Cancer Epidemiology

Global Cancer Burden

• In developed countries, an unhealthy diet and inactive lifestyle are attributed to as many cancer cases as smoking.
• A third of all cancer deaths are linked to cigarette smoking, while obesity is associated with colon, breast, uterine, oesophageal, and kidney cancers.
• Lung cancer is the leading cause of cancer deaths, accounting for 19.4% of total deaths, followed by liver, colorectal, stomach, and breast cancers.

Cancer Mortality Rates

• According to WHO (2017), lung cancer accounted for 1.69 million deaths, liver cancer for 788,000 deaths, and colorectal cancer for 774,000 deaths.
• According to GLOBOCAN (2018), lung cancer accounted for 1.76 million deaths, liver cancer for 781,631 deaths, and colorectal cancer for 551,269 deaths.

Projections and Forecast

• By 2025, the number of new cancer cases is expected to increase to 19.3 million per year due to population growth and ageing.
• By 2030, the cancer burden is expected to more than double, with 26.4 million new cases and 17 million deaths.
• By 2040, the number of new cancer cases is expected to increase to 30 million, with the greatest increases in low- and middle-income countries.

Cancer in Nigeria

• The burden of cancer in Nigeria is unknown due to limited access to health services.
• 92% of cancer statistics from sub-Saharan Africa are derived from hospital-based cancer registries.

What is Cancer?

• Cancer is a disease characterized by abnormal growth of cells, invasion of adjacent tissues, and eventual death if left untreated.
• There are over 200 different types of cancer, with four types (lung, breast, prostate, and large bowel) accounting for more than half of all cases.

Categories of Cancer

• Cancer can be categorized based on the cells affected, including:
  • Carcinomas (epithelial cells)
  • Sarcomas (mesodermal cells)
  • Lymphomas (cells of bone marrow and immune system)

Global Burden of Cancer

• Cancer is one of the leading causes of death, with an estimated 20 million new cases in 2023.
• One in 5 people develop cancer in their lifetime, with one in 5 men and one in 6 women worldwide developing cancer during their lifetime.
• Infections are attributed to 13% of all cancer cases, with an age-standardized incidence rate of 25.0 cases per 100,000 person-years.