Evening star., 1938-11-18
By THOMAS r. HENRY.

ON xIIOIxAC 416lNN1
Evidence of q cancer causative
factor In mothers milk has just been
reported to the National Cancer
Institute of the United States Pub
lie Health Service by DR.. John J.
Bittner, research worker at the Ros-
coe B. jackson Labratory at Bar
Harbor, Me.
DR.. Bittner has been working
under a grant from the national
cancer research funds administered
by the council. The finding is of
great significance because it shows
definitely an extra -chromosomal
cancer cause, DR.. r. R. Spencer,
executive assistant to the director
of the institute, told the Washington
Academy Of Sciences in announcing
the discovery last night.
For some years past, DR.. Maude
slye in Chicago has been breeding
cancerous strains of white mice.
producing families in which the sus-
ceptibility to cancer, handed down
from generation to generation, Is
very high. DR.. Bittner took Off
spring from strains which very sell
dom develop any cancerous groWtns
and placed them Immediately after
birth with nursing mothers OF one
of the cancerous strains, although
these mothers themselves did not
necessarily have any malignant
growths.
Might Apply to Humans.
He has found. according to his re-
port to the council, that these young
animals developed markedly
greater number of cancers, of a type
peculiar to rats. than their brothers
and sisters which were nursed BY
their own mothers. The fact is
highly suggestive. DR.. Spencer said.
although it does not necessarily
mean that the same conditions
would obtain in human beings.
One of the outstanding hopes Of
the council, which is making re-
search grants to workers all over the
country, DR.. Spencer said, is of iso-
lating a mammalian cancer virus,
similar to the filterable viruseS
which are responsible for 50 many
human and animal diseases.
The general viewpoint at present
taken by the institute, he said. Is
that there are three factors in the
causation of malignant growths.
two or more of which may be opera
tive in any particular case. One Is
hereditary predisposition, demon
started by DR.. Slye's breeding ex-
periments over many generations.
This alone probably is seldom suf-
ficient to cause the disease. Next Is
the remote cause. Several such have
been demonstrated, such as various
tar products, irritation of tissue. etc.
Such a remote cause, acting upon
tissue already predisposed by hered-
ity, sets in operation "proximate
cause" presumably something like
q filterable virus.
Remote Cause Definite Factor.
The creation or release of the sub
stance seems to require the remote
cause to set 1t off. Once the process
is started, however, the cancer de-
velops very rapidly-perhaps in two
or three weeks. It may require
months for the remote cause to set
OF the proximate cause, depending
on the susceptibility of the tissue.
Once this happens the remote cause
Is no longer necessary and the
progress of the malignant growth
goes on if it is entirely removed.
Only two such filterable sub
stances have been obtained to date.
One, found years ago and used in
many experiments, is Rous' chicken
sarcoma virus. One, just reported
to the institute, Is from a cancer
found only in frogs. The Rous virus
will cause very rapid cancer forma-
ton in other chickens and the frog
virus in other frogs. All efforts to
get anything of the sort out Of a
cancer of man or any other man.
NAL have proved futile to date.
1t is apparently extremely elusive,
DR.. Spencer said, and passes from
cell to cell by cell heredity." Thus
. cancer starts slowly, but its prog
ress is accelerated more and more
as there are larger and larger gen.
erations Of descendants from the