Re: ABO blood group and the risk of pancreatic cancer

Blood group determinates incidence for pancreatic cancer in Germany

Background: Genetic risk factors for sporadic pancreatic cancer are largely unknown but actually under high exposure. Findings of correlations between the AB0 blood group system (Chromosome 9q34,1—q34,2) and the risk of pancreatic cancer (PC) in patients from Asia, America and south Europe have already been published. So far it is unclear, whether this correlation between blood group an PC incidence can be found in German patients as well.

Methods: One hundred and sixty-six patients who underwent a resection of PC were evaluated in a period between 2000 and 2010. Blood group reference distribution for the German population is given as: 0: 41%; A: 43%; B: 11%; AB: 5%; Rhesus positive: 85%; Rhesus negative: 15%. Analyses were done using the non-parametric Chi²-test (p-value two sided; SPSS 19.0).

Results: Median age was 62 (34–82) years. Gender: female 73/44%; male: 93/56%. Observed blood group proportions: 0: 43 (25.9%)/A: 94 (56.6%)/B: 16 (9.6%)/AB: 13 (7.8%)/Rhesus positive: 131 (78.9%)/negative: 35 (21.1%). We detected a significant difference to the German reference distribution of the AB0 system (Chi² 19.34, df 3, p < 0.001). Rhesus factor has no impact on AB0-distribution (Chi² 4.13, df 3, p = 0.25), but differs significantly from reference distribution—probably due to initial AB0-variation (Chi² 4.82, df 1, p = 0.028). The odds ratio for blood group A is 2.01 and for blood group 0 is 0.5.

Conclusions: The incidence of PC in the German cohort is highly associated with the AB0-system as well. More patients with blood group A suffer from PC (p < 0.001) whereas blood group 0 was less frequent in patients with PC (p < 0.001). Thus, our findings support the results from other non-German surveys. The causal trigger points of this carcinogenesis correlation are still not known.

A and B blood group antigens in human pancreatic ductal adenocarcinomas

OBJECTIVES

The aim of this study was to determine the clinicopathological significance of blood group expression patterns in patients with surgically resected pancreatic ductal adenocarcinomas.

METHODS

Pancreatic ductal adenocarcinomas from 459 patients were analyzed for immunohistochemical expression of A and B blood group antigens on tissue microarrays. Correlations were established by Fisher's test, χ(2) test, and logistic regression models, and relationships to postsurgical overall survival were analyzed by Kaplan-Meier method, log-rank test, and multivariate Cox models.

RESULTS

Tumors expressing blood group A antigen predicted fewer lymph node metastases (<3) and had longer postoperative survival by univariate and multivariate analysis. Loss of A antigen tumor expression in A blood group type patients correlated to vascular invasion.

CONCLUSION

In patients with resectable pancreatic ductal adenocarcinomas, blood group A antigen expression predicted fewer lymph node metastases and was associated with improved outcome after pancreaticoduodenectomy.

Detection of pancreatic adenocarcinoma using circulating fragments of fibrinogen

BACKGROUND

There is an urgent need for biomarkers to detect pancreatic cancer in the early, potentially curable, stages.

METHODS

We have used SELDI profiling to analyze serum from 75 patients with pancreatic cancer and 61 patients with nonmalignant pancreaticobiliary diseases.

RESULTS

A peak in the SELDI spectra corresponding to a 53 residue fragment of the α-chain of fibrinogen is remarkably elevated in approximately 50% of the cancer patients. In addition, fibrinogen degradation products were measured using the DR-70 assay. The areas under the receiver operating characteristic curves for the SELDI-detected fibrinogen fragment, DR-70 and CA19-9 were 0.65, 0.75 and 0.86, respectively. Class prediction models using combinations of these markers did not increase the area under the receiver operating characteristic curve compared with CA19-9. The novel fibrinogen fragment was not elevated to the same extent in other malignancies but was elevated in some patients with benign pancreatic disease.

CONCLUSION

Both the SELDI-detected fragment of fibrinogen and DR-70 are significantly elevated in the serum of pancreatic cancer patients. However, they do not seem to improve pancreatic cancer detection over CA19-9 alone.

New strategies in pancreatic cancer: emerging epidemiologic and therapeutic concepts

Pancreatic cancer (PC) is a highly lethal disease with complex etiology involving both environmental and genetic factors. Although cigarette smoking is known to explain 25% of cases, data from recent studies suggest that obesity and long-term type II diabetes are two major modifiable risk factors for PC. Furthermore, obesity and diabetes seem to affect the clinical outcome of patients with PC. Understanding the mechanistic effects of obesity and diabetes on the pancreas may identify new strategies for prevention or therapy. Experimental and epidemiologic evidence suggests that the antidiabetic drug metformin has protective antitumor activity in PC. In addition to insulin resistance and inflammation as mechanisms of carcinogenesis, obesity and diabetes are linked to impairments in endothelial function and coagulation status, which increase the risks of thrombosis and angiogenesis and, in turn, the risk of PC development and progression. The associations of the ABO blood group gene and NR5A2 gene variants with PC discovered by recent genome-wide association studies may link insulin resistance, inflammation, and thrombosis to pancreatic carcinogenesis. These exciting findings open new avenues for understanding the etiology of PC and provide opportunities for developing novel strategies for prevention and treatment of this disease.