Cancer is characterized by abnormal cell growth, invasion of tissues, and spread to distant organs. The genetic material in cells can become damaged or mutated, causing abnormal cell growth and division that may form tumors. Benign tumors are non-cancerous masses, while malignant tumors are cancerous and can rapidly grow and invade nearby tissues and spread to distant sites. Carcinogenesis is the process by which normal cells are transformed into cancer cells through stages like hyperplasia, dysplasia, and neoplasia. Some major causes of cancer include environmental factors, lifestyle and dietary factors, and genetic predispositions. Common cancer types vary between developed and developing nations.

1. Cancer Intro & Pathogenesis
By – Shivani Shukla

3. What is CANCER?
• Cancer is group of diseases characterized by
– Abnormal growth of cells
– Ability to invade tissue and even distant organs
– The situation of each cancer patient is unique, which is why the
symptoms can differ greatly.
• The molecular mechanisms of tumor
metastasis remain largely unknown
and undefined.

4. Origin of cancer
• Cells grow and divide in a controlled way to produce more
cells
• The genetic material (DNA) of a cell can become damage or
changed, producing mutation that affect normal cell
growth and division.
• Extra cell thus formed may form a mass of tissue called a
Tumor.

5. Tumors?
• Benign tumors are not a cancer: these tumors are generally
slow growing expansive masses often with a pushing
margin and enclosed within a fibrous capsule.
• Malignant tumors are cancer: these tumors are generally
rapidly growing, invading the local tissue and spreading the
distant sites.

6. Carcinogenesis
• Carcinogenesis: A Process by which normal cells gets transformed into cancer cells.
• Hyperplasia: Abnormal proliferation of normal cells within a tissue and may result
in the enlargement of an organ or formation of a benign tumor.
• Dysplasia: Condition characterized by an abnormal expansion of immature cells
within a tissue, suggestive of an early neoplastic process.
• Neoplasia: Abnormal, uncoordinated proliferation of cells, usually causes a lump or
tumor. Neoplasms may be benign, pre-malignant or malignant.

7. Cancer statement
• World wide cancer related death is 20%.
• Most common cancer in Developed countries
– Lung cancer
– Breast cancer
– Prostate cancer
– Colorectal cancer
• Most common cancer in Developing countries
– Liver cancer
– Cervical cancer
– Oesophageal cancer

8. Signs of cancer
• Alteration in eating habit
• Loss of appetite
• Change in Bowel of habit
• Presence of a lump at any site
• Appearance of bleeding
• Unexplained recurrent pain
• Recurrent fever
• Unexplained weight loss
• Repeated infection which do not clear with
treatment

9. Major types of Cancer
• Carcinoma- cancer of skin or in tissues that line or
cover internal organs
• Sarcoma- cancer of bone, cartilage, fat, muscle, blood
vessels or other connective or supportive tissue
• Luekemia- cancer of blood-forming tissue such as the
bone marrow and causes large numbers of abnormal
blood cells
• Lymphoma-myeloma- cancers of the cells of the
immune system
• Central nervous system cancers- cancers of the brain
and spinal chord

10. Causes Of Cancer
• There are number of factors which cause cancer
such as
– Environmental factors
– Food habit
– Life style
– Genetic factor
– Inadequacy in detection and
reporting of cases

12. Environmental factors
• Use of Tobacco
– Causes lung cancer, mouth, larynx, bladder, esophagus, pancreas and probably
kidney cancer
• Use of Alcohol
– Excess of alcohol can cause esophageal and liver cancer
– Excess intake of beer may be cause rectal cancer
– Alcohol contributes 3% of all cancer death.
• Dietary factor
– Smoke fish is related to stomach cancer
– High fat diet to breast cancer
– Beef is to bowel cancer
– Food additive and contaminants have fallen under
suspicion as causative agent

13. • Radiations or exposures
– Occupational exposure reported 1-5% of human cancer
– These exposure includes arsenic, vinyl chloride, polycyclic
hydrocarbons, benzene etc.
– All industrial cancinogens
• Viruses
– Pappiloma(cervix cancer), retrovirus, hepatitis B
– HIV infection - kaposi’s carcinoma & AIDS - non Hodgkin’s
lymphoma
– Human T cell leukemia virus
• Sunlight, radiation, water and air pollution, pesticides
are the environmental factors for cancer

14. Breast Cancer
• Breast cancer is the most common
cancer among the women.
• About 9 lakh women are
Diagnosed every year and
causes 5,19,000 deaths
in a year worldwide.

15. Risk factors
• Age
– Uncommon below the age of 35
– Mean age in Indian women about 42
– Women who developed their first breast cancer under the age of 40 have 3
times the risk of developing a second breast cancer
– At the time of menopause there is a dip incidence of breast cancer

16. • Family history
– High to those with positive history in their family
– Especially if mother and sister has got breast cancer
during the menopause
• Age at menarche and menopause
– Early menarche and late menopause are risk factor
– 40 or more years of mensuration doubles the risk of
breast cancer as
compare to 30 years.

17. • Hormonal factor

18. References
• https://www.sciencedirect.com/science/article/pi
i/S2251729415000026
• https://cisncancer.org/cancer101/what_causes_c
ancer_02.html
• https://www.medindia.net/patientinfo/breast-
cancer.htm
• https://www.carelife.com/cancer/med_onc/natu
re_cancer.html
• https://sites.google.com/site/coloncancerucsi/ho
me/carcinogenesis