Tumor-Informed Approach Improved ctDNA Detection Rate in Resected Pancreatic Cancer.

Pancreatic cancer is one of the cancers with very poor prognosis; there is an urgent need to identify novel biomarkers to improve its clinical outcomes. Circulating tumor DNA (ctDNA) from liquid biopsy has arisen as a promising biomarker for cancer detection and surveillance. However, it is known that the ctDNA detection rate in resected pancreatic cancer is low compared with other types of cancer. In this study, we collected paired tumor and plasma samples from 145 pancreatic cancer patients. Plasma samples were collected from 71 patients of treatment-naïve status and from 74 patients after neoadjuvant therapy (NAT). Genomic profiling of tumor DNA and plasma samples was conducted using targeted next-generation sequencing (NGS). Somatic mutations were detected in 85% (123/145) of tumors. ctDNA was detected in 39% (28/71) and 31% (23/74) of treatment-naïve and after-NAT groups, respectively, without referring to the information of tumor profiles. With a tumor-informed approach (TIA), ctDNA detection rate improved to 56% (40/71) and 36% (27/74) in treatment-naïve and after-NAT groups, respectively, with the detection rate significantly improved (p = 0.0165) among the treatment-naïve group compared to the after-NAT group. Cases who had detectable plasma ctDNA concordant to the corresponding tumor showed significantly shorter recurrence-free survival (RFS) (p = 0.0010). We demonstrated that TIA improves ctDNA detection rate in pancreatic cancer, and that ctDNA could be a potential prognostic biomarker for recurrence risk prediction.

The feasibility of interval laparoscopic appendectomy and appropriate patient selection: A retrospective study of adult appendiceal masses.

INTRODUCTION: We examined the safety and effectiveness of interval laparoscopic appendectomy (ILA) for adult appendiceal mass (AAM) and then used a novel white blood cell (WBC) parameter to identify the types of AAM cases for which nonsurgical treatment followed by ILA is effective. METHODS: We reviewed the cases of 956 patients who had undergone appendectomy between April 2012 and March 2018 at our facility. Of these patients, 49 had AAM, including 34 who underwent ILA. We examined the safety and effectiveness of ILA by comparing it with laparoscopic appendectomy (LA); specifically, the 34 cases treated with ILA were compared with 477 cases of adult uncomplicated appendicitis treated with LA from the same patient cohort. We then examined the factors associated with not successfully completing the planned nonsurgical treatment and interval before ILA. Patient demographics and clinical variables were reviewed. RESULTS: Patients who had undergone ILA had longer operative times than those who had undergone LA (P = .0059), but they also had shorter postoperative hospital stays (P < .001). There were no significant differences in other perioperative variables. Multivariate analysis showed that a ratio of WBC count on day 3 and day 0 from the start of nonsurgical treatment (WBC day3/day0) of 0.906 or higher was significantly associated with not completing the nonsurgical treatment and interval before ILA (P = .045). CONCLUSION: A comparison of the procedures found that ILA for AAM was almost as safe and effective as LA for adult uncomplicated appendicitis. The WBC day3/day0 ratio can be an objective parameter to assess the effectiveness of the nonsurgical treatment before ILA earlier in the course of treatment.