If everyone stopped smoking today, feeding on junk food - pre-cooked, pastries, frozen pizzas - drinking sugary drinks, abusing alcohol, spending days on the couch and exposing themselves to the sun without protection, It would avoid 40% of future malignant tumors. These factors are the main enemies of public health, but there are also other invisible adversaries. Virus and bacterial infections cause 8% of cancer deaths in Spain, a team led by doctor Josep Maria Ramón, of the Bellvitge Biomedical Research Institute, has just calculated. Tobacco alone causes 22% of cancer deaths, according to the World Health Organization.
More than 110,000 people died from a malignant tumor in Spain in 2017. Ramón's group estimates that 9,115 of these deaths, about 8%, are attributable to cancers caused by infectious agents. Four microorganisms would be responsible for almost all of these deaths: the Helicobacter pylori bacteria (48%), the hepatitis C virus (31%), the human papillomavirus (15%) and the hepatitis B virus (4% ).
"Tobacco alone accounts for more than 28% of deaths from stomach and liver cancer," warns physician Joan B. Soriano
"It is the first study conducted in Spain that attempts to quantify and explain mortality from cancers whose origin is infectious factors," says Ramón. More than half of Spaniards live with the bacterium Helicobacter pylori , a microbe that occasionally causes stomach infections and increases the risk of gastric cancer. The scientific community suspects that it is transmitted by contaminated food and water, but there are no certainties.
The hepatitis C virus is transmitted through the blood and is a major cause of liver cancer. Already controlled transfusions of infected blood, the main routes of transmission are shared syringes and some risky sexual practices. The hepatitis B virus is also transmitted by contact with the blood or semen of an infected person.
“A flagrant example where we would avoid 100% of deaths is papillomavirus infection,” says Ramón. Some types of this virus - sexually transmitted - are considered high risk because of their role in the appearance of cervical tumors, although most infections do not cause cancer. "We are giving girls an effective vaccine against this virus and in the coming years we will see a significant decrease," says the doctor.
"Tumors associated with infections, in general, have a better prognosis," reassures the oncologist Juan de la Haba
"Infectious causes exist and are preventable, but they are a relatively minor cause of cancer and, therefore, of death from cancer," says doctor Joan B. Soriano, a professor at the Autonomous University of Madrid. "Without a doubt, the most important risk factor for cancer death, in Spain and in the world, is still tobacco," he warns.
Soriano is the coordinator in Spain of the Study of the Global Burden of Diseases, a world radiography directed by the University of Washington. “Tobacco alone accounts for more than 28% of deaths from stomach and liver cancer. This is 3.5 times more than 8% of this study, ”says the professor. "And in women, tobacco accounts for 21% of deaths from cervical cancer," he says.
The new research, published in the journal Clinical Medicine , analyzes mortality, not incidence. Josep Maria Ramón believes that infection-related tumors could be between 12% and 16% of all cancer cases, whether or not they end in death. “The figure is similar to that observed in countries of our level when studying mortality,” says Ramón.
The oncologist Juan de la Haba these figures add up to his experience at the Reina Sofía University Hospital in Córdoba. "Tumors associated with infections, in general, have a better prognosis," he reassures. “This study adds value by showing the importance of hygienic, dietary and sexual habits to avoid contagion. Not only to avoid tobacco, alcohol and obesity. We must also draw attention to the infectious causes of cancer, ”adds De la Haba, a member of the board of directors of the Spanish Society of Medical Oncology. "It's another way to prevent cancer."
You can follow Materia on Facebook, Twitter, Instagram or subscribe here to our newsletter