Oncology Basics.ppt

Basics of Oncology & Cancer

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Basics

2. ONCOLOGY -BASICS
WHAT IS CANCER?
NORMAL CELL CYCLE
CANCER & THE CELL CYCLE
WHAT ARE CARCINOGENS?
WHAT IS A TUMOR?
TYPES OF TUMORS
CLASSIFICATION OF CANCER
DIAGNOSIS OF CANCER
CANCER THERAPY
RADIOTHERAPY
CHEMOTHERAPY
ONCOLOGY -BASICS

3. ONCOLOGY -BASICS
Cancer is a group of diseases that are characterized by uncontrolled proliferation
(division) of abnormal cells.
Every minute, ten million cells divide in human body.
Normally, cell division, accompanied by growth and specialized development,
takes place in an orderly pattern.
But when a cell becomes malignant (cancerous), it acts in profoundly abnormal
ways.
Cancer develops from a single cell that has undergone mutations(changes) in its
DNA, the genetic material that carries the body's hereditary instructions.
Instead of maturing normally and dying, cancerous cells reproduce without
control.
They not only divide faster, but also never stop dividing, and they fail to mature.

4. WHAT IS CANCER?
When removed from the body and placed in a laboratory dish with
nutrients, they seem to be immortal.
The Word “Cancer” is from Hippocrates, the ancient Greek
physician.
He was first to recognize the difference between benign and
malignant tumors.
The invasion of tumors reminded him of crab claws that he called
the disease Karakinos, the Greek name for “Crab”.
In English, this term is known as Carcinoma.

5. CHARECTERISTICSOF CANCER
The 5 Characteristics of Cancer cells are:
•Uncontrolled growth
•Genetic difference
•Abnormal appearance
•Less differentiation
•Ability to metastasize

6. WHAT ARE CARCINOGENS ?
Agents which lead to the development of cancer are called Carcinogens
−Chemical: Substances in diet, tobacco, industrial chemicals &
radiation.
−Physical: Ionizing radiation from sunlight or other sources.
−Viral: Viruses such as HPV (Human Papilloma Virus) and
−EBV (Epstein Barr virus).
−Genetic: Genetic abnormalities and mutations.

7. WHAT IS A TUMOR?
Atumourisaswellingorlesionformedbyanabnormalgrowthof
cells
Tumorsarealsononcancerousinnature(Benign)
Asinglecancerouscell,whicheventuallybecomesamicroscopic
collectionofcellsandbeginstoinvadesurroundingtissueis
calledaMalignantTumors
Eachcancerrunsitsowndistinctivecourse
Inleukemia,theabnormalcellsdispersethroughoutthebodyinthe
bloodandbonemarrow

8. WHAT IS A TUMOR?
With most cancers, a mass of cancer cells called a tumor begins to grow.
Some tumors (particularly in children and young adults) may double their size
in a month.
Colon and lung tumors may require two months to double, and some take a
year or more.
Most tumors are diagnosed late with a mass of 10 grams
These cells may invade tissues and spread throughout the body through the
blood and lymph systems.
Tumor above one kg is not compatible with human life.

9. TYPES OF TUMORS
Tumors are of two types:
-Benign (Non-cancerous)
-Malignant (Cancerous)
Benign Tumors:
•Benign tumors remain localized to the tissue in which they arise; they may
grow large but will NOT spread to other parts of the body.
•If they grow into openings such as the trachea or a major blood vessel, they
can be fatal.
•In early cases, cure is possible through surgical removal or radiation.

10. TYPES OF TUMORS
Malignant Tumors:
•Malignant tumors are more serious in nature.
•Some of their cells break off, invading and destroying surrounding tissue.
•Travel across the blood or lymph streams to distant parts of the body,
where new tumors form.
•From these new tumors, malignant cells break off again and form even
more colonies.
•This process of invasion and spread is called "metastasis”(secondary
tumors)
•Common sites for metastases are the lymph glands, bones, lungs, liver and
brain.

11. CLASSIFICATION OF CANCER
•Cancer is an umbrella term for nearly 200 diseases.
•There are two broad types of cancers: Each type can affect any organ or part
of the body
-Solid Tumors: Cancers of body tissues other than blood, bone
marrow, or the lymphatic system.
i) Carcinomas
ii) Sarcomas
-Hematological Malignancies: Cancers of blood or blood forming
organs (bone marrow and the lymphatic system).
i) Lymphomas
ii) Leukemias

12. CLASSIFICATION OF CANCER
•Carcinomas: Originate in the outer layer of cells of the skin and internal membranes.
-Breast, Ovarian, Cervix, Lung, Colorectal, Bladder, Prostate, Head & Neck,
Hepatobiliaryand Skin cancers.
-They typically spread to bones, liver or other sites.
•Sarcomas: Originate from the connective tissues. Cancers that fall in this category
are:
-Bone, Muscle, Cartilage, Fat, Vascular or Hematopoietic tissues
-These are quite rare & frequently spread to affect the lungs.
•Leukemia: A cancer of the blood or bone marrow and is characterized by an
abnormal proliferation of blood cells, usually WBC (leukocytes). Eg: AML,ALL,CML,CLL
•Lymphoma: A cancer that begins in the cells of the immune system (lymphatic
system). Eg: Hodgkin’s and Non-Hodgkin’s Lymphomas.

13. DIAGNOSIS OF CANCER
Diagnosis Involves The Following Steps:
I.Diagnosis workup & Pretreatment
evaluation
II.Classification and Staging

14. DIAGNOSIS OF CANCER
I)Diagnosis Workup & Pretreatment Evaluation
•Early Detection: The key to cancer survival is early detection. The major tools used
to detect cancer at early stages are:
−Medical History
−Physical Examination
−Screening Tests (Eg: Mammography for breast cancer)
•Diagnostic Procedures: Can confirm the presence of a suspected cancer and also
evaluate it for classification and staging. These procedures are of 3 types:
−Laboratory Procedures (Eg: Blood tests, Tumor markers)
−Visualization Techniques (Eg: Imaging, Endoscopy, Scanning)
−Biopsies (Examination of suspicious tissues to check for malignancy)

15. DIAGNOSIS OF CANCER
II) Classification & Staging:
•Following a diagnosis of cancer, the classification and staging procedures are
conducted.
•The morphological characteristics of the cancer cells are evaluated for classification as
a specific type of cancer.
•The extent of disease is evaluated to understand the stage of the cancer.
TNM Staging:
•The TNM staging system was devised by the American Joint Committee on Cancer
•This system stages cancers from Stages I-IV based on the following
TUMOR -Size and location
NODE -Involvement of Lymph nodes
METASTASES -Spread of the Cancer

16. DIAGNOSIS OF CANCER
STAGE TNM Status
I
T: Small Tumor
N: No Lymph Node Involvement
M: No Metastasis
II
T: Greater Tumor Involvement
N: Some Regional Lymph Node Involvement
M: No Metastasis
III
T: Significant Tumor Involvement
N: Greater Lymph Node Involvement
M: No Metastasis
IV
T: Significant Tumor Involvement
N: Significant Lymph Node Involvement
M: Presence of Metastasis

17. CANCER THERAPY
Goals of Cancer Therapy:
The goals of cancer therapy can be
•Curative-To cure the disease
•To prolong survival
•To improve Quality of Life (QOL)
•Palliative-To relieve the symptoms of the disease

18. FACTORS IN THERAPY DETERMINATION
Following Factors Influence the Choice of Cancer Therapy:
•Classification & Stage
•Patient Factors-Age, gender, general health, psychological status and
preferences
•Performance Status-Measurement of physical and functional status to
determine the ability to withstand aggressive treatment.
•Current Therapy

19. FACTORS IN THERAPY DETERMINATION
Approaches to Cancer Therapy:
•Surgery
•Chemotherapy
•Radiotherapy
−Combination of surgery & chemotherapy / surgery & radiotherapy /
chemotherapy & radiotherapy
−Combination of surgery, chemotherapy and radiotherapy

20. SUPPORTIVE THERAPY
Pain Management
Nutritional Support
Management of Infection
Blood and Blood products
Management of side effects of Chemotherapy & Radiotherapy
Psycho -Social support

21. RESPONSE TO TREATMENT
•Complete Response: Complete disappearance of signs & symptoms
for at least one month.
•Partial Response: 50% or greater reduction in all measured lesions
for at least one month with no new lesions.
•Stable Disease: No change in the status of the disease.
•Progression: 25 % or more increase in lesions or appearance of new
lesions.
•Improvement in QOL:Improvement in quality of life in terms of
physical well-being, mental function and social interactions.

22. RADIOTHERAPY
Radiotherapy is the use of ionizing radiation to treat diseases
Radiotherapy can cure some cancers and can reduce the chance of a cancer
coming back after surgery, but can cause side effects
It can be used to reduce cancer symptoms
Many people with cancer will have radiotherapy as part of their treatment
This can be given either asExternal Radiotherapy from outside the body,
using x-rays or cobalt irradiation or from within the body as Internal
Radiotherapy
Radiotherapy works by destroying the cancer cells in the treated area
Normal cells are sometimes damaged by radiotherapy, can repair
themselves more effectively

23. RADIOTHERAPY
Methods of Radiation Therapy:
•Teletherapy -Radiation is administered externally.
•Brachytherapy -Radiation is administered internally, in which a
sealed radiation source is placed within the body.
•Systemic Therapy -Radioisotopes are injected into the systemic
circulation.

24. RADIOTHERAPY
Mechanism of Action of Radiation Therapy:
Radiation exerts two major effects on cancer cells:
•Direct Effects -Damages the genetic material of the cell.
•Indirect Effects -Damages the cell components such as cell
membrane, proteins, carbohydrates and enzymes. Also produces
cytotoxic compounds.

25. RADIOTHERAPY
Complications of Radiotherapy:
•Acute -Effects on skin, GI tract, bone marrow & hair follicles
•Delayed -Fibrosis in organs, sterility, somatic mutations.

26. CHEMOTHERAPY
•Chemotherapy is the use of drugs to kill cancer cells.
•Chemotherapy is used in the treatment of both solid tumors as well as
hematological malignancies.
Role of Chemotherapy in Cancer Treatment:
•Primary Therapy: Induction therapy aimed at achieving complete or partial
response.
•Maintenance Therapy: Drug therapy started after the primary therapy to
sustain remission. Lower dose is used in this setting.
•Neoadjuvant Therapy: This is the initial drug therapy in order to reduce the
tumor size before surgery or radiation.
•Adjuvant Therapy: Drug therapy after surgery or radiation.

27. CHEMOTHERAPY
Mechanism of Action of Chemotherapeutic Agents:
•Cytotoxicity induced by interfering with DNA synthesis and
function
•This is achieved in one of the following action:
−Producing breaks in the strands
−Damaging components of the DNA
−Causing cross links among the strands
−Damaging enzymes necessary for DNA repair

28. CHEMOTHERAPY
Classification of Chemotherapeutic Agents:
Based on MOA:
CLASS EXAMPLES
Alkylatingagents
Melphalan, Cyclophosphamide, Ifosfamide,
Chlorambucil, Carboplatin,Cisplatin, Oxaliplatin,
Busulfan, Temozolomide
Antimetabolites
Thioguanine, Fluorouracil, Capecitabine,
Gemcitabine
Mitotic inhibitor Docetaxel, Paclitaxel, Vinblastine, Vincristine
Antitumor antibioticsDoxorubicin, Epirubicin, Bleomycin, Hydroxyurea
Topoisomerase inhibitors Topotecan, Irinotecan, Etoposide
Tyrosinekinase inhibitorsErlotinib, Gefitinib, Imatinib

29. CHEMOTHERAPY
Routes of Administration:
Topical
Oral
Intramuscular or subcutaneous
Intravenous
Intra-arterial
Intraperitoneal
Intrapleural
Intravesical

30. CHEMOTHERAPY
Combination Chemotherapy:
•Because single agent therapy does not cure cancer, combinations of agents
are the basis of chemotherapy regimens
Resistance to Chemotherapy:
•Genetic mutations in cancer cells may produce resistance to chemotherapy.
•This is the major reason for treatment failure in cancer
•Strategies such as the use of high dosages or new combination regimens are
used to overcome resistance

31. CHEMOTHERAPY
High-Dose Chemotherapy & BMT:
•In many cases, high dose chemotherapy produces an increase in clinical
response
•In order to avoid major complications from myelosuppression, the bone
marrow of the patient is harvested before chemotherapy administration
•Reinfusion is done after chemotherapy

32. CHEMOTHERAPY
Complications of Chemotherapy:
•Hair loss (Alopecia)
•Myelosuppression leading to low blood counts (Anemia / Neutropenia /
Thrombocytopenia)
•Nausea and Vomiting
•Tiredness and Fatigue
•Weight and appetite loss
•Cardiotoxicity / Neurotoxicity / Nephrotoxicity

33. CHEMOTHERAPY
Advantages of Chemotherapy:
•Systemic Therapy
•Specific for rapidly dividing cells
•Helps prevent metastases
•Minimal deformity or loss of function
•Can treat hematological malignancies
Disadvantages of Chemotherapy:
•Significant side-effects
•Resistance develops in course of time
•Some tumors are not chemo-sensitive
•Potentially carcinogenic

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