No abstract

Ductal carcinoma in situ (DCIS) is a risk factor for the subsequent development of invasive breast cancer. High-risk features include age <45 years, size >5 cm, high-grade, palpable mass, hormone receptor negativity, and HER2 positivity. We have previously shown that immune infiltrates are positively associated with these high-risk features, suggesting that manipulating the immune microenvironment in high-risk DCIS could potentially alter disease progression. Patients with high-risk DCIS were enrolled in this 3 × 3 phase 1 dose-escalation pilot study of 2, 4, and 8 mg intralesional injections of the PD-1 immune checkpoint inhibitor, pembrolizumab. Study participants received two intralesional injections, three weeks apart, prior to surgery. Tissue from pre-treatment biopsies and post-treatment surgical resections was analyzed using multiplex immunofluorescence (mIF) staining for various immune cell populations. The intralesional injections were easily administered and well-tolerated. mIF analyses demonstrated significant increases in total T cell and CD8+ T cell percentages in most patients after receiving pembrolizumab, even at the 2 mg dose. T cell expansion was confined primarily to the stroma rather than within DCIS-containing ducts. Neither cleaved caspase 3 (CC3) staining, a marker for apoptosis, nor DCIS volume (as measured by MRI) changed significantly following treatment. Intralesional injection of pembrolizumab is safe and feasible in patients with DCIS. Nearly all patients experienced robust total and CD8+ T cell responses. However, we did not observe evidence of cell death or tumor volume decrease by MRI, suggesting that additional strategies may be needed to elicit stronger anti-tumor immunity.

502 Background: Cholangiocarcinoma (CCA) is an epithelial malignancy of the intrahepatic or extrahepatic biliary tree, primarily driven by chronic inflammation and fibrosis. Given fibrosis has shown to correlate with malignancy and the aminotransferase-platelet ratio index (APRI) score, a marker for hepatic fibrosis, has shown to be useful in prognosticating hepatocellular carcinoma, this study aimed to assess the utility of APRI score in prognosticating post-surgical outcomes in CCA patients. Methods: 152 CCA patients at the Mayo Clinic that underwent surgical resection were retrospectively analyzed. Statistical analyses were then conducted to determine the relationship between APRI score and demographic factors, laboratory values (CA19-9, albumin, bilirubin, INR, alkaline Phosphatase, ALT, AST, and platelet count), pathology features, and outcome data. Results: When looking at demographic factors, no relationship between APRI score and age (r = -0.19, p = 0.02), sex (2-sample t-test p = 0.16) and race (ANOVA p = 0.81) were identified. There was a negative correlation between APRI score and albumin (m = -0.35, r = -0.35, p < 0.01) and a positive correlation with bilirubin (m = 0.13, r = 0.23, p = 0.01) and ALT (m = 0.01, r = 0.47, p < 0.01). No correlation between the other laboratory values analyzed was identified. Similarly, there was no relationship between APRI score and pathology features (tumor grade t-test p = 0.41, N Stage ANOVA p = 0.94, Vascular Invasion t-test p = 0.59, and Perineural invasion t-test p = 0.14), except for T3 stage which had a higher APRI score compared to T1, T2, and T4 (ANOVA p = 0.01). Likewise, APRI also did not correlate with post-surgical outcomes like recurrence (t-test p = 0.22) and mortality (t-test p = 0.39). Conclusions: In summary, despite being driven by chronic inflammation, APRI score, a marker for hepatic inflammation and a surrogate for liver fibrosis, did not serve as a reliable prognostication tool of post-surgical outcomes in CCA patients. These data suggest that although chronic inflammation is thought to be one of the primary drivers of disease, the role of other factors such as genetic and cellular signaling abnormalities may play a more prominent role in patients with CCA. In conclusion, APRI score did not serve as a useful prognostication tool in surgically resected CCA patients. Future studies should focus on other prognostic factors such as genomic and transcriptomic biomarkers in CCA.

We investigated the clinicopathologic features of 5 follicular lymphomas (FL) that transformed to morphologic diffuse large B-cell lymphomas (DLBCL) and had a primary mediastinal large B-cell lymphoma (PMBL)-like gene expression profile (tFL-PMBLsig-pos). None of the tFL-PMBLsig-pos arose in the mediastinum, all cases tested had a germinal center B-cell phenotype, 20% were CD30+, 60% CD23+, 80% MAL+, 20% CD200+, and 0% CD273/PDL2+. Whole exome sequencing detected alterations in genes associated with both FL/DLBCL (CREBBP, KMT2C, KMT2D, ARID1A, HIST1 members, and TNFRSF14) and PMBL (JAK-STAT pathway genes, B2M, and CD58). Copy number (CN) analysis detected gains/amplification of REL and STAT6 in 60%, gains of SOCS1 in 40%, and gains of chromosome 16, including IL4R, in 40%. CN gains/amplification of BCL6 and MYC and loss of TNFRSF14 and TNFAIP3 were identified in 20%. 3/5 cases lacked a BCL2 rearrangement. Despite having some features that are less common in DLBCL (MAL and CD23 expression, JAK-STAT activation), these tFL-PMBLsig-pos cases lack the most characteristic CN alteration seen in PMBL (9p24.1 gain/amplification). This cohort expands the biologic heterogeneity of tFL, illustrating a subset with gene expression and some genetic features reminiscent of PMBL, with potential treatment implications that include the use of novel targeted therapies.