), and BMI ≥ 25 kg/m2 (OR 2.67, 95% CI 1.04-6.97, p = 0.042) were associated with positive cytology in multivariate logistic regression model. The associated ROC curve had an AUC of 0.7507, suggesting adequate discrimination of those with positive peritoneal cytology. CONCLUSION: Diagnostic laparoscopy remains an important adjunct to the workup, diagnosis, and staging of pancreatic adenocarcinoma. Patients with locally advanced disease, significantly elevated serum Ca19-9 at diagnosis, and BMI ≥ 25 kg/m2 may be at higher risk for positive peritoneal cytology, regardless of whether neoadjuvant therapy is administered.

Performance of Surveillance MR Enterography (MRE) in Asymptomatic Children and Adolescents With Crohn's Disease.

BACKGROUND: MR enterography (MRE) is the primary modality for evaluating small bowel disease in pediatric Crohn's patients. Standard clinical practice includes imaging patients at diagnosis and during symptomatic recurrence. The role for MRE in surveillance of asymptomatic Crohn's patients has not yet been established. PURPOSE: To determine whether MRE imaging features are associated with clinical recurrence. STUDY TYPE: Retrospective. POPULATIONS: Pediatric Crohn's patients who underwent MRE while asymptomatic, defined by pediatric gastroenterologists using a physician global assessment; 35 MREs were identified. FIELD STRENGTH/SEQUENCE: 1.5T including T2 -weighted single-shot fast spin echo, balanced steady-state free precession, diffusion-weighted, and contrast-enhanced multiphase T1 -weighted gradient recalled echo sequences. ASSESSMENT: MREs were reviewed by three radiologists independently for mural thickening, T2 -weighted hyperintensity, diffusion restriction, hyperenhancement, vasa recta engorgement, and overall assessment of disease activity. Two pediatric gastroenterologists reviewed patient medical records for 6 months following MRE to evaluate for recurrence, defined as Crohn's-related treatment escalation, surgery, or hospitalization. STATISTICAL TESTS: Fisher's exact test, Wald chi-square test, and model selection by Akaike information criterion minimization were used to assess statistical significance of MRE imaging features. RESULTS: Of 35 MREs identified, seven cases demonstrated clinical recurrence at 6 months (20%); 28 cases remained in remission (80%). Imaging features of active disease were present in 86% of patients with recurrence compared to 29% of patients in remission (P = 0.01). Wall thickening, T2 -weighted hyperintensity, hyperenhancement, and diffusion restriction were significantly associated with recurrence. Multivariate regression analysis determined diffusion restriction to be the best predictor of recurrence within 6 months (P = 0.001, area under the curve 0.786). DATA CONCLUSION: MRE performed on young asymptomatic Crohn's patients can identify patients who have a high probability of developing clinical recurrence in a 6-month period, indicating a potential role for surveillance imaging to assess for subclinical active disease. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage 5 J. Magn. Reson. Imaging 2019;50:1955-1963.