Prevention can be 3 types:
* Primary prevention: it’s all measures aimed at preventing the occurrence of disease in the general population
* Secondary prevention: it concerns individuals who are exposed to a risk but are not yet ill
* Tertiary prevention: it affects patients, to encourage them not to expose themselves to risk
For most cancers, the curative treatment remain disappointing, even if success is emerging in certain pathologies.
But
* Is the location of the disease requires a significant mutilation (removal of one lung, larynx removed, removal of the esophagus, removal of the bladder) to try to cure the patient
* Either the disease has already spread throughout the body and the treatment is simply to contain the evolution thereof.
No medication has made its case today in the primary prevention of cancer.
Thus, the only “treatment” of an effective cancer prevention, ie removing the causes of cancer.
Some cancers may decrease more than 90%, if living, collective and individual, the causes of these cancers.
Tobacco
The cigarette smoking is responsible for more than 95% of lung cancers.
The bladder cancer is directly linked to tobacco by the action of tars absorbed with the smoke, being eliminated in the urine, stagnate in the bladder.
Alcohol
Associated with tobacco is the leading cause of cancer of the pharynx and larynx in France.
Solar Ultraviolet Radiation
The incidence of skin tumors has increased steadily since the increased exposure to sunlight and in his early childhood.
Early sex
The incidence of cancer of the cervix is directly related to the early and multiple sex without a condom.
It is interesting to emphasize the preventive vaccine against the papilloma virus is now supported by the National Health Insurance.
Antioxidants and Cancer
Real antidote formidable free radicals, antioxidants arouse passion undeniable.
While many studies confirm basic daily their major involvement in many diseases, the discordance of clinical studies, the designs often empirical or imaginary, may lead to some disappointment and a real ambiguity.
This is particularly true for one of the most difficult: the management of oxidative stress in cancer.
The difficulty here is that certain antioxidants or antioxidant cocktails, in some cases, at certain doses, may protect the tumor, or even promote tumor proliferation.
It is well recognized, however, that the reactive forms of oxygen (free radicals) involved in the pathogenesis of many cancers.
Indeed, free radicals in excess uncontrolled by inadequate antioxidant defenses, created by oxidizing certain bases, mutations and strand breaks in DNA and initiating carcinogenesis.
However it appears that their effects involve more complex mechanisms, particularly by inhibiting or otherwise stimulating the expression of genes involved in regulating the proliferation or cellular differentiation or apoptosis (apoptosis is the programmed death of certain cells, especially those with abnormal cancerous).
Many studies (including studies SUVIMAX) have shown the benefits of antioxidants in the prevention of many cancers, and it is unanimously recognized that a diet rich in fruits and vegetables is an essential preliminary step to prevention.
Things are complicated considerably when it comes to proposing strategies antioxidant in cancer and specifically during treatment by radio and chemotherapy in order to “treat” their oxidative effects.
At high concentrations, free radicals can induce apoptosis of cancer cells (programmed death), and is in fact a means to destroy tumor cells.
Treatment with radiotherapy, as many molecules used in chemotherapy are based mainly on the induction of an overproduction of free radicals in tumor cells, and this mechanism would be responsible for at least part of their antitumor effect.
The anticancer drugs can induce production of free radicals belong to different classes, among which we note:
Intercalating agents, anthracyclines such as doxorubicin, the topoisomerase inhibitors, antimetabolites as of 5-fluorouracil, mitomycin C and platinum derivatives such as cisplatin and oxaliplatin, taxanes and hormone receptors as tamoxifen.
Understandably so easily that any antioxidant can potentially oppose the action of these treatments and limit their effectiveness.
However, one major limitation of these molecules derive their toxicity on normal cells and many therapeutic protocols lead to some irreversible damage.
Some anticancer drugs are toxic to certain special organs, anthracyclines have a toxic effect on the heart related to the production of free radicals that oxidize the lipid structures of cells and mitochondria, others have pulmonary toxicity related to a irreversible fibrosis, also linked to the release of free radicals.
It may therefore appear reasonable to try to oppose or at least limit this toxicity ‘pro-oxidant’.
The difficulty is to limit the toxic effects without compromising treatment efficacy.
Many antioxidants have been proposed to reduce the side effects of cancer treatments, such as N-acetyl cysteine or Co-Enzyme Q10 has shown interest in the prevention of anthracycline cardiotoxicity.
More recently many teams are interested to SOD (super oxide dismutase), and more specifically to chemical compounds that mimic the activity of SOD.
Many compounds have been tested, some with only mimicking the activity of SOD, but the most interesting are those who also have an activity ‘catalase’ and glutathione reductase, two key enzymes in the detoxification and antioxidant protection of the cell.
Very recent studies have shown that treatment with N-acetyl cysteine, a precursor of glutathione, induced an increase in tumor cell proliferation, while some mimetic of SOD and the glutathione reductase decreased.
These results confirm the extraordinary complexity of the subject and that any antioxidant supplements “blind” in the context of cancers and their treatment is avoided.
These new approaches and undoubtedly promising, still require a rigorous monitoring biological markers of oxidative stress, knowing that the rate of antioxidant enzymes such as SOD and peroxidase and glutathione reductase are not reliable markers of oxidative stress.
Finally, if things are simpler in prevention, we must not forget however, that studies have shown that some high-dose antioxidants such as beta carotene increased the risk of cancer.
Antioxidants are undoubtedly significant interest in preventing cancer as many degenerative diseases.
Their use in the legitimate aim to restrict the pro-oxidant deleterious effects of radio and chemotherapy of cancers, however, must be very cautious in the current state of our knowledge.
Such strategies can be thought that in a medicalized, and guided by a rational biological seriously.
It is however legitimate to support the oxidative stress of all patients treated by radio and / or chemotherapy, remote cures and respect the few rules dictated by the work we have, and again at s relying on diagnostic biological screening of oxidative stress.
Individual screening
There are also cases of individual screening legitimate outside the defined group, for some cancers.
Screening should be supervised by a consultation of individual risk assessment by the physician.
Clinique
Due to the development mode and location, a cancer is revealed by clinical symptoms related to it invades the body, in situ and near, and the disorders it engenders.
Mass Syndrome
The discovery of a tumor, usually irregular and hard to palpate, guides to the diagnosis:
* Lump in the breast tumor breast
* Swallowing disorders: esophageal tumor
* Digestive disorders: gastrointestinal tumor
* Headache, vomiting, seizures: brain tumor
* Pollakiuria: bladder tumor
Local Invasion and Locoregional
The tumor invades the body and causes malfunctions or runs nearby:
* Dysphonia by flooding of a head and neck cancer
* Constipation by invasion of colon tumors
* Phenomenon of orange peel at the skin tissue against invasion by a breast cancer
* Swelling below the tumor compression of the drainage system: large arm of breast
* Pain from nerve damage in their peripheral course: ischial bone tumors
Hemorrhage
The cancerous tumor requires a blood supply system important to feed all the cells, and this system of neo vessels are fragile, so easily bleeds.
It is a way of revealing common cancers:
* Hemoptysis in lung cancer
* Hematemesis and melena in stomach cancer
* Haematuria in bladder cancer
* Hémospermie in prostate cancer
* Rectal bleeding in rectal cancer
* Bleeding in cancer of the cervix during sex and endometrial cancer
Discovery of a Metastasis
In 15% of cases, cancer is found by a distant metastasis of the original tumor, which may sometimes not be found.
* Lymph node metastasis: lymph indurated
* Liver Metastasis: digestive disorders, pain, jaundice or liver
* Pulmonary Metastasis: incidental findings on radiographs or breathlessness
* Metastasis cerebral seizures occurring in adults with no history of epilepsy
