What is Localized Prostate Cancer?
Prostate cancer is a disease that most commonly affects men, being the second most frequently diagnosed cancer in this demographic globally. In 2018, an estimated 1.2 million cases were identified. The same year, it was the leading type of cancer for men over 55 and ranked third as a cause of cancer-related deaths in men in North America and Europe. However, compared to liver, stomach, and esophageal cancer, prostate cancer was the sixth leading cause of cancer deaths worldwide.
The prostate is a small organ (weighing between 20-30 grams in a healthy adult male) that produces most of the fluid found in semen. It’s located at the front of the rectum and surrounds the tube that carries urine and semen out of the body (the urethra). The prostate is close to nerves that play a role in controlling urine and facilitating erections, which are important things to consider when treating prostate cancer. The structure of the prostate was described in 1968 and is still used to understand the disease today, with approximately 70 to 80% of prostate cancers occurring in the outermost part, and rarely in the central region.
The American Joint Committee on Cancer classifies prostate cancer according to the tumor, node, metastasis (TNM) system, which categorizes the disease based on it’s local invasiveness, spread to nearby lymph nodes and distant organs. Most commonly, prostate cancer spreads to certain lymph nodes and into the bones. However, spread to organs such as the lungs or liver is unusual and often indicates a poorer prognosis.
In current clinical practice, prostate cancer is grouped as follows:
- Localized prostate cancer
- Locally advanced prostate cancer
- Metastatic cancer
This info specifically covers localized prostate cancer, which are the early stages of the disease caught through investigations like ultrasound or MRI, or identified after a surgical procedure called a radical prostatectomy.
Prostate cancer usually progresses slowly, especially when it is localized where it can take years to cause issues. Men with low-grade tumors are unlikely to die from prostate cancer, but more likely to succumb to other causes. Conversely, men with aggressive cases are more likely to die from prostate cancer within ten years without extensive treatment. The outlook for men with intermediate-risk cancer is harder to define. However, due to the higher risk compared to low-risk disease, doctors are often inclined towards extensive treatment. This approach is debated amongst medical professionals. Certainly, understanding the likely progress of the disease will be of considerable interest to patients.
What Causes Localized Prostate Cancer?
There are various factors that can increase the risk of developing prostate cancer, but unfortunately, the most significant ones cannot be changed. These include:
Age
Prostate cancer is very uncommon in men under the age of 50, with only 1 in 350 chance of developing the disease. However, the likelihood of developing prostate cancer increases dramatically as men age. By the age of 59, the chance of getting prostate cancer rises sharply to 1 in 52. For men aged 65 and older, the chance is greater than 1 in 2, although many men at this age may not be aware they have the disease. Nowadays, thanks to commonly used tests that can detect a protein called prostate-specific antigen (PSA) in the blood, most men are diagnosed with prostate cancer when the disease is still localized in the prostate. On average, men are diagnosed around the age of 66.
Race
African-American men are the group with the highest rates of prostate cancer worldwide. They are more likely to develop the disease, and often at a younger age. This is also true for Afro-Caribbean men and men of West African descent. On the other hand, Hispanic men and men from South-East Asia are less likely to develop prostate cancer compared to Caucasians. The reasons for these differences in rates aren’t fully understood but seem to be related to both genetics and factors in the environment, such as diet.
Family History
While only a small percentage of prostate cancer cases are strictly inherited, having a family history of prostate cancer can increase one’s risk. If a close family member, like a father or brother, has had prostate cancer, a man’s chances of having it almost double. If two or more close relatives have had the disease, the risk increases about 8 times.
There are also other factors which slightly increase the risk of developing the disease. These include certain inherited gene mutations such as BRCA2 and HOXB13, as well as physical characteristics; taller men are at a higher risk of prostate cancer. There is no established connection between diet and the chance of developing prostate cancer. However, being obese does increase the risk of the disease progressing to an advanced stage.
Risk Factors and Frequency for Localized Prostate Cancer
Prostate cancer, which primarily affects men as they grow older, is the second most common type of cancer diagnosed globally. People of African-American descent living in the United States are at the highest risk, while Asian men living in their home countries are at the lowest. How often prostate cancer occurs and how deadly it is can greatly vary around the world. This variation is largely due to inconsistencies in screening for the disease before symptoms appear.
For instance, Western Africa, a low-income region, has a relatively low incidence rate of 31.9 cases per 100,000 people. However, their mortality rate is high: 18.6 deaths per 100,000 individuals. On the other hand, North America, a high-income area, has a higher incidence rate of 73.7 per 100,000, but their mortality rate is lower: 7.7 per 100,000. This difference is often because high-income countries are better at detecting and treating the disease early on, thanks to tests like the Prostate-Specific Antigen (PSA) screening.
The frequency of prostate cancer has also seen significant changes worldwide over the past 30 years, further highlighting the effect of PSA screenings. For example, between 1986 and 1992, the incidence of prostate cancer in the U.S. doubled, which matches up with the implementation of widespread PSA tests. Something similar also happened in Europe and Australia. Yet, the popularity of screening has gone down recently because it often leads to overdiagnosis, which has caused the incidence rates to fall. In the meantime, death rates from prostate cancer, which have been declining over the past two decades, have seen a slight increase. Current guidelines from the US Preventative Services Task Force offer further clarification on PSA screening.
Signs and Symptoms of Localized Prostate Cancer
Normally, localized prostate cancer doesn’t cause any noticeable symptoms. Often, any symptoms related to the lower urinary tract, such as difficulty starting urination or weak urinary flow, are due to the prostate gland’s benign (non-cancerous) enlargement, a widespread condition among men over 50 years of age. However, symptoms might also be caused by prostate inflammation, urinary tract infections, urethral narrowing, or overactive bladder. This situation can lead to the incidental detection of early-stage cancer, the impact of which on long-term survival is uncertain. Prostate cancer can cause new instances of erectile dysfunction or, in rare cases, blood in the ejaculate or urine.
- Lower urinary tract symptoms like difficulty starting urination, dribbling after urination, and poor urine flow
- Blood in urine
- Blood in ejaculate
- New instances of erectile dysfunction
Testing for Localized Prostate Cancer
To identify if a patient has localized prostate cancer, there are several tests doctors typically use. They include testing blood for prostate-specific antigen (PSA) levels, performing a digital rectal examination (DRE), having a multiparametric MRI (mpMRI), and doing a needle prostate biopsy. These days, it’s quite rare to discover localized prostate cancer during treatment for an unrelated condition such as an enlarged prostate. PSA testing proactively screens for prostate cancer, stirring debates over its effectiveness.
Studies show that PSA screening can improve the chances of catching prostate cancer early by about 30%. Despite this, there’s no clear evidence that this testing has improved overall survival rates for prostate cancer.
Over-diagnosis is a term used to represent cases that are unlikely to progress into a severe illness during a man’s lifetime. Diagnosing such cases is viewed as unnecessary as the treatment may not provide any benefits and can lead to overtreatment. Some of the procedures for diagnosis and treatments can have significant side-effects that can reduce the quality of life.
Given these factors, routine PSA testing is not recommended in the United States and Europe. Instead, the American Cancer Society only recommends this test for certain high-risk groups after discussing the potential risks and benefits, along with the uncertainties about prostate cancer screening. These groups include men aged 50 or older, men aged 45 or older with a high risk of prostate cancer, and men aged 40 or older who have a significantly higher risk.
PSA levels can fluctuate due to many factors. This includes sexual activity, manipulation of the prostate, urinary tract infections, vigorous exercise, and naturally occurring changes in PSA protein. If the initial PSA test results are borderline, doctors usually suggest a repeat test in a few weeks.
DRE is often performed alongside PSA testing. If the DRE test appears suspicious, even with a low PSA level, further investigation is recommended because almost 20% of localized cancers occur without increased PSA levels.
Moreover, doctors may use a multiparametric MRI scan (mpMRI) which provides detailed pictures of the prostate by combining anatomical and functional information. This imaging test can give a score, with higher scores indicating a greater likelihood of cancer being found in biopsy analysis.
A definitive diagnosis of prostate cancer requires a positive needle biopsy, typically performed under local anesthetic. Imaging-assisted procedures (like real-time MRI scan or ultrasound image) are used to guide the needle during the biopsy. These procedures are performed through the rectum (transrectally) or the skin between the anus and scrotum (transperineally). Both methods have pros and cons.
In order to get an accurate cancer grading, doctors normally sample multiple areas of the prostate. This leads to the detection of more significant prostate cancers but also has a higher chance of finding other non-threatening conditions. After a biopsy, antibiotics are given to patients to prevent infections. Patients should be informed about potential side-effects like bleeding and discomfort.
After confirming the diagnosis of prostate cancer, the next step is to determine the severity of the disease. This step helps to plan out the necessary treatment and further investigations, like PSA level testing, grade group monitoring, and staging. This evaluation classifies patients into low, high, and intermediate risk groups. High-risk patients usually have further investigations to detect any spread of the disease. In intermediate-risk patients, the need for such tests is usually determined on a case-by-case basis.
Treatment Options for Localized Prostate Cancer
Localized prostate cancer usually has a good prognosis if untouched but can also lead to severe patient anxiety upon diagnosis. The treatments for this type of cancer can cause side effects that might negatively affect a patient’s quality of life over the short, medium, or even long term. Therefore, it’s crucial to consider not just the disease’s specifics, such as its stage, grade, and volume, but also take into account the patient’s overall health, life expectancy, and personal priorities.
Figuring out the optimal treatment for localized prostate cancer involves discussing it with a multidisciplinary team. This group includes radiation and medical oncologists, urologists, pathologists, radiologists, and specialist nurses. They combine their expertise and familiarity with the patient to decide the best course of action.
Studies show that shared decision-making (SDM) leads to better quality of life and less regret about treatment for prostate cancer patients. The process involves clinicians working hand-in-hand with patients to make collaborative decisions based on the best available evidence and understanding of the patient’s values. It requires good physician empathy and strong communication skills. Clinicians can help alleviate patient anxiety by conveying that prostate cancer often grows slowly and explaining the pros and cons of various treatment approaches.
The standard approaches to localized prostate cancer include watchful waiting, surgery, radiation therapy, and emerging focal therapies.
Many men diagnosed with localized prostate cancer, especially older ones, die with the disease, not from it. However, some cases do progress over time. The likelihood of progression to advanced or metastatic disease is higher with more and higher-grade cases. As such, watching and waiting, often employed for older or low-risk patients, involves careful counseling and close monitoring. Treatment can be deferred until symptoms appear or the disease progresses.
Surgical options include open, laparoscopic, or robotically assisted prostatectomy. Innovative techniques have shorter hospital stays and require fewer blood transfusions. Radiation therapy is another option, where intensity-modulated radiation therapy (IMRT) allows more precise targeting of the prostate, reducing toxicity to surrounding organs. Yet, it may lead to complications such as GI toxicity, urinary problems, and secondary cancer. Androgen deprivation therapy is commonly used alongside radiation therapy in intermediate and high-risk prostate cancers. However, it can have significant cardiovascular side effects.
Brachytherapy, the implantation of radioactive seeds, is used for primary treatment in low-risk and low-volume intermediate risk cases. It may also be added to EBRT for more advanced cases. But, it frequently leads to urinary side effects and can cause erectile dysfunction.
Emerging focal therapies, such as focal laser ablation, high-intensity focal ultrasound (HIFU), irreversible electroporation (IRE), photodynamic therapy (VTP), and focal cryotherapy, aim to impose less burden on the patient by specifically targeting the tumor. While these appear promising in terms of preserving quality of life, there is still uncertainty about their long-term effectiveness. Hence, they should so far only be offered within a clinical trial setting.
What else can Localized Prostate Cancer be?
When diagnosing localized prostate cancer, doctors also consider a number of other conditions that can cause Lower Urinary Tract Symptoms (LUTS) similar to prostate cancer. These conditions include:
- Benign Prostatic Hyperplasia (BPH) – a noncancerous enlargement of the prostate
- Prostatitis – inflammation of the prostate
- Urethral stricture – narrowing of the urethra
- Urinary Tract Infection (UTI)
- Overactive bladder – a condition where there’s an urgent need to urinate frequently
- Bladder cancer
- Advanced prostate cancer
It is crucial to look at these possibilities and conduct the necessary tests to ensure the right diagnosis is reached.
What to expect with Localized Prostate Cancer
Prostate cancer is a common condition, but interestingly it has the highest 5-year survival rate of all cancers at 98%. This means that the majority of people with this type of cancer live for at least five years after being diagnosed. Localized prostate cancer, which is confined to the prostate gland, is frequently slow to progress and often has an excellent prognosis even if it’s not treated immediately. However, patients with high-grade, high-volume cancer bear a higher risk of their disease advancing and spreading to other parts of the body. This risk can be reduced with early detection and treatment.
Research has shown that patients who go through active surveillance (regular check-ups to monitor the status of the cancer), surgery, and radiotherapy (treatment with high-energy rays to kill cancer cells) have similar outcomes. However, the patient’s preferences and potential side effects should be taken into account when deciding on a treatment approach. It’s also important for patients who choose active surveillance to understand that they have a small increased risk of their cancer progressing. If it does, about half of these patients will need more aggressive treatment. This further treatment is needed often because patients are worried about their condition or because tests show signs of their disease progressing.
Possible Complications When Diagnosed with Localized Prostate Cancer
Complications with localized prostate cancer are generally from the side effects of the treatment. When surgery is chosen as the method of treatment, patients often experience nerve damage which can lead to urinary incontinence or erectile dysfunction. Additionally, all types of surgery involve some degree of risk, like anesthesia-related complications and excessive blood loss. When patients are treated with radiation therapy, risks include gastrointestinal issues, urinal problems, local toxicity, and the possible development of other types of cancer in the future.
Side Effects:
- Nerve damage from surgery leading to urinary incontinence or erectile dysfunction
- Complications from anesthesia
- Excessive blood loss from surgery
- Side effects from radiation therapy like gastrointestinal issues and urinal problems
- Local toxicity from radiation
- Potential development of other cancers in the future due to radiation therapy
Preventing Localized Prostate Cancer
Most of the risk factors for prostate cancer – like a person’s age, race, and family health history – cannot be changed. Therefore, it’s crucial that people are aware of these factors so that those in high-risk groups can take the PSA test. The PSA test, which stands for Prostate-Specific Antigen, helps detect prostate cancer early.
However, it’s important to explain to patients interested in the PSA screening about the risk of detecting a harmless cancer, leading to unnecessary anxiety and treatment. Also, if people don’t meet the criteria for this test, they should be reassured that it might not be necessary for them.
Even though certain lifestyle factors don’t increase the probability of developing prostate cancer, they could affect the progression of the disease. Hence, people who have been diagnosed with prostate cancer should be advised to lead a healthy lifestyle – this includes a balanced diet and regular exercise. Such steps can help slow down the disease’s progression. It’s worth noting that obesity can increase the risk of prostate cancer becoming a more advanced, aggressive disease.
