Prostate Cancer Screening

You just need to remember about the prostate. Prostate Cancer Screening

If the topic did not imply an extreme degree of seriousness of the conversation, Prostate cancer could be called a pig in a poke. For a long time, measured in years, the disease can develop absolutely asymptomatically. Without pain, discomfort, any other manifestations of ill health. And then simultaneously "shoot" with all volleys at once. And, alas, often - to defeat.

It makes no sense to start being afraid ahead of time. But even less of it is to do nothing in a situation where you can find and neutralize the disease before it goes on the attack.

Be a man go to the doctor

Why is this needed?

The statistics of oncologists does not imply discrepancies: prostate cancer is a disease that is diagnosed more often than other oncopathologies. Even such common oncological diseases as lung cancer, colorectal cancer and breast cancer give way to the leader's place. Only about half of the cases of detected malignant tumors of the prostate have early stages of the disease, which, of course, affects the complexity of the treatment of the disease and its positive outcome. At the same time, if the disease is detected at an early stage, the probability of a complete recovery reaches 100%! Therefore, regular preventive examinations should justifiably be the first thing on the list of priorities for a modern and responsible man.

What is the point of screening?

Until now, the most common method for diagnosing prostate pathologies has been and remains the method of palpation during an internal examination by a urologist (digital rectal examination DRE). However, the traditional nature of the method in this case is not equivalent to its effectiveness. As a rule, malignant neoplasms detected in this way are already quite large. And an additional examination can reveal the spread of cancer cells to neighboring and distant organs.

An important element for the diagnosis of prostate cancer is also transrectal ultrasound. But this method cannot be called unambiguously reliable and decisive for the diagnosis. Given the characteristics of a prostate tumor, almost every second case of prostate cancer remains "invisible" for ultrasound.

The most informative at present is a blood test for PSA.

PSA - prostate-specific antigen - a protein that is produced exclusively by the prostate gland. Normally, its presence in the blood is permissible in low concentrations. Exceeding the threshold value of PSA may indicate pathological changes in the structure of the gland and the processes occurring in it.

Thus, Screening for prostate cancer primarily involves a blood test for PSA in all men aged 50 to 65.

It is no coincidence that screening examinations are indicated for this particular age group. According to many years of confirmed data, malignant tumors of the prostate in men under 40 years of age are extremely rare. For another 10 years, the risk of pathology remains low. (The exception is men with a hereditary predisposition to prostate cancer.) But after 50 years, the likelihood of developing malignant neoplasms increases dramatically in all men, which is directly related to age-related changes in the body. At the same time, tumors are most often aggressive and, in the absence of timely and effective treatment, pose a direct threat to the patient's life. In men older than 70 years, if cancer has not been detected so far, there is no point in looking for it purposefully: as a rule, the tumor is so insignificant that it does not affect the overall well-being and quality of life. Or treatment at this age, the more radical, will not be of fundamental importance for the quality and duration of the patient's life.

Given these circumstances, a blood test for PSA with a frequency of 1 time in 2 years in men over 50 years old, as the first stage of preventive screening for early diagnosis of prostate cancer, most oncologists recognize as more than justified.

If the level of prostate-specific antigen exceeds the permissible limits, a second stage of examinations is provided. Namely: a systematic biopsy of the prostate gland under the control of transrectal ultrasound.

The upper limit of the norm is considered to be the content of PSA in the blood at a concentration of 4 ng / ml. However, in recent years, experts are inclined to reduce the threshold value of the PSA level to 2.5-3 ng / ml in men under the age of 55, believing that this can significantly increase the chances of diagnosing malignant tumors in the initial stage of development.

A biopsy is the only sure way to confirm or deny the presence of cancer cells. A systematic biopsy involves at least 6 punctures at the same time to exclude the disease.In some cases, their number can be significantly increased. The procedure is unpleasant, but for its implementation the most modern and effective painkillers are used to minimize pain and discomfort for the patient.

Scan is not to be missed

Actually, each reader can put a comma where he sees fit.

After all, it makes no sense to dissemble: the scientific community of oncologists has not yet come to a consensus on the unconditional benefits of screening for prostate cancer. The same level of PSA in the blood, for example, can be increased in a number of cases far from oncology. It is possible to detect an excess of the permissible concentration of the antigen with equal success, both with actual prostate cancer and with benign prostatic hyperplasia, and even after passionate intimacy on the eve of the analysis. It is for this reason that the presence of a malignant tumor is confirmed only in 30-50% of men with elevated PSA levels in the blood.

But here, perhaps, the most compelling argument for men should be a reminder: if there is at least a minimal chance to prevent the disease, it is foolish not to use it. At least for the sake of not turning the comma into a dot.

Prostate cancer screening

Summary. The purpose of this work is to analyze the use of prostate-specific antigen in the diagnosis of prostate cancer and highlight the latest screening data. Preliminary research has shown that screening for prostate cancer using prostate-specific antigen improves early diagnosis and reduces mortality from this disease, but overdiagnosis and overtreatment are holding back the introduction of mandatory screening at the state level.

Prostate cancer (PC) is currently one of the most common malignant neoplasms in men. In the USA, prostate cancer ranks first in the structure of oncological morbidity; in Europe, prostate tumors are also the most common neoplasms along with lung cancer.

Over the past 10 years (2003-2013), the incidence of prostate cancer has increased by 56.4%, in 2013 the number of primary patients exceeded 8.0 thousand people - 40.5 per 100 thousand population (standardized indicator - 25.8). population), and significantly lower than the economically developed countries of the world (69.5 per 100 thousand population). patients with prostate cancer 1.

Against the background of a general downward trend in cancer mortality, the mortality rate from this pathology increased by 28.9% over 10 years and amounted to 17.4 per 100 thousand of the population, the number of deaths exceeded 3.4 thousand people

Such a wide spread of prostate cancer puts it on a par with the most important social problems of our time 1.

Over the past 20 years, clinicians have focused their attention on the use of prostate-specific antigen (PSA) for the early diagnosis of prostate cancer, before it becomes incurable. This resulted in a significant increase in the detection of the disease and, since 1994, an annual decrease in mortality by 3.7% 2. Many questions arose with the use of screening: an increase in the frequency of diagnosis in some cases was due to overdiagnosis, which worsened the quality of life; controversy also applies to the effectiveness of reducing mortality, that is, in order to prevent one death from PCa, it is necessary to unnecessarily screen a large number of men 3. As a result of the efforts of many studies, effective approaches and recommendations for PSA assessment, diagnosis and treatment of prostate cancer.

The purpose of this paper is to analyze the use of PSA in the diagnosis of PCa and highlight the latest screening data.

The aggressiveness of the course of prostate cancer varies greatly and largely depends on the degree of differentiation of the tumor at the time of diagnosis. In patients with an indicator of 8-10 points on the Gleason scale, a local tumor can metastasize quite quickly, which leads to the death of the patient. At the same time, patients with a score of 6 on the Gleason scale may have no symptoms of the disease at all, and the tumor may not even progress, and as a result, the death of the patient will occur from other causes, and not PCa 4. Indeed, during autopsy of deceased men aged 85 years and older from various causes, in almost 75% of cases, clinically insignificant PCa is noted 5.

J. Johansson and co-authors in 1989-2013 published a series of papers following a cohort of 223 PCa patients in Sweden who were not receiving treatment. The authors analyzed trends in disease progression, disease-free survival, and PCa mortality in these patients. Thus, the data from this study can be considered representative of a population that has not been screened for PSA.Data obtained 5 and 10 years after the start of observation showed a very low mortality rate from prostate cancer: survival associated with this disease was 94% after 5 years and 87% after 10 years. Thus, in patients with a life expectancy of about 10 years, it is probably not necessary to resort to aggressive methods of treatment 6, 7. Follow-up data, however, showed that in the group of patients who survived for 15-20 years after diagnosis PCa, mortality from PCa (rather than from other causes) increases 8, 9. In the final report, according to data obtained 30 years after the start of observation of these patients, the following indicators were noted: the frequency of local progression - 41%, the frequency of progression with the development of distant metastases - 18%, mortality from PCa - 17% 10. The average time for the appearance of metastases was 9.2 years, and death due to PCa occurred after 9.5 years. The higher the initial degree of malignancy of the tumor, the higher was the mortality rate - it was 55% in the case of tumors with 8-10 points on the Gleason scale, 23% - in tumors with a score of 3 + 4 7 points and 20% - in the case of tumors with indicator 4 + 3 7 points 10.

P. Albertsen et al published a follow-up of a similar cohort of 767 untreated PCa patients from the Connecticut Cancer Registry, USA, who were diagnosed with PCa before PSA screening became widespread. After 15 years from the start of follow-up, mortality in patients with low initial Gleason scores (2-4 or 5 points) was low: 4-7 and 6-11%, respectively 11. Mortality in patients with an initial Gleason score of 6 was 18 -thirty%. Regardless of age, when the diagnosis was established in patients with an initial Gleason score of 7 or 8-10 points, a high mortality rate from prostate cancer was noted (42-70 and 60-87%, respectively). The identified trends persisted after 20 years of observation 12.

Thus, the data of the two groups of researchers discussed above demonstrate in their works a high level of mortality in patients in whom the Gleason score was initially determined at 7 points. It can be assumed that patients with a life expectancy of >10 years who initially had a Gleason score of 7 would benefit the most from a screening protocol and definitive treatment.

The search for a marker of prostate cancer is an actual problem of oncourology. In 1987, T. Stamey et al. 13 showed that an elevated PSA level in the blood serum of PCa patients is associated with a widespread process, and the PSA content is proportional to the estimated tumor volume. It has been suggested that PSA may serve as a serum marker for PCa. In 1991, the results of the first study were published in which PSA was used as a screening test for prostate cancer. It recommended biopsy at 4 ng/mL 14. W. Catalona et al demonstrated that the combination of PSA determination and digital rectal examination (DRE) was superior to DRE alone in detecting PCa. When performing only DRI without additional PSA determination, the diagnosis of prostate cancer could be missed in 32.0% of cases. M. Brawer et al 15 conducted a similar study with the same cut-off PSA level and showed that the diagnosis of PCa could be missed in 37.5% of cases. Shortly thereafter, PSA testing became widespread in the United States, although no large prospective clinical study was conducted to guide the selection of optimal screening strategies.

The widespread use of screening has significantly affected the incidence and mortality of PCa 16,17. Prior to the introduction of PSA testing, the incidence of PCa tended to increase steadily by about 2% per year between 1975 and 1987. Peak incidence was in 1992, which was associated with the early detection of cases of prostate cancer, as well as with the detection, possible only by this method. This was followed by a decrease in the incidence, which is explained by the fact that with the help of a new, more sensitive method, more cases of prostate cancer have already been “selected” from the population than previously. In addition, with the introduction of the PSA method into practice, the 5-year survival rate has significantly improved. The relative 5-year survival rate was up to 100% between 2003 and 2009 compared to 68% between 1975 and 1977 (before PSA testing). , probably due to a combination of factors: PSA screening, certain changes in the biology of this disease over time, the use of more aggressive treatments. In addition, in some cases, the causes of death of patients are not directly related to PCa. R.Etzioni et al18 used two mathematical models to analyze the association between PSA screening and PCa mortality rates and demonstrated that PSA screening contributed between 45% and 70% in reducing PCa mortality.

In addition to significant changes in morbidity and mortality rates, the use of PSA testing has also led to a significant increase in the proportion of patients with prostate cancer in whom the malignant process did not extend beyond the prostate at the time of diagnosis. Thus, over the period from 1984 to 2005, the proportion of patients in whom the tumor had spread outside the gland at the time of diagnosis of the disease decreased from 79.3 to 24.7%. Such changes are mainly due to the widespread use of PSA screening, although in recent years the recorded trend towards a decrease in the number of cases of advanced PCa has slowed down somewhat 19, 20.

Although PSA is used as a marker for PCa and its use in screening is well documented, the main limitation of its use is that PSA is not specific for PCa. Indeed, serum PSA may be elevated in benign processes such as benign prostatic hyperplasia, acute urinary retention, prostatitis, inflammation, and prostate trauma. Historically, the value of 4 ng/ml was taken as such a level, above which a biopsy was recommended. However, I. Thompson and co-authors 21 convincingly showed that with the content of PSA

Prostate cancer screening

Chapter 5. Screening for prostate cancer

In the previous chapter, we dwelled in detail on modern diagnostic methods. But questions arise: how to use all the mentioned studies, when, in what sequence, from what age. These questions are due to the fact that prostate cancer in stages I and II of the disease is not clinically manifested, i.e. the initial stages of the disease can be detected only by active preventive examinations of the male population. Opinions are contradictory about the value of mass examinations of men for the detection of prostate cancer (Table 17). There is a significant discrepancy between the prevalence of disease with clinical manifestations and the prevalence of microscopic foci of cancer. In addition, it is impossible to accurately predict in which category of patients the disease will progress. Thus, the early detection of symptomatic cancer has not yet provided conclusive evidence for improved survival. There is no doubt that early detection should reduce the incidence of complications and thus improve the quality of life and increase survival. However, in older men, the positive effect may not be as significant as in younger patients, since they are less likely to have a significant progression of the disease during their lifetime.

Table 17. Mass screening for prostate cancer.

Benefits: Availability of simple tests (PSA, digital examination of the prostate) Detection of the tumor at an early stage, when a complete cure is possible Favorable psychological effect on men whose results are negative May reduce the incidence of complications and mortality from prostate cancer.

Disadvantages: Slow-growing tumors are more likely to be detected Efficacy in reducing mortality has not been proven Some detected cases may never develop into a symptomatic disease False-positive results alarm patients Expensive and time-consuming methods Transrectal ultrasound-guided biopsy is complicated by infection in 2 % of cases.

For the early diagnosis of prostate cancer, it is necessary to solve the following problems: what method to conduct examinations, what studies should be used, how sensitive and specific they are, and what gives early diagnosis for the results of prostate cancer treatment. Although at first glance the questions posed seem simple, far from all have been resolved so far, and discussions around them continue. Therefore, we will dwell in more detail on the screening of prostate cancer.

Currently, screening programs aimed at the early detection of tumor diseases are considered as the main components of the fight against cancer. The success of screening depends on such factors as the biological characteristics and clinical course of the tumor process, research methods, their sensitivity, specificity and the correct choice of performance criteria.

In recent years, there has been increased interest in the problem of screening for prostate cancer due to the fact that it is one of the most common malignant neoplasms in men.In some developed countries, as we noted above, mortality from this disease ranks second among all causes of death from cancer. The increase in the incidence of prostate cancer and, to a certain extent, the increase in mortality from prostate cancer occur much faster than the increase in life expectancy of the population. The reasons for what is happening have not yet been established. In the early stages of the disease, prostate cancer is not clinically manifested, and the appearance of symptoms of the disease is most often associated with advanced tumor growth. Therefore, in approximately half of the patients at the time of treatment, the tumor spread beyond the prostate gland. In such cases, the prognosis is very poor, as the average survival does not exceed 30 months.

When the disease is limited to the prostate, the results of surgery or radiation treatment are good: the median survival for patients with prostate cancer in stage B (clinical stage) exceeds 15 years. Over the past 10 years, the use of methods for early diagnosis and treatment at early stages justify the growing interest in the problem of Screening for prostate cancer. Despite the publication and favorable results of individual studies on the early diagnosis of prostate cancer, supported by a number of authors, this has not led to the development of screening at the population level. And at the same time, in the absence of prospects for primary prevention, screening for prostate cancer in recent years is considered as a possible way to reduce the mortality of this form of cancer. Currently, the most effective methods for early detection of prostate cancer is a combination of palpation examination through the rectum, determination of prostate specific antigen (PSA) and transrectal ultrasound (TRUS) (Woolf HS, 1994; Schwab L. et al; 1991).< /p>

So Lee et al. in 1988, 784 men older than 60 years of age who applied on their own were examined. The study was designed to compare the clinical significance of TRUS and digital rectal palpation in the detection of prostate cancer. With the help of TRUS, 20 cases were detected, and 10 cases of prostate cancer were detected by the digital method. The sensitivity of TRUS was 2 times higher compared to the digital method. Studies conducted in the USA (Metlin C et al., 1991) showed that the sensitivity of TRUS is significantly higher than the digital examination (77.7% vs. 57.9%; p