Cancer Risk Factors Older Adults Are Most Likely to Overlook

Persistent, low-level inflammation — sometimes called "silent inflammation" — is increasingly recognised as a contributor to cancer development. Unlike the acute inflammation that follows an injury, chronic inflammation can simmer for years without obvious symptoms. It creates a cellular environment in which DNA damage may accumulate and tumour-promoting signals can become active.

Conditions such as obesity, type 2 diabetes, and inflammatory bowel disease are all associated with elevated inflammatory markers. Older adults managing multiple chronic conditions may already carry a higher baseline inflammatory burden without realising its broader implications. Research published by the National Cancer Institute and others has highlighted links between chronic inflammation and cancers of the colon, liver, stomach, and esophagus, among others.

Most people associate sun damage with beach holidays or sunburns in youth. But skin cancer risk is largely cumulative — it builds with every unprotected hour spent outdoors over decades. By age 60 or older, many adults carry a substantial lifetime UV burden, even if they rarely deliberately sunbathe.

Melanoma and non-melanoma skin cancers are among the most common malignancies in older US adults. Routine outdoor activities — gardening, walking, yard work — contribute meaningfully to UV exposure when sun protection is not used consistently. Our detailed overview of sun exposure and skin cancer risk covers how this risk accumulates and what the evidence supports.

Alcohol is classified as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC), meaning there is sufficient evidence that it causes cancer in humans. It is linked to cancers of the mouth, throat, esophagus, liver, colon, rectum, and breast. Despite this, many older adults are unaware that moderate or even light drinking carries some level of increased risk.

Alcohol's cancer-promoting effects operate through several mechanisms, including the conversion of alcohol into acetaldehyde, a toxic compound that can damage DNA. The risk appears to increase with the amount consumed, but no threshold has been identified below which risk is entirely absent. For a thorough breakdown of the evidence, see our article on alcohol and cancer risk.

Adults who worked in construction, manufacturing, agriculture, mining, or certain industrial settings may have been exposed to carcinogens — including asbestos, benzene, silica dust, or vinyl chloride — decades before their cancer risk became clinically relevant. Because many cancers have latency periods of 20 to 40 years, diseases triggered by exposures in one's 30s or 40s may only surface in later life.

Radon, a naturally occurring radioactive gas that accumulates in poorly ventilated homes, is the second leading cause of lung cancer in the United States according to the EPA. Many older homeowners have never tested their properties. Our plain-language overview of environmental exposures and cancer risk explains these pathways in accessible terms.

While most cancers are not directly inherited, a personal or family history of certain cancers can meaningfully raise risk and influence when and how often screening should occur. Mutations in genes such as BRCA1, BRCA2, Lynch syndrome-related genes, and others are associated with substantially elevated lifetime risk for specific cancer types.

Older adults whose relatives were diagnosed before age 50, or who had multiple primary cancers, may be candidates for genetic counselling they have never pursued. Understanding inherited risk can also prompt earlier or more frequent screenings. Our guide on cancer risk and genetics explains gene-linked patterns and when to ask about formal genetic evaluation.

Both physical inactivity and excess body weight — particularly adiposity around the abdomen — are independently associated with increased risk for several cancer types, including cancers of the colon, endometrium, kidney, pancreas, and postmenopausal breast. These risk factors are also among the most modifiable for many older adults.

Excess body fat influences cancer risk partly through hormonal pathways (particularly estrogen and insulin-related signalling) and through promoting chronic inflammation. Regular physical activity, by contrast, is associated with lower risk across multiple cancer types. The evidence base for these relationships is reviewed in our article on lifestyle factors linked to lower cancer risk.

Certain viral and bacterial infections are established cancer risk factors, yet older adults may carry them without knowing. Helicobacter pylori, a bacterial infection of the stomach lining, is associated with gastric cancer and is estimated to be present in a significant portion of older US adults, often without causing noticeable symptoms. Similarly, chronic hepatitis B or C infections raise the risk of liver cancer substantially.

Human papillomavirus (HPV) is linked not only to cervical cancer but also to oral, throat, and anal cancers — relevant to both men and women. Persistent oral HPV infection, in particular, is increasingly recognised as a driver of oropharyngeal cancer in older adults. Our overview of oral and throat cancers covers the signs that often go unrecognised.