Background: Colorectal cancer is the third most deadly cancer among African Americans (AA). When compared to Caucasian Americans (CA), AA present with more advanced disease and lower survival rates. Here, we investigated if differences in tumor immunology could be contributive to disparities observed between these populations. Methods: We examined gene expression of tumor and non-tumor adjacent tissues from AA and CA by whole transcriptome sequencing, and generated scores for immune cell populations by NanoString. In addition, we utilized “The Cancer Genome Atlas” (TCGA) database from AA and CA as a validation cohort. Finally, we measured the secretion of cytokines characteristic of effector T helper cell (T h ) subsets by ELISA using plasma from each AA and CA participant. Results: Colon tumors from AA patients showed significant fold-change increase in gene expression when compared to CA for FOXP3 (6.22 vs. 3.22), IL1B (103 vs. 11.4) and IL8 (220 vs. 28.9) ( p < 0.05). In contrast, among CA we observed statistically higher gene expression of markers associated with antitumor activity such as GZMB (Granzyme B), IFNG and the immunotherapy targets PDL1 ( CD274 ) and CTLA4 ( p < 0.05). TCGA data validated our observed higher gene expression of GZMB and PDL1 in CA patients when compared to AA. Notably, our observations on immune cell populations show that AA tumors have significantly higher number of exhausted CD8+ cells ( p < 0.01), mast cells ( p < 0.02) and increased T regulatory cells when compared to CA. AA colon cancer patients differed from CA in cytokine production patterns in plasma (i.e., reduced IL-12). Conclusions: Our study demonstrates significant differences of the immunological profiles of colon tumors from AA compared to CA that suggest a deficiency of appropriate immune defense mechanisms in terms of gene expression, recruitment of immune cells and systemic secretion of cytokines. As such, these immune differences could be mitigated through population-specific therapeutic approaches.

BackgroundWe speculated that a laparoscopic approach to emergent/urgent partial colectomy for colonic obstruction would be associated with less morbidity and shorter length of stay with similar mortality to open colectomy. We compared the outcomes of laparoscopic and open approaches to emergent/urgent partial colectomy for colonic obstruction from colonic cancer using data from the National Surgical Quality Improvement Program (NSQIP) database for the period of 2012-2017. Methods Multivariate analysis compared NSQIP data points following laparoscopic, laparoscopic converted to open, and open colectomy for emergent/urgent colectomy for colonic obstruction from colon cancer from 2012 to 2017.Results A total of 1293 patients who underwent emergent colectomy for colon obstruction from colon cancer during 2012-2017 were identified within the NSQIP database. Laparoscopic approach was used for colonic obstruction in 19.3% of operations with a conversion rate of 28.5%. A laparoscopic approach to obstructing colonic cancers was associated with lower morbidity (50% vs. 61.8%, AOR: 0.67, P = 0.01) and shorter hospitalization length (10 days vs. 13 days, mean difference: 3 days, P < 0.01) compared with an open approach. However, the mean operation duration was longer in laparoscopic operations than open operations (159 min vs. 137 min, P < 0.01). ConclusionA laparoscopic approach to malignant colonic obstruction is associated with decreased morbidity. This suggests that efforts should be directed towards increasing the utilization of laparoscopic approaches for the surgical treatment of colonic obstruction.

Background We hypothesized that a laparoscopic approach to sigmoidectomy for perforated diverticulitis is associated with less morbidity and mortality. Methods The NSQIP database was used to investigate adult patients who underwent emergent colectomy with end colostomy for perforated diverticulitis. A multivariate analysis using logistic regression was used to compare outcomes of patients by surgical approach. Results We found a total of 2937 adult patients who underwent emergent colectomy for perforated diverticulitis during 2012-2017. The rate of minimally invasive surgery (MIS) was 11.4% with 38.6% conversion rate to open. The 30-day mortality and morbidity rates were 8.8% and 65.8%, respectively. Following adjustment using a multivariate analysis, the open approach was associated with higher morbidity (67.2% vs 56.8%, AOR: 1.70, P < .01) and mean hospitalization length of patients (13 days vs 10 days, P < .01) compared to the MIS approach. Respiratory complications of ventilator dependency (14.3% vs 6%, AOR: 2.95, P < .01) and unplanned intubation (7.4% vs 2.4%, AOR: 2.14, P = .03) were significantly higher in the open approach. However, patients who underwent the open approach were older (age >70; 33.5% vs 24%, P < .01) with more comorbid conditions such as COPD (10.8% vs 7.2%, P = .04) and CHF (9% vs 3.1%, P < .0). Conclusion The MIS approach to emergent partial colectomy for perforated diverticulitis is associated with decreased morbidity and hospitalization length of patients. Utilization of the MIS approach for partial colectomy for perforated diverticulitis is 11.4% with a conversion rate of 38.6%. Efforts should be directed toward increasing the utilization of laparoscopic approaches for the surgical treatment of perforated diverticulitis.