One of the hardest things for people who have been diagnosed with cancer is coming to grips with the feeling that so much about their prognosis seems so out of their control. To be sure, scientists have uncovered causal link to cancer that are well within most people’s control: Abstaining from tobacco and keeping one’s weight under control are two good examples. But those actions alone do not guarantee a cancer-free life, nor do they promise full recovery for those who are diagnosed with the disease.

The simple fact is that so much about cancer remains unknown to science that fear of the unknown remains one of the disease’s most common side effects. But scientists continue to chip away at the mystery, and officials hope a major nationwide cancer prevention study planned by the American Cancer Society will help make things even clearer.

At least 300,000 people between the ages of 30 and 65 who have never been diagnosed with cancer are being sought for the study, which will follow participants for 20 to 30 years to try to understand some of the lifestyle and genetic factors that cause cancer. At the outset of the study, participants will complete detailed surveys, have their waist measurements taken and submit small blood samples. Follow-up surveys every couple of years thereafter will help researchers track the changes in participants’ health.

This will be the third Cancer Prevention Study completed by the Cancer Society, and it represents an excellent opportunity for people to make a real difference in the proliferation of this deadly disease. Previous studies helped expose the cancer links to smoking and obesity. This new study could be equally valuable.

So far, Hampton Roads is underrepresented in the nationwide sample, and organizers are encouraging area residents to join the effort by enrolling for the study on June 15 at Sentara Belleharbour or during one of the other enrollment dates in June around Hampton Roads. To make an appointment or for more information, visit www.cps3hamptonroads.org.

The study is made possible through the fundraising efforts of the American Cancer Society, which raises a significant amount of money for cancer research each year during the Relay for Life. Participating in the relay is another way folks can help fight cancer. Suffolk’s Rockin’ Relay for Life is set for 6 p.m. May 17 at Bennett’s Creek Park, and the American Cancer Society is still accepting registrations for walkers and donations from those who wish to support them. For more information about the relay, visit www.relayforlife.org/suffolkva.

Cancer may not yet be completely preventable or entirely treatable, but that doesn’t mean we have to feel helpless in the fight against it.