Interview with Stefanie Klug, Chair of Epidemiology
"The beauty is that everyone can be active in prevention"
She has been a member of the German Standing Committee on Vaccination (STIKO) since 2011 and has made significant contributions in terms of recommendations for immunization against the Humane Papilloma Virus (HPV).
TUM: How high is the participation rate for cancer screening - can you provide any general statements on this issue?
Prof. Stefanie Klug: Let's use the Pap smear (Note: a cervical smear for the detection of possible signs of cervical cancer at an early stage) as an example: This procedure is harmless and many women do not even feel it, yet the annual participation rate is only 50 to 60 percent.
Then why do so many people voluntarily forgo a screening process?
SK: Some people are unaware this procedure even exists, while others fear a cancer diagnosis or simply have no trust in their doctor. But avoidance is indeed dangerous: If an individual who is sick waits too long to see a physician, the disease may have already advanced to a degree that it is no longer curable. The onus is on science to provide ways that could motivate such people to have an examination, despite their fears and misgivings.
How can we encourage people to subject themselves to a preventive examination?
SK: Quite some time ago we conducted a study known as MARZY, which addressed participation in early cancer detection. This study involved a total of over 5,000 participants. One of the outcomes of this study revealed that a personal invitation to the examination had a positive effect on older and lower income women. This outcome is likely also applicable to colon cancer screening. There are instances where individuals do not realize that preventive medical checkups are free, and a reminder from your family doctor could greatly help create awareness to this end.
How often should people undergo cancer screening?
SK: The frequency depends on age and the nature of the screening examination. The Federal Ministry of Health passed the Cancer Detection and Registration Act on the basis of the National Cancer Plan, which was adopted by the Bundestag, Germany's Federal Parliament, in 2013. An organized cancer screening program for cervical as well as colon cancer accompanied by a letter of invitation is to be introduced by 2018. Basic components of cervical screening: Women between the ages of 20 and 34 should continue to get an annual pap smear, whereas women older than 35 should only have a pap smear every three years. Yet – and we've been fighting a long time for this initiative – there will be an additional HPV test every three years for these older women, since we know that HPV is responsible for this type of cancer and most of the women tested are negative. In this instance there is a very low risk of the disease in women. The few HPV-positive women in this age group – which is less than ten percent – have to be continually monitored, because they have a higher risk of cervical cancer. However, for colon cancer there is also to be a personal invitation in the future for a colonoscopy at the age of 55. If everything is fine, a subsequent colonoscopy is to follow ten years later. Anyone with a family history of the disease will of course have the opportunity to get screened earlier.
For one of your research projects concerning skin cancer screening, data from approximately 60,000 patients were checked from 2002 to 2011. Although tumors were more often recognized at an early stage, they did not decline in the later stages. What conclusions can be drawn from this outcome?
SK: You are correct, the objective of skin cancer screening is to reduce the death rate (mortality), yet it was revealed that screening has not (to date) made a contribution in this respect. As a matter of fact, skin cancer screening is very controversial, we are the only country in Europe that offers skin cancer screening. For example, Australia has decided against skin cancer screening, although it has light-skinned inhabitants, strong radiation and a high incidence of melanoma. It may be too early to detect a decline in mortality, since further evaluation is required.
What do other countries actually have in place?
SK: Primary prevention. People are advised against too much exposure to the sun. But if you go out into the sun, wear sunscreen, long clothing, a hat, and avoid the midday sun – these measures would also be advisable for us, since screening solely remains secondary prevention for the purpose of detecting a change which potentially already exists. Nevertheless, the best form of prevention is the precautionary measures we can all take, for example, by getting a vaccination, exercising or even preventing sunburn, simply to ensure that tumors don't develop in the first place.
How do you obtain the data for your studies?
SK: We use data from the local residents' registration office, since we aim for a population-based sample of roughly all women between the ages of 30 and 40. We also want our studies to depict all social strata and population groups. People selected for this sample to participate in our studies are invited by a letter. In the MARZY study we analyzed data from nearly 10,000 women from Rhineland-Palatinate in order to obtain a representative cross-section of the women in that region.
What is the link between your area of expertise - which addresses the prevalence of certain diseases in the population - and sports?
SK: It is the area of prevention that creates the link with epidemiology. This applies not only to me and my specialization, but also to the faculty as a whole. My colleagues also devote their energies to the comprehensive field of prevention. To what extent can sports be used as a preventive measure to combat the widespread diseases of diabetes, cardiovascular disease, and cancer? This is an issue that requires more extensive research.
What do you have planned for new study projects?
SK: We're planning a larger study involving sports interventions, the objective of which is to motivate people to exercise. There are many studies of this type involving children, yet it would be equally important to explore this avenue with adults. Although it is important for children to get involved in sports, we believe that older individuals should likewise stay active. In fact, lack of exercise is already being branded as the "cigarettes of the future", since inactivity poses a dramatic risk factor for today's lifestyle diseases, akin to smoking and lung cancer.
And finally, a general question: What kind of recommendations can you provide?
SK: People should themselves take the initiative in the form of primary prevention. To elaborate: we should exercise every day - whether by taking the stairs, going for a walk or even cleaning and doing sports - anything that regularly gets you off the sofa several times a week and makes you sweat is a good thing!
Prof. Dr. Stefanie Klug
Technical University Munich
Chair of Epidemiology
Phone: +49 89 289-24951