Carcinoma of
the penis
Penile cancer is a malignant growth found on the skin or in
the tissues
of the
penis,
usually
originating
in the glans
and/or
foreskin. It
is a rare
form of
cancer with
an incidence
of 1 in
100,000 per
year in
developed
countries.
Risk factors
The American Cancer Society provides the following as risk
factors for
penile
cancer:
human
papillomavirus
(HPV)
infection,
smoking,
smegma,
phimosis,
treatment of
psoriasis,
age, and
AIDS. The
other
etiologic
factor most
commonly
associated
with penile
carcinoma is
poor
hygiene.
There is
some
evidence
that lichen
sclerosus
(also known
as balanitis
xerotica
obliterans)
may also be
a risk
factor.
Risk
The lifetime risk of a man developing invasive penile cancer
(IPC) in the
United States
is 1 in 600
if he is
uncircumcised,
and more
than 3 times
lower if he
was
circumcised
neonatally.
This and other evidence suggests that childhood circumcision
reduces the
incidence of
penile
cancer.
Studies have
found that
circumcision
decreases
the risk of
HPV
infection in
males and
thereby the
risk of
developing
penile
cancer.
Symptoms
A draining sore on the foreskin or glans of the penis may be
a sign of
penile
cancer.
Anyone with
these
symptoms
should
consult a
doctor
immediately.
Pathology
* A. Precancerous Dermatologic Lesions
* B. Carcinoma in Situ (Bowen Disease, Erythroplasia of
Queyrat)
* C. Invasive Carcinoma of the Penis
Staging
Like many malignancies, penile cancer can spread to other
parts of the
body. It is
usually a
primary
malignancy,
the initial
place from
which a
cancer
spreads in
the body.
Much less
often it is
a secondary
malignancy,
one in which
the cancer
has spread
to the penis
from
elsewhere.
Doctors use
the extent
of
metastasis
to estimate
what stage
the disease
is in, to
aid in
treatment
decisions
and
prognosis.
The stages
are assessed
as follows:
* Stage I - Cancer has only affected the glans and/or
foreskin.
* Stage II - Cancer has spread to the shaft of the penis.
* Stage III - Cancer has affected the penis and
surrounding
lymph nodes.
* Stage IV - Cancer has moved beyond the groin area to
other parts
of the body.
* Recurrent - Cancer that has returned after treatment.
Prognosis can range considerably for patients, depending
where on the
scale they
have been
staged.
Generally
speaking,
the earlier
the cancer
is
diagnosed,
the better
the
prognosis.
The overall
5-year
survival
rate for all
stages of
penile
cancer is
about 50%.
Treatment
There are several treatment options for penile cancer,
depending on
staging.
They include
surgery,
radiation
therapy,
chemotherapy,
and
biological
therapy. The
most common
treatment is
one of four
types of
surgery:
* Wide local excision - The tumor and some surrounding
healthy
tissue are
removed
* Microsurgery - Surgery performed with a microscope is
used to
remove the
tumor and as
little
healthy
tissue as
possible
* Laser surgery - laser light is used to burn or cut away
cancerous
cells
* Circumcision - cancerous foreskin is removed
* Amputation (penectomy) - a partial or total removal of
the penis,
and possibly
the
associated
lymph nodes.
This is the
most common
and
effective
treatment.
Radiation therapy is usually used adjuvantly with surgery to
reduce the
risk of
recurrence.
With earlier
stages of
penile
cancer, a
combination
of topical
chemotherapy
and less
invasive
surgery may
be used.
More
advanced
stages of
penile
cancer
usually
require a
combination
of surgery,
radiation
and
chemotherapy.
Vaccine
A quadri-valent vaccine to prevent HPV infection, Gardasil,
has been
developed,
successfully
tested and
approved for
women by the
US Food and
Drug
Administration.
Approval for
men is
expected in
2008. It is
licensed and
in
production,
and could
substantially
reduce the
incidence of
HPV
infection in
men, the
incidence of
genital
warts and
ano-genital
cancers
including
penile
cancer, and
mortality.
It is
unclear why
the drug's
manufacturer
chose to
stagger
testing of
the vaccine,
potentially
leaving many
men
needlessly
vulnerable
to HPV
infection.
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