Day 017 - 25 Jul 94 - Page 05
1 MR. JUSTICE BELL: What was the last one?
A. From the blood forming tissues these are called
3 MR. RAMPTON: So far as cancer of the breast is concerned, are
you principally concerned with one particular type of
A. Cancer of the breast is an adenocarcinoma. The breast
5 in many respects is a modification of the skin, so it is a
carcinoma. The breast itself is not too dissimilar from
6 other ducts which one can see on the skin surface, but it
is obviously modified largely for the production of milk
7 for the feeding of infants after childbirth. But it is
essentially a modification of the skin and therefore is an
9 Q. What about cancers of the colon and rectum?
A. Right, well, these are also adenocarcinomas. They are
10 again carcinomas because they arise from a covering
tissue, the surface -- we called it epithelium -- the
11 lining epithelium, a lining covering of the intestine.
Although they are adenocarcinomas, when you actually look
12 at them under a microscope, the characteristics of the
cells and structure of the tissue, the cancer itself, is
13 quite different from that of breast carcinoma. Although
they are both called adenocarcinomas ("adeno" just means
14 of glandular origin) they are quite distinct.
15 Q. We use carcinoma; it is a broad term but it has to do with
the location of the tumour?
16 A. Yes, and the tissue of origin.
17 Q. Can you, before I come to aetiology, which is what we are
concerned with in this case, just give us a brief summary
18 of how a cancer, a tumour, is initiated, how it develops?
A. Right. Well, I think the first thing I have to say is
19 that a lot of the mechanisms in this are poorly
understood. A lot of what we believe about the process is
20 inferred rather than there being actual, direct laboratory
evidence, but it would seem that initially there is the
21 process of initiation. This implies that some change
within the genetic mechanism within the cell itself is
22 probably irreversible. It can arise, we believe, for a
variety of reasons such as radiation exposure, or it may
23 be there is some genetic predisposition. We are now
believing there are certain oncogenes -- that is genes
24 capable of promoting the development of tumours -- and
that in life there are inhibitors as well promoters. It
25 is the balance which keeps us all healthy. For some
reason or another, the inhibition may be lost, allowing
26 the cell to change in this way.
27 Now because the cell changes and is initiated it does not
necessarily need to form a cancer. The cell can remain as
28 it is unchanged and not have any influence on one's life
expectancy, but then the next stage is believed to be
29 promotion. This is a reversible process. It seems to be
related not only to chemical exposure but perhaps viral
30 infection or other biological factors, such as genetic
predisposition, but the factors which are influencing