Day 035 - 12 Oct 94 - Page 52
1 within that population, be it a national or a Continental
2 population or whatever, are actually carrying cells in
3 which the initiative process has already taken place but
4 have not been developed into tumours?
5
6 MR. JUSTICE BELL: Is that right?
7 A. No, not in my understanding. I am trying to make sure
8 I understand you. One can -----
9
10 Q. How do you get anywhere near a realistic estimate of how
11 many people during their lives have cancer initiators,
12 I am trying to put it in lay terms, but not promoted?
13 A. Yes. One can take samples of tissue. For example,
14 individuals who are killed in traffic accident; one can
15 study their tissue and look for individual cells that are
16 abnormal but have not begun to multiply. Those studies,
17 I believe I made reference to them with regard to ---
18
19 Q. I understand that.
20 A. -- prostate cancer.
21
22 Q. But how do you get from that to any half decent
23 guesstimate of how many people in the population? In this
24 country we only have postmortems, generally speaking, in
25 cases of violent death or such as your car accident or
26 where there is no explanatory history of disease before
27 death. It is probably much the same in the States?
28 A. Yes. The only really two sources would be traumatic
29 death, because you would not necessarily want to use
30 people who had died of some sort of metabolic disease, or
31 the removal of an organ during surgery, for example, say
32 breast reduction surgery or something like that, where
33 there is no disease process. That would be the only way
34 that I could imagine that might be responsive to your
35 question.
36
37 MR. RAMPTON: It follows then, does it not, that it is not
38 possible to make any sensible estimate of the number of
39 people in the country that might be carrying cancers that
40 have been initiated but not promoted?
41 A. As I mentioned earlier in my example of prostate
42 disease, some people have made estimates that would go to
43 that, yes.
44
45 Q. Do you know of any work -- let us take it a stage further
46 -- that has proposed what proportion of the population
47 are carrying cancers of the colon or cancers of the breast
48 that are awaiting promotion?
49 A. I do not recall; I do not know that literature.
50
51 Q. I paused at the top of page 52 of this British government
52 document. I asked the question I did because this
53 committee, this panel, said: "A number of mechanism
54 whereby fat could be involved in cancer promotion has been
55 suggested". Would you agree that in the study of the
56 aetiology of cancer it is important to distinguish between
57 initiation and promotion?
58 A. In some context, yes, that is important.
59
60 Q. It goes on ----
