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Prostate cancer (prostate)
previously traditionally considered a tumor of older people. Most of the affected men died due to tumor progression, or from old age – even before prostate cancer reached the last stage.
However, over the past twenty years, prostate cancer has become a model disease with an effective cure if diagnosed early.
Features of prostate cancer
- an increase in morbidity among men who have recently crossed middle age;
- the presence of a family and, possibly, congenital predisposition;
- modern early diagnosis makes complete cure possible at operable stages;
- the possibility of using wait-and-see tactics of “delayed therapy” in cases where there are no symptoms of the disease yet, but cure is impossible (for example, distant metastasis in elderly patients);
- a radical change in the quality of life in a sexually active age due to changes in sexual function caused by therapy
- successful primary and secondary prevention based on the results of ethnographic and epidemiological studies
Prevalence of prostate cancer
The incidence of prostate cancer is constantly increasing. In Western industrialized countries, this tumor is the second most common in men after bronchogenic lung carcinoma.
For example, according to German researchers, among 10 million German men aged between 50 and 75 years, about 30% have a documented increased risk of prostate cancer.
Among these three million men, a tumor is discovered almost by chance in “only” 40 thousand people a year.
The United States is the country where prostate carcinoma is most common, with a significant predominance of African Americans among those affected. In these patients, prostate cancer displaces bronchial carcinoma from the first place in the scale of causes of death.
In Germany in 2003, about 26 thousand new cases of prostate cancer were detected. Mortality from this disease has increased by 25% over the past 16 years.
Mortality caused directly by the tumor is currently about 30%.
In Germany, prostate cancer is the third leading cause of death among men. In the new federal states the situation is similar.
In Austria, prostate cancer is the most common malignant tumor in men and the most common cause of death from malignant diseases.
In Switzerland, the incidence of prostate cancer is in second place after lung cancer – about three and a half thousand new cases of the disease and about one and a half thousand deaths due to prostate cancer are recorded there every year.
Since there is no scientific evidence that prostate cancer is preceded by predisposing diseases (unlike lung cancer), it is not possible to determine the relative likelihood of the disease in men aged 50-80 years.
If only the patient’s age is considered as a risk factor, then the cumulative probability that a man will develop the disease during his lifetime is as follows:
- 50-55 years: 2%;
- 70-75 years: 8%;
- 85 years: 24%.
The use of PSA (Prostate Specific Antigen) screening most significantly increases the rate of early detection of prostate cancer in men aged 50 to 60 years. This shift in the peak incidence of diagnosed disease from the age category over 70 years allows us to say that “the diagnosis of prostate cancer is getting younger.”
In the event that a practically healthy man between the ages of 50 and 70 years is diagnosed with a local limited focus of prostate carcinoma, and this patient does not receive therapy, the probability of his death in 10 to 15 years from the tumor is extremely high.
The increase in incidence can also be explained by an increase in the life expectancy of men – by 20 years over the past seven decades.
In addition, the increase in the frequency of tumors detected de novo is the result of active diagnostic tactics using modern early screening capabilities through the use of the serum tumor marker PSA.
While the influence of the patient’s hormonal status and exogenous factors (carcinogens) on the increase in the incidence of malignant degeneration of prostate tissue has already been proven, lifestyle and nutrition seem increasingly likely cofactors of this process.
Until recently, statistics showed a peak incidence of prostate carcinoma after 65 years of age. The disease was considered a tumor of old age.
Today it has been shown that in the sixth decade of life the proportion of clinically asymptomatic tumors increases.
Up to 70% of early-stage organ-confined carcinomas can be detected solely by elevated levels of the tumor-associated PSA marker.
Causes of prostate cancer
- Predisposing factors in different ethnic groups.
- The subtle etiological mechanisms of prostate carcinoma, like most other tumors, are not known.
- Ethnographic data with a high degree of reliability demonstrate a low risk of the disease among residents of Southeast Asia – China and Japan and Mediterranean countries, and a high risk among residents of central and northern Europe, North America and Australia.
- Environmental and lifestyle factors (diet, physical activity, protection from stress) play a determining role in the development of the disease (Moyad u. Caroll 2004, Schmitz-Dräger et al. 2004).
Prostate cancer incidence
varies widely in different regions of the planet.
Mortality from prostate cancer
In Southeast Asian countries it is less than 10 cases per 100.000 men per year. This rate is highest in Western industrialized countries, primarily among the black American population – more than 100 cases per 100.000 men per year.
Central Europe ranks in the middle, with a risk of prostate cancer of 40/100.000. Prostate cancer is much less common in southern Europe – Italy, Spain, Portugal and Greece.
The Science of Prostate Cancer
The currently relevant theory of prostate cell proliferation, worsening with age to hyperplasia and/or carcinoma, is as follows:
- increased activity of the prostatic enzyme 5-α-reductase, which catalyzes the conversion of testosterone to dihydrotestosterone, which has pronounced androgenic activity;
- an increase in serum estrogen levels, which stimulates prostate stromal tissue;
- dysregulation of prostate growth factors due to increased dihydrotestosterone levels and estrogen-mediated stromal proliferation;
- abnormal proliferation of stem cells, which leads to the growth and proliferation of differentiated epithelial cells;
In vitro studies reveal many different growth factors in the aging prostate. They act indirectly through changes in the activity of androgens and estrogen in the epithelium and stroma. The practical use of such growth factors as Transforming Growth Factor (TGF α/β), Epidermal Growth Factor (EGF), Fibroblast Growth Factor (FGF) as “anti-aging” agents for the prostate today is still a long way off.