Anal Cancer: A Sexually Transmitted Disease - GMSH

ANAL CANCER
A Sexually Transmitted
Disease
February 2008
IRV SALIT
Director,
Immunodeficiency Clinic,
Toronto General Hospital

ANAL CANCER
THE ANAL CANAL

The Case of GR
• 45 year old male with HIV
• He had AIDS
• Was doing very well on ARV’s (1996)
• In 2000, he had anal symptoms and
went to anorectal clinics several
times
• Finally he was diagnosed with anal
cancer
• He needed surgery to remove his
lower bowel
The Case of GR
• He did research and told me about
anal cancer
• We found some ways of preventing
anal cancer

ANAL CANCER
• Uncommon cancer in the general
population
• It involves the anal canal and skin
around the anus
• This is not colon cancer
• Like cervical cancer, it is caused by a
virus called the Human
Papillomavirus (HPV)
• Anal cancer has increased
substantially since the 1980s
ANAL CANCER
Symptoms
• The symptoms of anal cancer
resemble those of common anal
problems
• There may be bleeding, pain,
itchiness, swollen glands

ANAL CANCER
Treatment
• Radiation and chemotherapy
• Sometimes bowel removal is
necessary and a colostomy
Age- & Sex-Adjusted Anal Cancer
Incidence, 1971-2002
0.26/100,000 1.06/100,000
J. Tinmouth OHTN Conference 2006

Anal Cancer is very
similar to Cervical
Cancer
SCJ: where one type of tissue joins
another type of tissue
Cancers start here at
SCJ

Anal cancer in MSM
In MSM:
annual incidence est:
35/100,000
CERVICAL CANCER:
40-50/100,000 annual
incidence (pre ’60s)
ANAL PAP SMEARS
Routine cervical Paps
?annual incidence
8/100,000 annual
incidence
WHO GETS ANAL CANCER?
• MSM
• Poor immune system (HIV,
transplants)
• Especially HIV+ MSM (50-150 fold
risk)
• Women with cervical or vulvar cancer

ANAL CANCER IN OUR HIV
CLINIC
• Second most common cancer
• 1% of the current clinic population
• Most have very immune systems
(CD4) and low viral loads
• As people live longer, there will be
more cancers
HPV

HPV TYPES
• >100 types in humans: 40 infect the
anus and genital tract
• Genital warts: types 6 and 11
• Cancers: types 16, 18, 45, 31, 33, 52,
58 = >95%
Commonest STD
• >75% of sexually active adolescents
and adults, ages 15-49, get at least one
HPV infection during their life
• Likelihood of infection rapidly
increases with first 5 partners
• If HIV-negative, tend to get rid of HPV
and low cancer risk

PRE-CANCEROUS
LESIONS
(Dysplasia)
HPV INFECTION
Normal Tissues
Low grade lesions (AIN1)
High grade lesions (AIN 2/3)
= Dysplasia
Cancer

CAN WE PREVENT
ANAL CANCER?
How do we detect
Anal Pre-cancer
(Dysplasia) ?

TORONTO
SCREENING STUDY
TORONTO
RESEARCH
for ANAL
CANCER
EVALUATION
TRACE Study

HPV DETECTION
HPV DETECTION
• Any HPV found in about 95%
• High-risk (cancer-producing) types of
HPV were found in about 90% of
men

ANAL CYTOLOGY
(Pap Smear)
ANAL PAP SMEAR
Cell collection

HIGH GRADE CHANGES

HIGH RESOLUTION
ANOSCOPY
(HRA)

NORMAL SQUAMO-COLUMNAR JUNCTION
SQUAMO-COLUMNAR
JUNCTION
RECTUM
ANUS

RESULTS
• Anal HPV found in about 95%
• ANAL PAP SMEARS - Abnormal in
66%
• BIOPSY – High-grade grade pre-cancers
(AIN 2/3) in 25%
CAN WE TREAT and
REMOVE ANAL PRE-
CANCERS?

IRC
IRC (Laser)
• Treatment done once
• 20-30 minutes
• Painful so must use freezing
• May have some pain and/or bleeding
for a few days

• Painless
TCA (Acid)
• Quick (5-10 minutes)
• Need repeated visits and treatments
(once per month x 4 months)
WHICH IS BETTER?
Outcomes are the same

CONCLUSION
Routine screening for anal cancer should
be implemented for gay men once
adequate experience has been
gained from studies such as this.
• OHTN
• CANFAR
• NCIC
FUNDING

THANK YOU !