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The Other Face of Cancer by Dr Manu Kothari and Dr Lopa Mehta
Cancer As A Biological Phenomenon
Regardless of all the notoriety accorded to
it, cancer presents itself as an integral part of biology
- a spontaneous, intrinsic universal phenomenon found in
both plant and animal kingdoms, not excluding insects.
There is no reason to think that cancer is a disease
which has been as it were, superimposed on life. On the
contrary, cancer is certainly an integral factor in the
evolutionary process, and has a history as long as the
type of life which it affects.17 It has
been suggested that life, as we understand it today,
emerged from the purposeless, incessantly proliferating
cancerous mass called pre-life.18 Stated below
are features of cancer that accord it its rightful place
in biology.
Cancer Cell and Normal Cell
Every normal cell in
the body has the potentiality of turning
cancerous by the property of cell differentiation
- a part of its repertoire.19 Cell
differentiation is the process by which a cell
irreversibly changes its character to turn into
another type of cell. The same process by which
an embryonic cell changes into a normal liver
cell occurs when a normal liver cell turns into a
cancerous one.
The human body is made up of a wide variety of
cell types -skin, liver, muscle, retina, etc.
Although all the cells of an individual have the
same genetic content, they manage to develop,
look, and behave differently, as distinct cell
types, through the as yet ill- understood process
called differentiation 253-255 -
generally defined as the creation of new types of
cells not present earlier. The formation of a
cancer cell, from a normal cell of the body at
any age, is once again the creation of a
distinct, new cell type - one that looks and
behaves differently despite having the same
genetic content as all the other normal cells of
the body. It is now generally agreed 253
that the formation of a cancer cell involves the
same process of differentiation as gives rise to
normal cells of the body. No wonder that the
seemingly gross malfunctioning by cancer cells -
such as the secretion of carcino embryonic
antigen (CEA)256, or ectopic hormones 257
is now being understood as mere quantitative
variations 256,257 of normal cell
function.
There is no
consistent single, structural, immunological, or
biochemical dividing line between a normal cell
and its cancerous counterpart. Thus a cancer cell
does not have any feature which is not observed
in some normal body cell.
The above points can be rendered more clear by
taking, say, leukemic cells as an example:
Since the leukemic cells originate from
transformation (cell differentiation) of normal
hematopoietic cells, they retain many of the
normal cells properties, and their
proliferative behaviour is in many ways
similar.315. More specifically:
Attempts to distinguish normal from
leukemic cells bio- chemically have failed to
demonstrate qualitative differences in virtually
every instance.98
Cytokinetically, both leukemic and normal cells
demonstrate equivalent cell renewal
activity.98, 258. Nor can they
be differentiated morphologically or
immunologically.98
The difference
between a normal cell and a cancer cell lies in
their behaviour. A cancer cell, unlike a normal
cell which only divides to replace cell loss and
maintain the constancy of cell number, divides by
its own self-determined rhythm without the
bodys need. Unlike a normal cell, a cancer
cell also migrates from its site of origin and
colonizes at distant sites.
Cancer
in an Individual
Each cancer, human or
animal, is, to borrow Rene Dubos phrase, unprecedented,
unparalleled, and unrepeatable. The
uniqueness of a cancer lies in its cells as also
in the way the cells are arranged and behave.
This very uniqueness 3,15,155,156 of
every cancer rules out the possibility of having
any specific drug or vaccine as curative or
preventive against cancer. Writing in The
Lancet on Uniqueness of malignant
tumours, Spriggs and co-workers239 concluded:
It is impossible to, prove the negative -
that identical carcinomas never occur - but the
present tests confirm an impression, obtained
from thousands of cases, that naturally occurring
cancers are extremely diverse even when they
carry the same diagnostic label.
The course of a
cancer is as unpredictable as that of the
individual. Having formed, it may not grow;
having grown, it may not dis-ease or trouble;
having dis-eased, it may not kill. Many a cancer
dies with its owner. Hence it is the cancer
and not the therapy given, that determines the
outcome in a human being or an animal.
Cancer in its
occurrence exhibits a predictable certainly at
the level of herd, but always remains a matter of
chance or probability at an individual level.
World over, the overall cancer occurrence is one
in five humans.55 One in five is a
matter of certainty; which one, is that of
probability. This holds good even in animals21
specially inbred in laboratories for studying
cancer-occurrence generation after generation.
Cancer is neither
hereditary nor familial. It is its very
commonness that makes it occasionally seem so.
Willis20 has generalized that most of
the cancer families exemplify only
the laws of chance. Scheinfelds 240
incisive comments on the problem - Thus, in
grandmother, mother and daughter, where all have
breast cancers, each of their cancers may be
entirely unrelated to the others ... The breast
cancers in the three generations of women might
be no more related than three cases of stomach
trouble, one resulting from over-eating, another
from drinking bad liquor, and the third due to
stomach ulcers. - made way back in 1939,
has a resounding echo in the But so
what? reassurance from Frazer Robert 241:
This is a very common condition.
A cancer is for the
owner, a part of his or her own flesh and blood.
It cannot be attacked with impunity without
damaging other normal tissues. All anticancer
agents treat cancer cells in the same manner as
they treat all normal cells. This inseparableness
of cancer from normal tissues has rendered cancer
radiotherapy obsolete22
and cancer chemotherapy an absolute
farce22. In the laboratory
cancer chemotherapy produces 100% success because
the so-called cancer is a transplanted mass of
cells that never belonged to the test animal.6 In
the laboratory and by the bedside, chemotherapy
is a 100% failure if the cancer is autochthonous,
i.e. the one that arose by itself in the
individual.23
Cancer
in a Herd
The type of cancer
that occurs is species specific - of the kidneys
in frogs, of the nasal sinuses in dogs, of the
eyes in Hereford cattle, breasts in bitches, as
leukemia in Scottish terriers, and as melanoma of
the skin in grey horses. 30,31
A predominant
involvement of a particular organ or system is
seen in the different races of man too, as
exemplified by the very high incidence of stomach
cancer in the Japanese who, as a compensation,
have the lowest incidence of leukemia in the
whole world.32 This varying prevalence
is not dependent on the environment. It is the
racial or the ethnic genetic constitution which
governs the type of cancer in a given population.
The high incidence of stomach cancer is as much a
Japanese feature as are the stub nose and the
slit eyes.
However, the total incidence of cancer, in a
herd, is determined by genetic constitution of
mankind irrespective of racial and geographic
variations. Thus the aggregate incidence of
cancer remains the same world over. Smithers 165
has generalized that although the anatomic
distribution of cancers in different parts of the
world is extremely varied, the overall death-rate
from cancers at all sites is remarkably constant
for humans the world over.
The
environmentalistic claim 242, 243 that
migrants readily develop a cancer profile typical
of the host community made regardless of the
manifestly inadequate244
data and the many difficulties associated with
the study of migrants, 244,293 fails
to find support epidemiologically.245
Japanese migrants in the USA maintain the high
rates of stomach cancer typical of Japan, as also
the characteristics low rates of breast and
cervical cancers, and of leukemias.
Cancer
as a Senescent Process
Cancer is a
manifestation of aging, like hardening of
arteries, development of cataract, etc.
Most spontaneous tumours in animals, as in
man, occur in middle -aged or elderly
animals.20 In children, too
cancer is but a form of senescence. (See Chapter
Eleven)
As is typical of
biologic processes, cancer in its many facets
exhibits gaussian (normal/continuous/bell-shaped)
distribution, as may be evinced from, say, the
age-incidence of a particular cancer in a human
population.6,20 This may also be true
for its other facets such as growth rate,
invasiveness, site of origin, size of cells, etc.6
Cancer
and Death
The fatal bite of the
cancerous crab often lies in its spread. The
spread of a cancer occurs throughout the length
and breadth of the body, but usually manifests
itself, apart from the original site of
occurrence, at four sites - lung, liver, bones,
and brain. No place in the body is, however,
exempt from this process. The spread of cancer
fools the clinician, frustrates the surgeon, and
kills the patient. The when, where, and how
much to spread is determined by the inherent
nature of a cancer. Treatment of cancer can
precipitate its spread.
Cancer apparently
serves the natural function24 of herd
mortality, which simply means increasing
mortality with increasing age. The
age-specific mortality rate for cancer increases
with age in much the same way that the overall
rate does.25 To put it simply,
the increase in mortality rate with age in cancer
is similar to the increase in mortality rate with
age in general.
The nature of the link between cancer and death
is debatable as may be realized from the
computation that, were cancer eliminated
altogether from mankind, it would just add a
little more than a year to the human life span.26
Animals would fare no better, in the futuramic World
Without Cancer.27
Death is a natural
function, not dependent on the presence or
absence of a particular disease.28 It
would seem death does what it wants to, and gives
the pre-death disease a bad name. Zumoff and
co-workers29 analyzed the mortality
statistics for series of patients with diverse
diseases - liver cirrhosis, metastatic breast
cancer, chronic leukemia and heart attack.
It was found that the four diseases
analyzed shared an unexpected relationship of
mortality rate to duration of disease: the basic
mortality rate remained constant during the
course of disease; prognosis was neither better
nor worse for the patient late in the disease
than for the patient early in the disease.
The workers 29 concluded that all the
above diseases shared a common alteration of
the undefined physiological systems
that govern susceptibility to aging and dying.
The causes of death
in human cancer, Jones11 surmised have
less to do with the extent of cancer growth than
with some other explanation of the metabolic
state in cancer. Jones 11 emphasized
that only a fraction of cancer follow-up
suggests that death is due to recurrence of the
cancer in an advanced state. Jones11
pointed out that the death rate from intercurrent
disease, in cancer, is as great as the rate of
death from cancer itself. He speculated that
there may be a general metabolic basis of
cancer as a disease, a phenomenon that may
explain why our intense search for cancer cures
has been very poorly rewarded. ... the
population that shows cancer may be already aged
from the standpoint of intact metabolic function,
so that cancer is only one of the manifestations
that occurs in the diseased population.11
Summarizing the biologic features of
cancer, one could say that cancer cell is an
altered normal cell; that in an individual,
cancer exhibits self-determined uniqueness; that
at the level of a herd, while the cancer types
vary, the total quantum does not, the world over;
that cancer is an evident part of oveall
vertebrate aging and senescence; and that in
relation to death, cancer is NOT the villain of
the piece, as portrayed.
Were cancer to have ears and a tongue, it would
listen to all our wailings and then
apologetically declare its helplessness because
of its being rooted in the very thing called
life. Thanatologists have, rightly, started
preaching from public rostra that death is an
inevitable, and an indispensable necessity. Can
it not occur to us that this is true for cancer
also and that cancer is not a problem but a
solution to the problem of dying? Sir George
Pickering,33 Regius Professor of
Medicine at Oxford, summed this up well:
Aging as a preparation for death is a
concept so fundamental that it needs emphasizig
before we consider the disease of old age. After
all, it is these diseases which kill and make way
for the new life. Without them none of us would
be living as we are today. And so it is,
with cancer. Cancer will be with us till
eternity; let it be.