Cancers

Neoplastic diseases
Neoplasms
Tumours
Cancerous growths
Sarcomas
Carcinoma in sita
Cancer

Nature

A tumour, or neoplasm, is a tissue growth with no physiological function. The first sign of tumour growth in a tissue is the appearance of a small number of cells which multiply with uncontrolled division and lose lose their capacity for differentiation. The tumour enlarges solely as a result of multiplication of its own cells. Tumour growth proceeds through stages of disorderly increase in the number of cells, focal growth, benign growth and malignant growth; the stages immediately preceding malignancy are called precancerous.

Background

Cancers emerged as a recognized global health concern in the early 20th century, as industrialization and improved diagnostics revealed rising incidence rates worldwide. Landmark epidemiological studies in the mid-1900s linked environmental, lifestyle, and genetic factors to cancer prevalence, prompting international collaboration in research and public health. The late 20th and early 21st centuries saw cancer’s burden escalate, particularly in low- and middle-income countries, underscoring its significance as a universal and complex challenge.

Incidence

Cancers represent a leading cause of morbidity and mortality worldwide, with an estimated 20 million new cases and nearly 10 million deaths reported in 2022, according to the World Health Organization. The burden is rising globally, affecting all regions and socioeconomic groups, with particularly rapid increases in low- and middle-income countries due to aging populations and changing risk factors.
In 2023, India reported a significant surge in cancer diagnoses, with over 1.4 million new cases documented by the National Cancer Registry Programme. The most common types included breast, lung, and oral cancers, highlighting the growing public health challenge in the region.

Claim

Cancer is a disease of the genome, which means it’s characterised and caused by changes in our genes that can drive a healthy cell to mutate into a cancerous one. Cancer remains difficult to treat because each cancer is different, even within the same cancer type, such as breast or bowel. Each tumour has a genetic code that makes it unique, but there are also genetic differences within the tumours themselves. And tumours can evolve over time to become resistant to treatment.

Counter-claim

Up to 90% of cancer is preventable. "Environmental or nutritional factors probably account for up to 90% of human cancers. These factors include smoking; diet; and exposure to sunlight, chemicals, and drugs. Genetic, viral, and radiation factors may cause the rest." (The Merck Manual, 17th edition, pp. 2591-2592)