Prostate cancer

Is the most commonly diagnosed cancer in men over 40 years of age. It seems likely that more men die with a diagnosed prostate cancer than from prostate cancer. Not every prostate cancer decreases the quality of life or life span. The diagnosis is based on the digital rectal examination (DRE), as well as determination of the prostate specific antigen (PSA) in blood and if the findings are suggestive of prostate cancer a biopsy is taken. The prostate specific antigen (PSA) in the serum is produced only by prostate cells. It is increased in benign prostatic hyperplasia and prostatitis and therefore is not cancer specific and is of limited significance. A digital rectal exam only increases the PSA insignificantly. Each suspicious finding on palpation should be investigated further, independent of the PSA, with a fine needle aspiration cytology if it has therapeutic consequences. In case of a normal rectal examination and only slightly elevated PSA ( 4-10 ng/ml ) the incidence of prostate cancer is about 30%. In this case a biopsy should be performed even if the DRE is normal as long as it has a therapeutic consequence. Therapeutically the radical prostatectomy stands first in line. However, in only makes sense for patients with a life expectancy of more than 10 years. Otherwise, it is recommended that PSA levels between 4 and 10ng/ml be controlled yearly along with a DRE.

Therapy

Radical prostatectomy: Removal of the prostate, seminal vesicles and regional lymph nodes is an accepted treatment of localized prostate cancer. Even if the cancer reaches or infiltrates the prostate capsule, survival rates of 5 years are achieved in 90% of patients . The mortality rate of surgery is low and postoperative morbidity, with exception of impotence, is low in the hands of an experienced surgeon. Improvement of long-term results with postoperative radio- or chemotherapy is questionable and prospective studies are underway. A renewed increase in PSA is noted in up to 80% of cases within 5 years after radiotherapy.

Hormonal therapy: Patients with symptomatic metastasized or locally advanced cancer are treated with hormonal therapy. There is no known advantage of early treatment as long as the patient is asymptomatic over later therapy started, when the patient has developed symptoms.

Subcapsular orchiectomy still is the leading therapeutic modality, even though newer forms of treatment with oral medication are available. The one great advantage is that the hormonal ablation is guaranteed for life. Side effects such as hot flashes occur in 70% of patients .

Lutenizing hormone releasing hormone (LH-RH) agents: Tumor control is comparable to that with orchiectomy or estrogens. Several products are available (Triptorelinacetate, Goserelin etc). Initially testosterone secretion is stimulated and can lead to a tumor flare-up in about 10% of patients. Therefore a therapy with an antiandrogen, such as Androcur or Casodex, should be initiated prior to starting the LHRH-therapy and continued for 2 weeks.

Estrogens: Estrogentherapy is equivalent to orchiectomy. Estrogens are administered orally with estradiolsulfate daily or by injection with polyestradiolphosphate i.m. once a month. As with orchiectomy erectile impotence is an obligatory side effect. Enlargement of the breasts (gynecomastia) can be controlled by radiation of the breast glands. Fluid retention due to hyperestrogenemia can be controlled with diuretics. Thromboembolism is one of the main drawbacks of this therapy and has lead to its replacement by LHRH-analogues. Thromboembolic complications are less frequent with oral doses under 2 mg or monthly intramuscular injection.

Antiandrogenes: Antiandrogenes target the prostate cancer cell directly. They lead to a reduction of serum testosterone with loss of libido and impotence. The nonsteroidal drugs Flutamide and Bicalutamide inhibit the effect of dihydrotestosterone on the cell nucleus. Libido and erectile function usually remain preserved, at least initially. It remains to be seen if the antiandrogene monotherapy is in adequate dosage and continued application equivalent to LHRH-therapy or orchiectomy. As yet, antiandrogene monotherapy should not be considered a standard form of therapy.

Due to the similar mechanism of action on testicular testosterone synthesis a combined therapy of orchiectomy or estrogen does not give better results than the monotherapy.

Novel therapeutic approaches, such as the intermittent androgen therapy and brachytherapy are in development. Even though the results are promising, these forms of therapy must still be considered experimental.  (Publication Dr. D.M. Aebersold and PD G. Thalmann, pdf, 2384 KB)