HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE COVER ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Submit a letter to the editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Yamagiwa, K. Articles by Ichikawa, K. Search for Related Content PubMed PubMed Citation Articles by Yamagiwa, K. Articles by Ichikawa, K.

CA: A Cancer Journal for Clinicians, Vol 27, 174-181, Copyright © 1977 by American Cancer Society

Experimental Study of the Pathogenesis of Carcinoma

The following conclusions may be drawn:

1. Papillomatous new growths (which we term folliculoepitheliomata) may be produced on the-rabbit's ear by the application of coal-tar for 30 to 100 days. The proportion of folliculoepitheliomata to the total number of ears treated gradually rises.

2. By the repeated application of coaltar, eight cases of carcinoma in its earliest stage, 16 in an early stage, and seven complete carcinomata were produced. The carcinomatous change was discovered between the 55th and the 360th day; in most of the cases it was found after the 150th day.

3. The hyperkeratotic pedunculated or sessile folliculoepitheliomata produced by irritation with coal-tar continued to grow after the irritant had been discontinued, and eventually developed into cutaneous horns. Some of these horns grew for a year after the with drawal of the coal-tar, while others fell off spontaneously; in the great majority of the latter animals new cutaneous horns grew again from the same base, or from the neighboring epithelium, as is the case in man.

4. The seventh and 16th cases of carcinoma in its early stage developed from cutaneous horns about 300 days after the tar had been discontinued.

5. The presence of metastasis was microscopically proved in the regional lymph nodes in the fourth case of carcinoma.

6. The animals which bore folliculoepitheliomata did not begin to emaciate while the new growth maintained its benign character.

7. Yamagiwa's hypothesis has been confirmed: The repetition or continuation of chronic irritation may cause a precancerous alteration in epithehium previously normal. If the irritant continues its action, carcinoma may be the outcome, even though no specific agent has been interpolated.

This article has been cited by other articles:

				J. UNWIN, J. COCKER, E. SCOBBIE, and H. CHAMBERS An Assessment of Occupational Exposure to Polycyclic Aromatic Hydrocarbons in the UK Ann. Hyg., June 1, 2006; 50(4): 395 - 403. [Abstract] [Full Text] [PDF]