Evening star., 1939-11-28
Of Stars, Men
And Atoms
Notebook Of Science Progress
In Field, Laboratory
And Study
By Thomas r. Henry.

Cancer is not directly inherited in man.
In the light of present knowledge no
body needs worry about belonging to a
family with tendency toward cancer
declares DR.. Clarence c. Little, director
OF the jackson Memorial Laboratory at
Bar Harbor Me-, in a summary of the
present status of cancer research pre-
pared for the American Society for the
Control of Cancer.
Much confusion has existed in the past
on this point, DR.. Little says, because of
reports on hereditary tendencies toward
neoplasms in various organs. These re-
ports, he points out, have been Of ex-
periments with mice. With these animals,
whose total life span is three years so
that many generations can be studied,
1t is easy to demonstrate hereditary
factors, but In families which have been
inbred for long time so that the tend
ency Is markedly exaggerated. 1t would
be almost impossible to show anything of
the sort in mouse families taken at
random.
"A similar condition does not and can
not exist in man." he says 1--WE do not
at present know Of any specific heredi-
tary factor that leads to cancer.
I'VE are certain that cancer is not
passed directly from parent to offspring.
Heredity does, however, seem to be re-
lated to frequency of cancer IN various
parts of the body. This type of Inherit
ance is so complex and so uncertain that
it very largely can be forgotten by the
individual. There is evidence that the
tendency to form cancer in man may be
inherited, but the tendency is so indirect
that heredity of cancer need not be
source Of worry to any person."
One Of the great advances in cancer
research. DR.. Little stresses, has been
the finding that cancer tissue is i'm
mortal"
Although the life span of the labora-
tory mouse he says, seldom exceeds
three years. it has been possible by sue
cessive transplantations of bits of a
single mouse cancer to keep it growing
with undiminished vigor for 40 years.
There is no evidence that cancer ages,
or slows down in its rate of growth. The
possibility of producing an unlimited
amount of cancer tissue from a bit of
mouse which, as an adult, weighed no
more than 30 grams, is certainly present
Unless infection due to carelessness
is introduced, the life of cancer appears
to be limitless. We are dealing not with
a sickly or diseased tissue, but with one
which has tremendous vigor and power
of growth.
Mice have been found to be almost
ideal for experimental study of cancer
because in their short lives they provide
man with shorthand version of his own
life history A mouse year old is
roughly comparable to a man of 40. A
mouse 2 years old is like a person IS
or 10. In a three-year period one can
observe the whole life span of these
little animals. This saves vast amount
OF time, especially as mice of certain
strains are very prone to form cancer
without artificial treatment of any sort.
"One OF the most difficult fields in
cancer research is that which deals
with the internal chemistry of the can
Ger cell. A living cell is a sort of self
sufficient unit which is able to perform
almost miraculous functions. 1t can
receive through its surrounding envelope
food material which it can then trans
form into substance of it's own making
1t can store such material until a GER
tain point is reached, after which it
begins to reorganize its own material as
dual system which later breaks apart
to form from its original substance two
daughter cells of equal size. 1t can
give off certain waste products which it
no longer needs in order to fulfill its
normal functions. To some extent all
these activities can be measured and
recorded. In this way certain general
differences between cancer and normal
cells have been observed
1.-The body possesses several glands
which pour secretions of a particular
sort into the blood. These secretions
have in them chemical substances called
hormones. The Importance of such
hormones to the development and func-
tion of the body in general and of can
Ger in particular cannot be overesti-
mated. The sex glands of both male
and female have been made the object
OF extensive study. The relation of
these glands to cancer is already mat
ter of recognized Importance and forms
the basis for much present research.
I'm male mice cancer of the breast is
practically unknown-male mice in a
strain of which more than 80 per cent of
the females developed breast cancer.
When ovaries of the sister animals were
transplanted to these males, however,
cancers developed in about the same
proportion as in the females. When,
however, the same experiment was tried
in stock of mice in which the normal
females did not have breast cancer, the
feminized males did not produce breast
cancer.
"Other glands of internal secretion,
such as the pituitary, the adrenals, the
thyroid and the spleen, can be removed
and the effects on cancer and on the
chemical characteristics of the indi-
vidual can be observed. This type of
biological and chemical research is pro-
ducing extremely significant and i'm
portant results"
Denies District Rents
Are Excessive.