Cancer epidemiology: age, environment, predisposing conditions (and Colombia) !
- Topic
Who gets cancer depends on age, habits, infections, where one lives and a few inherited genes. Many cancers can be prevented.
Updated 2026-11-01
What it is
Cancer risk is shaped by age, environment and lifestyle, infections, predisposing conditions and heredity. Age is the strongest single risk factor because mutations accumulate over a lifetime. Differences between countries and changes in migrants show that environment weighs more than genes for most cancers, and about a third or more of cancers could be prevented by avoiding known risk factors.
Key facts
- Advancing age is the most important risk factor for cancer overall.
- Migrant studies: people who move from a high-risk to a low-risk country (for example for gastric cancer) take on the new country's risk within one or two generations.
- In low- and middle-income countries, infection-related cancers make up a large share (cervix, stomach, liver).
- In children, leukaemia is the most common cancer; carcinomas are rare.
Main groups of cancer risk factors
| Factor | Examples | Typical cancers |
|---|---|---|
| Age | Accumulated mutations, weaker repair and immune surveillance | Most carcinomas rise steeply after middle age; children have mostly leukaemias, brain tumours and embryonal tumours |
| Tobacco | Smoking, chewing, second-hand smoke | Lung, head and neck, oesophagus, bladder, pancreas, kidney |
| Alcohol | Regular and heavy drinking | Mouth, pharynx, oesophagus, liver, breast, colorectum |
| Diet, obesity and inactivity | Processed and salted foods, excess weight, sedentary life | Colorectal, endometrial, breast after menopause, oesophageal adenocarcinoma, stomach |
| Infections | HPV, hepatitis B and C, H. pylori, EBV, HIV | Cervix, liver, stomach, lymphomas, Kaposi sarcoma |
| Reproductive and hormonal history | Early menarche, late menopause, few pregnancies, oestrogen without progestogen | Breast, endometrium, ovary |
| Environment and occupation | Asbestos, aromatic amines, benzene, arsenic, radon, air pollution, sunlight | Mesothelioma, bladder, leukaemia, skin, lung |
| Predisposing conditions | Chronic inflammation, immunodeficiency, precursor lesions | Colitis-associated colorectal cancer, Barrett adenocarcinoma, lymphomas |
| Heredity | Germline mutations (BRCA, mismatch repair, APC, RB1) | Breast, ovary, colon, retinoblastoma (about one in ten cancers or fewer) |
Clinical notes
- Colombia: breast cancer is the most frequent cancer in women and prostate cancer in men; gastric cancer is among the leading causes of cancer death, especially in the Andean highlands.
- Cervical cancer still kills many young women in Latin America, despite being preventable with HPV vaccination and screening.
- Lung and colorectal cancers are increasing as tobacco use and urban diets change.
- Late diagnosis (advanced stage) is a major cause of poorer survival in the region, which makes early detection programmes important.
Test yourself
Think of the answer, then tap the question to see it.
What is the single most important risk factor for cancer overall?
Advancing age, because DNA mutations accumulate over time.
What do migrant studies show about cancer risk?
That environment and lifestyle outweigh genes: migrants and their children acquire the cancer pattern of their new country.
Why do infection-related cancers matter so much in Colombia?
Infections such as HPV, H. pylori and hepatitis viruses are common, so cervical, gastric and liver cancers make up a large share, and many are preventable.
Which cancer is most common in children?
Leukaemia (mainly acute lymphoblastic leukaemia), followed by brain tumours.
Related
- Chemical carcinogens: initiation, promotion and the table to know
- Radiation and cancer: ultraviolet and ionizing
- Oncogenic viruses and H. pylori: the table to know
- Hereditary cancer syndromes: the table to know
- Precancerous conditions: when chronic inflammation, metaplasia or hyperplasia raise the risk
- Diet, cancer and systemic disease
- Tobacco: how smoking injures tissue
- Alcohol: how it injures the liver, brain, heart and fetus
- Obesity: leptin, adipokines and its consequences
- Tumours of infancy and childhood
Related conditions
- Gastric cancer
- Cervical cancer
- Breast cancer
- Prostate cancer
- Lung cancer
- Colorectal cancer
- Hepatocellular carcinoma
- Acute leukaemia (AML and ALL)
- Obesity
- Tobacco use disorder
- Alcohol use disorder
Elsewhere in DurgiPedia
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Age and Cancer Risk (National Cancer Institute (NCI), 2026); Cancer (World Health Organization (WHO), 2026); Gastric Cancer (StatPearls (NCBI Bookshelf), 2024); Cervical cancer mortality among young women in Latin America and the Caribbean: trend analysis from 1997 to 2030 (BMC public health, 2022).
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Representative model, for educational purposes only.