State of the art vaccination strategies as primary prevention to reduce incidence of gastrointestinal cancers
Immunizations have influenced the epidemiology of numerous gastrointestinal cancers. Human papillomavirus (HPV) is a common sexually transmitted infection (STI). Although most infections are transient and asymptomatic, persistent infections with oncogenic strains of HPV can progress to cervical, anal, penile, vaginal, vulvar, and oropharyngeal cancers. The introduction of HPV vaccinations has drastically reduced incidences of HPV-vaccine related infections and HPV related cervical cancers. The vaccine has proven to be safe and effective however, HPV vaccination rates have yet to reach target goals in the U.S. and many countries worldwide have not incorporated the vaccine into national immunization programs. The first successful nationwide vaccination program was employed against hepatitis B virus (HBV) in Taiwan in 1984 and demonstrated a statistically significant decrease in the incidence of hepatocellular carcinoma (HCC) in the 6 to 10 years after implementation of universal HBV vaccinations in infants. Twenty-year follow-up studies have continued to demonstrate statistically significant decreased rates of HBV related HCC among vaccinated populations. Despite the successful decrease in incidence of HBV-related HCC, efforts to create an effective prophylactic vaccination against hepatitis C virus (HCV) to prevent chronic HCV infection and its associated morbidity, including HCV-related HCC, have to date been unsuccessful.