Cancer Epidemeology

1. CANCER
Haliru MY
Head of Radiotherapy Department,
Lagos University Teaching Hospital.
Lecturer ,College of Medicine

2. Cancer Epidemiology
• Definition : cancer is defined as uncontrolled abnormal cell
growth with capacity for invasive and propensity for distance
metastasis
• Cancer can originate form any cell of the body that has blood
supply and is no respecter of barrier.

9. Introduction
• Cancer is a public health problem worldwide
• Affecting all categories of persons.
• It is the second common cause of death in developed
countries
• Among the three leading causes of death in low and medium
income countries.
• Incidence in LMIC increased with reduction of mortality from
communicable diseases.

10. • Incidence on the rise as incidence of communicable falls
• An estimated 12.7 million new cancer cases were
diagnosed worldwide in 2008.
• Lung, female breast, colorectal and stomach cancers
were the most commonly diagnosed cancers, accounting
for more than 40% of all cases

11. List of Common Types of Cancers
• Lung cancer
• Breast cancer
• Prostate cancer
• Colorectal, Stomach and other Gastro-
intestinal cancers
• The Above are the most commonly diagnosed
cancers, accounting for more than 50% of all
cases

12. • Worldwide, an estimated 7.6 million deaths
from cancer occurred in 2008.
• Lung, stomach, liver, colorectal and female
breast cancers were the most common
causes, accounting for more than half of all
cancer deaths

13. Etiology/ Risk factors
• Chemicals/Environment
• Asbestos Exposure
• Agricultural fertilizer
• Industrial waste
• Formaldehyde
• Dyes
• Paints

14. • Food-
• High residue diet
• Aflatoxin in grains
• Preservatives in can foods
• Artificial Sweeteners
• Fluoridated Water

15. Genetics
• BRCA1 and BRCA
• P53
• FAP

16. • Hormones
• Ostrogen
• Testosterone

17. • Infectious Agent
• HIV = Kaposi's sarcoma
• HPV= cervical cancer
• Herpes virus = vulvar cancer
• Schistosoma = bladder adenocarcinoma

18. Radiation Exposure
• UV from sun = basal and squamous cell ca
• telephone Mast
• Miners
• Radiation worker

19. Tobacco
• Smoking
• Passive smoking
Alcohol
combined effect synergistic

20. Immunity
• Organ transplant
• Prolong Steroid use
• AIDS

21. Pathophysiology of cancer
Genetic changes
There are two broad categories of genes which
are affected by this change:
• Oncogenes
• Tumor suppressor genes

22. Genomic amplification
• Sometimes there may be genomic amplification.
• Here a cell gains many copies (often 20 or more) of a small
chromosomal locus, usually containing one or more
oncogenes and adjacent genetic material.

23. Point mutations
• Point mutations occur at single nucleotides.
There may be deletions, and insertions
especially at the promoter region of the gene

24. Translocation
• Translocation is when two separate
chromosomal regions become abnormally
fused. e.g. Philadelphia chromosome or
translocation of chromosomes 9 and 22,
which occurs in chronic myelogenous
leukaemia

26. Management
Multidisciplinary approach(MTD)
• Team of medical
• Clinical & Radiation Oncologist
• Surgeon
• Gynecologist
• Pathologist
• Oncology Nurses
• Radiologist etc.

27. • Investigation : Medical history
Clinical examination
Hematological general /specific
Radiological
Biopsy

28. Main mode of treatment:
• Surgery
• Radiotherapy
• Chemotherapy
• Hormonal therapy
• Targeted therapy

29. • Other modes includes
• Pain control
• Counseling
• Control of side effect of treatment

30. • Surgery:
a, Biopsy : FNAC , FNAB , Core needle biopsy
(Incision biopsy) and Excision biopsy
b, Resection, amputation , e.g. hemi-colectomy ,
mastectomy and prostatectomy
c, Toilet procedure (Palliation).
• Surgery is a Localized treatment usually for
localized or early disease.

31. • Radiotherapy: use of ionizing radiation for treatment of
mainly malignant disease .
• Ionising Radiation was accidentally discovered in 1895 and
this has had immense impact in medicine both in diagnosis
and intervention.
• Radiotherapy is a form of interventional medicine which has
undergone great evolution over the years for use of
superficial machine (KV) to megavoltage machines (MV)

32. Marie and Pierre Curie with Henri
Becquerel

33. • Radiotherapy can be Brachytherapy or Teletherapy
• Brachytherapy: placing radio isotope in close contact to
target point , usually for small volume tumour , usually with
curative intent.
• Brachytherapy is subdivided into mould therapy,
intra-cavitory brachytherapy ,
interstitial brachytherapy
• principles of inverse square law is employed , deliver high
dose to small area limiting radiation to immediate
surrounding

34. Cancer commonly treated with brachytherapy includes :
• Adenocarcinoma of the Prostate
• Squamous cell carcinoma
• Adenocarcinoma of the Thyroid
• Adenocarcinoma of the Endometrium etc.

35. Teletherapy :
• Use of ionizing radiation from a source that is at distant from
the target point (area treated).
Type of radiotherapy machines are
• Superficial treatment machine
• cobalt 60
• Linear accelerator
Type of beam generated
• Gamma rays
• electron beams

36. • Teletherapy is used in treatment of large volume tumours
which may be superficially located or deeply sighted.
Teletherapy could be used for
• Curative
• Palliative
• Neo-adjuvant
• Adjuvant
Indication for teletherapy
• Breast carcinoma post mastectomy
• Locally advanced Prostate carcinoma
• Hemostatic radiotherapy
• Pathological fracture etc.

37. • Chemotherapy :
• systemic treatment, use of cytotoxic drugs as main treatment
neoadjuvant , adjuvant , maintenance regime
• Cytotoxic drugs inhibit the proliferation of cancer cells, usually
by interfering directly or indirectly with DNA replication.
• They target cells that proliferate frequently, but in so doing can
affect normal cells that also proliferate frequently.
• These include bone marrow cells, cells of the gut lining, and hair
follicles, as discussed above.
• Damage to these cells leads to the common side effects of
immune suppression, nausea, and hair loss.

38. Types of cytotoxic drugs
Alkylating agents:
• Alkylating agents directly damage DNA, thereby preventing
cell division.
• These drugs can insert themselves into the DNA double
helix, thereby providing a physical block to the replication
of DNA.
• Alkylating agents include cyclophosphamide, melphalan,
carmustine
• busulfan
• Dacarbazine
• and thiotepa.

39. • The platinum drugs
• cisplatin
• carboplatin
• and oxaliplatin
• are sometimes grouped with alkylating agents

40. • Antimetabolites
• Antimetabolites interfere with DNA and RNA synthesis by
causing malformed nucleotides which are the building-blocks
for DNA and RNA.
• These agents damage cells during the S phase.
• Examples of antimetabolites include 5-fluorouracil, 6-
mercaptopurine
methotrexate
gemcitabine
and cytarabine

41. • Anti-tumor antibiotics
• Anthracyclines. Are anti-tumour antbiotics ,
• They interfere with enzymes involved in DNA replication
and are not cell-cycle-specific.
• Side effect : Heart toxicity is a common adverse effect.
Examples include daunorubicin
doxorubicin
bleomycin, and mitomycin-C.
• The drug Mitoxantrone is an anti-tumor antibiotic, but also
works by inhibiting the enzyme topoisomerase II, which is
used during DNA unwinding (DNA must be unwound prior
to replication).

42. • Topoisomerase inhibitors
• Topoisomerase II inhibitors include
• etoposide and teniposide.
• Topoisomerase I inhibitors include topotecan and irinotecan.
• Used in cervical carcinoma

43. • Mitotic inhibitors
• Certain mitotic inhibitors can be derive from plant alkaloids,
• They interfere with the mitosis phase of the cell cycle and
can also have effects in other phases.
• A common adverse effect is peripheral nerve damage.
• Mitotic inhibitors include taxanes such as paclitaxel and
docetaxel, and also vinca alkaloids such as vinblastine and
vincristine.

44. Corticosteroids
• Certain stecroids can be used to inhibit some types of
lymphoma, leukemias, and multiple myeloma
• Example steroids include prednisone and
methylprednisolone.

45. • Targeted therapy drugs
• Targeted therapy drugs are designed to inhibit a specific
protein involved in cancer progression.
• Target proteins are identified during the drug discovery
process as being different in some way in cancer cells versus
normal cells.

46. • Gefitinib and erlotinib are epidermal growth factor receptor
(EGFR) inhibitors.
• EGFR is a type of receptor tyrosine kinase (RTK), which are a
family of proteins involved in signal transduction.
• Avastin (bevasuzimab ) anti VEGF receptor

47. Hormones
• Certain genital hormones, or hormone-like drugs, can be
effective against breast, prostate, and some other
hormone-dependent cancers.
• They prevent a cancer cell from using the hormone as a
growth factor, or prevent the body from making the
hormone.
• Examples include estrogens, anti-estrogens, tamoxifen,
and anastrozole

48. • Immunotherapy
• They act by stimulating the body’s own immune system or
are antibodies or other immune system components made
outside of the body. Examples include interleukin-2 (IL-2)
and alemtuzumab.
• IL-2 is an immune system signaling molecule that plays an
important role in the body’s response to microbial
infection.
• Alemtuzumab is a humanized monoclonal antibody
indicated for the treatment of Chronic lymphocytic
leukemia.

49. • Thanks