Facts on File Encyclopedia of Health and Medicine

Antibiotic chemotherapy agents The anthracy-
clines and the related DRUGbleomycin are antibi-
otics that come from the FUNGUS Streptomyces
verticillus, which naturally occurs in soils primarily
in Japan though also can be cultivated. These
chemotherapy drugs work by forming free radicals
that disrupt the structure of cellular DNA. They
are particularly effective against leukemia, lym-
phoma, and many types of CARCINOMA, notably
breast cancer. Bleomycin is similar to the anthra-
cyclines, derived also from the S. verticillusfungus,
but a different chemical composition and action in
cells. It is most effective in combination with other
chemotherapy agents for treating lymphoma and
TESTICULAR CANCER. The most significant SIDE EFFECT
of the anthracyclines is damage to the HEART, and
of bleomycin damage to the LUNGS, as a result of
free radical activity.

COMMON ANTIBIOTIC CHEMOTHERAPY AGENTS

bleomycin dactinomycin
daunorubicin doxorubicin
epirubicin idarubicin
mitoxantrone

Camptothecins, etoposide, and vinca alkaloids
The camptothecins block the function of topoiso-
merase, an enzyme cells need to synthesize DNA.
Their original source was the bark of the Camp-
totheca acuminatatree native to China. Etoposide
has the same action but comes from the bark of
the mandrake tree. Vinca alkaloids derive from
the leaves of the Vinca roseaplant, a type of peri-
winkle. The vinca alkaloids disrupt cell division.
Like the alkylating agents, the camptothecins,
etoposide, and vinca alkaloids are effective in
treating a broad spectrum of cancers from
leukemia and lymphoma to carcinomas and some
sarcomas.

COMMON CAMPTOTHECINS,

ETOPOSIDE, AND VINCA ALKALOIDS

etoposide vincristine
vinblastine vinorelbine
irinotecan topotecan

Taxanes The taxanes come from the bark of
the Taxus brevifolia—the Pacific yew tree. They
work as chemotherapy agents by blocking the

ability of cells to form the structures necessary to

divide. They also appear to enhance a number of

immune functions and are particularly effective in

treating some types of metastatic breast cancer.

Currently there are two taxanes, each of which is

often more effective in combination with other

chemotherapy agents than alone. As well, each

taxane has specific side effects: docetaxel can

cause severe EDEMA(fluid retention) and paclitaxel

can cause MUSCLEpain. Both drugs can cause NEU-

ROPATHY(dysfunction of the nerves) and severe

depletion of neutrophils (NEUTROPENIA), white

BLOOD cells (leukocytes) important for fighting

INFECTION. Neutropenia raises the risk for infection.

TAXANES

docetaxel

paclitaxel

Platinum compounds Platinum compounds

disrupt cellular DNA function as well as the ability

of cells to synthesize DNA. These chemotherapy

agents are particularly effective in treating LUNG

CANCER, testicular cancer, and colorectal cancer.

They can cause kidney damage and neuropathy.

PLATINUM COMPOUNDS

carboplatin cisplatin oxaliplatin

Risks, Side Effects, and

Complications of Chemotherapy

Because chemotherapy is a systemic treatment, it

affects all cells in the body. Those most severely

affected are those that grow and divide rapidly.

Though cancer cells are at the head of that list,

some healthy cells in the body also grow and

divide rapidly. Among them are the cells of hair

follicles (which produce hair), blood, and gastroin-

testinal tract, accounting for the most significant

side effects of chemotherapy: hair loss, ANEMIA,

increased susceptibility to infection, nausea, VOM-

ITING, and DIARRHEA. However, the extent to which

these side effects occur varies across the spectrum

of chemotherapy drugs, and many people receiv-

ing chemotherapy do not experience them.

Medications and complementary remedies such

as GINGER may help with chemotherapy-related

nausea. ACUPUNCTURE also provides relief from

nausea and other discomforts. Antinausea medica-

376 Cancer