cancer

2. CONTENTS:
 WHAT IS CANCER?
 TYPES OF CANCER
 CHARACTERSTICS OF CANCEROUS CELLS
 CAUSES
 PROGENITOR CELLS
 ONCOGENES
 TUMOR SUPPRESSOR GENES
 THERAPEUTIC INTERVENTIONS OF UNCONTROLLED
CELL GROWTH.

3. What is cancer?
a disease in which some of the body's cells grow uncontrollably and
spread to other parts of the body.
o In humans, cell differentiation and proliferation are highly manipulated
and regularized by the cell division mechanism.
o Uncontrolled cell division occurs when a process called contact
inhibition fails.
o In healthy organisms, during this process, when cells come in contact
with other cells, the process of cell replication ceases.

5. Cancer
Causes
- Cigarette smoking
- Poor diet
- Physical inactivity
- Occupational exposures
- Viruses and other
biological agents
- Reproductive factors
- Alcohol
High risk populations
- Poor
- Less educated
- Racial and ethnic
minorities
- Persons with a
family history of
cancer
- Elderly
Consequences
- High health care costs
for treatment
- Lost work productivity
- Insurance denial
- Disability
- Psychosocial problems
- Treatment complications
(e.g. Increased risk of
second cancers)
- Premature mortality
Metastasis means that cancer has spread to a different part of your body part than where it
started. When this happens, doctors say the cancer has “metastasized.”
Metastases is the plural form of metastasis. Metastases most commonly develop when
cancer cells break away from the main tumor and enter the body's bloodstream or lymphatic
system. These systems carry fluids around the body.
This means that the cancer cells can travel far from the original tumor and form new tumors
when they settle and grow in a different part of the body.

6. Tumors
Benign No metastasis
Maligna
nt
Proliferate from
one part to
another.
Types of cancer
Carcinoma;
(>80%)-epithelial tissues
(lung,breast,colon,prostate)
Sarcoma
(<2%)-mesodermal layer of
tissues(cartilage,gums,bones,fat
tissues)
Lymphoma and leukemia
(15-18%)
Affects lymphatic system
In liquid-high WBC

9. CHARACTERSTICS OF CANCEROUS CELL:
self-sufficiency in growth signals,
• insensitivity to anti-growth signals,
• tissue invasion and metastasis,
• limitless replicative potential,
• sustained angiogenesis (blood vessel growth),
• and evasion of apoptosis (cell death).
Causes
Cancer arises from the transformation of normal cells into tumor cells in a multi-stage
process that generally progresses from a pre-cancerous lesion to a malignant tumor.
These changes are the result of the interaction between a person's genetic factors and
three categories of external agents, including:
•physical carcinogens, such as ultraviolet and ionizing radiation;
•chemical carcinogens, such as asbestos, components of tobacco smoke, alcohol,
aflatoxin (a food contaminant), and arsenic (a drinking water contaminant); and

10. •biological carcinogens, such as infections from certain viruses, bacteria, or parasites.
WHO, through its cancer research agency, the International Agency for Research on Cancer
(IARC), maintains a classification of cancer-causing agents.
The incidence of cancer rises dramatically with age, most likely due to a build-up of risks for
specific cancers that increase with age. The overall risk accumulation is combined with the
tendency for cellular repair mechanisms to be less effective as a person grows older.
Risk factors
Tobacco use, alcohol consumption, unhealthy diet, physical inactivity and air pollution are risk
factors for cancer and other noncommunicable diseases.
Some chronic infections are risk factors for cancer; this is a particular issue in low- and
middle-income countries. Approximately 13% of cancers diagnosed in 2018 globally were
attributed to carcinogenic infections, including Helicobacter pylori, human papillomavirus
(HPV), hepatitis B virus, hepatitis C virus, and Epstein-Barr virus (2).
Hepatitis B and C viruses and some types of HPV increase the risk for liver and cervical
cancer, respectively. Infection with HIV increases the risk of developing cervical cancer six-
fold and substantially increases the risk of developing select other cancers such as Kaposi
sarcoma.

11. A progenitor cell: is a biological
cell that can differentiate into a specific
cell type. Stem cells and progenitor
cells have this ability in common.
However, stem cells are less specified
than progenitor cells.
Progenitor cells can only
differentiate into their "target" cell
type.
The most important difference between
stem cells and progenitor cells is that
stem cells can replicate indefinitely,
whereas progenitor cells can divide
only a limited number of times.
Controversy about the exact definition
remains and the concept is still
evolving. The primary role of progenitor cells is to
replace dead or damaged cells.
EXAMPLES:
 Satellite cells in muscles.
 Radial glial cells in cortex of brain.
 Hematopoietic progenitor cells (HPCs)
 Lymphoid progenitor cells (also known as
lymphoblasts)
 Myeloid progenitor cells

12. ONCOGENES:
• Oncogenes are the genes which encodes proteins that
promote loss of growth control and conversion of cell to
malignant state.
• Oncogenes are derived from proto-oncogenes.
• Most commonly mutated oncogene in human tumors is-
Ras; which encodes for GTP binding proteins that function
as molecular switches regulating pathways responsible for
proliferation and cell elongation.
• Oncogenes:
 BCL-2:encodes for protein that inhibits apoptosis.
overexpression of BCL-2 suppress apoptosis,allowing abnormal
cells to proliferate to form lymphoid tumors.
 Sis oncogenes:Brain tumors. Due to over-expression of PDGF
(Platelet Derived Growth Factor).
 SRC:1st oncogene discovered ;
breast,prostate,head,lung,pancreas,etc.
 RAS
 MYC gene
 Raf.
 erbB.

13. TUMOR SUPPRESSOR GENES:
o A type of gene that regulates cell
growth(proliferating pathway).
o When a tumor suppressor gene is mutated,
uncontrolled cell growth may occur –
Cancer.
o These genes act as cell brakes.
o They encode proteins that restrains cell
growth and prevent cells from becoming
malignant.
o Anti-oncogene.
o Absence of such gene is corelated with
development of tumors i.e, these genes
suppress cancer.
 p53 protein-TP53 gene
 pRB gene – retinoblastoma protein
 Pten.

14. Therapeutic interventions of uncontrolled cell growth:
The most common treatments are surgery, chemotherapy, and radiation. Other options include targeted
therapy, immunotherapy, laser, hormonal therapy, and others.
 Surgery : Surgery is a common treatment for many types of cancer. During the
operation, the surgeon takes out the mass of cancerous cells (tumor) and some of
the nearby tissue. Sometimes, surgery is done to relieve side effects caused by a
tumor.
 Chemotherapy: refers to drugs used to kill cancer cells. The drugs may be given
by mouth or into a blood vessel . Different types of drugs may be given together at
the same time or one after the other.
 Radiation therapy: uses x-rays, particles, or radioactive seeds to kill cancer cells.
Cancer cells grow and divide faster than normal cells in the body. Because
radiation is most harmful to quickly growing cells, radiation therapy damages
cancer cells more than normal cells. This prevents the cancer cells from growing
and dividing, and leads to cell death.

15. The two main types of radiation therapy are:
•External beam : This is the most common form. It aims x-rays or particles at the tumor from outside the
body.
•Internal beam : This form delivers radiation inside your body. It may be given by radioactive seeds placed
into or near the tumor; a liquid or pill that you swallow; or through a vein.
 Targeted Therapies: Targeted therapy uses drugs to stop cancer from growing and spreading. It does
this with less harm to normal cells than other treatments.
Standard chemotherapy works by killing cancer cells and some normal cells. Targeted treatment zeroes in on
specific targets (molecules) in cancer cells. These targets play a role in how cancer cells grow and survive. Using
these targets, the drug disables the cancer cells so they cannot spread.
Targeted therapy drugs work in a few different ways. They may:
•Turn off the process in cancer cells that causes them to grow and spread
•Trigger cancer cells to die on their own
•Kill cancer cells directly
Targeted therapies are given as a pill.
 Immunotherapy: immunotherapy is a type of cancer treatment that relies on the body's ability to fight
infection (immune system). It uses substances made by the body or in a lab to help the immune system work
harder or in a more targeted way to fight cancer. This helps your body get rid of cancer cells.

16. Immunotherapy works by:
•Stopping or slowing the growth of cancer cells
•Preventing cancer from spreading to other parts of the body
•Boosting the immune system's ability to get rid of cancer cells
These drugs are designed to seek and attack certain parts of a cancer cell. Some have toxins or radioactive
substances attached to them.
 Hormonal therapy: Hormone therapy is used to treat cancers that are fueled by hormones, such as
breast, prostate, and ovarian cancers. It uses surgery, or drugs to stop or block the body's natural hormones.
This helps slow the growth of cancer cells.
The surgery involves removing organs that make hormones: the ovaries or testes. The drugs are given by
injection or as pills.
 Hyperthermia: uses heat to damage and kill cancer cells without harming normal cells.
It may be used for:
•A small area of cells, such as a tumor
•Parts of the body, such as an organ or limb
•The whole body
The heat is delivered from a machine outside the body or through a needle or probe placed in
the tumor.

17.  Laser Therapy:
uses a very narrow, focused beam of light to destroy cancer cells. Laser therapy can be used to:
•Destroy tumors and precancerous growths
•Shrink tumors that are blocking the stomach, colon, or esophagus
•Help treat cancer symptoms, such as bleeding
•Seal nerve endings after surgery to reduce pain
•Seal lymph vessels after surgery to reduce swelling and keep tumor cells from spreading
Laser therapy is often given through a thin, lighted tube that is put inside the body. Thin fibers at the end of the tube
direct the light at the cancer cells. Lasers are also used on the skin.
Lasers are most often used with other types of cancer treatment such as radiation and chemotherapy.
 Photodynamic Therapy:
a person gets a shot of a drug that is sensitive to a special type of light. The drug
stays in cancer cells longer than it stays in healthy cells. Then, the doctor directs light from a laser or other source at
the cancer cells. The light changes the drug to a substance that kills the cancer cells.
 Cryotherapy: Also called cryosurgery, this therapy uses very cold gas to freeze and kill cancer cells. It is
sometimes used to treat cells that might turn into cancer (called pre-cancerous cells) on the skin or cervix, for
example. Doctors can also use a special instrument to deliver cryotherapy to tumors inside the body, such as the
liver or prostate.

18. THANK YOU