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Following
on the heels of recent revelations that x-ray mammography may be contributing
to an epidemic of future radiation-induced breast cancers, in a new article
titled, "Radiation Treatment Generates Therapy Resistant Cancer Stem Cells
From Aggressive Breast Cancer Cells," published in the journal Cancer July
1st, 2012, researchers from the Department of Radiation Oncology at the UCLA
Jonsson Comprehensive Cancer Center report that radiation treatment actually
drives breast cancer cells into greater malignancy.
The
researchers found that even when radiation kills half of the tumor cells
treated, the surviving cells which are resistant to treatment, known as induced
breast cancer stem cells (iBCSCs), were up to 30 times more likely to form
tumors than the nonirradiated breast cancer cells. In other words, the
radiation treatment regresses the total population of cancer cells, generating
the false appearance that the treatment is working, but actually increases the
ratio of highly malignant to benign cells within that tumor, eventually leading
to the iatrogenic (treatment-induced) death of the patient.
Last
month, a related study published in the journal Stem Cells titled,
"Radiation-induced reprogramming of breast cells," found that
ionizing radiation reprogrammed less malignant (more differentiated) breast
cancer cells into iBCSCs, helping to explain why conventional treatment
actually enriches the tumor population with higher levels of treatment-resistant
cells. [i]
A
growing body of research now indicts conventional cancer treatment with
chemotherapy and radiation as a major contributing cause of cancer patient
mortality. The primary reason for this
is the fact that cancer stem cells, which are almost exclusively resistant to
conventional treatment, are not being targeted, but to the contrary, are
encouraged to thrive when exposed to chemotherapy and radiotherapy.
In
order to understand how conventional treatment drives the cancer into greater
malignancy, we must first understand what cancer is….
What
Are Cancer Stem Cells, And Why Are They Resistant To Treatment?
Tumors
are actually highly organized assemblages of cells, which are surprisingly
well-coordinated for cells that are supposed to be the result of strictly
random mutation. They are capable of building their own blood supply
(angiogenesis), are able to defend themselves by silencing cancer-suppression
genes, secreting corrosive enzymes to move freely throughout the body, alter
their metabolism to live in low oxygen and acidic environments, and know how to
remove their own surface-receptor proteins to escape detection by white blood
cells. In a previous article titled "Is Cancer An Ancient Survival Program
Unmasked?" we delved deeper into this emerging view of cancer as an
evolutionary throw-back and not a byproduct of strictly random mutation.
Because
tumors are not simply the result of one or more mutated cells "going
rogue" and producing exact clones of itself (multi-mutational and clonal
hypotheses), but are a diverse group of cells having radically different
phenotypal characteristics, chemotherapy and radiation will affect each cell
type differently.
Tumors
are composed of a wide range of cells, many of which are entirely benign.
The
most deadly cell type within a tumor or blood cancer, known as cancer stem
cells (CSCs), has the ability to give rise to all the cell types found within
that cancer.
They
are capable of dividing by mitosis to form either two stem cells (increasing
the size of the stem population), or one daughter cell that goes on to
differentiate into a variety of cell types, and one daughter cell that retains
stem-cell properties.
This
means CSCs are tumorigenic (tumor-forming) and should be the primary target of
cancer treatment because they are capable of both initiating and sustaining
cancer. They are also increasingly recognized
to be the cause of relapse and metastasis following conventional treatment.
CSCs
are exceptionally resistant to conventional treatment for the following reasons
CSCs
account for less than 1 in 10,000 cells within a particular cancer, making them
difficult to destroy without destroying the vast majority of other cells
comprising the tumor.[ii]
CSCs
are slow to replicate, making them less likely to be destroyed by chemotherapy
and radiation treatments that target cells which are more rapidly dividing.
Conventional
chemotherapies target differentiated and differentiating cells, which form the
bulk of the tumor, but these are unable to generate new cells like the CSCs
which are undifferentiated.
The
existence of CSCs explains why conventional cancer treatment has completely
missed the boat when it comes to targeting the root cause of tumors. One reason
for this is because existing cancer treatments have mostly been developed in
animal models where the goal is to shrink a tumor. Because mice are most often
used and their life spans do not exceed two years, tumor relapse is very
difficult, if not impossible to study.
The
first round of chemotherapy never kills the entire tumor, but only a
percentage. This phenomenon is called the fractional kill. The goal is to use
repeated treatment cycles (usually six) to regress the tumor population down to
zero, without killing the patient.
What
normally occurs is that the treatment selectively kills the less harmful
populations of cells (daughter cells), increasing the ratio of CSCs to benign
and/or less malignant cells. This is not
unlike what happens when antibiotics are used to treat certain infections. The
drug may wipe out 99.9% of the target bacteria, but .1% have or develop
resistance to the agent, enabling the .1% to come back even stronger with time.
The
antibiotic, also, kills the other beneficial bacteria that help the body fight
infection naturally, in the same way that chemotherapy kills the patient’s
immune system (white blood cells and bone marrow), ultimately supporting the
underlying conditions making disease recurrence more likely.
The
reality is that the chemotherapy, even though it has reduced the tumor volume,
by increasing the ratio of CSCs to benign daughter cells, has actually made the
cancer more malignant.
Radiotherapy
has also been shown to increase cancer stem cells in the prostate, ultimately
resulting in cancer recurrence and worsened prognosis.[iii] Cancer stem cells
may also explain why castration therapy often fails in prostate cancer
treatment.[iv]
Non-Toxic
Natural Substances Which Target and Kill CSCs
Natural
compounds have been shown to exhibit three properties which make them suitable
alternatives to conventional chemotherapy and radiotherapy:
High
margin of safety: Relative to chemotherapy agents such as 5-fluorouracil
natural compounds are two orders of magnitude safer
Selective
Cytotoxicity: The ability to target only those cells that are cancerous and not
healthy cells
CSCs
Targeting: The ability to target the cancer stem cells within a tumor
population.
The
primary reason why these substances are not used in conventional treatment is
because they are not patentable, nor profitable. Sadly, the criteria for drug
selection are not safety, effectiveness, accessibility and affordability. If
this were so, natural compounds would form an integral part of the standard of
care in modern cancer treatment.
Research
indicates that the following compounds (along with common dietary sources) have
the ability to target CSCs:
Curcumin (Turmeric)
Quercetin (Onion)
Sulforaphane (Brocolli sprouts)
Parthenolide (Butterbur)
Andrographalide (Andrographis)
Genistein (Cultured Soy; Coffee)
Piperine (Black Pepper)
Additional
research found on the GreenMedInfo.com Multidrug Resistance page indicate over
50 compounds inhibit multidrug resistance cancers in experimental models.
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