Q: My mother has been diagnosed with breast cancer at the age of 55. Our uncle has had colon cancer. My brother and I worry about our risk for cancer. Is screening helpful?
A: Family history plays a role in certain cancers. Breast and colon cancer have familial tendencies. Cancer results from the interaction of genetic and environmental factors. Family history may influence the genetic component, and environmental factors may trigger or promote the process of carcinogenesis (the causes of cancer).
Environmental factors include radiation; ultraviolet radiation from sunlight; tobacco smoke; the pandemic of obesity related to consumption of processed, fatty, and refined calorie-dense foods; alcohol; inactivity; and industrial and occupational pollutants and irritants, including asbestos and carbon tetrachloride. Nitrosamines and polycyclic aromatic hydrocarbons generated during tire manufacture and vulcanization (a chemical process for converting natural rubber or related polymers into more durable materials) are also implicated in various cancers. These potentially dangerous substances are found everywhere, from dry cleaners to tire depots and what we choose to ingest and inhale. We are truly surrounded!
Genetic and environmental factors play significant roles in carcinogenesis. Environmental factors are the more readily modified and controlled. Avoid tobacco in any form. Avoid alcohol (there is no safe level of alcohol intake regarding carcinogenesis). Strive to achieve ideal body weight, or BMI (body mass index). Eat a healthful, balanced vegetarian diet (red meat consumption is causally associated with colon cancer). Plant foods are rich in fiber, phytochemicals, and antioxidants, which help to combat malignancy. Be conscious of the actual environment and voluntary exposure to dangerous substances. Be aware of occupational dangers and the safety measures in many workplaces; preventive measures—such as the wearing of masks and protective clothing, and taking recommended breaks—are effective only as they are implemented and practiced!
Screening for cancer is helpful for individuals known to be at increased risk as indicated by family history and exposure to environmental risk factors. All screening should be done in consultation with your physician and in the context of the specific patient—you!
Screening tests for breast cancer include manual palpation (least reliable), mammography, ultrasound, and genetic testing for BRCA1 and BRCA2 genetic mutations. This latter genetic testing is recommended for those with a strong family history of breast cancer. For women with an average risk for breast cancer, annual mammograms are recommended from age 45 to 54, and every other year thereafter. As risk increases, so does intensity of screening.
For colorectal cancer the gold-standard test for screening is colonoscopy. For those with an average risk, testing every 10 years is indicated between the ages of 50 to 75. More frequent testing is needed if there has been previous cancer, precancerous polyps, certain inflammatory bowel diseases, and familial polyposis. An annual fecal occult blood test is helpful in detecting blood that may not be obvious but may indicate an underlying cancer.
A positive family history of cancer warrants increased vigilance, including screening. Prevention, where possible, remains better than cure. In another House Call we will consider screening for other cancers.
Peter N. Landless, a board-certified nuclear cardiologist, is director of the General Conference Health Ministries Department.
Zeno L. Charles-Marcel, a board-certified internist, is an associate director of Adventist Health Ministries at the General Conference.