The BBVA Foundation has granted Colombian epidemiologist Nubia Muñoz its Frontiers of Knowledge award in Development Cooperation, for her work in establishing that infection with human papillomavirus (HPV) is the principal cause of cervical cancer, one of the leading causes of death among women in developing countries. Muñoz has also been instrumental in the development of the first effective vaccine against this virus, capable of preventing 70% of all cervical cancers.
The Award jury noted that Dr. Muñoz “is an example of a woman researcher working on diseases that affect women, particularly in the developing world.” The citation added, “This was the first vaccine specifically targeting the prevention of cancer.”
Personal reasons for devoting her life to medicine
Dr. Muñoz, who has spent her entire professional life at the International Agency for Research on Cancer (IARC), at the age of six experienced first-hand the devastating impact of infectious diseases when her father, a farm worker in Cali, died of diphtheria, leaving her mother alone to raise five children.
Despite growing up in modest surroundings, Dr. Muñoz was an exceptional student. Not only did she win entry to the School of Medicine at the University of Cali, but by consistently achieving the top marks in her class, she was able to complete most of her degree on scholarship.Her father’s death was particularly painful, since it could have been prevented had he received the right treatment with penicillin, which at the time was hard to obtain in Colombia. It was this early loss that inspired her to devote her life to medicine.
After graduating, she began working with her mentor, Pelayo Correa, head of the pathology department at the university, who advised her to move into cancer epidemiology if what she wanted was, as she said, “to achieve the greatest benefit for society.”
Muñoz would subsequently obtain an IARC grant to study public health at Johns Hopkins University in the United States. In 1970, she was hired to work at the IARC headquarters in Lyon. Her first projects there involved research into infectious agents suspected of being linked to certain types of cancer; among them the herpes simplex 2 virus, then under investigation as a possible cause of cervical cancer. This hypothesis, proposed by German scientist Harald zur Hausen, turned out to be mistaken. But not long after, zur Hausen himself proposed another possible cause: human papillomavirus. This time his intuition was correct, and his discovery, made at the start of the 1980s, won him the Nobel Prize for Medicine in 2008.
In the mid-1980s, as head of her own team at IARC, Muñoz launched a major international effort to confirm the link between papillomavirus and cancer of the cervix. Thanks to her collaboration with Xavier Bosch of the Catalan Institute of Oncology, she was able to confirm the presence of papillomavirus in patients in Colombia and Spain. The search was extended in the 1990s to another thirty countries, with the same result.
As Muñoz herself explains, “Harald zur Hausen’s group molecularly identified the first types of human papillomavirus and developed laboratory tests to detect patients’ exposure. I continued the studies, which concluded that the virus was the main cause of cervical cancer. There are around 100 types of human papillomavirus, and just over twenty are linked to the disease. Knowing this was vital so that pharmaceutical companies could start working on a vaccine.”“Nubia Muñoz’s work,” said Bosch yesterday after hearing of the award, “provided the breakthrough information enabling the development of a universal vaccine against cervical cancer.”These studies not only proved that HPV infection is the principal and necessary cause of cervical cancer. They were also able to show that in all countries, it was the same HPV strains that were doing the damage: genotypes 16 and 18.
A vital vaccine for developing countries
The HPV vaccine has been available since 2006. And it is commonly estimated that it can now prevent up to 90% of the cases of cervical cancer, as well as other cancers where HPV is implicated. These include 80% of cases of anal cancer, 60% of vaginal cancer, 40% of vulvar cancer and also some cases of mouth and throat cancer.
The vaccine is considered of paramount importance in developing countries, where few women have access to techniques to detect pre-cancerous lesions through regular smear tests – meaning the disease only shows up in its later stages. Over 80% of cervical cancer cases occur in developing countries. And the disease is among the three top causes of cancer deaths among women living there.
Muñoz is at pains to stress the vaccine’s safety and effectiveness: “We know that the biggest causes of cancer are smoking and infectious agents. Among this last group are papilloma, Helicobacter pylori and hepatitis B and C. We have had hepatitis vaccines for over thirty years and now have a comparable weapon against papilloma. We know how to prevent 40% of cancer cases, and the tragedy is that we are not using that knowledge.”
The vaccine, she adds, is fully available in 84 countries, most of them in the developed world. So “the important thing now is to continue rolling it out in the developing countries, where it is most needed.”
A major step to achieving this would be if the studies now under way confirm that just one dose will suffice, instead of the current three: “That would mean the price could come down, which is an obstacle to the vaccine’s implementation, and one of the reasons why few African countries have taken it up.”
Talking about her devotion to science, the laureate explains “for me, it has never been a burden, but always a pleasure, because I am doing what I love. I went into research in order to help people.”