International Agency for Research on Cancer (IARC) - Summaries & Evaluations


VOL.: 10 (1976) (p. 121)

CAS No.: 14901-08-7
Chem. Abstr. Name: (Methyl-ONN)azoxymethyl-b-D-glucopyranoside

5. Summary of Data Reported and Evaluation

5.1 Animal carcinogenicity data

Cycasin is carcinogenic in mice, rats, hamsters, guinea-pigs, rabbits and fish; it produced a variety of malignant tumours, mainly in the liver, kidney and intestine. It is carcinogenic in rats, hamsters, guinea-pigs, rabbits and fish following its oral administration. It is active in newborn and suckling mice and newborn rats and hamsters after its subcutaneous injection both in single doses and following prenatal exposure. The carcinogenicity of its aglycone, methylazoxymethanol, has been demonstrated in rats following its intraperitoneal administration and in hamsters following its intraperitoneal or intravenous administration. The closely-related synthetic substance, methylazoxymethanol acetate, is carcinogenic in rats by various routes of administration (see Appendix).

5.2 Human carcinogenicity data

The one epidemiological study reported showed no appreciable increase in cancer mortality 2 to 7 years after heavy intake of cycads. This negative result is insufficient to exclude a possible carcinogenic effect of cycasin in man. No case reports or other epidemiological studies of cancer in relation to exposure to cycasin or methylazoxymethanol were available to the Working Group.

Previous evaluation: Vol. 1 (1972)

Subsequent evaluation: Suppl. 7 (1987) (p. 61: Group 2B)

For definition of Groups, see Preamble Evaluation.

Synonyms for Cycasin

Last updated: 22 March 1998

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       Toxicological Abbreviations