2012年2月29日 星期三

Prostate Cancer - Overall


Device external radiation treatment

Example of an ultrasound affected by prostate cancer (ultrasound can be used to guide a biopsy). Cancer develops from the tissues of the prostate, a gland in the male reproductive system when cells will mutate to spread so uncontrollably.

These can spread (metastasize is) in migrating from the prostate to other parts of the body (especially bones and lymph nodes).

Prostate cancer occurs regardless of benign prostatic hypertrophy (or prostate adenoma). It is in the vast majority of cases adenocarcinoma.

Prostate cancer can cause pain, difficulty urinating, erectile dysfunction and other symptoms. Treatment is by surgery, radiotherapy, hormone therapy and sometimes chemotherapy, or combination of these methods.

Frequency

The rate of breast cancer varies widely throughout the world. It is less widespread in South Asia and Far East, more common in Europe and even the United States. According to the American Cancer Society, breast cancer is rare among Asians and more prevalent among blacks (high rates may also be influenced by the increased effort detection).

Prostate cancer develops most often in men over fifty years. This is the type of cancer most common in men, where he is responsible for more deaths than any other cancer (except lung cancer). However, many men who develop prostate cancer symptoms do not, do not undergo any therapy and die for other reasons. Many factors of genetic origin, toxicological and diet-related seem involved in the development of this cancer.

We find outbreaks of cancer cells in 30 to 70% of cases in studies performed in autopsies of men 70 to 80 years; prostate cancer remains the most often asymptomatic: the probability of a man 50 years know a diagnosis of prostate cancer is only 10%. In 3% of cases, this cancer will be fatal.

Geography of Prostate Cancer

There are significant differences in the expression of this cancer, which seems more common among the black man, or where the family has a history pathological with this condition. From 1983-2002, while deaths from cancer were generally higher in the Caribbean city, deaths from prostate cancer and stomach were twice as common in the Caribbean in the mainland (while colorectal cancer and lung cancer were three times less frequent). This could be explained by both genetic reasons and food (green tea and / or soybeans or other foods rich in selenium) which appear to protect most Japanese living in Japan (while living in the United States is not).

Causes

They are not known with precision.

There is a genetic predisposition and the presence of certain genes seems slightly correlated with the onset of the disease. In particular, a mutation on chromosome 8 might explain the higher incidence of this cancer in black American.

Nutritional causes were discussed with a potentially protective role of lycopene. Similarly, exercise may have a slightly protective effect and tobacco a deleterious effect.

Symptomatology and detection

In most cases, prostate cancer is asymptomatic, ie it is discovered when it does not own event to it. It is most often found:

During blood tests, including investigation of the PSA (specific antigen for prostate, whose predictive value and use, without proven benefit to public health, has recently been called into question). The PSA is a protein normally secreted by prostate cells, but cancer cells secrete 10 times more than a normal cell. This property has raised many hopes in terms of screening. The blood level of PSA can be increased by many other factors (the prostate volume, infections and / or inflammation, the mechanical (digital rectal other)...) or decreased by certain treatments for benign hypertrophy (ministered). The thresholds of significance are therefore difficult to establish. It is recognized, however, rates of PSA between 4 and 10 ng / ml are doubtful, but it is clearly significant beyond. Some authors have proposed to bring the rate to its actual weight of the prostate, or assess the free PSA / total PSA, or the kinetic growth rate over 2 years. Scorer still uncertain for screening, the PSA level is, however, a key indicator for monitoring and treatment of cancers reported.

During a rectal examination, conducted as systematic or because of symptoms related to another illness (especially benign prostatic hypertrophy) incidentally, on parts of resection of the prostate during surgical treatment of prostate adenoma.

When it is symptomatic prostate cancer is most often at an advanced stage. It can lead to: acute retention of urine, hematuria, sexual impotence, impaired general condition pain and / or malfunction or failure of other organs associated with the presence of metastases

Diagnosis

The diagnostic orientation based on two key elements: the digital rectal examination and determination of PSA blood. The abnormality of one or both leaves suspect prostate cancer. It will be confirmed or not, by taking a sample of the prostate (biopsy) for examination under a microscope. Only the positivity of these biopsies permits to plan and begin treatment of this cancer. Once confirmed the diagnosis of prostate cancer, we conduct a bone scan in search of bone metastases and abdomino-pelvic CT or MRI abdomino-pelvic to clarify the extension of the tumor in the prostate and houses of possible pelvic lymph node metastases, retroperitoneal or liver.

Clinique

Clinical examination is the fundamental digital rectal exam.

The most specific induration of the gland. This induration may be nodular, it may also involve an entire lobe or the entire gland palpable. A heterogeneous consistency or asymmetry are much less specific signs, which can also translate a simple adenoma, particularly when the prostate is larger.

Ultrasound trans-rectal biopsies

There is currently no consideration imaging practice that could only detect an outbreak of prostate adenocarcinoma with a sensitivity and specificity satisfactory.

Contrary to popular belief still widespread, and although this review and is still often prescribed endorectal ultrasound alone has no relevance to the positive diagnosis of prostate cancer, under the inconvenience it is likely to cause. It shall, however, when its interest is used to guide prostate biopsies. Other imaging modalities (scan, MRI) have an interest in the balance sheet expansion.

Technique

An endorectal ultrasound probe equipped with a guide needle is inserted into the rectum. Biopsies were performed with needles fitted with a notched mandrel. The mandrel penetrates the first. The needle just cover, and decide to imprison and the fragment of prostate located in the notch. The movement of chuck and the needle are automated by a system of springs and the taking is a few hundredths of a second. The screen of the ultrasound, with a landmark representing the path of the needle, permits, thus firing biopsy very precise.

The number of biopsies, and where they should be, are not well codified and many protocols have been proposed: the aim is to obtain a sample as representative as possible. Currently, it is frequently performed 5 to 6 samples per lobe, or 10 to 12 in total. These numbers may be reduced or increased depending on the size of the prostate, tolerance of the patient, or if a second set of biopsies.

Preparation and conduct

This is a frequently performed as an outpatient, ie without hospitalization, or during hospitalization "for days". A rectal preparation (enemas) is often advocated. Many centers now offer systematic antibiotic (short antibiotic treatment to reduce infectious complications). The concomitant anticoagulation is in principle against inappropriate and that any treatment can be subject to arrest or a temporary modification.

Tolerance

Acceptance of the review is particularly variable from one patient to another. Each biopsy is shooting itself very painful. However, their repetition, and especially the presence and movement of the probe are the main factors of discomfort. The inconvenience of this review may justify the use of local or general anesthesia. Local anesthesia with a gel anesthetic (lidocaine gel) has never demonstrated its effectiveness. Local anesthesia by injection of lidocaine on each side of the prostate (nerves pudendaux) has shown in many studies improved tolerance of the examination, however incomplete, because of its low efficiency discomfort associated with the presence of the probe. Anesthesia "general" Mild equimolar mixture of oxygen and nitrous oxide ( "MEOPA") has recently been evaluated and appears very effective in this indication. It is even more interesting that easy to implement because does not require an anesthetist and seems almost devoid of side effects. General anesthesia "classic" is rarely used, reserved for patients who have suffered greatly during the first of a series of prostate biopsies.

Suites

Any pain disappear in a few tens of minutes. Can occur fairly frequent small bleeding through the anus and in urine for 24 to 72 hours without gravity. Small nets blood may also interfere with sperm for several days, again without any consequences.

Anatomopathologie

Cancer begins peripheral portion of the gland, unlike benign prostatic hypertrophy of interest to the central area, périurétrale.

The diagnosis is focused on the examination of the biopsy or surgical specimen.

The seriousness of evolution is correlated with the microscopic appearance (Gleason score), the level of PSA and the spread of the disease.

Bilan extension

The spread of the disease when the disease must be determined in order to better tailor therapy. Therefore the presence of bone metastases, lung and liver, knowing that bone metastases are most frequent. We must look for lymph node metastases in the pelvis and the retrograde (around the abdominal aorta). it must finally try to clarify the extension of the tumor in the prostate, particularly whether the latter exceeds the prostate capsule or not.

The means of imaging used in routine generally low ability to show (ultrasound scan, MRI) or to precisely locate (scan) the original prostate lesions, owing to the low blood of breast cancer. MRI is the least bad review to determine the local extension.

MRI scanners or new generation (volume) are used to search the achievement of lymph nodes, but only nodes whose size is increased are detected. New products in contrast MRI, so-called "super-para-magnetic" could improve the detection of lymph nodes affected.

The positron emission tomography (PET camera, PET-scan) did not indicate however, because of very little or no hypermetabolism prostate cancer.

a blood test can check the status of kidney and liver functions.

Treatment

The age, overall health of humans as well as the extent of spread, appearance under the microscope and the response of cancer to initial treatment are important to predict the outcome of the disease.

As prostate cancer is a disease of elderly men, many will die for other reasons before the prostate cancer could spread or cause symptoms. This makes the difficult choice of treatment. Decide whether or not we treat localized cancer of the prostate (a tumor confined within the prostate) with intent to heal is that arbitration must be made between the positive and negative expected to point of view of patient survival and quality of life.

The treatment should be discussed on a case by case basis following the extension of cancer, the patient's general condition and related diseases. A simple monitoring may be recommended in the elderly or among holders of a very localized.

Medical treatment

Hormone

There is a correlation between the production of testosterone (male hormone) and the multiplication of cancer cells. A blocking or greatly reducing the production of this hormone can effectively curb the disease. Some drugs are administered as a subcutaneous injection every 3 months. Others are administered orally. Side effects are, however numerous, but rarely serious. The hormone, which was the treatment of advanced forms, or metastatic, saw its indications extended to the treatment of tumors rejected for surgery (because of the size of the tumor, the risk of surgery not complete ,...) and why the rate of relapse after radiotherapy remained important. The overall control of the disease, adding radiotherapy and hormone therapy for 3 years, can improve significantly the number of patients for whom the disease remains undetectable. The pulpectomy (testicular tissue ablation) is no longer used since the 90s.

Chemotherapy

Until the early 2000s, the use of cytotoxic chemotherapy in metastatic prostate cancer, and whose usual treatment hormonotherapy by becoming ineffective (tried in particular on increasing PSA despite repeated androgen suppression) 's has proved a failure. The advent of docetaxel (Taxotere °) amended the therapeutic possibilities, Entr'ouvert by mitoxantrone (Novantrone °) some years earlier. For the first time, a drug used in advanced stages of the disease, managed to improve survival and quality of life of patients. Three controlled studies confirm these results. Others are underway to integrate chemotherapy early in the history of the disease for locally advanced tumors, where organic growth but before the onset of metastases, and why not, immediately after surgery to treat possible micro-metastases.

Surgery

It is based on the prostatectomy, known as radical or total. It involves the removal of the prostate and seminal vesicles and may be preceded by a levy of lymph drainage of the prostate. The surgery can be done through open (surgical incision in the abdomen or at the perineum) or by abdominal Coelioscopy; surgery is reserved for cancer localized to the prostate and offers great chance of cure if the cancer is actually located and slightly or moderately aggressive (aggressiveness estimated by the Gleason score), and may lead to urinary incontinence, most often temporary and erectile dysfunction. Currently, there is no superiority of one technique over another with regard to cancer outcomes and results urinary and sexual function.

Coelioscopy

Coelioscopy prostatectomy was used by an American team which published it abandoned in 1997 after 8 cases as the intervention was difficult. It is the French teams that end 1997 and early 1998 took the torch and showed that this technique was feasible. Gaston de Bordeaux, and VALLANCIEN Guillonneau Paris and developed the technical standardization. VALLANCIEN and his team published the technique by transpéritonéale then through peritoneal under which seems simpler. It is now recognized worldwide. With an experience of almost 3,000 transactions, the surgical team Montsouris Institute in Paris has shown the benefits of prostatectomy Coelioscopy: we must retain the shorter hospital stay (5 days against 8 in average according to statistics PMSI 2004, the post operative pain near zero even lower, the rate of transfusion of about 2 to 3% against an average of 15% for open surgery. The strictures of the suture between the bladder and urethra canal are more rare (1.5%). The resumption of activity is fast after about a week.

Cryoablation

The prostate cancer tissue may be destroyed by local application of a very cold gas. The cryoprobe (most often cooled with liquid nitrogen) is introduced in endourétral until the prostate, the correct position of cryode can be verified by various techniques including endoscopy conducted by a pubic trocard addition, transvésical. A cycle of freezing and thawing will be implemented for a few minutes and repeated if necessary, a probe is placed urétrovésicale end technology and allow the evacuation progressive tissue nécrosés by applying the cold, some practicing Transurethral resection of tissue mortified by cryotherapy to accelerate the process. Another technique involves placing special needles through perineal ultrasound and under control.

More about Prostate Cancer: http://treatmentnews.blogspot.com.








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