Cancer is a group of over 100 diseases characterised by the uncontrolled growth and spread of abnormal cells that bypass normal controls on division and death. The common feature is the potential — if untreated — to invade healthy tissue and spread to distant organs through a process called metastasis.

What are the most common cancers worldwide?

The five most common cancers by incidence (IARC Globocan 2022) are lung (12.4%), breast (11.6%), colorectal (9.6%), prostate (7.3%) and stomach (4.9%). By mortality, lung cancer leads, followed by colorectal, liver, stomach and breast. The most common types differ by sex and region.

Cancer is caused by genetic mutations accumulating over time, driven by both hereditary factors and external carcinogens. Leading modifiable causes are tobacco (responsible for ~22% of cancer deaths), alcohol, overweight and obesity, physical inactivity, infections (HPV, HBV, H. pylori), UV radiation and occupational exposures. Around 5-10% of cancers result from inherited gene mutations.

Can cancer be prevented?

At least 40% of cancer cases could be prevented by eliminating known risk factors. Stopping smoking, limiting alcohol, maintaining healthy weight, staying physically active, protecting against HPV and hepatitis B infections, and avoiding excessive UV exposure are the main evidence-based prevention strategies.

What is staging and why does it matter?

Staging describes how far cancer has spread — from Stage I (localised) to Stage IV (metastatic). It determines whether surgery, radiation, chemotherapy, immunotherapy or combination therapy is appropriate, and predicts prognosis. Early-stage cancers are generally more curable, which is why screening programmes that detect cancer before symptoms develop save lives.

What is immunotherapy?

Immunotherapy removes the "brakes" that cancer cells place on immune responses, using checkpoint inhibitors (pembrolizumab, nivolumab) or other mechanisms. It has transformed outcomes for melanoma, lung, bladder and other cancers. Side effects (immune-related adverse events) can be serious. It works well only for some cancer types and not all patients — biomarkers help select likely responders.

Why is cancer care worse in low-income countries?

In LMICs, cancer is frequently diagnosed at late stages because of limited screening, shortage of diagnostic equipment, and barriers to specialist care. Radiotherapy, chemotherapy and surgery are often unavailable or unaffordable. Over 70% of global cancer deaths occur in LMICs, which receive a disproportionately small share of cancer research funding.

What is WHO's approach to cancer?

WHO's cancer work centres on the Global Initiative for Cancer Registry Development (GICR), the cervical cancer elimination initiative (90-70-90 targets), childhood cancer, and access to essential medicines and radiotherapy. WHA73.8 (2020) committed member states to accelerating NCD action including cancer.

What is cervical cancer and how is it being eliminated?

Cervical cancer is caused by persistent HPV infection and kills approximately 350,000 women per year — almost entirely in LMICs. WHO's 90-70-90 strategy targets 90% HPV vaccination of girls, 70% of women screened by age 35 and 45, and 90% of those with cervical disease treated. If achieved, cervical cancer can be eliminated as a public health problem within decades.

What are the hallmarks of cancer?

The "Hallmarks of Cancer" framework (Hanahan and Weinberg, 2000, updated 2011) describes capabilities normal cells must acquire to become malignant: self-sufficient growth, insensitivity to growth inhibitors, evading apoptosis, unlimited replication, angiogenesis, and tissue invasion and metastasis. Later additions include immune evasion and cellular senescence reprogramming. This framework has organised two decades of cancer biology research.

What is the economic impact of cancer?

The economic burden of cancer is estimated at over $1.16 trillion per year globally in direct health costs and productivity losses. Cancer is one of the top causes of catastrophic health expenditure in LMICs and a major barrier to achieving universal health coverage. Investment in cancer early detection and treatment is highly cost-effective — delays increase costs.

How does GMJ News cover cancer?

GMJ News follows new cancer research, regulatory approvals, IARC updates and equity dimensions of cancer care. Georgia has a high burden of gastric and colorectal cancers that are priorities for the Georgian Medical Journal, and PHIG's accreditation work directly touches cancer care quality standards.

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Cancer

GMJ News knowledge hub · last reviewed September 2026 · Georgian Medical Journal

Summary Statistics Glossary GMJ news FAQ Documents Organizations Research

Cancer accounts for nearly one in six deaths globally: about 20 million new cases and 9.7 million deaths a year (WHO/IARC GLOBOCAN 2022), with the burden projected to rise sharply by 2050. Yet 30–50% of cancers are preventable — tobacco control, HPV and hepatitis B vaccination, and reduced alcohol and obesity — and screening plus early diagnosis dramatically improves survival for breast, cervical and colorectal disease. GMJ News tracks the evidence across prevention, screening, immunotherapy and precision oncology.

Key messages

Scale

20 million new cancer cases and 9.7 million deaths in 2022 — 1 in 5 people will develop cancer during their lifetime (IARC Globocan 2022).

Prevention

At least 40% of cancers are preventable. Tobacco, alcohol, excess weight, physical inactivity, infections (HPV, HBV, H. pylori) and UV radiation are the leading modifiable causes.

Equity

Over 70% of cancer deaths occur in low- and middle-income countries, where diagnosis is late and treatment — surgery, radiotherapy, essential medicines — is severely limited.

Screening

Cervical, breast and colorectal screening demonstrably reduce mortality. WHO's 90-70-90 cervical cancer elimination strategy is the global model for what screening can achieve.

Treatment advances

Immunotherapy, targeted therapy and precision oncology have transformed outcomes for many cancers — but these advances remain almost entirely confined to high-income countries.

Early detection

More than 30% of cancer deaths could be prevented with timely diagnosis and treatment. The WHO Guide to Cancer Early Diagnosis provides the evidence framework.

Key statistics

20M

new cases/year

IARC 2022

9.7M

cancer deaths/year

IARC 2022

1 in 5

people develop cancer

IARC 2022

40%

of cancers preventable

WHO

70%+

deaths in LMICs

IARC 2022

$1.16T

economic cost/year

WHO 2020

New cancer cases worldwide per year (millions) — IARC Globocan estimates

Source: IARC Global Cancer Observatory (Globocan). Estimates updated every 2-3 years.

Glossary of key terms

Malignant tumour
IARC/WHOA mass of cancer cells capable of invading surrounding tissue and spreading to distant sites (metastasis), unlike a benign tumour which does not invade or spread.

Carcinoma
ICD-11/WHOThe most common type of cancer, arising from epithelial cells. Includes lung, breast, colon, prostate and cervical cancers.

Metastasis
IARCThe spread of cancer cells from the primary tumour to distant parts of the body via bloodstream or lymphatics. Metastatic cancer is generally harder to treat.

Staging
TNM/AJCCA system describing how far cancer has spread. Stage I is localised; stage IV is metastatic. Staging guides treatment and predicts prognosis.

Immunotherapy
FDA/EMATreatments using the immune system to destroy cancer cells. Checkpoint inhibitors (PD-1/PD-L1 blockers) have transformed outcomes in melanoma, lung and other cancers.

Carcinogen
IARCAny substance or agent capable of causing cancer. IARC classifies into Groups 1 (confirmed), 2A (probable), 2B (possible). Tobacco is Group 1.