It takes thousands of people and as long as ten years before results from prevention studies are known. Doctor Ernest Hawk is vice president of MD Anderson's Division of Cancer Prevention. He says they are trying to expand what cancer prevention studies look at, like what has been done with cardiovascular disease where the focus is on high blood pressure and cholesterol.
"We're approaching that in the same way, that is trying to dissect apart the elements that lead to cancer overtime so that we can address the risk factors for cancer rather than just treating the cancer once it occurs."
Still it takes a long time and a definitive answer is not likely to come from one study.
"It's one of the reasons why participating in the research is so important because over time by replication of results we are able to have greater confidence in what we can recommend to someone so it really is a progression of science over time and it's careful attention to how studies interconnect and relate to one another."
Researchers start a trial looking for the benefit, but sometimes they find a risk. Sometimes it'll seem like one study contradicts another. Hawk says there needs to be better understanding in the media and public about how trial work together.
"As much as bringing light to something you can cause confusion by early release of things and by sound bites that don't put the evidence in the proper context. It's a terribly important issue I know, I recently came from the National Cancer Institute where we actually held seminars both with the public but also with the press to try to lay out the strategy of how trials and how studies fit together, one to the other, to build an evidence base."
Hawk advocates for better self-monitoring by scientists in the field to decide when studies are appropriate for broad public consumption.
Capella Tucker, Houston Public Radio News.