Being over the age of 50 and smoking are the two most significant risk factors associated with developing any cancer, according to a new study in the journal Cancer. While other characteristics such as body mass index (BMI), diet, exercise, and family history of disease were all important, the researchers say that age and tobacco use dramatically impact a person’s chances of developing a tumor.
The study authors analyzed data relating to 429,991 people in the US with no personal history of cancer, following up on each individual for a period of five years. In doing so, they sought to determine the factors associated with a greater than two-percent absolute risk of developing any cancer over a five-year timescale.
“The absolute risk of developing any cancer within five years was [equal to or greater than two percent] regardless of risk factor profile for nearly all men and women aged 50 years or older and was as high as 29 percent in men and 25 percent in women for some risk factor profiles at the oldest ages,” write the researchers. “After age, the most important risk factor for developing any cancer in five years was smoking history.”
In total, 15,226 cancers were diagnosed among the study’s participants within five years of enrollment, with prostate and lung cancer being the most common in men and breast and uterine cancer the most frequent in women. After age and smoker status, the biggest risk factors for men were alcohol use, family history of cancer, red meat consumption, and physical inactivity.
For women, factors such as BMI, type 2 diabetes, hysterectomy, and having had children were all associated with an elevated five-year risk for any cancer.
Among men under the age of 50, risks exceeded two percent only in those aged 45 and above who were either current smokers or had quit tobacco less than 30 years ago. The highest risk of 2.7 percent applied to males in this age range who were exposed to all of the aforementioned risk factors.
Among women under 50, absolute risks rose above two percent beginning at 35 years of age for smokers, with a 5.8 percent risk calculated for those older than 45 with exposure to multiple other factors.
“As we consider the possibility that future tests may be able to identify several types of cancer, we need to begin understanding who is most at risk for developing any type of cancer,” said study author Alpa Patel in a statement. “These types of data are not widely available, but necessary to inform future screening options, such as blood-based multi-cancer early detection tests that could help save lives.”