Shreya M. Modi
P. G. Department of Microbiology.
Department of Life Science, Patan. Dt.-8/8/2011.
Types of cancer.
Causes of cancer.
Characteristics of cancerous cells.
The goals of cancer treatments.
Treatments of cancer.
How cancer is treated?
How can cancer be prevented?
Disease in which abnormal cells grow &
divide without control & are able to invade
other tissues that is called Cancer.
Cancerous cells can spread to other parts of
the body through the blood & lymph system.
Diagnosis & treatment of this cancerous cells
that is called Anti-cancer treatment.
There are two types of tumor but not all
tumors are cancerous.
1)Benign tumors are not cancerous.
-They can often be removed & in most
cases, they don’t come back.
-Cells in benign tumors don’t spread to other
parts of the body.
2)Malignant tumors are cancerous.
-Cells in these tumors can invade nearby
tissues & spread to other parts of the body.
Types of Cancer:
- There are 5 types of Cancer.
1) Carcinoma : - It begins at the skin (or) at tissues
that cover internal organs.
2) Sarcoma : - It begins at bone, cartilage, muscle,
blood vessels & other connective tissue.
3) Leukemia : - It begins at blood-forming tissue
such as the bone marrow.
4) Lymphoma & myeloma : - It begins at the cells of the
5) Central nervous system cancers : - It begins at the tissues of the brain
& spinal cord.
Common types of Cancer:
1) Blood Cancers: - Leukemia (or) Lymphoma.
2) Bone Cancers: - Osteosarcoma.
3) Brain Cancers: - Adult brain tumor.
4) Breast Cancers: - Inflammatory breast cancer.
- Invasive types of breast cancer.
5) Digestive/Gastrointestinal Cancers: - Gastrointestinal cancer.
- Colon cancer & Liver cancer.
- Pancreatic cancer & Small intestine cancer.
6) Eye Cancers: - Retinoblastoma.
7) Endocrine Cancers: - Thyroid cancer & Parathyroid cancer.
- Pituitary tumor.
8) Gynecologic Cancers: - Cervical cancer & Ovarian cancer.
9) Head & Neck Cancers: - Salivary gland cancer.
10) Respiratory Cancers: - Lung cancer.
11) Skin Cancers: - Melanoma & Non-melanoma cancer.
Causes of Cancer:
Normal cells in the body follow a path of
growth, division & death.
But, Cancer is ultimately the result of
damaging DNA & inducing mutation to the
cells, that uncontrollably grow & divide but
When, programmed cell death process breaks
down, cancer begins to form & leads to
growth of abnormal cancerous cells.
There are some cancers occur by the certain viruses:
Viruses. Tumors induced.
-Herpes viruses. Epstein – Barr virus. Burkitt’s lymphoma,
-Papova viruses. Human papilloma viruses. Cervical cancer.
-C-type Viruses. Rous sarcoma virus. Sarcomas.
-Retro Viruses. Human T-cell leukemia virus. Leukemias / Lymphomas.
Characteristics of Cancerous Cells:
Cancer cells divide rapidly.
They are “immortal”.
Cell-cell communication is altered.
Ability to metastasise.
Molecular changes in cell membrane
The Goals of Cancer Treatments:
-Total irradication of cancerous cells.
-Alleviation of symptoms.
-Avoidance of life-threatening toxicity.
-Increased survival & improved quality of life.
-Attempt to eradicate microscopic
cancer after surgery.
e.g. breast cancer.
Treatments of cancer:
The discovery of oncogenes & tumor
suppresor genes will allow the development
of new drugs that act selectively against the
Most of the drugs currently used in cancer
treatment either damage DNA (or) inhibit
Consequently, these drugs are toxic not only
to cancerous cells but also to normal cells.
The use of drugs that inhibit tumor growth
by interfering with angiogenesis (blood vessel
formation) (or) distrupting tumor blood
vessels, rather than acting directly against
FDA to approve the use of the first
angiogenesis inhibitor, a monoclonal antibody
against vascular endothelial grow factor
(VEGF), for treatment of colon cancer.
Two small molecule inhibitors of the VEGF
receptor have also been approved for
treatment of kidney cancer.
How cancer is treated?
Cancer treatment depends on the type of cancer,
the stage of the cancer, age, health status &
additional personal characteristics.
There is no single treatment for cancer & patients
often receive a combination of therapies.
There are certain therapies used for cancer treatment.
3) Chemo therapy.
4) Immuno therapy.
5) Hormone therapy.
6) Gene therapy.
7) Recombinant DNA approach.
Surgery is the oldest known treatment for
If a cancer has not metastasized, it is
possible to completely cure a patient by
surgically removing the cancerous cells
surrounding non-tumorous tissues.
This is often seen in the removal of the
prostate (or) breast.
After the disease has spread,
however, it is nearly impossible
to remove all of the
Side effects of surgery:
Loss of appetite.
Swelling around the site of surgery.
Drainage from the site of surgery.
Bruising around the site of surgery.
This treatment focuse
high-energy rays on
cancerous cells & causing
Mutations are more likely
to kill rapidly growing
Location of a tumor must
be clearly defined before
treatment is begin.
This therapy can’t be used
on metastatic tumors.
Radiotherapy utilizes high-energy X-rays &
gamma-rays that are emitted from metals such
Side effects of radiation:
Cell damage & regeneration
Cell regeneration on children.
chemicals that interfere with
the cell division process -
damaging proteins (or) DNA.
So, that cancerous cells will
Chemotherapy is generally
used to treat cancer that
has spread (or) metastasized
because the medicines travel
throughout the entire body.
Combination therapies often include multiple
types of chemotherapy (or) chemotherapy
combined with other treatment options.
Principles of Combined Chemotherapy:
Each drug is active against the cancer.
Each drug has a different mechanism of action.
Each drug has a different mechanism of
Non-overlapping toxicities among the drugs.
Some Druges used in cancer chemotherapy:
Class of drugs. Drugs. Mechanism of action.
Antimetabolites. Methotrexate. Inhibit pathways for biosynthesis
5-fluorouracil. of nucleic acids by substituting
6-mercaptopurine. for normal compound.
Antibiotics. Actinomycin D. Bind to DNA.
Alkylating agents. Nitrogen mustard. Chemically modify DNA.
Mitotic inhibitors. Vincristine. Interfere with mitosis.
Others. Asparaginase. Degrade the a. acid asparagine.
• Mechanism of action:
cross-link two strands
of DNA leading to
impairment of DNA
replication & RNA
Immunotherapy aims to get
the body's immune system
to fight the tumor.
It improves cancer-fighting
abilities by stimulating the
entire immune system.
By introduce various
vaccines & antibodies into
the body can inhibit the
growth of various cancerous
There are two types of immunotherapy
1) Local immunotherapy: It injects a treatment
into an affected area.
For example, to cause inflammation that
causes a tumor to shrink.
2) Systemic immunotherapy: It treats the
whole body by administering an agent such
as the protein interferon alpha
that can shrink tumors.
•Bone marrow transplantation can also be
considered immunotherapy because the donor's
immune cells will often attack the tumor (or)
cancerous cells that are present in the host.
Side effects of immunotherapy:
Several cancers have been
linked to some types of
hormones, most notably in
breast & prostate cancer.
Hormone therapy is
designed to alter hormone
production in the body so,
that cancerous cells stop
growing (or) are killed
Breast cancer hormone
therapies often focus on
reducing estrogen levels.
(a common drug for this
Prostate cancer hormone
therapies often focus on
reducing testosterone levels.
In addition, some leukemia
& lymphoma cases can be
treated with the hormone
Side effects of hormone:
Hormones. Drug. Mechanism of action.
Estrogen. Tamoxifen. Inhibit growth of particular
Anastrozole. hormone that are necessary
Cortisone. for the growth of certain
Some drugs which used in Hormone therapy:
The goal of gene therapy is
to replace damaged genes.
For example, researchers
are trying to replace the
damaged gene that signals
cells to stop divide.
Other gene-based therapies
focus on further damaging
cancerous cell DNA, where,
the cell commits suicide.
There are two types of genes:
1)Tumor suppressor gene:
-It regulating the cell cycle & apoptosis.
-when it is active it “suppresses” tumors.
-when it is inactive it may involve DNA
-It is derived from protooncogenes.
-It normally play role in signal transduction &
-It promotes uncontrolled growth of tumor.
-Oncogenes in retroviruses are referred to as
V-onc & those in tumors as C-onc.
There are two types of gene therapy:
1)Germ line gene therapy:
- In this gene therapy, Germ cells, i.e., sperm
(or) eggs are modified by the functional genes,
which are integrated into their genomes.
- The change due to therapy would be
heritable & would be passed on to later
2)Somatic gene therapy:
- In this gene therapy, the therapeutic genes
are transferred into the somatic cells of a
-Any modifications & effects will not be
inherited by the patient's later generations.
7)Recombinant DNA approach:
This approach delivering the killer genes only
to the tumor cells & not to normal cells.
Most successful gene therapies employ an
ex-vivo approach, in which cells are removed
from the body, manipulated & returned.
But this approach can’t be used against tumor
cells, because tumor cells can’t be removed
from the body.
For this approach we must used method that
will allow in-vivo delivery of genes to targeted
How can cancer be prevented?
Cancers that are the easiest to prevent.
By, - to avoid smoke tobacco,
- to avoid drink alcohol.
Diet is also an important part of cancer prevention.
-many women receive a human papillomavirus
vaccines which can prevent the causes of cervical
-Hepatitis B vaccines which can prevent the causes
of liver cancer. etc…
Breast self-examination, are common methods
-Mammograms, for screening of
-Testicular self-examination, various cancers. etc…
The cell, a molecular approach, 5th edition,
By – Geoffrey M. Cooper &
Robert E. Hausman.
Instent notes in immunology.