Role of neoadjuvant therapy for nonmetastatic pancreatic cancer: Current evidence and future perspectives

Pancreatic adenocarcinoma (PDAC) is one of the most common and lethal human cancers worldwide. Surgery followed by adjuvant chemotherapy offers the best chance of a long-term survival for patients with PDAC, although only approximately 20% of the patients have resectable tumors when diagnosed. Neoadjuvant chemotherapy (NACT) is recommended for borderline resectable pancreatic cancer. Several studies have investigated the role of NACT in treating resectable tumors based on the recent advances in PDAC biology, as NACT provides the potential benefit of selecting patients with favorable tumor biology and controls potential micro-metastases in high-risk patients with resectable PDAC. In such challenging cases, new potential tools, such as ct-DNA and molecular targeted therapy, are emerging as novel therapeutic options that may improve old paradigms. This review aims to summarize the current evidence regarding the role of NACT in treating non-metastatic pancreatic cancer while focusing on future perspectives in light of recent evidence.

Preoperative maximum standardized uptake value and carbohydrate antigen 19-9 were independent predictors of pathological stages and overall survival in Chinese patients with pancreatic duct adenocarcinoma

Background

Purpose of this study was to analyze whether preoperative maximum standardized uptake value (SUVmax) and carbohydrate antigen 19–9 (CA19–9) levels might provide prognostic information in Chinese patients with pancreatic duct adenocarcinoma (PDAC) after pancreaticoduodenectomy (PD).

Methods

Standard PD was performed on 109 patients with PDAC by the same operative team, and all patients received preoperative positron emission tomography/computed tomography examination and blood test.

Results

Patients had a mean age of 59 ± 9.35 years. Females accounted for 38.5%. Mean levels of SUVmax, carcino-embryonic antigen (CEA) and CA19–9 were 5.70 ± 2.76, 3.95 ± 4.16ng/mL and 321.62 ± 780.71kU/L. In univariate Logistic regression analysis, preoperative SUVmax, CEA and CA19–9 levels (p < 0.05 for all) rather than other preoperative variables (p > 0.05 for all) were significantly related to AJCC stages. Multivariate Logistic regression analysis showed that preoperative SUVmax and CA19–9 levels (p < 0.05 for all) rather than other preoperative variables (p > 0.05 for all) were significantly associated with AJCC stages. Mean overall survival (OS) was 21 ± 14.50 months. In univariate Cox regression analysis, age, SUVmax, CEA and CA19–9 levels before operation (p < 0.05 for all) rather than other preoperative variables (p > 0.05 for all) were significantly related to OS. Multivariate Cox regression analysis showed that age, SUVmax and CA19–9 levels before operation (p < 0.05 for all) rather than other preoperative variables (p > 0.05 for all) were significantly associated with OS.

Conclusions

This study demonstrated that preoperative SUVmax and CA19–9 levels independently predicted pathological stages and OS of patients with PDAC after PD. These preoperative variables might have significant prognostic implication in patients with PDAC after PD. Patients with abnormal SUVmax and CA19–9 levels should be paid special attention to in operative strategy and perioperative management.

CRABP-II is a highly sensitive and specific diagnostic molecular marker for pancreatic ductal adenocarcinoma in distinguishing from benign pancreatic conditions

CRABP-II, a retinoic acid binding protein, shuffles retinoic acid from cytoplasm into nucleus and forms a complex with nuclear retinoic acid receptor to facilitate transcriptional activities of retinoic acid. In this study, we studied the expression patterns of CRABP-II in pancreatic ductal adenocarcinoma (PDAC) compared with those in normal pancreas, chronic pancreatitis, and precancerous lesions. We showed no detectable expressions of CRABP-II in normal pancreatic parenchyma, normal ductal epithelium, and chronic pancreatitis. In contrast, the expression of CRABP-II was readily detected in all PDACs including metastatic PDACs. CRABP-II staining was also observed and progressively increased from pancreatic intraepithelial neoplasia 1 to 3. In addition, when fine needle aspiration specimens were evaluated from patients with PDAC, CRABP-II was positive in 55.6% cases if cytology diagnosis was "atypia," and in 87.5% cases, if "malignancy." Our study suggests that CRABP-II is highly and specifically expressed in PDAC and is more commonly expressed in high-grade precursor cancerous lesions than in low-grade lesions. Therefore, overexpression of CRABP-II is a late event of pancreatic carcinogenesis, and it could be used as a diagnostic marker to distinguish PDAC from other benign pancreatic conditions in both resection and cytology specimens.

Relationship between expression of Wilms' tumor gene, insulin-like growth factor Ⅰ receptor and cell apoptosis in human pancreatic duct adenocarcinoma

AIM: To investigate the roles of Wilms' tumor gene (WT1), insulin-like growth factorⅠreceptor expression (IGF-IR) and cell apoptosis as well as their correlations in human pancreatic duct adenocarcinoma.

METHODS: Immunohistochemical analysis was used to detect the expression of WT1 and IGF-IR in human pancreatic duct adenocarcinoma (n = 49) and normal pancreatic tissues (n = 15). The cell apoptosis of pancreatic duct adenocarcinoma was estimated by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) method and apoptosis index (AI) was calculated.

RESULTS: In normal pancreatic tissues, the positive rates of WT1, IGF-IR were 26.67% (4/15), 40.00% (6/15), respectively, and in pancreatic duct adenocarcinoma their positive rates were 71.43% (35/49), 77.55% (38/49), respectively. There were significant differences between cancer and normal tissues (P < 0.05). A positive relationship existed between the expression of WT1 and IGR-IR in pancreatic duct adenocarcinoma (r = 0.385, P < 0.05). The values of AI were 0.41 ± 0.13 and 5.93 ± 4.18 in the normal tissues and adenocarcinoma, respectively, and there was also a significant difference between them (P < 0.05). The value of AI was increased with the rising of tumor differentiation degree in adenocarcinoma, and it was lower in the IGF-IR-positive group than that in the negative group (4.11 ± 3.68 vs 12.21 ± 5.67, P < 0.01).

CONCLUSION: The apoptosis is inhibited in pancreatic duct adenocarcinoma, in which the over-expression of WT1 and IGF-IR may play crucial roles.