Epedemiology, etiology of cancer and occupational cancers

1. Epidemiology, Etiology of cancer and
Occupational cancers
Dr Kiran

2. WHAT IS CANCER?
Cancer, known medically as a malignant neoplasm, is a broad
group of various diseases, all involving unregulated cell growth.
In cancer, cells divide and grow uncontrollably forming malignant
tumors and invade nearby parts of the body.
The cancer may also spread tomore distant parts through lymph
or blood.

3. Burden of the disease- WORLD
• Cancer is one of the leading causes of morbidity and mortality worldwide,
with approximately 14 million new cases in 2012.
• The number of new cases is expected to rise by about 70% over
the next 2 decades .
• Cancer is the second leading cause of death globally, and was responsible
for 8.8 million deaths in 2015 .Globally, nearly 1 in 6 deaths is
due to cancer.
• Approximately 70% of deaths from cancer occur in low- and
middle-income countries.
• The overall age standardized cancer incidence rateis almost 25%
higher in men than in women, with rates of 205 and 165 per
100,000, respectively

4. Burden of thedisease-INDIA
• The InternationalAgency for Research on Cancer GLOBOCAN
projecthas predicted that India’s cancer burden willnearly double in
the next 20 years , from slightly over a million new cases in 2012
tomore than 1·7 million by 2035.
• These projections indicate that the absolute number of cancer deaths
will also rise from about 680 000 to 1·2 million in the same period

5. Estimated cancer incidence, 2018 (GLOBOCAN)

6. Indian ICMR Data

7. Estimated age standardized incidence and mortality rates, 2018
(GLOBOCAN)- WORLD
M ales
Females

8. Estimated age standardized incidence and mortality rates, 2018
(GLOBOCAN)- INDIA
M ales
Females

9. Regional variations in the age-adjusted incidence
rates of cancer in men and women indifferent
regions of India

10. ETIOLOGY

11. What causes Cancer?

12. ROAD MAP FOR DISCUSSION
A. Tobacco
B. Cancer Susceptibility Syndrome
C. DNA Viruses & RNAViruses
(15-
D. Inflammation
E. Chemical Factors
F. Physical Factors%)
G. Dietary Factors
H. Obesity and PhysicalActivity

13. CARCINOGENS ANDTOBACCO-INDUCED CANCERS
Lung PAH, NNK, Isoprene, Aldehydes,
Benzene
Larynx PAH
Nasal NNK, NNN
Oral Cavity PAH, NNK, NNN
Esophagus NNN, Other Nitrosamines
Liver NNK, Other Nitrosamines
Pancreas NNK, NNAL
Cervix PAH, NNK
Bladder AromaticAmines
Leukemia Benzene
Colorectal Heterocyclic AromaticAmines

14. CANCER SUSCEPTIBILITY GENES&
ASSOCIATED SYNDROMES
Associated
SyndromeRegulation of Translation PTEN
LKB1
Cowden Syndrome
Peutz-Jeghers
Syndrome
PTCH 1
Nevoid Basal Cell
Syndrome
Regulation of
Proliferation NF 1 Neurofibromatosis 1
(AD)
APC FamilialAdenomatous
Polyposis (AD)
Genomic Integrity and
Apoptosis BLM Bloom’s Syndrome
TP53 Li-Fraumeni Syndrome

15. HUMAN VIRUSES WITHONCOGENIC PROPERTIES
Virus Family Type Assoc Tumors Cofactors
Flaviviruses Hepatitis C Hepatocellular Ca -
Hepadnavirus Hepatitis B Hepatocellular Ca Aflatoxin,Alcohol,
Smoking
Herpesviruses EBV Burkitt’s Lymphoma,
Nasopharyngeal
Carcinoma, HL,
Gastric Cancers
Malaria
Nitrosamines
KSHV(HSV8)
Kaposi’s Sarcoma,
Pulmonary Effusion
Lymphoma,
Castleman’s Disease
HIV Infection
Papillomaviruses HPV 16,18 Anogenital Cancers Smoking
Polyomaviruses Merkel Cell
Virus
Merkel Cell
Carcinoma
Immunosuppression
Retroviruses HTLV-1 Adult T Cell
Leukemia
Uncertain

16. Pathological Condition Associated Tumors Etiological Agent
Sjogren Syndrome,
Hashimoto’s Thyroiditis
Mucosa-assoc lymphoid
tissue lymphomas
-
Reflux esophagitis,
Barrett’s esophagus
Esophageal Carcinoma Gastric acid,Alcoholism,
Smoking
Liver Cirrhosis Hepatocellular Carcinoma Alcoholism
IBD Colorectal carcinoma -
Cystitis, Bladder Bladder Carcinoma Chronic indwelling, urinary
inflammation catheters
Asbestosis, Silicosis Mesothelioma, Lung
Carcinoma
Asbestos fibres, Silica
particles
INFLAMMATORY CONDITION

17. CHEMICAL CARCINOGENS
Lung & Pleura Tobacco, Arsenic,
Asbestos, Silica, Coal tar
Aluminum production, coal
gasification, coke
production, hematite
mining, painters,
Oral Cavity Tobacco, Alcoholic, nickel
compounds
Boot and shoe production,
Furniture manufacturer
Gastric Smoked, salted and
pickled foods
-
Colon Heterocyclic amines,
Asbestos
Pattern Makers
Liver Aflatoxin, vinyl chloride,
alcoholic beverages -
Bladder Tobacco smoke, Benzidine,
Phenacetin
Magenta manufacture,
auramine manufacture

18. Ionizingradiation
UltravioletRadiation
RF & MicrowaveRadiation
ElectromagneticFields
Asbestos
Nanoparticles

20. DIET
Mutagens in foods, due to heatingof
proteins, can cause damage to DNA.
Alcohol - Best established dietary risk factor
Fat – Cancers of breast, colon, prostate, and
endometrium.
Red meat - Increased risk ofcolorectal
cancer.

21. CONTD..
Regular consumption - Increased risk of colorectal cancer.
The association is strongest for processed meat.
Anabolic hormones used in meat production.
Heterocyclic amines and PAH formed during cooking.
High amounts of heme iron, and nitrates and related
compounds convert to carcinogenic nitrosamines in the
colon.

22. CONTD..
Fruits and vegetables have been hypothesized in
cancer prevention.
Contain antioxidants, minerals, fiber, potassium,
carotenoids, vitamin C, folate, and other vitamins.
Supply less than 5% of total energy intake but
concentration of micronutrients in these foods is
greater than in most others.

23. Endogenous Risk ofOverweight
Endometrial
& Obesity estrogen levels & Breast Cancer
Established risk factor for colon cancer in both men and
women.
Increased physical activity - Protective for colon cancer.
Impact on insulin sensitivity and IGF profiles, and
inflammation, as well as some colon-specific mechanisms
Physical activity stimulates stool transit in the colon,
decreasing the exposure of colonic mucosa to carcinogens in

24. OCCUPATION AL
CAN CERS

25. Kn ow n Hum a n
Occu pa tion a l Lu ng
Ca nce rs
• Arse nic
• Asb estos
• Beryllium
• Ca dmium
• Ch lor om eth yl
eth ers
• Ch rom ium
• Coa l-related
prod ucts
• Mu stard gas
• Nicke l
• Ra don
• Vinyl ch lor ine

26. Lung Can ce r - Asbestos
• Chrysotile is the most comm on form of
asb estos (Oth er for m s are amosite ,
cr ocid olite , trem olite )
• Asb estos affe cts parench ym a and pleura
of lungs
• Ca n ca use ca nce r of laryn x, GI tract
(stom ach ) as we ll as lung
• Lon g la tency
• Syn ergism with sm okin g

27. Asbestos - Mesoth eliom a
• Un com m on
• No evid ence for dir ect rela tion sh ip
• Dose – resp on se rela tion sh ip exists,
althou gh no th resh old th eor ize d
• No interact ion with sm okin g
• All fib er typ es may ca use
mesoth eliom a
– Cr ocid olite (lon g, th in fiber) is th e
most pote nt typ e

28. Lu ng Can ce r -
Ch lor om ethyl ether
• Ch lor om eth yl m eth yl eth er
(CMME) a nd Bis (ch lor om eth yl)
eth er (BCME)
• BCME mor e pote nt th en CMME
• Oa t ce ll typ e
• In term edia te prod uct use d in ion-
exch ange resins, bacte ricid es,
pesticid es and solve nts

29. Lung Can ce r - Arse nic
• Ma y cause skin ca nce r, as we ll as lung
ca nce r
• Syn ergistic with sm okin g
– Be tw een additive a nd m ultip lica tive
• Most ofte n se en in upper lob es
• Cop per sm elting and pesticid e
prod uct ion
• Fou nd in natu ral and man-m ade sou rce s
– Seafood sou rce is non -toxic
– Toxic in Fow le r’s solu tion (u sed for

30. Lung Can ce r - Mustard
Ga s
• Bis (beta-ch lor oe th yl) su lfid e
• Poison ou s gas use d in WWI
• Causes squam ous cell lung CA
• Exce ss lu ng ca nce rs se en in
Japanese and Ge rman wor ke rs
manufa ctu rin g mustard gas

31. Lung Can ce r - Ra don
• “Wa stin g dise ase of th e mou ntains”
se en in m iners b y Agricola and
Pa race lsu s
• Ra don daughter prod ucts
• Cig arette sm okin g acts
syn ergistica lly with radon
• Life tim e dose in ce rtain dwe llin gs
is con ce rn

32. Pr eve ntion of
Occu pation al Lung Ca nce r
• Pr im ary preve ntion is im por tant
– Sm okin g ce ssa tion
• Se con dar y pr eve n tion (m edica l
mon itor in g)
– OSHA mandate s mon itor ing for
a sb e s tos, a cr ylon it r ile , ar se nic, silica ,
and vin yl ch lor ide
– NIOSH recom m ends mon itor ing for
b e r ylliu m , ca r b on b la ck, ch r om iu m VI,
coa l t a r p r od u cts, in or g a n ic n icke l a n d
coa l gasifica tion

33. Up per Re sp irator y
Ca nce rs
• Sin o-n asa l
– Nicke l, wood dust, ch rom ium , cu tting
oils, mustard gas
• La ryn geal
– Asb estos, nicke l, mustard gas, cu tting
oils

34. Hematolog ic Ca nce rs
• Risk Factor s
– Ion izin g radiation
– Be nze ne
– Agricu ltural wor k
– Cytotoxic drugs

35. Hematologic Cancer -
Ion izin g Ra dia tion
• Stu die s from atom ic bla sts from
WWII
all le uke mia typ es• Associated with
exce pt CLL
• ALARA (a s low as reason ably
ach ie va ble )

36. Hematologic Cancer -
Be nze ne
• Associa ted with pancytop enia and
AML
• In dustria l rubber wor ke rs, refin ery
wor ke r s , ch e m ica l wor ke r s (soa p s ,
dye s, cosm etics, perfum es),
exp losive s in dustry
• Sa fe exp osu re le ve l unkn own

37. Hematologic Cancer -
Agricu ltural Exp osu re
• Farm ers
• Mu ltiple etiolog ie s, inclu ding
pesticid es and herbicid es
• Le uke m ia , Mu ltip le Mye lom a,
Hod gkin ’s Dise ase and N on -
Hod gkin ’s Lym phom a

38. Hematologic Cancer -
Medica l Exp osu res
• Anti-neop la stic drugs
• Eth yle ne oxid e
• Ra dia tion

39. Bladder Ca nce r
• Esp ecia lly dye /p igm ents and tir e/r ubber
mfg.
of bladder CA related to
• Up to 20 % occu pation
• Kidney con ce ntrates toxin ; prolon ged exposu re in bladder
• Benzidene
• 2-Naphylamine
• 4-Nitrobiphenyl
• 4,4-meth ylene-bis-(2-chlor oa niline) or

40. Bla dder Can ce r Scr eening
• Hem atu ria – h igh risk pop ula tion s
on ly
• Ur in e cytolog y
• Newe r areas of detect ion :
quantitative flu or esce nce im age
analysis (QF IA) and DN Aflow
cytom etry.
• Se nsitivity/sp ecificity issu es

41. GI Tract
• Ga stric
– Asb estos, wood dust, rubber industry
• Colon
– Se dentary wor k is risk fa ctor
– Asb estos and rubber industry
su sp ecte d
– Screening (Digital Rectal Exam vs.
stool guia c vs. sigmoid oscop y)

42. GI Tra ct - Live r
• Hepatitis B&C, alcoh ol, afla toxin s
• Asb estos su sp ecte d
• Solve nts associa ted with hepatic
fibrosis
• Hepatic Angiosa rcom a
– Vinyl ch lor ide
– Th or otr ast
– Arse nic

43. Skin Ca nce r
• Ion izin g radia tion
• Arse nic
• Polycyclic arom atic hydroca rbon s
• UV radia tion

44. Cancer Control
Primary Prevention
Control of tobacco & alcohol
consumption
Personal hygiene
Immunization
Foods, drugs & cosmetics
Air pollution
Precancerous lesions
Legislation
Cancer education
Secondary Prevention
Cancer registration
Hospital based registries
Radiation Population-based
Occupational exposures registries
Early detection of cases
Treatment
* * * Palliative care
ONE THIRD of all cancers are PREVENTABLE !

45. Cancer screening
“ Search for unrecognized malignancy by means
of rapidly applied tests”
Why is cancer screening possible?
Methods of screening:
Mass screening by comprehensive cancer detection
examination
Mass screening at single sites
Selective screening

46. Examples of Screening
Screening for cancer Cervix
Pap smear
Visual inspection based screening tests such as
visual inspection with 5 per cent acetic acid {VIA}
VIA with magnification {VIAM} and
visual inspection post application of Lugol's iodine (VILI)
Screening for Breast cancer
breast self-examination (BSE) by the patient
palpation by a physician
thermography, and
mammography

47. Government initiatives to fight
Cancer
National Cancer Registry
Program
National programs
NCCP
NPCDCS

48. National Cancer Registry Program
(NCRP)
NCRP was commenced by the Indian Council of Medical
Research (ICMR) with a network of cancer registries across
the country in December 1981.
The main objectives of this Programme were:
1. To generate reliable data on the magnitude and patterns of cancer
2. Undertake epidemiological studies based on results of registry data
3. Help in designing, planning, monitoring and evaluation of cancer
control activities under the National Cancer Control Programme
(NCCP)
4. Develop training programmes in cancer registration and
epidemiology.

49. Population-based cancer
registries (total 29) seek to
collect data on all new cases
of cancer occurring in a well
defined population. Usually,
the population is that which
is resident in a particular
geographical region
Hospital-based cancer
registries (total 09) maintain
data on all patients diagnosed
and/or treated for cancer at a
particular facility. The focus of
the hospital-based cancer
registry is on clinical care and
hospital administration

50. NCCP
1975-76- NCCP was launched with priorities given for equipping the
premier cancer hospitals. Central assistance at the rate of Rs.2.50 lakhs
was given to each institution for purchase of cobalt machines.
1984-85- The strategy was revised and stress was laid on primary
prevention and early detection of cancer cases.
1990-91- District Cancer Control Program was started in selected
districts (near the medical college hospitals).
2000-01- Modified District Cancer Control program initiated.
2004 - Evaluation of NCCP was done by National Institute of Health &
Family Welfare, New Delhi.
2005 - The programme was further revised after evaluation.
RCC – new/strenthening; Oncology wing; Decentralised NGO scheme

51. NPCDCS
• ServicePackage for Cancer
• Sub center
• Health promotion for behavior change and counseling.
‘Population based/ Opportunistic’Screening of common NCDs
including cancer.
• Awareness generation of early warning signals of common
cancer & other risk factors of NCD (Cancer)
• PHC + CHC/RH = Subcentre +
• ‘Population based/ Opportunistic’Screening of 3 common
cancers (oral, breast, and cervicalby VIA).
• Identification of early warning signals of common cancer.
• DH= PHC/CHC+
• Follow up chemotherapy in cancer cases, Rehabilitation and
physiotherapy services.

52. • Service Package for Cancer
• Medical College
• Mentoring of District Hospitals, Early diagnosis and
management of Cancer
• Training of health personnel, Operational Research.
• Tertiary Cancer Centre
• Mentoring of District Hospital and outreach activities,
Comprehensive cancer care including prevention, early
detection, diagnosis, treatment, palliative care and
rehabilitation.
• Training of health personnel &
• Operational Research

53. The distribution of the population (2011) and cancer mortality
(2010) in five zones of India compared with the corresponding
proportions of radiotherapy centres, oncology departments,
and
postgraduate oncology training positions

54. Burden of thedisease-INDIA
The International Agency for Research on Cancer
GLOBOCAN project has predicted that India’s cancer
burden will nearly double in the next 20 years ,
from slightly over a million new cases in 2012 to more
than 1·7 million by 2035.
These projections indicate that the absolute number of
cancer deaths will also rise from about 680 000 to 1·2
million in the same period

55. Thank you
!!!