world cancer report - iarc

solution, containing a 1% solution of
potassium arsenite in aqueous alcohol).
The no-longer used radioactive X-ray
contrast medium Thorotrast was associated
with increased risk of angiosarcoma.
Certain others have been found to
be carcinogenic in experimental animals
but have not been linked to cancers in
humans despite extensive study. Some
of these drugs have been withdrawn
from clinical use (e.g. phenolphthalein),
while others continue to be used
because the benefit to individual
patients is great and the risk of cancer is
considered very slight (e.g. iron dextran,
injectable; phenobarbital; phenytoin).
Some drugs that have been recently
introduced into human medicine, including
the antiretroviral drugs zidovudine
(AZT) and zalcitabine (ddC), are carcinogenic
in experimental animals and may
possibly be carcinogenic to humans
(IARC Group 2B), although there is as yet
no direct evidence of increased cancer
risk in treated patients [6].
Surgical implants of various kinds are
widely used for both therapeutic and
cosmetic purposes [7]. Foreign bodies of
many kinds cause development of malignant
tumours of connective tissue (sarcomas)
when implanted in tissues or
body cavities of experimental rodents
and left in place for long periods.
Foreign bodies include both metallic and
non-metallic solid objects, and nonabsorbable
or very slowly absorbable
liquid suspensions. Sarcomas develop in
rodents immediately adjacent to the foreign
body, in the soft connective tissues
or in bone and/or cartilage. There have
been more than 60 published case
reports of sarcomas and other kinds of
cancers that have developed in humans
at the sites of surgical implants or other
foreign bodies. However, there are no
controlled studies that would allow a
conclusion that these cancers were
indeed caused by the pre-existing foreign
body. Female breast implants have
been extensively studied, and for silicone
implants there is evidence suggesting
lack of carcinogenicity for breast carcinoma
in women who have received
these implants.
Drug or drug combination Cancer site/cancer
IARC Group 1
Analgesic mixtures containing phenacetin Kidney, bladder
Azathioprine Lymphoma, skin, liver
and bile ducts, soft
connective tissues
N,N-bis(2-chloroethyl)-2-naphthylamine (Chlornaphazine) Bladder
1,4-Butanediol dimethane-sulfonate (Myleran; Busulfan) Leukaemia
Chlorambucil Leukaemia
1-(2-Chloroethyl)-3-(4-methyl-cyclohexyl)-1-nitrosourea Leukaemia
(Methyl-CCNU)
Ciclosporin Lymphoma,
Kaposi sarcoma
Cyclophosphamide Leukaemia, bladder
Diethylstilbestrol Cervix, vagina
Etoposide in combination with cisplatin and bleomycin Leukaemia
Fowler's solution (inorganic arsenic) Skin
Melphalan Leukaemia
8-Methoxypsoralen (Methoxsalen) plus ultraviolet radiation Skin
MOPP and other combined [anticancer] chemotherapy Leukaemia
including alkylating agents
Estrogen therapy, postmenopausal Breast, uterus
Estrogens, non-steroidal Cervix/vagina
Estrogens, steroidal Uterus, breast
Oral contraceptives, combined a Liver
Oral contraceptives, sequential Uterus
Tamoxifen b Uterus
Thiotepa Leukaemia
Treosulfan Leukaemia
a There is also conclusive evidence that these agents have a protective effect against cancers of the ovary
and endometrium.
b There is conclusive evidence that tamoxifen has a protective effect against second breast tumours in
patients with breast cancer.
Table 2.13 Medicinal drugs that are classified as being carcinogenic to humans (IARC Group 1).
Medicinal drugs 49