Sarcoma in patients with Lynch syndrome and response to immunotherapy.

BACKGROUND: Lynch syndrome (LS) is an autosomal dominant genetic predisposition to multiple malignancies and is characterized by deficient DNA mismatch repair. Increased incidence of sarcomas is not formally ascribed to LS; however, increasing evidence suggests a preponderance of these malignancies in affected families. Sarcomas typically possess a low tumor mutational burden and incite a poor immune infiltrate, thereby rendering them poorly responsive to immunotherapy. METHODS: We searched the University of California, Los Angeles (UCLA) sarcoma program database for patients with a diagnosis of sarcoma and LS from 2016 to 2023. Three such patients were identified and all three were treated with PD1 blockade. RESULTS: We present three cases of LS-associated sarcomas (two soft tissue sarcoma and one osteosarcoma) with increased tumor mutational burdens. These patients were each treated with an anti-PD1 antibody and experienced a response far superior to that reported for non-LS-associated sarcomas. CONCLUSIONS: Increased mutational burden and immune infiltrate are observed for sarcomas associated with LS. Although unselected patients with sarcoma have demonstrated poor response rates to immunotherapy, our findings suggest that patients with Lynch-associated sarcomas are more likely to respond to treatment with anti-PD1. These patients should be given consideration for immunotherapy.

Clonal redemption of B cells in cancer.

Potentially self-reactive B cells constitute a large portion of the peripheral B cell repertoire in both mice and humans. Maintenance of autoreactive B cell populations could conceivably be detrimental to the host but their conservation throughout evolution suggests performance of a critical and beneficial immune function. We discuss herein how the process of clonal redemption may provide insight to preservation of an autoreactive B cell pool in the context of infection and autoimmunity. Clonal redemption refers to additional recombination or hypermutation events decreasing affinity for self-antigen, while increasing affinity for foreign antigens. We then review findings in murine models and human patients to consider whether clonal redemption may be able to provide tumor antigen-specific B cells and how this may or may not predispose patients to autoimmunity.

IGF2BP3 as a Prognostic Biomarker in Well-Differentiated/Dedifferentiated Liposarcoma.

BACKGROUND: Although IGF2BP3 has been implicated in tumorigenesis and poor outcomes in multiple cancers, its role in soft-tissue sarcoma (STS) remains unknown. Preliminary data have suggested an association with IGF2BP3 expression among patients with well-differentiated/dedifferentiated liposarcoma (WD/DD LPS), a disease where molecular risk stratification is lacking. METHODS: We examined the survival associations of IGF2BP3 via univariate and multivariate Cox regression in three unique datasets: (1) the Cancer Genome Atlas (TCGA), (2) an in-house gene microarray, and (3) an in-house tissue microarray (TMA). A fourth dataset, representing an independent in-house TMA, was used for validation. RESULTS: Within the TCGA dataset, IGF2BP3 expression was a poor prognostic factor uniquely in DD LPS (OS 1.6 vs. 5.0 years, p = 0.009). Within the microarray dataset, IGF2BP3 expression in WD/DD LPS was associated with worse survival (OS 7.7 vs. 21.5 years, p = 0.02). IGF2BP3 protein expression also portended worse survival in WD/DD LPS (OS 3.7 vs. 13.8 years, p < 0.001), which was confirmed in our validation cohort (OS 2.7 vs. 14.9 years, p < 0.001). In the multivariate model, IGF2BP3 was an independent risk factor for OS, (HR 2.55, p = 0.034). CONCLUSION: IGF2BP3 is highly expressed in a subset of WD/DD LPS. Across independent datasets, IGF2BP3 is also a biomarker of disease progression and worse survival.

Cancer-Associated B Cells in Sarcoma.

Despite being one of the first types of cancers studied that hinted at a major role of the immune system in pro- and anti-tumor biology, little is known about the immune microenvironment in sarcoma. Few types of sarcoma have shown major responses to immunotherapy, and its rarity and heterogeneity makes it challenging to study. With limited systemic treatment options, further understanding of the underlying mechanisms in sarcoma immunity may prove crucial in advancing sarcoma care. While great strides have been made in the field of immunotherapy over the last few decades, most of these efforts have focused on harnessing the T cell response, with little attention on the role B cells may play in the tumor microenvironment. A growing body of evidence suggests that B cells have both pro- and anti-tumoral effects in a large variety of cancers, and in the age of bioinformatics and multi-omic analysis, the complexity of the humoral response is just being appreciated. This review explores what is currently known about the role of B cells in sarcoma, including understanding the various B cell populations associated with sarcoma, the organization of intra-tumoral B cells in tertiary lymphoid structures, recent trials in immunotherapy in sarcoma, intra-tumoral immunoglobulin, the pro-tumor effects of B cells, and exciting future areas for research.

Lifelong Imaging Surveillance is Indicated for Patients with Primary Retroperitoneal Liposarcoma.

BACKGROUND: Surveillance imaging of patients with retroperitoneal liposarcoma (RP-LPS) after surgical resection is based on a projected risk of locoregional and distant recurrence. The duration of surveillance is not well defined because the natural history of RP-LPS after treatment is poorly understood. This study evaluated the long-term risk of recurrence and disease-specific survival (DSS) for a cohort of patients with at least 10 years of progression-free survival (10yr-PFS) from their primary resection. METHODS: The prospective University of California, Los Angeles (UCLA) Sarcoma Database identified RP-LPS patients with 10yr-PFS after initial resection. The patients in the 10yr-PFS cohort were subsequently evaluated for recurrence and DSS. The time intervals start at date of initial surgical resection. Cox proportional hazards models were used to determine factors associated with recurrence and DSS. RESULTS: From 1972 to 2010, 76 patients with RP-LPS had at least 10 years of follow-up evaluation. Of these 76 patients, 39 (51%) demonstrated 10yr-PFS. The median follow-up period was 15 years (range 10-33 years). Among the 10yr-PFS patients, 49% (19/39) experienced a recurrence at least 10 years after surgery. Of those who experienced recurrence, 42% (8/19) died of disease. Neither long-term recurrence nor DSS were significantly associated with age, sex, tumor size, LPS subtype, surgical margin, or perioperative treatment with radiation or chemotherapy. CONCLUSION: Patients who have primary RP-LPS treated with surgical resection ± multimodality therapy face a long-term risk of recurrence and disease-specific death unacknowledged by current surveillance imaging guidelines. Among the patients with 10yr-PFS, 49% experienced a recurrence, and 42% of those died of disease. These findings suggest a need for lifelong surveillance imaging for patients with RP-LPS.

Conventional open versus hybrid aortic arch repair: a meta-analysis of propensity-matched studies.

BACKGROUND: Comparison of conventional (open) surgical versus hybrid aortic arch repair remains debatable. While the majority of previous comparative studies including meta-analyses contained primarily risk-unadjusted cohorts, those focusing on propensity-matched comparisons were limited by their small sample size. We aimed to compare outcomes of these two approaches through an up-to-date search and meta-analysis of the best evidence currently available in the literature. METHODS: The PubMed/MEDLINE, EMBASE, and Cochrane library from inception to September 2019 were searched to identify articles reporting propensity-score matching data on open versus hybrid aortic arch repair. Patients' baseline characteristics and clinical outcomes were extracted from the articles and pooled for analysis. Heterogeneity and biases were assessed among the included studies. RESULTS: Five studies, including a total of 378 patients (189 pairs), were included in the study. The two groups were similar in patients' baseline characteristics. Stroke rate favoured the open group [2.1% versus 14.3%, OR 0.18 (0.07, 0.46), P=0.0004, I2=0%]. There was no significant difference between the two groups with regard to paraplegia. The hybrid group had numerically higher short-term mortality, but lower rate of acute renal failure requiring dialysis. There was a statistically significant difference between the mid-term survivals of the open and hybrid groups, with lower pooled mortality seen for the open group at 1-year and 2-years (P=0.02). CONCLUSIONS: Open and hybrid repairs do not offer equivalent outcomes. Compared with hybrid aortic arch repair, conventional surgical aortic repair could be associated with favourable outcomes including postoperative stroke. Hybrid repair does not appear to provide better survival. Operative approaches should be carefully selected in treating aortic arch pathology.

Epicutaneous immunization with modified vaccinia Ankara viral vectors generates superior T cell immunity against a respiratory viral challenge.

Modified Vaccinia Ankara (MVA) was recently approved as a smallpox vaccine. Variola is transmitted by respiratory droplets and MVA immunization by skin scarification (s.s.) protected mice far more effectively against lethal respiratory challenge with vaccinia virus (VACV) than any other route of delivery, and at lower doses. Comparisons of s.s. with intradermal, subcutaneous, or intramuscular routes showed that MVAOVA s.s.-generated T cells were both more abundant and transcriptionally unique. MVAOVA s.s. produced greater numbers of lung Ova-specific CD8+ TRM and was superior in protecting mice against lethal VACVOVA respiratory challenge. Nearly as many lung TRM were generated with MVAOVA s.s. immunization compared to intra-tracheal immunization with MVAOVA and both routes vaccination protected mice against lethal pulmonary challenge with VACVOVA. Strikingly, MVAOVA s.s.-generated effector T cells exhibited overlapping gene transcriptional profiles to those generated via intra-tracheal immunization. Overall, our data suggest that heterologous MVA vectors immunized via s.s. are uniquely well-suited as vaccine vectors for respiratory pathogens, which may be relevant to COVID-19. In addition, MVA delivered via s.s. could represent a more effective dose-sparing smallpox vaccine.

A meta-analysis comparing transaxillary and transaortic transcatheter aortic valve replacement.

BACKGROUND: The alternative access route of choice for transcatheter aortic valve replacement (TAVR) remains to be elucidated due to lack of evidences. We performed a meta-analysis comparing the outcomes of two common alternative access routes, transaxillary (TAx) and transaortic (TAo) approaches. METHODS: The PubMed/MEDLINE, Embase, and Cochrane library from inception to December 2018 were searched to identify the articles reporting data on both TAx-TAVR and TAo-TAVR. Patients' baseline characteristics, procedural outcomes, and clinical outcomes were extracted from the articles and pooled for analysis. RESULTS: Four studies, a total of 750 (374 TAo and 376 TAx) patients were included in the study. The two groups were similar in patients' baseline characteristics, although the TAx group comprised few female patients. The two groups differ in outcomes including 30-day mortality, rates of pacemaker implant and acute kidney injury, and length of hospital stay. There were no differences between the two groups with regard to device success, paravalvular leak, stroke, vascular complications, and 1-year mortality. CONCLUSION: Compared with the TAo approach, the TAx approach is associated with favorable short-term mortality, lower incidence of acute kidney injury, and shorter length of hospital stay, but increased pacemaker requirement. TAx could be considered over TAo as the preferred alternative access for TAVR.

IL1α Antagonizes IL1ß and Promotes Adaptive Immune Rejection of Malignant Tumors.

We assessed the contribution of IL1 signaling molecules to malignant tumor growth using IL1ß-/-, IL1α-/-, and IL1R1-/- mice. Tumors grew progressively in IL1R-/- and IL1α-/- mice but were often absent in IL1ß-/- mice. This was observed whether tumors were implanted intradermally or injected intravenously and was true across multiple distinct tumor lineages. Antibodies to IL1ß prevented tumor growth in wild-type (WT) mice but not in IL1R1-/- or IL1α-/- mice. Antibodies to IL1α promoted tumor growth in IL1ß-/- mice and reversed the tumor-suppressive effect of anti-IL1ß in WT mice. Depletion of CD8+ T cells and blockade of lymphocyte mobilization abrogated the IL1ß-/- tumor suppressive effect, as did crossing IL1ß-/- mice to SCID or Rag1-/- mice. Finally, blockade of IL1ß synergized with blockade of PD-1 to inhibit tumor growth in WT mice. These results suggest that IL1ß promotes tumor growth, whereas IL1α inhibits tumor growth by enhancing T-cell-mediated antitumor immunity.

Right Transaxillary Transcatheter Aortic Valve Replacement Using the "Flip-n-Flex" Technique.

BACKGROUND: Right transaxillary transcatheter aortic valve replacement (TAx-TAVR) is rarely performed due to challenging vascular tortuosity and unfavorable implantation angles. We explored this procedure using the newer-generation balloon-expandable SAPIEN 3 (Edwards Lifesciences, Irvine, CA) valve and our novel "flip-n-flex" technique. The safety and effectiveness of the procedure and the learning curve of our early experiences were investigated. METHODS: The first 10 consecutive patients undergoing right TAx-TAVR performed at our center from June 2016 to May 2018 were included in the study. Patients' preoperative characteristics, procedural outcomes, and clinical outcomes were studied. Intraoperative fluoroscopy times were also reviewed to analyze the procedural learning curve. RESULTS: The 10 patients were a mean age of 81.8 ± 8.7 years, and 5 patients (50%) were women. Mean Society of Thoracic Surgeons Predicted Risk of Mortality was 12.0% ± 9.5%. Procedural success was achieved in all cases without vascular complications. Paravalvular leak was absent or mild in all patients. Two patients (20%) required permanent pacemaker implantation. The median postoperative length of stay was 4 days (range, 2-13 days). The 30-day mortality was 0%. Mean transvalvular gradient improved from 38.4 ± 12.6 mm Hg to 9 ± 4.4 mm Hg postoperatively. New York Heart Association Functional Classification improved in all patients. The fluoroscopy time showed marked reduction from 44.1 ± 8.2 minutes to 17.4 ± 2.9 minutes with the use of the flip-n-flex technique. CONCLUSIONS: Our early experience of right TAx-TAVR with the SAPIEN 3 valve demonstrated satisfactory outcomes and a quick learning as facilitated by the flip-n-flex technique. This could be a beneficial TAVR approach to suitable patients.

Survival of tissue-resident memory T cells requires exogenous lipid uptake and metabolism.

Tissue-resident memory T (TRM) cells persist indefinitely in epithelial barrier tissues and protect the host against pathogens. However, the biological pathways that enable the long-term survival of TRM cells are obscure. Here we show that mouse CD8+ TRM cells generated by viral infection of the skin differentially express high levels of several molecules that mediate lipid uptake and intracellular transport, including fatty-acid-binding proteins 4 and 5 (FABP4 and FABP5). We further show that T-cell-specific deficiency of Fabp4 and Fabp5 (Fabp4/Fabp5) impairs exogenous free fatty acid (FFA) uptake by CD8+ TRM cells and greatly reduces their long-term survival in vivo, while having no effect on the survival of central memory T (TCM) cells in lymph nodes. In vitro, CD8+ TRM cells, but not CD8+ TCM cells, demonstrated increased mitochondrial oxidative metabolism in the presence of exogenous FFAs; this increase was not seen in Fabp4/Fabp5 double-knockout CD8+ TRM cells. The persistence of CD8+ TRM cells in the skin was strongly diminished by inhibition of mitochondrial FFA ß-oxidation in vivo. Moreover, skin CD8+ TRM cells that lacked Fabp4/Fabp5 were less effective at protecting mice from cutaneous viral infection, and lung Fabp4/Fabp5 double-knockout CD8+ TRM cells generated by skin vaccinia virus (VACV) infection were less effective at protecting mice from a lethal pulmonary challenge with VACV. Consistent with the mouse data, increased FABP4 and FABP5 expression and enhanced extracellular FFA uptake were also demonstrated in human CD8+ TRM cells in normal and psoriatic skin. These results suggest that FABP4 and FABP5 have a critical role in the maintenance, longevity and function of CD8+ TRM cells, and suggest that CD8+ TRM cells use exogenous FFAs and their oxidative metabolism to persist in tissue and to mediate protective immunity.