?????

?????

(?)

?????????

??????????????????34-(benzopyrene);???;?????????????

()?

??????A???O???

()

???????????????^

()??

??????????????????(precancerous conditions)???(precancerous lesions)

1.????

(1)???????

(2)????10%????510

(3)????????????15%40%?2cm?????1%

(4)?????10??

(5)????????????

(6)????(Menetrier)??????????????10%??

2.???

(1)??????????(anaplasia)??

(2)(?)?????(?)?????2?a?????;b?????

??

(?)?

????????????

()?

1.

???????...