Well-Being Prevention & Cures

Older age, smoking deemed most important risk factors for any type of cancer: study

“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.”
A person smoking cigarettes.

Story at a glance

  • Although a host of studies on risk factors for individual cancers exists, data are lacking with regard to developing any type of cancer at all.

  • A new investigation of more than 425,000 individuals found older age and smoking were the greatest cancer risk factors. 

  • Over the course of five years, 15,226 cases of invasive cancer were diagnosed. 

As more and more studies are conducted on cancer, it seems like an ever-growing list of risk factors can contribute to the disease’s occurrence. However, a large new study conducted by the American Cancer Society found older age and smoking are the most salient risk factors for relative and absolute five-year risk for any cancer type. 

Results are based on two prospective cohort studies carried out among 429,991 individuals with no prior cancer history. Individuals were followed-up for five years during which 15,226 invasive cancers were diagnosed. 

In addition to older age (50 or over) and being a current or former smoker, other risk factors among women included high body mass index (BMI), type 2 diabetes, hysterectomy, having ever given birth, a family history of cancer, hypertension, tubal ligation and physical inactivity. 

Additional risk factors in men were alcohol intake, family history of cancer, red meat consumption and physical inactivity. 

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“Single cancer type-specific screening recommendations are based on risk factors for that specific type of cancer,” Alpa Patel, senior vice president of population science at the American Cancer Society and the study’s co-author, said in a statement.  “Our findings are encouraging as we are working to define subgroups in the general population who could benefit from enhanced cancer screening and prevention,” Patel continued.  

Nearly all individuals studied aged 50 or older and current or former smokers had an absolute five-year risk of cancer greater than 2 percent. 

After five years, absolute risk of cancer among men was 29 percent, compared with 25 percent for women.

“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,” Patel noted. 

“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.”

Overall, researchers suggest the identified individuals could benefit from enhanced cancer screening and prevention efforts.

The investigation did not include data on gene variants or chronic viral infections that could also increase cancer risks, marking a limitation. Researchers were also unable to stratify risks based on racial and ethnic groups. 

“These results suggest that more detailed risk assessment can identify currently non targeted groups in the general population younger than 50 years that are at equivalent or higher risk as populations older than 50 years,” they concluded.