Diagnosis - Then What?
A Method to Predict Recurrence May Be Here
pink ribbon campaigns to increase awareness of breast cancer and
educate women about the benefits of early detection are working.
The ability to diagnose cancer in its early stages has never been
cancer screening becoming more accepted, as many as 80 percent of
those diagnosed with cancer today are told that their cancer has
been detected early and can be removed.
among those with early-stage cancer, about half will experience
(relapse) following surgery because microscopic cells have spread
to other areas (micro-metatastic cancer). In breast cancer, this
rate is slightly lower if the cancer is caught in the earliest stage.
creates a dilemma for patients and oncologists who must decide whether
to decide against post-surgical treatment, thereby running the risk
that the cancer will return, or undergo chemotherapy and radiation
treatments that have serious side effects and may be unnecessary.
Clinicians will usually recommend the treatments, erring on the
side of caution.
half of those with early stage cancer will experience relapse, that
means about half will either be overtreated - or undertreated -
because there are no good methods for identifying which cancers
will come back.
decision of whether to undergo treatments is difficult for the doctors
and the patient. If there is a 50 percent chance that the cancer
will come back, can you pass up treatments that might prevent it?
On the other hand these treatments are highly toxic - they are designed
to kill cells - they don't care if the cells are cancer or heart
a decision is made not to treat a patient who has potentially micro-metatastic
disease, the opportunity to destroy the tumor in its early stage,
when only a few tumor cells exist, is lost. When the cancer reaches
detectable levels in these patients it is generally difficult to
completely remove it.
decision to treat someone who is not at risk of relapse from micro-metatastic
disease means being subjecting healthy cells to the debilitating
effects of chemotherapy.
upon the chemotherapy used, these patients are unnecessarily subjected
to adverse long-term consequences such as mutated DNA, heart complications,
secondary cancers, and premature aging.
Apoptosis Proteins Predict Survival in Early Cancer?
John Reed, MD, PhD, is the President and CEO of the Burnham Institute,
La Jolla, CA, where he leads a team of some 40 researchers who are
examining diagnostic testing methods aimed at pinpointing the likelihood
of cancer relapse among patients with early-stage breast, colon
or prostate cancer. Dr.
Reed presented the status of their research during his presentation
entitled, "Can Apoptosis Proteins Predict Survival in Early
Colon Cancer?," at the 55th Annual Meeting of the American
Association of Clinical Chemistry (AACC).
When tumors arise, they often develop defects in the machinery that
controls the lifespan and death of cells (the apoptosis machinery).
tumors also exhibit certain behaviors that make them resistant to
cell death mechanisms. If a normal cell that grows in either the
breast, color or prostate detaches from where it grew, it will try
to circulate in the blood or lymph and go elsewhere.
cells cannot do this. These
cells die, because their survival is dependent upon the signals
they receive from the organ where they belong. A normal breast tissue
cell cannot move to another place and continue to grow.
cells have defects in the apoptosis machinery, that signals the
cell to die. They continue to flourish, despite being detached from
their host organ.
survive in the circulating blood and lymph fluids and lodge in other
organs where they continue to grow and multiply - making copies
of themselves with the faulty mechanism and interfering with the
normal cells in these organs.
how apoptosis works is the focus of the Reed lab. He and his colleagues
are researching antibody-based tests using immunological methods
and apoptosis biology to examine the proteins encoded by various
genes related to breast, prostate and colon cancer.
they are applying immuno-diagnostics to patient tumor specimens
using samples of tumors that have been saved for research.
retrospective approach allows them to correlate their results with
the actual patient outcomes from samples provided nearly a decade
ago. They have a tumor sample from a patient and know that the patient
survived and was cancer free. They also have tumor samples where
they know that the tumor came back... the patient had a recurrence.
on that knowledge, they have identified those that look promising
and are now using them on other patient cohorts to ensure that the
results are reproducible.
group that they are studying is comprised of 120 patients diagnosed
with early stage II colon cancer which had been removed with margins
free of tumors, had received no other therapy, and were clinically
followed for eight years.
half of these patients relapsed and eventually died.
original tumors were obtained and have been used to conduct 50-60
different types of experimental tests. Of this large number of potential
tests, four have been identified that, when used in certain combinations,
predict with 98 percent accuracy who will relapse and who will not.
The fruits of the genome, coupled with tests like those now being
identified, mean that in the foreseeable future laboratories will
be able to identify molecular and genetic signatures in cancers
that will allow physicians to know which diseases are more aggressive
and have acquired metatastic capabilities, and which tumors have
information will result in better clinical decisions about what
the optimal therapies are for those diagnosed with early stage breast,
colon and prostate cancer.
American Association for Clinical Chemistry (AACC) is the worlds
most prestigious professional association for clinical laboratorians,
clinical and molecular pathologists, and others in related fields.
AACCs members are specialists trained in the areas of laboratory
testing, including genetic disorders, infectious diseases, tumor
markers and DNA. Their primary professional commitment is utilizing
tests to detect, treat and monitor disease.
for Clinical Chemistry (AACC) (Newswise)
on the Web:
Breast Cancer Recurrence A Complex Decision
Cancer: Treating Recurrence
updated June 30, 2006