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Surgery poses many risks to a cancer patient. The
known side effects associated with the surgical removal of tumors
include anesthesia complications, infections, and immune suppression.
A surgery side effect of concern to cancer patients is that the
removal of the primary tumor may directly stimulate cancer spread (the
propagation of metastatic lesions). Metastatic tumors require the
formation of new tumor blood vessels (called angiogenesis) to grow.
Once the primary tumor has been surgically removed, the amount of
endostatin and angiostatin to control new tumor blood vessel growth is
drastically reduced, and metastasized lesions begin proliferating out
of control. If the immune depression that surgery induces is factored
in, the failure of surgery to meaningfully prolong the life of cancer
patients becomes quite understandable. Surgery reduces growth control
factors (endostatin and angiostatin) while simultaneously weakening the
immune surveillance that might be keeping metastatic lesions under some
degree of control (Oliver et al. 1996).
Cancer has long baffled medical science. Until recently, scientists
did not fully understand why the disease so often begins rapidly
spreading throughout the body after surgery. This protocol identifies
previously unknown factors involved in the long-term failure of cancer
surgeries. The educated patient now has access to drugs to facilitate
systemic control of cancer rather than to promote metastasis.
Even more exciting is the news that drugs such as endostatin and
angiostatin are in clinical trials. If the FDA approves these drugs,
the surgical removal of a large primary tumor might actually "cure"
many more cancer patients. In the meantime, there are other anti -
angiogenesis drugs that may help prevent the rapid growth of metastatic
lesions after the primary tumor is removed.
How Tumors Grow
Almost every tissue in the body derives blood from the
thinner-than-a-hair capillaries that lace our tissues. Through
capillaries, nutrients, oxygen, and various signaling molecules diffuse
into cells. These mechanisms maintain health, fight disease, and allow
the body to flourish and grow.
Tumors start out without a vascular circulation. In the early stages
of tumor development, they are limited to nutrients that can diffuse
from the nearest capillaries. Then, tumors begin to stimulate healthy
tissue to make thousands of new blood vessels to supply the cancerous
growth--a process called angiogenesis. Without this ability to nourish
itself and grow, a tumor cannot enlarge. If the blood supply can be
reduced or cut off, the tumor will shrink or die.
Removing One Tumor May Stimulate the Growth of Many More
Recurrence is the point when cancer cells from the primary tumor are detected following the primary treatment for the cancer.
Ipsilateral breast tumor recurrence following conservative surgery
and radiation for early stage invasive cancer occurs in approximately
15% of all patients at 10 years and is reduced with surgical excisions
which achieve negative margins (Fowble 1999). Local recurrence
continues to be a major problem following surgical treatment for rectal
cancer, because of the frequency with which it occurs (varying from 4%
to 51%), its impact on quality of life, the fact that treatment is
rarely successful (McLeod 1997), and the proposed ways of reducing this
remain controversial (McCall et al. 1995).
All patients undergoing laparoscopic surgery for malignancies should
have careful follow-up with special attention to the port sites, as
port-site metastasis after laparoscopic lymphadenectomy is a phenomenon
that occurs following this type of cancer surgery (Tjalma et al. 2001).
Several drugs--including interferons, steroids, and certain hormonal
agents--have been developed to stop or slow angiogenesis. In fact, at
least 11 anti-angiogenic drugs are in clinical trials, and three have
proved effective enough to make it to the final phase.
Some of the drugs, like endostatin, are derived from natural
proteins, while others are based on smaller molecules. Ironically, one
promising drug in clinical trials is thalidomide, which once was sold
as a sedative that caused notorious birth defects.
Another drug, 2-methoxyestradiol (2-ME), is a natural estrogen
metabolite believed to be an inhibitor of angiogenesis and also an anti
- tumor agent.
In addition, researchers are investigating a drug called Col-3 and
are negotiating with several biotechnology companies to examine other
anticancer compounds.
Of all the anti - angiogenic drugs, endostatin and angiostatin
appear to hold the greatest potential for saving lives. These drugs are
nontoxic and have shown efficacy against every type of cancer tested.
These drugs suppressed metastatic tumor growth rates by 90% (Hajitou et
al. 2002). Another study showed primary tumors regressing to become
dormant microscopic lesions (O'Reilly et al. 1997).
Based on this new information, angiostatin and endostatin may
greatly increase the number of cancer patients who become disease-free
after surgery.
How to Enter Clinical Trials
Endostatin was the first endogenous angiogenesis inhibitor to enter
into clinical trials. Endostatin given to 21 advanced solid tumor
patients daily as a 1-hour intravenous infusion (for 28 days) was well
- tolerated (Thomas et al 2003).
The safety and efficacy of recombinant human Angiostatin protein
administered in combination with chemotherapy (paclitaxel and
carboplatin) to patients with non-small-cell lung cancer is currently
being investigated in a clinical trial: http://clinicaltrials.gov/ct/search?term=angiostatin
For more information about cancer clinical trials call the Cancer Information Service, (800) 4-CANCER.
Physicians may request information about trials from the PDQ Search
Service by calling (800) 345-3300, faxing (800) 380-1575, or e-mailing
pdqsearch@icicc.nci.nih.gov.
There are many anti-angiogenesis drugs in clinical studies. In some
cases, the FDA may allow an unapproved drug to be released before it is
officially approved. Here are some of the anti-angiogenesis drugs being
tested and the sponsoring companies:
|
Drug |
Phase |
Sponsor |
|
TNP-40 |
II |
TAP Pharmeceuticals Inc., Deerfield, WI |
|
Squalimine |
II |
Genera Pharmaceuticals Inc., Plymouth Meeting, PA |
|
Vitaxin |
I |
Ixsys Inc., San Diego , CA |
|
Thalidomide |
II |
Extremed Inc., Rockville, MD |
|
RhuMab, VEGF |
II |
Genentech, Inc., South San Fransisco, CA |
|
SU5416 |
II |
Sugen Inc., Redwood City, CA |
|
Marimastat |
III |
British Biotech Inc., Annapolis, MD |
|
Bay 12-9566 |
III |
Bayer Corp., West Haven, CT |
|
AG3340 |
III |
Agouron Pharmaceuticals Inc., La Jolla, CA |
|
Col-3 |
I |
CollaGenex Pharmaceuticals, Newton, PA |
|
CM101 |
I |
Carbomed Brentwood, TN |
The First anti-angiogenesis drug is approved
After many years of study, the drug Avastatin® has been approved by
the FDA to treat colon cancer. It may also be effective against other
cancers.
In a well-performed Phase III trial, Avastatin® was shown
impressively to prolong survival for patients with metastatic
colorectal cancer that could not be removed by surgery (unresectable). (O'Neil et al. 2003).
Avastatin® (bevacizumab) is an anti - angiogenesis drug, used in
molecular targeted therapy to stop tumors from making new blood
vessels. It works by keeping VEGF (vascular endothelial growth factor)
from initiating the growth of new blood vessels. Without new blood
vessels, tumor growth is inhibited. Avastatin® is now being studied for
the treatment of many different cancers.
Patients with newly diagnosed metastatic colon cancer who received
Avastatin® along with a chemotherapy combination (known as IFL) had
substantially longer overall survival times than patients who received
the chemotherapy but with a placebo instead of bevacizumab.
A randomized Phase III trial to compare the effectiveness of two
combination chemotherapy regimens with or without bevacizumab in
treating patients who have locally advanced, metastatic, or recurrent
colorectal cancer is underway via the National Institutes of Health
(NIH). A Phase I trial to study the effectiveness of bevacizumab
combined with fluorouracil and external-beam radiation therapy in
treating patients who have stage II or stage III rectal cancer is also
ongoing via the NIH.
Protecting Against Surgery-Induced Immune Suppression
Human and animal studies demonstrate that surgery suppresses immune
function. In fact, surgical stress directly reduces natural killer (NK)
cell activity, and other immune factors (Hansbrough et al. 1984; Pollo
c k et al. 1991; Udelsman et al. 1991). NK cells have a fundamental
role in destroying cancer cells and are involved in inhibiting
metastasis (Herberman et al. 1981; Gorelik et al. 1982; Hanna 1985;
Wiltrout et al. 1985; Ben-Eliyabu et al. 1999).
A regrettable consequence of surgery is suppression of vital NK cell
activity, thereby making the patient more susceptible to developing
metastatic lesions. In the animal model, surgery-induced immune
suppression has been linked to tumor metastasis to the lung (Page et
al. 1994 a ; 1994b; Ben-Eliyahu et al. 1999). Human studies demonstrate
that those with low NK cell activity have an increased risk of
metastatic lesions (Levy et al. 1985; Schantz et al. 1987; Tartter et
al. 1987; Fujisawa et al. 1997; Koda et al. 1997).
Despite the known immune-suppressing effects of surgery, removal of
the primary tumor is often mandatory in order to provide the cancer
patient with an opportunity for a cure. What oncologists have
overlooked are the many adjuvant therapies that can promote immune
function, specifically natural killer cell activity.
In the Cancer Adjuvant Therapy
protocol, natural approaches to boosting immune function are discussed.
The cancer patient contemplating surgery may want to consider
supplementation with melatonin, lactoferrin, echinacea, and a mushroom
extract called AHCC for the purpose of enhancing NK cell activity
(Ghoneum et al. 2000; Currier et al. 2001; Huang et al. 2002; Tsuda et
al. 2002). While these therapies are by no means a cure for cancer,
they do provide patients with an opportunity to mitigate the immune
suppression associated with surgical procedures.
Avoid Analgesic Drugs That Promote Metastasis
After cancer surgery, the patient often experiences pain and
requests an analgesic drug for immediate relief. The drug of choice is
often morphine or an other opiates. The problem with these drugs is
that they impair immune function, specifically NK activity,
lymphocyte-macrophage production, and other key immune cytokines. It is
during this postsurgical period that healthy immune function is
required to kill cancer cells that have escaped from the primary tumor
and are seeking to set up metastatic colonies.
Unfortunately, morphine is often prescribed to post - surgery cancer
patients at the very time when optimal immune function is most needed
to eradicate residual tumor cells. Instead of accepting morphine and
other opiates, ask your doctor for an analgesic drug called "tramadol."
Unlike morphine, tramadol does not suppress immune function. On the
contrary, tramadol has been shown to stimulate NK activity in animals
and humans. In a study on rats, tramadol was able to block the
enhancement of lung metastasis induced by surgery, whereas morphine did
not produce this beneficial effect (Gaspani et al. 2002).
Because tramadol produces a good analgesic effect combined with
immune-enhancing properties, it may be the drug of choice for
controlling postoperative pain in cancer patients.
Morphine has other deleterious effects on the cancer patient. In
addition to impairing immune function, morphine stimulates angiogenesis
(new blood vessel growth that feeds rapidly dividing tumors), activates
a tumor cell survival signal, and inhibits apoptosis (programmed cell
death) of cancer cells (Gupta K. et al. 2002). All of these negative
effects occur at morphine doses typically given to cancer patients.
In one study, morphine was specifically shown to promote the growth
of a human breast tumor implanted into an animal. Interestingly, an
analgesic-antagonist drug called naloxone inhibited tumor growth
(Maneckjee et al. 1990). Based on these findings, it was suggested that
the pro - angiogenesis effect of opioids (morphine) might be
detrimental to cancer patients (Gupta et al. 2002).
These studies help explain why cancer patients given morphine often
succumb quickly. This may be desirable for terminal cancer patients in
the hospice setting. For cancer patients undergoing potentially
curative surgery, it appears imperative that they refuse morphine and
any other opiate-type analgesic. They should instead request the drug
tramadol to alleviate postoperative pain.
SUMMARY
For many forms of cancer the surgical removal of the primary tumor
is crucial if long-term remission is to occur. Anti-angiogenesis drugs
given prior to cancer surgery may improve the chances of a long-term
remission. These drugs would also theoretically be of value in the post
- operative setting, though they may slow the rate of healing.
Surgery suppresses important immune functions needed to kill
metastatic tumor cells. The patient should consider taking supplements
that enhance immune function, such as melatonin, lactoferrin, and
garlic, before and after surgery.
Avoiding analgesic drugs, such as morphine and other opiates, helps
prevent immune suppression and the development of tumor angiogenesis.
For pain suppression in the postoperative environment, the drug
tramadol should be requested in lieu of morphine or other opiates.
For cancer patients undergoing surgery, or any other type of cancer
therapy, it is important to review the information that appears in the Cancer Adjuvant Treatment protocol.
Therapies discussed in this protocol can help protect against
surgically induced immune suppression, thus improving the odds of
long-term survival.
Product availability
Melatonin, lactoferrin, echinacea, and AHCC are available by phoning (800) 544-4440 or by ordering online.
Staying Informed
The information published in this protocol is only as current as the
day the manuscript was sent to the printer. This protocol raises many
issues that are subject to change as new data emerge. Furthermore,
cancer is still a disease with unacceptably high mortality rates, and
none of our suggested regimens can guarantee a cure.
The Vitamin Depot Online.com Foundation is constantly uncovering information
to provide to cancer patients. A special website has been established
for the purpose of updating patients on new findings that directly
pertain to the published cancer protocols. Whenever Vitamin Depot Online.com
discovers information that may benefit cancer patients it will be
posted on the website www.lefcancer.org.
Before utilizing the cancer protocols in this book, we suggest that you check www.lefcancer.org
to see if any substantive changes have been made to the recommendations
described in this protocol. Based on the sheer number of newly
published findings, there could be significant alterations to the
information you have just read.
Alternatively, call 1-800-226-2370 and ask a Health Advisor if your topic of interest has been updated on the website - www.lefcancer.org. |