Cancer Prevention

Eyad Alsaeed , MD,FRCPCConsultant Radiation OncologyPSHOCKFMC

PRIMARY PREVENTION

Primary prevention avoids the development of a

disease. Most population-based health promotion activities are primary preventive

measures

SECONDARY PREVENTION

Secondary prevention activities are aimed at early disease detection, thereby increasing opportunities for interventions to prevent progression of the disease and emergence of symptoms .

Example:

Primary : EducationENT : smoking , alcoholLung : smoking Breast : obesity , Exercise ,Alcohol , HRTColorectal :high fat, low fiber, high phos,low

caBladder :smoking ,Dye worker ,SchistosomaCervical : HPV, early Age of sexual activity,

multiple sexual partner, smokingEndometrial :obesity, Late menopause , null

parity

Secondary prevention

ScreenThe process by which unrecognized

disease are identified by test that applied rapidly on a large scale.

Criteria considered important for a

screening program to be valid The disease is causing public health problem Natural history well-known The disease can be detected in precancerous

stage or early stage The treatment available for the early stage

with less cost and morbidity. High sensitivity test available High specificity test available Acceptable by the patient population and not

morbid Cheap

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Types of screening

Mass screening: whole population Multiple screening: use variety of

screening test in the same occasion Targeted screening: to a group of

specific exposure Case finding: patient who consult

health practitioner for some other purpose

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Disadvantage of screening Cost false +ve False –ve treating clinically occult disease no available treatment over treating of borderline long period of morbidity screening test hazard

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Essential feature for screening program

TESTsensitivespecificacceptable by the Pt.

&Dr.safe cheap

Disease- high incidence- significant mortality

&morbidity- well known natural history- detection in early stage

and treatment alter the natural history

- effective treatment available

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GUILINES

Breast CancerColorectal

CervicalProstate

Canadian Breast Cancer Screening Recommendations

Age 40-49 Breast Exam By Health Professionals q 2 years Regular self Exam. And check up Age 50-69 (20y) Breast Mammogram q 2 years Exam By Health Professional q 2 years Regular self Exam. And check up Age > 70 Breast Exam By Health Professional q 2 years Regular self Exam. And check up

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Saudi Arabia

-baseline mammogram and Breast Examination at age 40

-or 5 years less than first relative in family

-no signs or symptomsUS if age less than 35

Colorectal

Average risk per sons (age ~ 50 yrs, a symptomatic, no FH): colonoscopy q lOyr (preferred) or

FOBT q 1yr + flexible sigmoidoscopy q 5yr or double-

contrast barium enema q 5 yr

CONT..

Inflammatory bowel disease: colonoscopy q 1-2yrs, initiate 8 yr s after symptom onset if pancolitis or 15 yr s aftersymptom onset if L-sided colitis

Family Hx (non-FAP/HNPCC): colonoscopy q 1-5yrs, initiateat age 40yrs or lOyrs prior to earliest cancer diagnosisin family

Cont..

Familial adenosis polyposis (lifetime cancer risk -100% by age 50): APC gene testing, early screening, colectomy or proctocolectomy after onset of polyposis

Hereditary nonpolyposis colorectal cancer: colonoscopy q 1-2 yr s, initiate at age 20-25 or 10 yrs younger than earliest cancer diagnosis in family

Cervical Cancer

Screening with Pap smear decreases mortality by 70%.

ACS recommends screening for all women who are sexually active or who are >18 yrs old

. After 3 normal annual exams, screening may be performed less frequently

Prostatic cancer

Screening recommendations from the ACS include annual PSA & DRE beginning at age 50 if life expectancy is > 10 yr .

Men with a +FR & African Americans may begin screening at 40-45 yrs