(1) Background: Circulating tumor DNA (ctDNA) has emerged as a promising biomarker for many kinds of tumors. However, whether ctDNA could be an accurate diagnostic biomarker in colorectal cancer (CRC) remains to be clarified. The aim of this study was to evaluate the diagnostic accuracy of ctDNA in CRC. (2) Methods: PubMed, Web of Science, and Cochrane databases were searched to identify studies reporting the use of ctDNA to screen and diagnose CRC, and all relevant studies published until October 2022 were enrolled for our analysis. These studies were divided into three primer subgroups: the subgroup of quantitative or qualitative analysis of ctDNA and the subgroup of septin9 (SEPT9) methylation assay. (3) Results: A total of 79 qualified articles with 25,240 subjects were incorporated into our meta-analysis. For quantitative studies, the combined sensitivity (SEN), specificity (SPE), and diagnostic odds ratio (DOR) were 0.723 (95% CI: 0.623–0.803), 0.920 (95% CI: 0.827–0.966), and 23.305 (95% CI: 9.378–57.906), respectively, yielding an AUC of 0.860. The corresponding values for qualitative studies were 0.610 (95% CI: 0.566–0.651), 0.891 (95% CI: 0.878–0.909), 12.569 (95% CI: 9.969–15.848), and 0.823, respectively. Detection of SEPT9 methylation depicted an AUC of 0.879, with an SEN of 0.679 (95% CI: 0.622–0.732), an SPE of 0.903 (95% CI: 0.878–0.923), and a DOR of 20.121 (95% CI:14.404–28.106), respectively. (4) Conclusion: Blood-based ctDNA assay would be a potential novel biomarker for CRC screening and diagnosis. Specifically, quantitative analysis of ctDNA or qualitative analysis of SEPT9 methylation exhibited satisfying diagnostic efficiency. Larger sample studies are needed to further confirm our conclusions and to make the ctDNA approach more sensitive and specific.

(1) Background: The accurate diagnosis of esophageal strictures is quite critical for optimizing medical intervention. However, the diagnosis of suspicious malignant esophageal strictures with intact mucosa appearance and negative biopsy results is challenging. This study aimed to evaluate the role of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in the diagnosis of suspicious esophageal strictures. (2) Methods: We retrospectively analyzed the cases with suspicious malignant esophageal strictures that underwent EUS-FNA, with or without rapid on-site evaluation (ROSE), in our hospital from April 2017 to September 2022. Their clinical manifestations, imaging examinations, gastroscopic examinations, EUS-FNA results, and therapeutic strategies were retrospectively recorded and analyzed. (3) Results: A total of 23 patients (15 male and 8 female) were enrolled in this study. Based on EUS-FNA results, 18 patients were diagnosed with malignancies, including 16 cases of primary esophageal cancer (13 squamous carcinomas and 3 adenocarcinomas), 1 case of mediastinal cancer, and 1 case of metastatic esophageal cancer; 1 case of tuberculosis was also confirmed by EUS-FNA. Among 4 cases of ambiguous diagnosis with EUS-FNA, 1 was diagnosed with an esophageal glomus tumor after surgical removal, and 2 patients survived for several years without medical intervention, which hinted at the possibility of benign esophageal strictures. No major complications, including bleeding or perforation, were observed. (4) Conclusions: EUS-FNA may serve as a safe and effective diagnostic tool in suspicious malignant esophageal strictures with accurate specimen acquisition, especially for biopsy-negative cases.

The incidence of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) has increased dramatically during the last few decades, and the number of rectal neuroendocrine tumors (rNETs) has increased...