Department of Gastroenterology;
National Cancer Institute;
Bari;
Italy;
Department of Surgical and Morphological Sciences;
Division of Pathology;
University of Genova;
Genova;
Italy;
Department of Gastroenterology;
General Hospital;
Sanremo;
Italy;
Department of Pathology;
General Hospital;
Sanremo;
Italy;
Division of Enviromental Epidemiology and Biostatistics;
National Cancer Research Institute;
Genova;
Italy;