182 Background: Exosomes play pivotal roles in cancer progression, metastasis and chemoresistance. CD63 and CD9 are widely accepted exosomal markers. Their pattern of expression and prognostic significance in patients with RSCC and LSCC is unknown. This study explored CD63 and CD9 expression and prognostic significance in patients with RSCC and LSCC using immunohistochemistry (IHC). Methods: Between 2015 and 2018, 63 patients underwent surgical resection of colon cancer for whom we had available tissues for CD63 and CD9 IHC staining. Two pathologists independently scored the CD63 and CD9 expression in the tumor and adjacent normal mucosa (ANM). Staining intensity was graded 1-3 and staining percentage was estimated in 10% increments. Mean Quick-score (Q-score) (intensity X percentage of staining) was calculated. Results: RSCC and LSCC represented 52% and 48% of the patients respectively. The ANM and Tumor CD63 Q-scores were 225 vs 191 (p = 0.009) in RSCC and 224 vs 154 (p = 0.0001) in LSCC, respectively. The ANM and Tumor CD9 Q-scores were 134 vs 152 (p = 0.142) in RSCC and 135 vs 154 (p = 0.137) in LSCC, respectively. In patients with RSCC and LSCC, the mean Tumor CD63 Q-score was 191 vs 154 (p = 0.024), while the mean ANM CD63 Q-score was 225 vs 224 (p = 0.920). The mean Tumor CD9 Q-score was 152 and 154 (p = 0.883), and the mean ANM CD9 Q-score was 134 vs 135 (p = 0.926). In our cohort, there was no difference in progression free survival (PFS) between patients with RSCC and LSCC (p = 0.2349). In all patients, there was no difference in PFS in patients with CD63 expression < 100 and ≥100 (p = 0.8284). Among patients with RSCC, there was a significantly lower PFS in patients with CD63 expression < 100 vs. ≥100 (p = 0.0259). However, among patients with LSCC, there was no difference in PFS in patients with CD63 expression < 100 vs. ≥100 (p = 0.3494). Conclusions: To our knowledge, this is the first study to show a difference in exosomal marker (CD63) expression pattern and its prognostic significance in patients with RSCC and LSCC. There was a significant positive correlation between progression free survival in patients with RSCC and higher exosomal expression.
e16096 Background: Adenocarcinomas arising from the distal one third of the transverse colon, splenic flexure, descending colon, sigmoid colon and rectum are often grouped together due to their hindgut embryologic origin and referred to as left-sided colorectal cancer (CRC). Rectal cancer represents a subset of CRC that has distinct differences in anatomical location, clinical behavior, prognosis and molecular background. In patients with left sided colon cancer (LSCC), the expression of exosomal marker CD63 was reported to be higher in the adjacent normal mucosa (ANM) compared to the tumor (224 vs 154, p = 0.0001). Here, we explored the pattern of CD63 expression using immunohistochemistry in patients with rectal cancer in comparison with patients with LSCC. Methods: Between 2015 and 2018, 53 patients underwent rectal cancer biopsy/resection and had available tissues for CD63 IHC staining. Two pathologists independently scored CD63 expression in the tumor and ANM. Staining intensity was graded from 1-3. Staining percentage was estimated in 10% increments. Mean quick-score (Q-score) was calculated (intensity x percentage). Paired t test was used for statistical analysis. Results: Median age was 60 (range 34-80). Females represented 26%. Caucasians and African Americans represented 74% and 26%, respectively. In patients with rectal cancer, the mean CD63 expression was higher in ANM compared to their expression in the tumor (147 vs 113, p = 0.0012). Compared to patients with LSCC (N = 30), the mean CD63 expression in patients with rectal cancer was lower in the ANM (224 vs 147, p < 0.0001) and in the tumor (154 vs 113, p = 0.01). Conclusions: In our cohort of patients with rectal cancer, exosomal marker CD63 expression was lower in tumor compared to ANM. This observation was similar to our previously reported findings in patients with LSCC. Compared to patients with LSCC, patients with rectal cancer had lower expression of CD63 in the tumor and ANM. To our knowledge, this is the first study to explore exosomal marker CD63 expression using IHC in patients with rectal cancer.
e15166 Background: In patients with locally advanced rectal adenocarcinoma (LARA), the response to neoadjuvant concurrent chemoradiation (NCCR) correlates with long-term outcomes. Neoadjuvant rectal (NAR) score ([5 ypN - 3 (cT - ypT) + 12]2/9.61) is a novel short-term surrogate endpoint for disease free survival (DFS) and Overall survival (OS). The prognostic significance of magnetic resonance imaging (MRI) findings following NCCR is yet to be explored. Here, we evaluated the agreement between post NCCR MRI yT and yN and pathological ypT and ypN. In addition, we calculated the post NCCR MRI NAR (mNAR) score using the MRI yT and yN ([5 yN - 3 (cT - yT) + 12]2/9.61) and explored its prognostic significance. Methods: Between 2014 and 2018, all patients with LARA were identified. Among those, 43 patients received NCCR, had post NCCR MRI and underwent surgical resection. Weighted Kappa was used to measure the agreement between post NCCR MRI yT and yN and pathological ypT and ypN. Paired t-test was used to compare the means between NAR and mNAR scores. NAR and mNAR scores were classified as low ( < 8), intermediate (8-16) and high ( > 16). DFS and OS were analyzed using Kaplan-Meier curves. Results: In our cohort, the agreement was slight between post NCCR MRI yT and Pathological ypT (p = 0.111), and fair between post NCCR MRI yN and pathological ypN (0.278). The mean NAR score was 16 and the mean mNAR score was 20 (p = 0.0079). Low-intermediate and high NAR scores were seen in 31 (72%) and 12 (28%) patients respectively. However, low-intermediate and high mNAR scores were seen in 20 (47%) and 23 (53%) patients respectively. The median DFS in patients with low-intermediate and high NAR scores was not reached and 30 months (p = 0.00063) respectively. The median OS in patients with low-intermediate and high NAR scores was not reached and 40 months (p = 0.00056) respectively. The median DFS in patients with low-intermediate and high mNAR scores was not reached in both groups (p = 0.058). The median OS in patients with low-intermediate and high mNAR scores was not reached in both groups (p = 0.15). Conclusions: Post NCCR MRI yT and yN had slight and fair agreements with ypT and ypN respectively. In our cohort, there was a difference between NAR and mNAR. NAR demonstrated prognostic significance for DFS and OS, while mNAR did not at the time of analysis.
e15119 Background: Embryologically, the right colon (cecum, ascending colon, hepatic flexure and proximal two-thirds of the transverse colon) is derived from the midgut, whereas the left colon (sigmoid colon, descending colon, splenic flexure and distal third of the transverse colon) is derived from the hindgut. There are clinical, pathological and molecular differences between patients with right-sided colon cancer (RSCC) and left-sided colon cancer (LSCC). Exosomes mediate intercellular communications and interactions and have pivotal roles in cancer behavior. CD63 and CD9 are widely accepted exosomal markers. Here we explored CD63 and CD9 expression using immunohistochemistry (IHC) in patients with RSCC and LSCC. Methods: Between 2015 and 2018, 63 patients underwent colon surgical resection for whom we had available tissues for CD63 and CD9 IHC staining. Two pathologists independently scored CD63 and CD9 expression in the tumor and adjacent normal mucosa (ANM). Staining intensity was graded from 1-3. Staining percentage was estimated in 10% increments. Mean quick-score (Q-score) was calculated (intensity x percentage). Unpaired t test was used for statistical analysis. Results: Median age was 64 (range 33-78). Females represented 60% of our cohort. Caucasians, African Americans and other Ethnicities represented 55%, 40% and 5% respectively. The sidedness was designated as RSCC in 52% and as LSCC in 48%. The ANM and Tumor CD63 Q scores were 225 vs 191 (p = 0.009) in RSCC and 224 vs 154 (p = 0.0001) in LSCC respectively. The ANM and Tumor CD9 Q scores are 134 vs 152 (p = 0.142) in RSCC and 135 vs 154 (p = 0.137) in LSCC respectively. In patients with RSCC and LSCC, the mean Tumor CD63 Q score is 191 vs 154 (p = 0.024), while the mean ANM CD63 Q score is 225 vs 224 (p = 0.920). The mean Tumor CD9 Q score is 152 and 154 (p = 0.883) and the mean ANM CD9 Q score is 134 vs 135 (p = 0.926). Conclusions: In our cohort of patients with RSCC and LSCC, the exosomal marker CD63 expression is lower in the tumor compared to the ANM. While ANM CD63 expression was similar between RSCC and LSCC, tumor CD63 expression was higher in RSCC compared to LSCC. The exosomal marker CD9 was not found to have significant differential expression between ANM and tumor and between RSCC and LSCC. To our knowledge, this is the first study to explore exosomal markers expression using IHC in patients with RSCC and LSCC.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.