DRD1 suppresses cell proliferation and reduces EGFR activation and PD-L1 expression in NSCLC.

Dopamine (DA) acts in various key neurological and physiological processes as both a neurotransmitter and circulating hormone. Over the past several decades, the DA signaling network has been shown to regulate the progression of several types of solid tumors, and considerable evidence has shown it is a druggable pathway in the cancer cell context. However, the specific activity and effect of these pathway components appears to be tissue-type and cell-context-dependent. In the present study, expression and methylation of dopamine receptor D1 (DRD1) were measured using RNA sequencing (RNAseq) and reverse transcription polymerase chain reaction (RT-PCR) in non-small cell lung cancer (NSCLC) samples, and validated using publicly available datasets, including The Cancer Genome Atlas (TCGA). In vitro and in vivo functional experiments were performed for cell proliferation and tumor growth, respectively. Mechanistic analyses of the transcriptome and kinome in DRD1-modulated cells informed further experiments, which characterized the effects on the epidermal growth factor receptor (EGFR) pathway and programmed cell death 1 ligand 1 (PD-L1) proteins. Through these experiments, we identified the DRD1 gene as a negative regulator of disease progression in NSCLC. We show that DRD1, as well as other DA pathway components, are expressed in normal human lung tissue, and that loss of DRD1 expression through promoter hypermethylation is a common feature in NSCLC patients and is associated with worse survival. At the cellular level, DRD1 affects proliferation by inhibiting the activation of EGFR and mitogen-activated protein kinase 1/2 (ERK1/2). Interestingly, we also found that DRD1 regulates the expression of PD-L1 in lung cancer cells. Taken together, these results suggest that DRD1 methylation may constitute a biomarker of poor prognosis in NSCLC patients while other components of this pathway could be targeted to improve response to EGFR- and PD-L1-targeted therapies.

Role of ablation therapy in conjunction with surgical resection for neuroendocrine tumors involving the liver.

BACKGROUND: Resection of hepatic metastasis from neuroendocrine tumors (NETs) improves quality of life and prolongs 5-year survival. Ablation can be utilized with surgery to achieve complete resection. Although several studies report long-term outcomes for patients undergoing ablation, none have explored perioperative effects of ablation in patients with metastatic NETs. AIM: To determine if intra-operative ablation during hepatectomy increases risk of adverse outcomes such as surgical site infections (SSIs), bleeding, and bile leak. METHODS: A retrospective analysis of the hepatectomy National Surgical Quality Improvement Program database from 2015-2019 was performed to determine the odds of SSIs, bile leaks, or bleeding in patients undergoing intraoperative ablation when compared to hepatectomy alone. RESULTS: Of the 966 patients included in the study, 298 (30.9%) underwent ablation during hepatectomy. There were 78 (11.7%) patients with SSIs in the hepatectomy alone group and 39 (13.1%) patients with a SSIs in the hepatectomy with ablation group. Bile leak occurred in 41 (6.2%) and 14 (4.8%) patients in the two groups, respectively; bleeding occurred in 117 (17.5%) and 33 (11.1%), respectively. After controlling for confounding variables, ablation did not increase risk of SSI (P = 0.63), bile leak (P = 0.34) or bleeding (P = 0.07) when compared to patients undergoing resection alone on multivariate analysis. CONCLUSION: Intraoperative ablation with hepatic resection for NETs is safe in the perioperative period without significant increased risk of infection, bleeding, or bile leak. Surgeons should utilize this modality when appropriate to achieve optimal disease control and outcomes.

Post-operative morbidity after neoadjuvant chemotherapy and resection for gallbladder cancer: A national surgical quality improvement program analysis.

BACKGROUND: Gallbladder cancer is the most common malignancy of the biliary tract. Neoadjuvant chemotherapy (NACT) has improved overall survival by enabling R0 resection. Currently, there is no consensus of guidelines for neoadjuvant therapy in gallbladder cancer. As investigations continue to analyze the regimen and benefit of NACT for ongoing care of gallbladder cancer patients, we examined American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database to determine if there was higher morbidity among the neoadjuvant group within the 30-day post-operative period. We hypothesized patients who underwent NACT were more likely to have higher post-operative morbidity. AIM: To investigate the 30-day post-operative morbidity outcomes between patients who received NACT and underwent surgery and patients who only had surgery. METHODS: A retrospective analysis of the targeted hepatectomy NSQIP data between 2015 and 2019 was performed to determine if NACT in gallbladder cancer increased the risk for post-operative morbidity (bile leak, infection rate, rate of converting to open surgery, etc.) compared to the group who only had surgery. To calculate the odds ratio for the primary and secondary outcomes, a crude logistic regression was performed. RESULTS: Of the 452 patients, 52 patients received NACT prior to surgery. There were no statistically significant differences in the odds of morbidity between the two groups, including bile leak [odds ratio (OR), 0.69; 95% confidence interval (95%CI): 0.16-2.10; P = 0.55], superficial wound infection (OR, 0.58; 95%CI: 0.03-3.02; P = 0.61), and organ space wound infection (OR, 0.63; 95%CI: 0.18-1.63; P = 0.61). CONCLUSION: There was no significant difference in the risk of 30-day post-operative morbidity between the NACT and surgery group and the surgery only group.

Radiation therapy prior to a pancreaticoduodenectomy for adenocarcinoma is associated with longer operative times and higher blood loss.

BACKGROUND: Pancreatic adenocarcinoma is currently the fourth leading cause of cancer-related deaths in the United States. In patients with "borderline resectable" disease, current National Comprehensive Cancer Center guidelines recommend the use of neoadjuvant chemoradiation prior to a pancreaticoduodenectomy. Although neoadjuvant radiotherapy may improve negative margin resection rate, it is theorized that its administration increases operative times and complexity. AIM: To investigate the association between neoadjuvant radiotherapy and 30-d morbidity and mortality outcomes among patients receiving a pancreaticoduodenectomy for pancreatic adenocarcinoma. METHODS: Patients listed in the 2015-2019 National Surgery Quality Improvement Program data set, who received a pancreaticoduodenectomy for pancreatic adenocarcinoma, were divided into two groups based off neoadjuvant radiotherapy status. Multivariable regression was used to determine if there is a significant correlation between neoadjuvant radiotherapy, perioperative blood transfusion status, total operative time, and other perioperative outcomes. RESULTS: Of the 11458 patients included in the study, 1470 (12.8%) underwent neoadjuvant radiotherapy. Patients who received neoadjuvant radiotherapy were significantly more likely to require a perioperative blood transfusion [adjusted odds ratio (aOR) = 1.58, 95% confidence interval (CI): 1.37-1.82; P < 0.001] and have longer surgeries (insulin receptor-related receptor = 1.14, 95%CI: 1.11-1.16; P < 0.001), while simultaneously having lower rates of organ space infections (aOR = 0.80, 95%CI: 0.66-0.97; P = 0.02) and pancreatic fistula formation (aOR = 0.50, 95%CI: 0.40-0.63; P < 0.001) compared to those who underwent surgery alone. CONCLUSION: Neoadjuvant radiotherapy, while not associated with increased mortality, will impact the complexity of surgical resection in patients with pancreatic adenocarcinoma.

Liver resection for metastatic GIST tumor improves survival in the era of tyrosine kinase inhibitors: a systematic review and meta-analysis.

INTRODUCTION: Survival for gastrointestinal stromal tumor (GIST) has been increasing over the years after the introduction of tyrosine kinase inhibitors. However, the role of metastasectomy for GIST is still controversial. Patients are currently treated with imatinib or sunitinib in case of imatinib failures as optimal medical therapy for metastatic GIST. METHODS: The Pubmed, EMBASE, and Cochrane Library were systematically searched. Overall survival following liver resection ± tyrosine kinase inhibitor treatment for metastatic GIST was compared to treatment with tyrosine kinase inhibitors alone. RESULTS: Eleven studies including both randomized control trials and retrospective cohort studies were included in the final analysis with a total of 988 patients. Seven studies encompassed data on 556 patients with isolated liver metastases (219 surgery ± drug groups and 337 drug-only groups) were included. Overall survival was significantly improved in patients undergoing liver resection ± drug therapy in comparison to drug therapy alone. [HR (95%CI) = 2.10 (1.58, 2.79); p<0.00001]. Subgroup analysis showed that patients also had improved progression free survival based on 4 studies. [HR (95%CI) = 1.92 (1.43, 2.56); p<0.00001]. In case of concurrent liver and peritoneal metastases, patients showed improved overall survival with aggressive surgical approaches based on 10 studies. [HR (95%CI) = 1.90 (1.56, 2.31); p<0.00001]. CONCLUSION: This meta-analysis found that liver resection for patients with metastatic GIST regardless of peritoneal metastases improved progression free and overall survival in conjunction with tyrosine kinase inhibitors as compared with medical therapy alone. Furthermore, liver resections did not have any immediate detrimental impact on survival in the group of patients selected.

Concurrent major hepatic resection with primary colorectal cancer increases risk of organ space infections.

INTRODUCTION: Patients with colorectal cancer frequently present with liver metastases requiring either concurrent colon and liver resection or staged resection for curative therapy. The goal of this study is to determine if synchronous resection increases risk of perioperative adverse outcomes such as surgical site infections (SSIs). METHODS AND PROCEDURES: We conducted a cross-sectional retrospective analysis of the targeted hepatectomy NSQIP database from 2015 to 2019. The primary outcome was surgical site infections stratified into superficial, deep, organ space, and wound dehiscence. We performed univariate followed by a multivariate logistic regression to determine if there were higher odds of SSIs in patients undergoing hepatic resection concurrently with primary colorectal resection. Additionally, we performed stratified analyses by size of hepatic resections (partial, total left, total right, and trisegmentectomy). RESULTS: Of the 7,445 patients included in the study, 431(5.8%) underwent synchronous resection and 7,014 metachronous resection. On average, synchronous resections prolonged surgery by 62 min. There was no difference in superficial and deep SSIs between the groups; however, there was a significant difference in organ space SSIs. Patients undergoing synchronous resection had 1.51 times the odds of developing an organ space SSI (OR 1.51, 95%CI 1.10, 2.17, p = 0.04) compared to patients with metachronous resection on multivariate analysis. Patients undergoing a total right hepatectomy concurrently with a colorectal resection had 2.30 times the odds of developing an organ space SSI (OR 2.30, 95%CI 1.20, 6.86, p = 0.010). CONCLUSIONS: Prior studies demonstrated that synchronous resections are safe in properly selected patients with no difference in long-term outcomes. Few studies have explored immediate perioperative outcomes between the two approaches. After controlling for confounders, we demonstrate that synchronous resection with major hepatic surgery increases the risk of organ space SSIs. Future studies should elucidate the precise source of organ space SSIs in order to decrease the risk of this adverse outcome.

RET T244I Germline Variant Mutation in a Patient with Pancreatic Paraganglioma and Primary Hyperparathyroidism.

Introduction: Paragangliomas are rare neuroendocrine tumors that arise from chromaffin cells. Often termed extra-adrenal pheochromocytomas, these tumors vary with regards to their functionality, location, and malignant potential. Mutations in the RET proto-oncogene are associated with multiple endocrine neoplasia syndrome type 2 (MEN-2) and paragangliomas. The phenotypes of the individual mutations are documented to help determine prognosis. Case Presentation: We report a case of a 64-year-old man with a history of parathyroid adenoma who developed a pancreatic retroperitoneal paraganglioma. Despite having laboratory evidence of excess circulating catecholamines, the patient's only presenting symptom was hip pain. The patient underwent resection, and histologic findings were consistent with paraganglioma with lymph node metastasis. Genetic testing revealed a variant of uncertain significance within the RET gene [c.731C>T (p.T244I)]. Conclusions: Paragangliomas are rare extra-adrenal neuroendocrine tumors that can be associated with germline mutations. Our patient was diagnosed with a pancreatic paraganglioma associated with a RET T244I mutation. Identifying patients with germline mutations is important for documenting phenotypic presentations of RET gene variants of uncertain significance, which will allow physicians to provide proper management and surveillance of paragangliomas and other associated tumors.