HPV-Related Cancers: On the Way to Better Prevention, Safer Detection and Better Treatment Results

Almost 2,000 scientists from 78 nations will be meeting from September 17th to 22nd, 2011, at the ICC Congress Center in Berlin to exchange the latest research findings about cancer-causing human papillomaviruses and diseases associated with these pathogens.

When, in 2008, Harald zur Hausen was awarded the Nobel Prize in Medicine, human papillomaviruses, or HPV for short, were temporarily in the public focus. Zur Hausen, a physician and scientist at the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) in Heidelberg, had been awarded this high distinction for his discovery that specific papillomaviruses cause cervical cancer. On the basis of his findings, it was possible to uncover the role of these pathogens in the development of cancer. This provided the basis for developing vaccines that protect against infection with oncogenic papillomaviruses and, thus, against cervical cancer.

"Many areas of HPV research are currently in a very exciting phase. First results provided by Australian colleagues show that the vaccine is effective," says DKFZ's Lutz Gissmann, who is one of the organizers of the Berlin conference. In 2007, Australia was among the first countries to establish a nationwide HPV vaccination program. First evaluations of this program have now provided evidence that the vaccination is effective not only under strictly defined clinical trial conditions, but also when applied to a broad population: In girls who were vaccinated at a young age and, thus, before they started having sexual contacts, the number of precancerous lesions declined by 60 percent. This trend is also confirmed by the significant decrease by 73 percent in the incidence of genital warts after vaccination with the quadrivalent vaccine Gardasil®.

These first data already invalidate those concerns which have been voiced by many concerning the effectiveness of the vaccines. They show that the immune system of girls at that age is very well capable of mounting a defense against infection. Moreover, the decrease in precancerous lesions shows that after "chasing away" the high-risk HPV types 16 and 18 by the vaccination, no other cancer-causing HPVs appear to have taken their place.

However, Andreas Kaufmann, a virologist of Berlin Charité, emphasized: "Several conference contributions show how currently available HPV vaccines can be further improved -regarding not only their spectrum of efficacy but also production methods and, thus, final prices." HPV virologists from the U.S.A. are testing the L2 protein of HPV as a vaccination antigen. An L2 vaccine can be produced in bacteria, which saves the high costs of cell culture production. Moreover, immunization with L2 would protect from a very broad spectrum of cancer-causing papillomaviruses.

Therapeutic vaccinations, i.e., immune therapies to cure existing precancers, are also already in the clinical trial stage. A research team headed by Cornelis Melief from Leiden University in the Netherlands is presenting a vaccine which consists of 13 different protein sections (peptides) of the HPV 16 oncoproteins E6 and E7. It has already proven successful for treating precancerous stages of vulvar carcinoma.

Even though HPV vaccination will spare many women the diagnosis of cervical cancer in the future, it is not possible to completely prevent this disease. Therefore, physicians continue to work towards better treatment methods for affected women. Twenty percent of cervical cancer cases occur between the ages of 15 and 39 years. Thus, cervical carcinoma is the gynecologic tumor which affects the youngest women. "This means that more and more women are confronted with the diagnosis of cervical cancer while they are still in their family planning phase," says Achim Schneider, head of the Department of Gynecology of Charité in Berlin. Tailored to the needs of such patients, Schneider and his co-workers have developed a fertility preserving surgical method in which part of the cervix is removed. However, a number of criteria have to be fulfilled for this surgical method to be an option. "The cancer must not be too advanced," says Schneider. "If these criteria are met, our patients wishing for a child achieve a pregnancy rate of more than 50 percent after this type of treatment."

The fact that maternal age is increasing also results in more cervical cancers being diagnosed during pregnancy. In such cases, Schneider and his colleagues use the lymph node status as a basis to determine whether it is justifiable to delay cancer treatment. "Thus we are able to continue nine out of ten pregnancies and in most cases we will perform a cesarean delivery after the 35th week of pregnancy."

For physicians attending the 27th International Papillomavirus Conference, the Preclinical Workshop on September 16th will offer a special service: The surgeons will transmit surgical procedures directly into the auditorium, where Achim Schneider will explain the crucial steps of the operations to the expert audience.