Blood Cancer Drugs Origin Cancer:
Recently
the media has reported that a class of blood Cancer medicine known as
angiotensin-receptor blocker (ARB) used by tens of millions of patients can
cause a significant increase in cancer especially lung cancer. This was the
conclusion drawn from a study published online recently by Sinai et al
in the medical journal Lancet Oncology.
A
cascade of hormonal reactions mainly referred to as the
renin-angiotensin-aldosterone (RAA) hormonal system is central in maintaining
blood Cancer. The first step in the chain is the production of rennin in the
kidneys when the kidneys detect lower blood Cancer. Rennin then stimulates the
formation of a protein called Angiotensin I, which is then converted to
angiotensin II by the angiotensin converting enzyme (ACE) in the lungs.
Angiotensin II is the most powerful constrictor of blood vessels known and this
constriction leads to elevated blood Cancer. Angiotensin II also causes the
secretion of the hormone aldosterone which further causes an additional blood Cancer
rise. Any drug that prevents the production of Angiotensin II via the RAA
system therefore is useful in reducing blood Cancer. The two classes of drugs
that have the most substantial effects on the RAA system are the angiotensin
receptor blockers (ARB) drugs and the angiotensin converting enzyme inhibitors
(ACE inhibitors) and are widely used for the treatment of hypertension, heart
failure and diabetes-related kidney damage. The mechanisms of action of both
these drugs are different although producing the same end result: reduction in
blood Cancer or is antihypertensive. For instance, ACE inhibitors lower blood Cancer
not only by blocking the production of Angiotensin II, but by increasing the
amounts of powerful chemicals, including nitric oxide, that widen the arteries.
Ever
since the use of reserving, a drug used for hypertension but no longer used,
has been associated with an increased risk of breast cancer more than 50 years
ago, the question of antihypertensive drugs and cancer has not come to rest.
Beta-blockers have been associated with lung cancer, thiamine diuretics with
renal cell carcinoma and colon cancer and calcium blockers with cancer in
general. In most instances, the risk is small and not supported by biochemical
experimental or epidemiological data. The relationship between diuretic therapy
and renal cell carcinoma is supported by a variety of clinical biochemical and
experimental data and remains of concern, particularly in women.
An
association between the ACE inhibitors and cancer was first indicated when the
results of the Candesartan in Heart Failure Assessment of Reduction in
Mortality and Morbidity (CHARM) study were published in 2003. The results of
the CHARM trial indicated that patients treated with candesartan had a
significant increase in the risk for fatal cancers compared with control
patients but that the investigators concluded this finding was likely due to
chance. Since then, several other studies, including LIVE, ONTARGET and TRANSCEND
noted an excess in malignancies in patients assigned the ARBs compared with
placebo.
For
that reason, Sinai et al conducted the meta-analysis to determine if
ARBs had an effect on new cancer diagnoses. Data were taken from all available
scientific and public randomized trials in which patients were treated with an
angiotensin-receptor blocker to treat hypertension, heart failure and
diabetes-related kidney damage. The five trials with new cancer data were
ONTARGET, PROFESS, LIFE, TRANSCEND, and CHARM-Overall. In addition, data were
available for cancer deaths in LIFE, TRANSCEND, VALIANT, and Val-Heft. In 85.7%
of the trials examined, Telmisartan which is also marketed as Miscarries, among
other names was used. Telmisartan has been commercially available to treat
hypertension since its approval in 1998. It is also approved for use in the
reduction of the risk of myocardial infarction, stroke, or death from
cardiovascular diseases (CVD) in patients 55 years of age or older who were at
high risk of developing major CV events and who are unable to take ACE
inhibitors. Hence, it is really the effect of telmisartan on new cancer that is
being accessed in this meta-analysis.
The
analysis followed about 61,590 patients: researchers found a rise of 11 percent
in cancer overall and 25 percent in lung cancer among patients who took ARB
drugs. Overall those patients on trial who were randomly assigned an ARB had an
increased risk for new cancer diagnosis compared with those patients assigned
placebo (7.2% vs. 6%). Among the solid-organ cancers examined, only an
increased risk for lung cancer was identified compared with control groups
(0.9% vs. 0.7%). That translates into the modest but significant effect of one
additional case of cancer for every 105 patients who take the drugs for four
years, which does not seem a high risk but is similar to that seen with passive
smoking. Nevertheless, this is the first time such an association has been made
and even if the risk for the individual patient is not huge, the clinical significance
of this potential excess cancer risk is unknown.
Given
the millions of patients on these drugs, this is an important number because it
gives an idea of potentially how many excess cancers could be caused by these
medications. The finding of a 1.2% increase in absolute risk for cancer over an
average of 4 years needs to be interpreted in view of the estimated 41%
lifetime cancer risk. In the background information for this meta-analysis, the
researchers said, to date, there have been no significant safety concerns
associated with the use of ARBs. "However, clinical trials of ARBs have
mainly assessed their effects on cardiovascular and renal endpoints and have
usually not reported incidence of cancers," the researchers wrote.
Angiotensin-receptor blockers can be replaced with other blood Cancer
medications, the researchers said, but they warned patients not to do anything
before consulting with a physician as these drugs have beneficial effects for
the control of blood Cancer and heart failure.
Officials
with Bushranger Ingelheim, makers of Ttelmisartan is putted the findings in a
statement, saying that the company's "comprehensive internal safety data
analysis of primary data contradicts the conclusions about an increased risk of
potential malignancies." They also concluded that the finding of a
modestly increased risk of new cancer diagnosis in the meta-analysis is "mainly
based on the combination arm of telmisartan and ramipril [Alsace, King
Pharmaceuticals], an ACE inhibitor, in ONTARGET and not on the trial arms of
each compound separately," it asserts, noting that the product labeling
for telmisartan does not recommend combining it with ACE inhibitors.
In
most studies and meta-analyses, the risk of cancer with the RAA system blockers
was either equal or lower than with their comparator (including placebo). Thus,
the present study showing a modestly increased risk of new cancer diagnosis
with ARBs is unexpected and certainly warrants scrutiny and further
investigation. While the meta-analysis has its strengths-particularly its size,
the thoroughness of the literature search, and the application of appropriate
filters to exclude potentially unreliable data, "there are also important
weaknesses, which the investigators acknowledge-including the post-hoc nature
of this investigation where only certain drugs within the ARB class are
examined and that the trials examined were not designed to explore cancer
endpoints.
In
an editorial accompanying this meta-analysis, Steven E. Nissan, said although
the researchers are "appropriately cautious" about drawing
conclusions from the analysis as it remains unknown whether other
ARBs-irbesartan (Vapor, Bristol-Myers Squibb/Sanofi-Aventis), valsartan (Divan,
Novartis), olmesartan (Benicia, Daiichi Sankyo), and eprosartan (Teeter,
Abbott)-are linked to a higher risk of new cancer incidence, it was still
"disturbing and proactive". Further investigation is needed to
conclusively define any cancer risk associated with these drugs. Also, the
mechanism for the possible increase in new cancer occurrences associated with
ARBs is uncertain, according the authors. There is little, if any, biological plausibility
that a drug exposure of a few years only would increase the risk of new cancer
diagnosis. Cigarette smoking, which is one of the most powerful risk factors
for lung cancer, will require 10 years or longer of exposure to significantly
increased risk of lung cancer. Thus, it's exceedingly unlikely that the
short-term drug exposure as happens in clinical trials ARBs would have a
clinically meaningful effect. Nevertheless, regulators must review the possible
association between ARB use and cancer, and promptly report their findings. In
the meanwhile, ARBs which are often over prescribed anyway should be reserved
for patients with intolerance to ACE inhibitors.
Our
book "Is you’re Food Killing You?" goes into more detail on how and
why your food causes Cancer and Diseases and much more. We pride ourselves on
giving you the whole picture and all the facts not just the shocking headlines
without any substance behind it. If you want to know more about how your food
affects your health then visit Food Myths Busted out what the Food and Medical
industry does not want you to know as well as why the Government is in on all
of this you deserve to know the truth about the food you consume.
