ALK-positive histiocytosis: Report of a rare case with exclusive involvement of the central nervous system in an adult woman.

ALK-positive histiocytosis is a rare histiocytic disease characterized by ALK positivity. It was first described in 2008 as a systemic disease in infants. The disease often shows positivity for CD68 and CD163 on immunohistochemistry, and genomic analysis frequently reveals KIF5B::ALK fusions. ALK-positive histiocytosis typically follows an indolent course and has a promising prognosis, with conventional treatments usually being effective. Here, we report a rare case of ALK-positive histiocytosis with exclusive involvement of the central nervous system in a 33-year-old Asian adult woman. Although cranial MRI suggested a meningioma, immunohistochemical workup showed that the ALK-positive tumor cells expressed macrophage/histiocyte markers such as CD163 and CD68. Additionally, second-generation sequencing revealed a KIF5B::ALK fusion. Our case highlights the importance of the differential diagnosis in adult central nervous system tumors, emphasizing the combination of morphology, immunophenotype, and molecular approach with ALK status evaluation to confirm a diagnosis of ALK-positive histiocytosis. This case also expands the clinicopathologic spectrum of ALK-positive histiocytosis.

Circulating tumor cells with increasing aneuploidy predict inferior prognosis and therapeutic resistance in small cell lung cancer.

AIMS: Treatment resistance commonly emerges in small cell lung cancer (SCLC), necessitating the development of novel and effective biomarkers to dynamically assess therapeutic efficacy. This study aims to evaluate the clinical utility of aneuploid circulating tumor cells (CTCs) for risk stratification and treatment response monitoring. METHODS: A total of 126 SCLC patients (two cohorts) from two independent cancer centers were recruited as the study subjects. Blood samples were collected from these patients and aneuploid CTCs were detected. Aneuploid CTC count (ACC) and aneuploid CTC score (ACS), were used to predict progression-free survival (PFS) and overall survival (OS). The performance of the ACC and the ACS was evaluated by calculating the area under the receiver operating characteristic (ROC) curve (AUC). RESULTS: Compared to ACC, ACS exhibited superior predictive power for PFS and OS in these 126 patients. Moreover, both univariate and multivariate analyses revealed that ACS was an independent prognostic factor. Dynamic ACS changes reflected treatment response, which is more precise than ACC changes. ACS can be used to assess chemotherapy resistance and is more sensitive than radiological examination (with a median lead time of 2.8 months; P < 0.001). When patients had high ACS levels (> 1.115) at baseline, the combination of immunotherapy and chemotherapy resulted in longer PFS (median PFS, 7.7 months; P = 0.007) and OS (median OS, 16.3 months; P = 0.033) than chemotherapy alone (median PFS, 4.9 months; median OS, 13.6 months). CONCLUSIONS: ACS could be used as a biomarker for risk stratification, treatment response monitoring, and individualized therapeutic intervention in SCLC patients.

Combining TIGIT blockade with IL-15 stimulation is a promising immunotherapy strategy for lung adenocarcinoma.

BACKGROUND: T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) is an immune checkpoint molecule that suppresses CD8+ T-cell function in cancer. However, the expression profile and functional significance of TIGIT in the immune microenvironment of lung adenocarcinoma (LUAD) remain elusive. Interleukin (IL)-15 has emerged as a promising candidate for enhancing CD8+ T-cell mediated tumour eradication. Exploring therapeutic strategies that combine IL-15 with TIGIT blockade in LUAD is warranted. METHODS: We investigated the regulatory network involving coinhibitory TIGIT and CD96, as well as costimulatory CD226 in LUAD using clinical samples. The potential role of TIGIT in regulating the pathogenesis of LUAD was addressed through a murine model with transplanted tumours constructed in Tigit-/- mice. The therapeutic strategy that combines TIGIT blockade with IL-15 stimulation was verified using a transplanted tumour murine model and a patient-derived organoid (PDO) model. RESULTS: The frequency of TIGIT+ CD8+ T cells was significantly increased in LUAD. Increased TIGIT expression indicated poorer prognosis in LUAD patients. Furthermore, the effector function of TIGIT+ CD8+ tumour-infiltrating lymphocytes (TILs) was impaired in LUAD patients and TIGIT inhibited antitumour immune response of CD8+ TILs in tumour-bearing mice. Mechanistically, IL-15 enhanced the effector function of CD8+ TILs but stimulated the expression of TIGIT on CD8+ TILs concomitantly. The application of IL-15 combined with TIGIT blockade showed additive effects in enhancing the cytotoxicity of CD8+ TILs and thus further increased the antitumour immune response in LUAD. CONCLUSIONS: Our findings identified TIGIT as a promising therapeutic target for LUAD. LUAD could benefit more from the combined therapy of IL-15 stimulation and TIGIT blockade.

New insights into the correlations between circulating tumor cells and target organ metastasis.

Organ-specific metastasis is the primary cause of cancer patient death. The distant metastasis of tumor cells to specific organs depends on both the intrinsic characteristics of the tumor cells and extrinsic factors in their microenvironment. During an intermediate stage of metastasis, circulating tumor cells (CTCs) are released into the bloodstream from primary and metastatic tumors. CTCs harboring aggressive or metastatic features can extravasate to remote sites for continuous colonizing growth, leading to further lesions. In the past decade, numerous studies demonstrated that CTCs exhibited huge clinical value including predicting distant metastasis, assessing prognosis and monitoring treatment response et al. Furthermore, increasingly numerous experiments are dedicated to identifying the key molecules on or inside CTCs and exploring how they mediate CTC-related organ-specific metastasis. Based on the above molecules, more and more inhibitors are being developed to target CTCs and being utilized to completely clean CTCs, which should provide promising prospects to administer advanced tumor. Recently, the application of various nanomaterials and microfluidic technologies in CTCs enrichment technology has assisted to improve our deep insights into the phenotypic characteristics and biological functions of CTCs as a potential therapy target, which may pave the way for us to make practical clinical strategies. In the present review, we mainly focus on the role of CTCs being involved in targeted organ metastasis, especially the latest molecular mechanism research and clinical intervention strategies related to CTCs.

Low platelet count is a risk factor of postoperative pneumonia in patients with type A acute aortic dissection.

BACKGROUND: Previous studies have already established that low platelet count is related to adverse outcomes in patients with type A acute aortic dissection (AAAD). However, there are yet limited studies investigating the association of platelet count and the risk of postoperative pneumonia in AAAD patients. METHODS: This retrospective cohort study was conducted in Xiangya Hospital of Central South University from January 2014 to May 2019. Clinical and laboratory data were collected. The correlation between platelet count and postoperative pneumonia was analyzed using multivariate logistic regression and the area under the receiver operating characteristic curve (AUC) was used to assess the predictive power of platelet count on pneumonia. RESULTS: A total of 268 patients with AAAD were enrolled. The overall incidence of pneumonia was 36.94% (n=99). Multivariate logistic regression revealed that platelet count was negatively associated with the risk of postoperative pneumonia (OR 0.93; 95% CI: 0.88-0.98) after adjusting for the confounders. Compared to the lowest platelet count tertile (T1), medium platelet count (T2) and highest platelet count (T3) had a lower risk of postoperative pneumonia after adjusting for the confounders (OR 0.80, 95% CI: 0.40-1.60; OR 0.30, 95% CI: 0.13-0.66; respectively). A similar trend was observed when the platelet count was handled as categorical variables (tertiles). The area under the ROC curve was 0.635 (95% CI: 0.565-0.707), with a sensitivity of 76.77%, a specificity of 50.89% and an accuracy of 60.45%. CONCLUSIONS: Our findings indicate that low platelet count is an independent risk factor of postoperative pneumonia in patients with AAAD and has a specific predictive power on the risk of postoperative pneumonia.