Theory:

In the previous theory, we saw cancer and types of cancers. In this theory, we shall see carcinogenic agents, treatment, preventive measures, and treatment.
Carcinogenic agents:
Agents which cause cancer are known as carcinogenic agents.
These agents may be physical, chemical, ionising radiation and biological agents.
 
1.  Physical irritant:
 
Physical irritants cause significant inflammation through friction, pressure, heat, dryness or occlusion.
  • Lung cancer, cancers of the oral cavity, pharynx (throat) and larynx are caused by heavy smoking.
  • Oral cancer is caused by betel and tobacco chewing.
  • Excessive exposure to sunlight may cause skin cancer.
2.  Chemical agents:
 
These are hazardous substances that can increase the risk of cancer.
Example:
Nicotine, caffeine, coal and oil combustion products, pesticides, asbestos, nickel, certain dyes, and artificial sweeteners are all known to cause cancer.
3.  Radiations:
 
Radiation such as X-rays, gamma rays, radioactive chemicals, and non-ionizing radiations such as UV rays cause DNA damage, which leads to cancer.
 
4.  Biological agents:
 
These include cancer-causing viruses known as oncogenic viruses.
Treatment of cancer:
The following are some of the methods involved in the treatment of cancer.
 
1.  Surgery:

It is a method in which the tumours are removed from the body to prevent the further spread of cancer.
 
2. Radiation therapy:
  
Tumour cells are irradiated with fatal doses of radiation while normal cells around them are protected.
 
450px-Radiation_therapy_for_cancer.jpg
An illustration showing radiation therapy
 
3. Chemotherapy:
  
It entails the administration ofanticancer medications, which stop cancer cells from dividing and are used to kill them.
 
chemotherapy.jpg
Chemotherapy
 
4.  Immunotherapy:
 
It's a cancer treatment that boosts your immune system's ability to fight cancer. In this method, the biological response modifiers such as interferons activate the immune system, thereby destroying tumours.
 
800px-Adoptive_T-cell_therapy.png
An illustration showing immunotherapy
Preventive measures for cancer:
  • Primary prevention and early detection should be the goal of cancer control programmes.
  • To prevent lung cancer, avoid tobacco smoking, and take precautions to avoid exposure to toxic industrial pollutants.
  • Should avoid excessive radiation exposure to prevent skin cancer.
shutterstock1371205883.png
A picture explains the prevention of heart disease.
Reference:
https://commons.wikimedia.org/wiki/File:Radiation_therapy_for_cancer.jpg
https://pix4free.org/assets/library/2021-03-25/originals/chemotherapy.jpg
https://commons.wikimedia.org/wiki/File:Adoptive_T-cell_therapy.png