PARA (Pancreatic Adenocarcinoma Etiology: Role of Asbestos) Study of Risk Factors for Exocrine Pancreatic Neoplasms.

Pancreatic adenocarcinoma (PDAC) ranks fourth among the causes of cancer death in Western countries, with an incidence almost comparable to mortality. The only therapeutic option with curative intent is surgery, but about 80% of subjects diagnosed with this neoplasm are not candidates for surgery due to the presence of distant metastases (stage IV according to the TNM system) or in the case of locally advanced disease (stage III), with an overall survival at 5 years of less than 10%.

Numerous risk factors have been related to the genesis of PDAC both environmental and genetic.

Environmental factors include cigarette smoking, dietary habits such as high intake of animal proteins and fats, high salt consumption, dehydrated foods, smoked meat, fried foods and smoked sugar, obesity, consumption of high amounts of alcohol, occupational exposure to chlorinated hydrocarbons, chronic pancreatitis and type II diabetes mellitus.

However, most of them are non-specific and there is often no concordance between the different studies conducted to evaluate them.

The role of asbestos exposure as an environmental risk factor in the etiopathogenesis of pancreatic cancer has been poorly investigated to date and with discordant results.

However, as previously demonstrated, asbestos, once inhaled, can enter the lymphatic circulation and therefore the bloodstream by accumulating in the tissues. In particular, a deposit of asbestos fibers in the liver has been demonstrated with the possibility of triggering chronic inflammatory mechanisms underlying the carcinogenic process. Similarly to what has already been demonstrated on the association between occupational exposure to asbestos and the risk of intrahepatic cholangiocarcinoma, this observational study aims to evaluate a possible correlation between this environmental risk factor and pancreatic cancer.

Materials and methods A prospective non-pharmacological single-center observational study will be carried out.

A total of 500 subjects will be involved between Group A and Group B, distributed as follows:

• 100 subjects of Group A will be patients seen on an outpatient basis and suffering from pancreatic adenocarcinoma with histological confirmation, contacted both during hospitalization and during outpatient or day service access;
• 400 subjects of Group B will be patients already included as controls in the CARA study (Cholangiocarcinoma Aetiology: Role of Asbestos - code 111/2013/UOSS evaluated in the meeting of the Ethics Committee of 19/11/2013) admitted to the Polyclinic in the ophthalmology, urology and gynecology departments not affected by the pathology under study, nor by pathologies associated with exposure to asbestos.

Upon obtaining informed consent, all subjects in Group A will be administered a standardized questionnaire (once per patient), containing questions from the ReNaM questionnaire (National Mesothelioma Registry), the work history of the subjects and some questions related to known risk factors.

Descriptive population statistics will be presented, stratifying according to case or control status. To estimate the strength of the association between asbestos exposure and pancreatic cancer risk, uni- and multivariate logistic models will be conducted.

On 30 cases subjected to the ReNaM questionnaire, the presence of asbestos fibers directly on histological sections of pancreatic cancer, obtained following surgical resection for curative therapeutic purposes according to the standard of care, will be evaluated.

Samples will be evaluated using light microscopy and scanning electron microscopy with attached chemical microprobe to highlight the presence of fibers within the tumor tissue.