Chemotherapy & targeted therapies
Constant innovation is transforming the treatment of cancer.
During World War II, scientists
discovered that a group of people
who were accidentally exposed to
mustard gas had low white blood
cell counts. Concluding that the gas
hindered the growth of rapidly
dividing cells, they speculated that
this otherwise deadly compound
might be a valuable weapon against
cancer — and chemotherapy was born.
Since then, researchers have been
seeking increasingly sophisticated drug
therapies for cancer and its symptoms.
Their innovations range from alternative
dosing strategies and methods of
delivering chemotherapy directly to
a tumor to the creation of altogether
new categories of life-extending anticancer
drugs.
New treatment techniques
These alternative approaches to chemotherapy
may help make treatments more powerful while
limiting side effects.
Chemotherapy resistance testing. Before your
treatment begins, your doctors can perform
laboratory tests on tumor cells to determine
which drugs are likely to be most effective
against the cancer. Not only does testing limit
unnecessary exposure to potentially toxic chemotherapy
agents, but it can be especially valuable
when there’s a choice between two or more
possible treatments.
Metronomic chemotherapy. The chemotherapy
is delivered in small, regular amounts over a
prolonged period rather than all at once. While
the individual doses used in metronomic
chemotherapy are smaller than typical doses,
giving them at frequent intervals can not only
shrink the tumor by inhibiting the growth of the
blood vessels that feed it, but may also destroy
cancer cells.This approach is also less toxic and
easier to tolerate than traditional chemotherapy,
in which the maximum tolerated dose (MTD) is used.
Intra-arterial chemotherapy (IAC). This treatment is
used most commonly in the treatment of liver
cancer, but may also be used for head, face, neck,
pancreatic, and pelvic cancers. The medication is
delivered through the arteries that lead to the site
of the tumor. The goal is to subject the cancer
to a very high dose of chemotherapy while
delivering less to the rest of your body.
Intraperitoneal chemotherapy. In this treatment for
ovarian cancer, chemotherapy is administered
directly to your peritoneal area, or abdominal
cavity, to prevent tumor cells from forming.
Targeted drug therapies
While traditional
chemotherapy agents
aim to destroy rapidly
dividing cells, new types
of drugs interfere with
the development of
cancer at the molecular
level. Because these drugs
target specific molecules,
they’re sometimes called molecular-targeted treatments.
Targeted therapies
are more selective than
traditional cancer therapies
and spare more
healthy cells. Ultimately
researchers hope to
develop targeted therapies
tailored to the unique
molecular characteristics
of each individual’s
tumor, resulting in truly
personalized treatment.
Many targeted therapies
are still in development,
but others are in clinical trials or have already been
approved by the FDA.
They are being tested for
use alone, in combination
with other targeted
therapies, and with conventional
treatments,
such as traditional
chemotherapy.
- Anti-angiogenesis drugs: Chemicals
in the body control the process of
angiogenesis, or the formation of
new blood vessels. These drugs are
designed to stop the spread of
cancer by cutting off the blood
supply that feeds tumors. Several
anti-angiogenesis medications are
already available and are used in
coordination with standard chemotherapy
to increase its effectiveness.
- Apoptosis-inducing drugs: Also known
as programmed cell death (PCD),
apoptosis is the orderly process
of cell death by which the body
disposes of abnormal, diseased,
or unnecessary cells. Unlike normal
cells, however, cancer cells are
unable to undergo apoptosis. These
drugs stimulate cancer cell death by
interfering with proteins and other
substances in tumor cells that cause
them to live longer than normal cells.
- Differentiation drugs: These drugs
cause immature cells to become
more differentiated, making them
function more like normal cells
and limiting the uncontrolled
growth associated with cancer.
This approach has potential for
cancer prevention, and the FDA
has already approved one such drug
to protect people who have a high
risk of developing colon cancer.
- Signal transduction inhibitors: These
drugs prohibit the spread of cancer
cells by interfering with the communication
signals they rely on to grow.
Also present naturally in foods
such as soy and citrus fruits, signal transduction inhibitors may help
stop cancer from spreading to
healthy tissue.