how it develops and progresses

CANCER

What is likely cause of these images?

Lesson Objectives

• Define cancer, the causes of cancer and how it develops and progresses.
• Define the term ‘tumour’
• Describe the different types of cancer and the risks they pose to people at different ages and stages of life.
• Explain how cancer can be treated.

Vocabulary

Russian

English

Cancer

Рак

Tumor/Tumour

Опухоль

Initiation

Инициирование

Promotion

Продвижение

Прогрессия

Progression

Carcinogenic factors

канцерогенные факторы

опухоль

Neoplasm

метастазировать

Metastasize

What is Cancer?

• Cancer – a large group of diseases characterized by the uncontrolled growth and spread of abnormal cells
• Neoplasm – new growth of tissue that serves no physiological function
• Malignant - cancerous
• Benign - noncancerous
• Biopsy – microscopic examination of cell development

What is cancer cont…

• Metastasis – malignant tumors that are not enclosed in a protective capsule have the ability to spread to other organs
• Mutant cells – disruption of RNA and DNA within normal cells may produce cells that differ in form, quality and function from the normal cell

What is Tumor/ Tumour?

• Tumor is a mass of abnormally arranged cells and may appear in any part of body tissues.

Two types of tumor;

• Benign Tumor: Slowly growing mass of cells and is noncancerous.
• Malignant Tumor: Fast growing cells which invade other tissues and may destroy them. They are cancerous.

Cancer development (Neoplasm)

Neoplasm has 3 basic phases;

• Initiation Phase: Exposure to carcinogenic factors causes mutations in cells.
• Promotion phase: When mutated cells are not destroyed by immune system, mutated cells divide, and transfer mutated abnormal genes to daughter cells.
• Progression phase: The divisions of daughter cells lead to rapid and excessive growth of tissue and the formation of a tumor/ tumour.

Cancer development cont…

Some of the neoplastic cells may become detached and be transported by the blood to other parts of the body, where they settle and enter a phase of expansion. If the cells metastasize , a neoplasm can attack other organs, considerably decreasing the organism's chances of survival.

Causes of cancer

Factors that cause cancer are called carcinogens when exposed to them for a long time.

They include;

• Tobacco smoke
• Strong solar radiations/ ultra-violet light
• Exposure to X-ray radiations
• Environmental pollution
• Contact with chemicals such as; asbestos, Lead (Pb), tar in hydrocarbons etc.
• Infection with viruses.
• Alcohol.

Types and incidences of cancer

Type of cancer

Occurrence by gender and age

Skin cancer

% death

Present in all categories of people

Lung cancer

Commonest in male

Commonest but treatable

Breast cancer

Account for 40% death

Common in females

Leukaemia/ blood cancer

Common in young people

Cervical cancer

Account for 25% death

Very difficult to treat

Female

Prostate cancer

Male

Liver cancer

Present in all categories of people

Treatment of cancer