Day 017 - 25 Jul 94 - Page 19

     
     1        particularly perhaps nowadays, the number of children and
              the age at which a woman first starts having children are
     2        social factors, are they not?
              A.  They are indeed.
     3
         Q.   I interrupted you.  I wanted to get that clear.  What else
     4        appears to be influential?
              A.  The other thing which is probably one of the most
     5        predominant features in breast cancer is a family history
              of breast cancer.  In other words, does some other member
     6        of the family  or has some other blood relative in the
              family had breast cancer, and this significantly increases
     7        the risk of a person, who is a blood relative, of
              developing breast cancer themselves.  This seems to be one
     8        of the most important features.
 
     9   Q.   Is there any similar factor thought to be at play in
              relation to cancer of the colon and rectum?
    10        A.  There is a very strong association in cancer of the
              colon and if a blood relative has developed cancer of the
         colon or rectum, the risk of a subsequent blood relative
              developing colon or rectal cancer is increased two to four
    12        times, so it is a significant increase in risk.
 
    13   Q.   I will finish with this question.  Is that now thought to
              be confined or not to those people or those families which
    14        have a history of familial polyposis?
              A.  No.  The familial polyposis, which is a condition
    15        which is found to run in families, is a direct genetic
              condition.  One can actually measure the genetic
    16        abnormality on chromosome No. 5 -- we have 48 chromosomes
               -- and that is the most obvious association between the
    17        genetic abnormality and the inevitable development of
              colon cancer at some time later.  But there do seem to be
    18        other syndromes where you actually cannot necessarily
              detect a genetic abnormality, but where we do know that
    19        people have an increased risk of the development of colon
              cancer.  For example, one of these syndromes seems to be
    20        associated with an increased risk of colon cancer in the
              right side of the colon or the ascending colon.
    21
              But we do know, for example, that again where one cannot
    22        detect necessarily a genetic abnormality, one sees this
              increased risk of cancer developing in blood relatives,
    23        and the more the number of blood relatives who actually
              develop cancer of the colon, so the risk increases for
    24        subsequent members of that family.  So whilst we cannot
              identify a genetic abnormality, there is an increasing
    25        feeling that genetics plays a very important part in the
              genesis of colon cancer. 
    26 
         Q.   Can we come back to breast cancer.  We stopped with what 
    27        might be a genetic predisposition as an important factor.
              What about age at menopause?
    28        A.  Well, again the later the age of menopause, it seems
              to be associated with an increased risk of the development
    29        of breast cancer.  Once again that is a phenomenon one
              finds mainly in western countries.
    30
         Q.   Finally, is there evidence to suggest a relationship