Background/Aims: Desmoplasia is a prominent feature of pancreatic ductal adenocarcinoma (PDA). Stromal desmoplasia reflects the low cellularity that is characteristic of PDA, and it may play a role in PDA chemoresistance. In this retrospective study, we evaluated the relationship between tumor cellularity in resected PDA specimens and long-term patient outcomes. Methods: We retrospectively reviewed the data from 175 patients who underwent PDA resection between January 2010 and December 2015 at Seoul National University Bundang Hospital, and analyzed their clinicopathological features and the relationship between tumor cellularity (high vs low based on a cutoff of 30% cellularity) and patient outcomes. Results: The high-cellularity group had significantly shorter overall survival (OS) (18.7 months vs 26.6 months, p=0.006) and disease-free survival (11.0 months vs 16.9 months, p=0.031) than the low-cellularity group. Multivariate analysis revealed that high tumor cellularity was an independent risk factor for poor OS (hazard ratio, 2.008; 95% confidence interval, 1.361 to 2.962; p<0.001). Adjuvant therapy improved OS in the low-cellularity group (16.3 months vs 41.3 months, p=0.001) but not in the high-cellularity group (15.9 months vs 24.4 months, p=0.107). Conclusions Tumor cellularity in PDA specimens may be a prognostic and predictive biomarker that could aid in identifying patients who would benefit from adjuvant therapy for PDA.

Background: Human umbilical cord blood-derived MSCs (hUCB-MSCs) have been studied in osteoarthritis (OA) and cartilage regeneration. Our previous study demonstrated that hUCB-MSCs combined with cartilage acellular matrix injection (CAM Inj.) represent potential therapeutic agents for structural improvement and anti-inflammatory effects in a rabbit model of OA. Methods: Based on a previous study, this study has evaluated the safety and efficacy of hUCB-MSCs combined with CAM Inj. in an anterior cruciate ligament transection (ACLT) with medial meniscectomy (MMx) in a goat model. In this study, 27 goats were divided into 5 groups: normal (n = 3), OA (n = 6), OA + CAM Inj. (n = 6), OA + hUCB-MSCs (n = 6), and OA + hUCB-MSCs + CAM Inj. (n = 6). Lameness and radiographic parameters were assessed 6 months after administration, and macroscopic and histological evaluations of the goat articular cartilage were performed 6 months after intervention. Results: The results showed significant improvement in lameness score only in the OA + hUCB-MSCs group at 5 months after treatment (*p < 0.05), whereas the K&L score showed significant improvement only in the OA + hUCB-MSCs + CAM Inj. group 6 months after intervention (*p< 0.05). In addition, the gross findings showed significance in OA + CAM Inj. and OA + hUCB-MSCs + CAM Inj. groups 6 months after treatment (*,p < 0.05 and **p < 0.01). Conclusion In conclusion, treatment with a combination of hUCB-MSCs and CAM Inj. reduced OA symptoms and induced effective cartilage tissue repair in a goat model. We suggest the combination of hUCB-MSCs and CAM Inj. as an alternative therapy for OA.

Background/Aims: There are few reports regarding mixed carcinoma, defined as a mixture of glandular and poorly cohesive components, in patients with gastric cancer (GC). The aim of this study was to evaluate the proportion and characteristics of mixed carcinoma in GC patients. Methods: A total of 7,215 patients diagnosed with GC at Seoul National University Bundang Hospital were enrolled from March 2011 to February 2020. GC was divided into four groups (wellmoderately differentiated GC, poorly differentiated GC, poorly cohesive carcinoma, and mixed carcinoma). The proportion of each GC type and the clinicopathological features were analyzed and divided into early GC and advanced GC. Results: The proportion of mixed carcinoma was 10.9% (n=787). In early GC, submucosal invasion was the most common in poorly differentiated (53.7%), and mixed carcinoma ranked second (41.1%). Mixed carcinoma showed the highest proportion of lymph node metastasis in early GC (23.0%) and advanced GC (78.3%). In advanced GC, the rate of distant metastasis was 3.6% and 3.9% in well-moderately differentiated GC and mixed carcinoma, respectively, lower than that in poorly differentiated GC (6.4%) and poorly cohesive carcinoma (5.7%), without statistical significance. Conclusions Mixed carcinoma was associated with lymph node metastasis compared to other histological GC subtypes. And it showed relatively common submucosal invasion in early GC, but the rates of venous invasion and distant metastasis were lower in advanced GC. Further research is needed to uncover the mechanism underlying these characteristics of mixed carcinoma (Trial registration number: NCT04973631).