ニュース

2013.04.24

Strategies for treatment of advanced cancer in adult (1)

In my previous essays, I have mentioned several adult cancers that occur relatively frequently in Japanese people over fifties and are closely related to lifestyle. I mentioned that every morbidity of those cancers has been increasing considerably these days, except for the morbidity of gastric cancer, uterine cervical cancer and esophageal cancer. Hormone-dependent cancers such as breast cancer as well as prostate cancer, and pancreatic cancer were so far not discussed. It is also important that some other cancer, categorized as head and neck cancer, has been also attracting attention recently. I would like to talk about those cancers near future in the next essay series.

My discussions have focused on strategies for cancer prevention in adult, mainly suggesting to improve diet and use supplements in terms of chemo-prevention and integrative medicine. In this essay I would like to go into more detail on these subjects.

What is chemo-prevention for cancer in adult?

Interest in food and supplements rose within the medical movement beginning in the 1970s, which developed into complementary and alternative medicine (CAM), or integrated medicine. This includes the term “chemo-prevention”, which is a trend for medical ideology in terms of precaution claim of efficacy even without elaborate basis of scientific evidence. Chemo-prevention includes anti-oxidant function and detoxification of redox reaction with the use of vitamins or natural resources from plants, herbs or natural inorganic chemicals as trace elements in our body. Its meaning is “strategies for cancer prevention and treatment mainly with the use of natural resources except for anti-cancer drugs”. It was led by European and US governments with a focus on development of anticancer drugs, and CAM. This movement of CAM became accepted by the public in 1990s. DSHEA is one of the most initiative acts in the United States of America to promote the health promotion campaign not only throughout the US, but also into the world. DSHEA is an abbreviation of Dietary Supplement Health and Education Act, which has begun and held from Jan.25, 1994 on. This act has been impacting throughout the world ever since. However, public officers as well as politicians related to the public health in Japan unfortunately have never had a shrewd receptors for it more than 17 years.

In the US, some prestigious medical schools have educational institutions that specialize in CAM . The education and research of CAM is supported by the government. In Japan, it is unfortunate that this movement has made little progress. This is the reason why I have referred to improving the diet in this series. I hope my suggestions will contribute to even very small progress of Japanese medicine in general.

This alternative movement has advanced to include naturopathy and homeopathy. Naturopathy involves various folk remedies, herbs, traditional Chinese medicine, aromatherapy, thalassotherapy and others. Homeopathy is so unique that ultimate dilution of remedy in term of dilution dimension of Avogadro number might be even one molecule of remedy chemicals effective on some receptor of cell in our body. It reminds me that salmon returning from the ocean to the river where this salmon hatched out and grew up can discriminate the very specific amino acids or peptides in the river waters in terms of sensing the dilution level of Avogadro number in the ocean.

I sometimes feel that “medical treatment” is becoming so comprehensive that it wouldn’t be overstating to say that medicine is a “borderless field”. However, generally speaking, such stuffs mentioned above are not based upon scientific evidence, upon the precaution claims. Double-blind control study in clinics is the first choice to evaluate the efficacy. On the other hand, case control study is also recommended to evaluate clinical trials by supplements. Simultaneously, experimental research including in vitro as well as in vivo studies should be necessary.

The example is as follows. The National Institute of Health in the US has a National Center for CAM, which subsidizes research and education of this field, in addition to conducting clinical trials. For example, there was a clinical suggestion from Cuba that shark cartilage was effective in halting cancers progress and metastasis by inhibiting nutritional support to cancer cells and blocking proliferation of blood capillaries. A clinical trial was conducted to examine this theory, and its effectiveness was not proven. This conclusion was reported on an international medical magazine.

On the contrary, Dr.J.Markus and his colleagues published a case report in the authorized journal named Dermatol Surg 2006: 32; 145-147. The title of this report is “Metastatic hemangiopericytoma of the skin treated with wide local excision and MGN-3. MGN-3 is an official name of BioBran.

What is advanced cancer?

I have mentioned that “cancer doesn’t develop in a day”. Cancer development usually takes more than ten years, sometimes over twenty years. Once a clump of cancer becomes large enough to be recognized by sight, it accelerates in its progression. If it develops in the digestive system, the cancer on the surface of mucosa spreads and develops in the wall of the stomach or large bowel, and finally into lymph vessels, termed lymph node metastasis or into blood vessels leading to hematogenous metastasis, termed remote metastasis. In the worst cases, cancer proliferates and invades directly through the wall into the peritoneum, followed by cancerous peritonitis. When the cancer grows into the lymph system, it spreads to nearby lymph nodes and finally to the whole body through blood vessels. Once cancer gets into a blood vessel, it spreads over the whole body, which is called remote metastasis.

Clinically speaking, patients with cancer should be categorized in stage classification, such as Stage I (early stage), Stage II, Stage III and Stage IV (advanced stage) in accordance with tumor size, lymph node metastasis, or metastasis to the remote organ etc. Stage classification is standardized throughout the world in terms of stage classification by WHO or World Congress of anti-cancer society.

Even in case of advanced cancer, primary solid tumor mass as well as metastatic site should be resected as much as possible. Local administration of anticancer drugs to the metastatic sites once was practical followed by no recall. However, even though efficacy of anticancer drugs in general might be so limited, I am wondering whether or not chemotherapy or radiotherapy should once be considered again.

Effects of anticancer drugs

Administration of anticancer drugs might be appropriate, in theory, for the purpose of eliminating cancer cells which may have already spread over the whole body. But this theory is only applicable if the anticancer drug selectively destroys only cancer cells. Unfortunately, these drugs don’t have this selective capability, unlike antibiotics, which can selectively eliminate only bacterial cells.

The concept of anticancer drugs was originally closely related to the manufacturing of toxic gas, named nitrogen mustard. This was the reason why a young US soldier with malignant lymphoma was faced to this toxic gas in the battle field followed by the remission of his disease. The word “cytostatic”, which means “slowing cellular growth”, was initially used in place of “anticancer”. In Japan, strangely speaking, it was called 制癌剤(Seikan-zai) in Japanese meaning a “drug for making slow in growing of cancer”.

The major characteristic of a cancer cell is “uncontrolled cancer growth”. The cells that make up our bodies are replicating DNA and growing at various speeds. Among them, hair follicle cells, leucocytes, epithelial cells of the digestive tract and spermatozoa cells proliferate rapidly. If an anticancer drug is administered, those rapidly proliferating cells are also damaged along with damaging of cancer cells.

Adverse effects of anticancer drugs may include hair loss, leucopenia, causing weaker resistance and susceptibility to infections, infertility, gastrointestinal hemorrhage, and nausea. The major effect of an anticancer drug is to attack DNA replication, although indiscriminately.

Currently, molecular target drugs are attracting attention. These do not directly attack DNA, but instead focus on a specific part of the cell membrane which has a receptor to a molecule related to cell proliferation.

Limit of efficacy of anticancer drugs

Anticancer drugs are sometimes administered immediately before cancer surgery or just after surgery. This medical technique is called “adjuvant therapy” or “neo-adjuvant therapy”. The difference is whether adjuvant is given before or after the surgery.
In case of adjuvant therapy, cancer tissue is removed and observed in a pathological examination with a light microscope. In many cases, anticancer drugs have obviously destroyed most of the cancer cells, but not all of them. As a result, some cancer cells, so-called cancer stem cells, survive and change to become more resistant. In some disastrous cases, most of the cancer cells survive and the patient becomes exhausted and looses his life.

There are so many kinds of anticancer drugs that are very expensive. It is extremely difficult to discern what drug is effective for which symptoms. Just looking back at the history of medicine, we may realize that if an anticancer drug is truly effective like antibiotics, its focus must be more limited. However, the reality is just opposite. There has never been a single miracle of anti-cancer drug. Even under treatment of whole bunch of anticancer drugs, patients with any cancer in Stage IV have a worst prognosis, indicating almost zero % in the survival rate in five years. We should not give up, because there might so far occur spontaneous remission of some advanced cancer reported. I should add that patients after anti-cancer treatment, such as surgery or radiation, must continue to feel scary for its recurrence and to suffer from adverse effect of anticancer drugs.

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