Biology of cancer and treatment

Done by:Tumadhir jilani

To:Dr:sabah

-Introduction.-The characteristics of cancer.-Cancer is genetic disease.-Types of cancer genes.-What causes cancer?-Carcinogens.-Benign and malignant.-Cancer treatment and prevention.

Index

The division of normal cells is precisely controlled. New cells are only formed for growth or to replace dead ones.Cancerous cells divide repeatedly out of control even though they are not needed, they crowd out other normal cells and function abnormally. They can also destroy the correct functioning of major organs.

Introduction of cancer

The Characteristics of Cancer

As genes switch on and off, they determine when and how fast the cell will grow and divide, when it will stop dividing, and even when it will die.

Cancer can result when controls over cell division are lost…

Cancer is a Genetic Disease

Cancer is a genetic disease that develops in a predictable sequence of steps..

Carcinogenesis• Transformation of a normal cell

into a cancerous cell.• Step-by-step transformation.

Carcinogenesis Occurs in Predictable Steps

A Common Type of Colorectal Cancer May Develop by These Steps

Types of cancer genes

Type of gene Normal function Mutated function Types of proteins

Enzymes for mismatch or excision repair

Fail to repair DNA mutations

Repair DNA mutations

DNA repair gene mutation

Checkpoint molecules

Fails to suppress division

Suppresses cell division

Tumor suppressor gene

Growth factorsPromotes division - abnormal time or cell type

Promotes division

Oncogene

What causes cancer?

Cancer arises from the mutation of a normal gene.Mutated genes that cause cancer are called oncogenes.It is thought that several mutations need to occur to give rise to cancer.Cells that are old or not functioning properly normally self destruct and are replaced by new cells.However, cancerous cells do not self destruct and continue to divide rapidly producing millions of new cancerous cells.

A factor which brings about a mutation is called a mutagen.

A mutagen is mutagenic.

Any agent that causes cancer is called a carcinogen and is described as carcinogenic.

So some mutagens are carcinogenic…

-Ionising radiation – X Rays, UV light.

-Chemicals – tar from cigarettes.

-Virus infection – papilloma virus can be responsible for cervical cancer.

-Hereditary predisposition – Some families are more susceptible to getting certain cancers.

carcinogens

Other Factors Also May Lead to Cancer

Breakdowns in immunityHealthy immune system can target and destroy cancer cells.When cancer cells have altered proteins at its surface, cells are not destroyed.

Risk of cancer increases: -With age.-When an immune system has been suppressed for a long time.-HIV infection.-Immunosuppressant drugs.-Anxiety and depression.

Benign and malignant?

Benign tumours do not spread from their site of origin, but can crowd out (squash) surrounding cells eg brain tumour, warts.

Malignant tumours can spread from the original site and cause secondary tumours. This is called metastasis. They interfere with neighbouring cells and can block blood vessels, the gut, glands, lungs etc.

Both types of tumour can tire the body out as they both need a huge amount of nutrients to sustain the rapid growth and division of the cells.

Main Features of Benign and Malignant Tumors

Cancer Spreads Step-by-Step

Some Major Types of CancerIn general, a cancer is named according to the type of tissue in which it first forms Sarcomas: cancer of connective tissue

Carcinomas: cancer arising from epithelium

Lymphomas: cancer of lymphoid tissue

Leukemias: cancer of stem cells

Gliomas: cancer of brain glial cells

Cancer Treatment and Prevention

When a person is diagnosed with cancer, a variety of weapons are available to combat it:

Chemotherapy drugs

Radiation therapy

Surgery

And other….

Drugs used to kill cancer cells; disrupt some aspect of cell division.Toxic to healthy cells; hair, bone marrow, lymphocytes, and epithelial cells of intestinal lining .Side effects include hair loss, nausea, vomiting, and reduced immune responses.

Chemotherapy

Radiation therapy

In radiotherapy, high-energy rays are used to kill cancer cells and stop them from growing and dividing. Like surgery, radiotherapy is a local treatment; it can affect cancer cells only in the treated area. Radiotherapy is usually given on an outpatient basis, 5 days a week, for several weeks. Patients are not radioactive during or after treatment.

The most common side effects are tiredness, skin reactions such as rash or redness, and loss of appetite. Radiation therapy may also cause a temporary lowering of the white blood cell count, cells that help protect the body against infection. The side effects are usually temporary, developing gradually over the weeks of the treatment, and improving gradually after treatment is completed.

Surgery therapy

Surgery is the primary method of treatment of most isolated solid cancers and may play a role in palliation and prolongation of survival. It is typically an important part of making the definitive diagnosis and staging the tumor as biopsies are usually required. In localized cancer surgery typically attempts to remove the entire mass along with, in certain cases, the lymph nodes in the area. For some types of cancer this is all that is needed for a good outcome.

Hormone therapy

Some types of cancer, for example, breast cancer and prostate cancer, depend on hormones to grow. For this reason, doctors may recommend therapy that prevents cancer cells from getting or using the hormones they need. Sometimes, the patient has surgery to remove the organs (like the ovaries or testes) that make the hormones. Or drugs are used to stop hormone production or change the way the hormones work.

Hormone therapy may cause nausea, swelling of the limbs or weight gain through water retention. In women, there may be irregular periods and vaginal dryness. In men, there may be impotence or loss of sexual desire.

Biological Therapy

Biological therapy, also called immunotherapy, uses the body's own immune system to fight infection and disease or protect the body from some of the side effects of other forms of treatment. Monoclonal antibodies, interferon, interleukin-2, and colony-stimulating factors such as GM-CSF and G-CSF, are forms of biological therapy.

These treatments often cause temporary flu-like symptoms such as fever and chills, muscle aches and weakness, loss of appetite and diarrhoea.

Good Lifestyle Choices Can Limit Cancer Risk-Avoid tobacco completely.

-Maintain a desirable weight; eat a low-fat diet with plenty of fruits and vegetables.

-Avoid alcohol .

-Make sure your living and work environment is safe from carcinogens.

-Protect your skin from the sun’s UV rays.

. Remember you can’t inherit cancer its just that you maybe more susceptible to getting it. so be careful and prevent your self…….

finally

Thank you