EXPLORING TREATMENT OPTIONS FOR BLADDER CANCER
"THE p53 TRIAL"
MVAC in Organ- Confined Bladder Cancer Based on p53 Status
This
is an important study designed to provide better understanding
of bladder cancer and how to treat patients with this disease.
This trial is funded by the National Cancer Institute, and will
enroll more than 500 patients in about three years from over 30
hospitals around the world.
Background information: Like all tumors, the development of bladder cancer
occurs through various mechanisms, which usually involve a change in one of
your genes. Genes are like blueprints for our bodies. They contain information
that determines our appearance and many aspects of our health. Chromosomes
are the packages of genes found in our cells. Like all cancers, bladder cancer
develops when alterations of the genes accumulate over time. The most common
gene alteration found in tumors occurs in a gene called "p53".
The p53 gene is located on chromosome number 17 (see figure 1). The normal
function of the p53 gene is to prevent the development of tumor growth, and
that is why when the p53 gene is altered, the chance of developing a tumor increases.

Figure 1. Each human cell contains 23 pairs of chromosomes
which can be distinguished by size and by unique banding
patterns. The p53 tumor suppressor gene is located on
chromosome number 17. (National Institutes of Health)
An abnormality of the p53 gene occurs in about 40% of patients with bladder cancer that has invaded into the bladder wall.
Some studies suggest that those bladder tumors with an abnormal p53 (also called p53 altered or p53+) may be slightly more aggressive
and therefore pose a greater risk for tumor recurrence after removal of the bladder.

Figure 2.Cross-section of the bladder wall. The stages of tumors which will be evaluated in this study are the P1, P2a,
and P2b tumors. (Cancer Research 37: 2838-2842, 1977).
Purpose
of the "p53 Trial": This study aims to determine whether
patients with tumors containing a normal p53 gene live longer
than patients with tumors containing an abnormal p53 gene. It
will also demonstrate whether chemotherapy can improve the survival
of patients with tumors containing an abnormal p53 gene.
To
get involved in the study: Individuals who meet certain
requirements will be invited to participate in this study. Once
you have completed surgery with total removal of bladder and tumor
(cystectomy), your physician will determine if your bladder tumor
is limited within the wall of the bladder (organ-confined), and
has not spread through the wall or to any other part of your body
(see figure 2). Once it is determined that
you are eligible for the trial, you may sign up (register) for
the trial. This will occur within 9 weeks following
your surgery.
Once
you have signed up (registered) for the p53-trial: (see
figure 3). Upon registration, your bladder tumor will be studied
to determine if there is an alteration in the p53 gene. To do
this, a sample of your tumor (removed at cystectomy) will be sent
to a laboratory at the University of Southern California (USC)
for special genetic analysis. This information will be kept confidential
by the investigators and the research committee. Specific study
related information will be made available to the National Cancer
Institute, the Food and Drug Administration, USC, and the hospital
where you are treated. If the results of this study are published
in medical literature, you will be identified by name.
If your bladder tumor contains a normal p53 you will not receive
any additional therapy, and you will be observed with a standard
follow-up schedule. Currently, close follow-up after surgery is
the standard-of-care for individuals with organ-confined bladder
cancer.
If your bladder tumor has
an abnormal p53, you will then be selected to receive either some
additional therapy (chemotherapy), or monitored with standard
follow-up. We will use a computer program to determine whether
you will be selected for standard follow-up or to receive chemotherapy.
This process is called randomization.
The
randomization process: If your bladder tumor is found
to have an abnormal p53 gene, and you have decided to become involved
in the study, you will then be randomized. This will occur within
10 weeks following your surgery.
Randomization is a procedure
similar to flipping a coin. You will be selected for one of two
options. This selection is not determined by your physician. The
decision is made by a computer. The options will be either standard
follow-up or some additional treatment (chemotherapy). Your chances
of being selected for either of the two treatment options are
equal.
The
timing and dosage of chemotherapy: If you are randomized
to receive chemotherapy, this will begin within 12 weeks following
your surgery. This will allow ample time to heal from your operation
prior to beginning the chemotherapy.
You will receive a total
of 3 ''cycles" of chemotherapy. This will include about 12
days of chemotherapy over the course of 3 months. The chemotherapy
will be administered by your medical oncologist though a vein
as an outpatient, or possibly as an inpatient. You will be monitored
and followed closely during and after your treatment.
Standard
follow-up: If you are selected for standard follow-up,
you will be monitored carefully. Currently, observation (no additional
treatment) is the accepted standard-of-care for patients with
this type of bladder cancer following surgery.
However, if your tumor
returns (recurs), you will be provided with the best available
treatment at that time.
The results of this trial will be important
in the future treatment of patients and the better understanding
of bladder cancer. Furthermore, we would like to express that
both chemotherapy and standard follow-up are very acceptable
forms of therapy.
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