Understanding Prostate Cancer
Among all the types of cells found in the prostate, most of the prostate cancers develop from the gland cells. Gland cells are responsible for making prostate fluid that is a part of semen. Some prostate cancers can grow and spread rapidly, but most grow slowly. Autopsy studies revealed that many men who died of other diseases also had prostate cancer, which never affected them during their lives. Some oncologists believe that prostate cancer starts out as a pre-cancerous condition. Some of the pre-cancerous conditions are Prostatic Intraepithelial Neoplasia (PIN) and Proliferative Inflammatory Atrophy (PIA).
According to the Atlanta Journal Report 2013 on prostate cancer, 1 in 6 men will be diagnosed with prostate cancer during his lifetime. As per data from GLOBOCAN 2012, approximately 23% of all prostate cancers diagnosed worldwide were from the Asia-Pacific region. Prostate cancer in the Asia-Pacific region is characterised by wide variations in incidence and mortality, combined with evidence of an increasing burden of incidence in many areas. In Singapore, prostate cancer accounted for an alarming 15.2% of all the cancers prevalent. In the Singapore Cancer Registry, Interim Annual Registry Report 2013, prostate cancer ranks third among the various types of cancers afflicting men.
With all these figures and statistics staring at our face, let us try and understand this big “C”.
Risks Factors and Causes
Every cancer has a set of unique risk factors. Some risk factors, like smoking or diet, can be changed, but others, like age or family history, can’t. Risk factors actually don’t tell everything; people with one or more risk factors may never get cancer, while some who get cancer may have had fewer or none of the known risk factors. The risk factors for prostate cancer could be attributed to one or more from among age, race/ethnicity, family history, genes, diet, obesity, smoking, workplace exposures, inflammation of the prostate, sexually transmitted infections, vasectomy.
Getting to the root, prostate cancer is caused by changes in the DNA of prostate gland cell. Further studies in understanding how normal prostate cells can grow abnormally, revealed that cancer can be caused by DNA changes that turn-on oncogenes and turn-off tumour suppressor genes. Such DNA changes can either be inherited or can be acquired during a person’s lifetime.
Prostate cancer can be detected early by testing the amount of Prostate Specific Antigen (PSA) in blood. It can also be detected byDigital Rectal Exam (DRE) or Transrectal Ultrasound (TRUS). Depending on the results of these tests, further testing like a prostate biopsy would be required to identifythe presence of a cancer.
Signs and Symptoms of Prostate Cancer
Advanced prostate cancer can manifest itself as:
- Problems passing urine, or the need to urinate more often, especially at night.
- Haematuria (blood in urine)
- Impotence or trouble getting an erection
- Back or hip pain or other areas if the cancer has spread to the nearby bones
- Loss of bladder or bowel control.
- Other diseases may also have similar symptoms; e.g. trouble passing urine can also be a symptom of Benign
- Prostatic Hyperplasia (BPH).
Treatment options for prostate cancer may include one or more from among surgery, radiation therapy, hormone therapy, chemotherapy and vaccine therapy. They could be used either individually or in combination. The treatment option would be selected by taking into account:
- Other concurrent serious health conditions
- Stage of cancer
- Weighing of the benefits and related risks
- Opinions of the patient and kin
The main types of doctors who treat prostate cancer include urologists (treats diseases of the urinary and reproductive system), radiation oncologists (treats cancer with radiation therapy) and oncologists (treats cancer with chemotherapyor hormone therapy).
Questions to doctors
It is the prerogative of the patient and kin to have an open discussion with the cancer care team. Any and all questions that come to mind should be asked and clarification sought for any doubts that exist. For example, a few pertinent questions that can be asked are:
- Is my cancer curable?
- What would be the cost of treatment?
- What is my expected survival rate?
- What are the side effects of treatment?
- Will alternative medicine work?
- Will I have impotence problems?
- Will treatment affect my daily activities?
- Will my cancer relapse after treatment?
- How often do I need to follow-up after treatment?
- Are there any medicines to prevent it from relapsing?
What’s next after treatment?
Usually treatment may remove or destroy the cancer. But sometimes the cancer may relapse or get benign. In such cases, treatment with hormone therapy or other therapies can help keep the cancer at checkfor long durations.
Scheduled follow-up visits
This will include regular scheduled doctor visits and PSA blood tests, with DRE if the prostate hasnot been removed. It will usually begin within a few months of treatment. Bone scans or other imaging tests may also be required, depending on the medical situation, to check for spread of the cancer to any adjacent bones.
Leading a healthier life
Taking steps to lead a healthier lifestyle can play a great role here. Maybe one could try to eat better or get more exercise; or maybe cut down on alcohol, or give up tobacco. Even things like keeping stress level under control can help.
Keeping a watch on diet
Eating healthy is a challenge for everyone, especially in people undergoing or who have undergone cancer treatment. In fact it can be very difficult, as treatment could change one’s sense of taste, accompanied by nausea. It’s best to seek advice from the cancer care team about seeing a dietitian, who can advise on how to deal with these treatment side effects.
Rest and Exercise
In some cases, fatigue or tiredness, can last a long time after treatment, and can make it very difficult for the patients to exercise and get about doing their normal activities. Some mild exercise can help overcome fatigue. By following a scheduled exercise plan, the patients can feel better, both physically and emotionally.
Keeping An Eye on What’s the Latest
Advanced research on genes linked to prostate cancer has enabled a better understanding on the development of prostate cancer. A mutation in a gene called HOXB13has been linked to early onset prostate cancer that runs in families.
Some Selenium and Vitamin E Cancer Prevention Trial (SELECT) studies have suggested that certain vitamin and mineral supplements (such as vitamin E and selenium) might lower prostate cancer risk. Another vitamin that may be important is vitamin D. Studies have found that menwith high levels of vitamin D seem to have a lower risk of developing the more lethal forms of prostate cancer.
The PSA test may not be the perfect test for an early detection of prostate cancer. It can miss some cancers, and in other cases it can be elevated when no cancer is present. Several newer blood tests seem to be more accurate than the PSA test. Other new tests being studied are urine tests. One test, called Progensa®, looks at the level of Prostate Cancer Antigen 3 (PCA3) in the urine. Another test looks for an abnormal gene change called TMPRSS2: ERG in prostate cells.
Standard ultrasound may not detect some areas containing cancer.A newer approach is to measure blood flow within the gland using a technique called Color Doppler Ultrasound (tumours often are more vascularised than normal tissue.) An even newer technique that involves injectingthe patient with a microbubbles contrast agent may enhance Color Doppler further. A University of Colorado Cancer Center has reported of a 3-D mapping biopsy technique that can detect prostate cancers that were missed by ultrasound guided biopsy, by about 3 times.
Enhanced MRI may help find lymph nodes that contain cancer. Another newer type of Positron-Emission Tomography (PET) scan that uses radioactive carbonacetate instead of labeled glucose can be helpful in staging prostate cancer. It can also help to determine if treatment has been effective.
Newer treatments are being developed, and leads are being made among many standard prostate cancer treatment methods.
If the nerves that control erections (that runs along either side of the prostate) are removed during the surgery, a man can become impotent. The use of nerve grafts to replace cut nerves and restore potency is being explored.
New computer programmes allow doctors to better plan the radiation doses and approaches for both external radiation therapy and brachytherapy. Planning for brachytherapy can now even be done during the procedure(intraoperatively). New treatments could be used after radiationtherapy in cases where it was not successful. One treatment, known as High-Intensity Focused Ultrasound (HIFU), destroys cancer cells by heating them with highly focused ultrasonic beams.
Some chemotherapeutic agents such as docetaxel and cabazitaxel have been shown to help men live longer. Targeted chemotherapy is a newer type of cancer treatment that identifies and attacks cancer cells while doing little damage to normal cells. Cabozantinib, a new drug molecule has shown good results in many men whose prostate cancer was no longer responding to hormones.
Unlike vaccines against infections, these vaccines are designed to help treat, and not prevent, prostate cancer. One possible advantage of these types of treatments is their very limited side effects. An example of this type of vaccine is Sipuleucel-T, which has received FDA approval. Another prostate cancer vaccine (PROSTVAC-VF) uses a virus that has been genetically modified to contain PSA.