Most people who have gone through cancer treatment feel that they have made it through a lot of upheaval in their lives, and while having to adjust to some losses, they are ready to leave cancer behind and move forward. It can be difficult to think about the need to prevent second cancers at this point, yet understanding your risk for a second cancer is important.
Even more essential is learning about the things you can do to decrease the likelihood of developing a secondary cancer. With this column, we begin to talk about what you can do to prevent and detect second cancers as part of a series on “late effects.” Late effects are side-effects of cancer treatment that do not show up for many years – second cancers are just one aspect of these late effects for you to monitor.
The latest research from the United States documents that about 18 per cent of all newly diagnosed cancers are second cancers. Some of these are new cancers in the same organ – for instance a second breast cancer, but in the breast not affected by the first cancer. However, many of them are new cancers in another place in your body. These are not metastases (where cancer cells from your first cancer have migrated to another organ), but brand new cancers requiring brand new treatments.
Most people will not develop second cancers. However, an important part of healthy survivorship is monitoring signs and symptoms for the cancers for which you may be at risk.
So what are your risk factors, and how can you prevent these second cancers?
One crucial risk factor involves lifestyle and health behaviours. These influence whether or not you may develop a second cancer, just as they may have influenced the development of your first cancer. Recent studies document that lifestyle choices may account for as much as 35 per cent of your risk.
But, there is hope! If smoking, obesity, lack of exercise and psychosocial stressors were risk factors in developing your first cancer, changing those behaviours and quitting those unhealthy habits can modify your risk for developing second cancers. Learn whether there are things you can do to reduce this risk.
A second risk is the type of treatment you may have received for the first cancer. So, for instance, radiation treatment often results in many years of cancer-free living, but can also carry a long-term risk for another cancer in the radiated area that most often appears five to 10 years post-treatment. Likewise, other cancer treatments can create vulnerabilities for new cancers many years later. Talk to your oncologist, nurse and family physician about what signs and symptoms of cancer you should watch for specifically related to your treatment.
A third risk category is predisposition. Some cancers come with a genetic or inherited risk, such as the risk that some families inherit with the BRCA1 or BRCA2 genes for breast and ovarian cancers. If you have such a cancer, understanding the inherited risk can also help you be more vigilant for signs and symptoms of cancer in yourself or other family members. Researchers are discovering new sources of genetic risk as time goes on, and we hope to build communication avenues with you as survivors so that we can inform you about what is learned about your type of cancer many years down the road. Again, your medical team can help you to understand whether you are at genetic risk.
Last on this list, but no less important, is prior exposure to viruses, toxins or environmental contaminants that can increase your odds of developing a second cancer. If you developed your cancer because you were exposed to the virus HPV, as in some cervical and head and neck cancers, you may remain at risk for a second cancer based on that exposure. Likewise, environmental exposures may remain a risk factor beyond your first cancer. Again, talk with your medical team to understand if there are toxins that are important for you to avoid with your type of cancer.
Each cancer is different and your doctor may recommend routine tests. Talk about your risks. Adopting a healthy lifestyle can have an impact on reducing your risk for second cancers. Making sure that you pay attention to signs and symptoms of cancer can prevent cancer, not just the first time – but the second time.