revolución científica global: inyección que previene cáncer

Editor’s Note: In 2006, the first vaccine against the human papillomavirus (HPV) – the Gardasil 4 vaccine – was approved by the FDA in the United States, officially marking the beginning of the prevention and control of HPV-related cancers, such as cervical cancer. Today, coinciding with the 20th anniversary of this landmark event, our country has also included the bivalent HPV vaccine in its immunization program two months ago. The significance of the HPV vaccine is not limited to preventing a single disease; it represents the first time in human history that a vaccine has been used to prevent a type of cancer, and it is clear evidence of how basic research can translate directly into public health outcomes that save lives.

Written by | Guo Bei Yi, Guo Xiao Qiang

The uterus is the "cradle" where lives are nurtured, and the cervix is the "important gateway" of that cradle. Unfortunately, this crucial part is also a high-incidence area for tumors. Cervical cancer is one of the most common gynecological malignant tumors among women and poses a serious risk: in 2022, approximately 661,000 new cases of cervical cancer were diagnosed worldwide, of which 348,000 resulted in fatalities. In our country, 151,000 new cases were registered in 2022, with an incidence rate of 13.8 per 100,000 women, ranking fifth among cancers affecting women. Deaths reached 56,000, with a mortality rate of 4.5 per 100,000, ranking sixth. These figures are sufficient to demonstrate that the prevention and control of cervical cancer are urgent. Given that advancements in cervical cancer treatment are limited, identifying its causes and focusing on prevention becomes essential.

One

The mystery of cervical cancer causes: from the "relationship with sexual transmission" to finding the "wrong culprit".

As early as the 1840s, Italian surgeon Domenico Rigoni-Stern discovered a strange phenomenon: the incidence rate of cervical cancer in single nuns was significantly lower than in married women. This led him to boldly conjecture that cervical cancer might be related to sexual activity. This finding was confirmed throughout the 20th century: numerous studies showed that sex workers, those who married young, those with many children, and those with multiple sexual partners had a notably higher risk of developing cervical cancer. Thus, the medical community concluded that cervical cancer is a "sexually transmitted" disease.

Since it was related to sexual transmission, scientists began to search for the "culprit" behind it. At that time, herpes simplex virus type 2 (HSV-2) was a commonly transmitted sexual virus and consequently became the focus of study. In 1967, researchers first reported that HSV-2 infection was associated with early lesions of cervical cancer (cervical intraepithelial neoplasia), and the positivity rate of HSV-2 antibodies in cervical cancer patients was much higher than in healthy women. Thus, the medical community of that time reached a general conclusion that HSV-2 was the "villain" responsible for cervical cancer. Subsequently, other studies found HSV-2-like particles in some cervical cancer tissues or detected fragments of the virus's DNA, which made this conclusion seem even more "definitive".

But this conclusion is fraught with flaws: first, the presence of positive antibodies for HSV-2 only indicates exposure to this virus, it cannot directly prove that it causes cervical cancer; secondly, to confirm that a virus is the culprit of cancer, it is necessary to find the complete genome of the virus within cancer cells, not just scattered fragments. It was not until the 1980s that German virologist Harald zur Hausen refuted this erroneous idea and identified the true "pathogen".

Two

HPV and cervical cancer: questioned hypotheses, truth verified over a decade.

Chu Er Hausen

The exploration path of the great masters of science.

On March 11, 1936, Chul Hausen was born in Gelsenkirchen, Germany, showing great interest in biology from a young age. World War II interrupted his studies, but did not extinguish his passion for scientific research. After the war, he studied medicine and biology at several universities, and in 1960 obtained his medical degree, firmly choosing cancer virology as his lifelong research direction. In the 1960s, while doing his postdoctoral research at the Children’s Hospital of Philadelphia, he participated in research on the relationship between the EB virus and Burkitt's lymphoma, confirming for the first time the existence of viral DNA in persistently infected tumor cells, which laid a solid foundation for his subsequent exploration of viral carcinogenesis mechanisms.

In 1972, Chul Hausen, at 36 years old, became a professor of virology at the university and began conducting independent research. At that time, cervical cancer was already the second most common tumor among women worldwide, claiming the lives of hundreds of thousands of women each year. He was determined to solve this problem. Initially, he followed the traditional approach, using nucleic acid hybridization techniques to validate the hypothesis that "HPV-2 causes cervical cancer," but after multiple experiments, he did not achieve the expected results. This led him to question the traditional conclusion: could it be that he had confused the virus?