C42. Carcinoma of the prostate: Treatment modalities

Treatment

In many cases of prostate cancer an “active surveillance” approach might be safer than outright treating the tumor. This is especially true for elderly people with comorbidities or people with a less than 10-year life expectancy, as the treatment might be worse than the disease.

For low-risk prostate cancer, active surveillance and surgery have the same outcome. For intermediate and high-risk disease, surgery has better outcome than surveillance. For intermediate-risk disease, radiotherapy and surgery have similar outcomes and odds of cure.

Metastatic prostate cancer cannot be cured. Palliative options include chemotherapy and hormonal therapy.

Active surveillance

Active surveillance is the preferred option for most prostate cancer which are low or low-intermediate risk. It involves routinely measuring PSA and repeating mp-MRI to assess for progression. If there is sign of progression, active therapy can be considered.

Active surveillance helps avoid cancer treatment which may be unneccessary, as low and low-intermediate risk prostate cancer may never metastasise or become symptomatic. However, the patient must live with the uncertainty that the cancer may progress.

Surgical therapy

Surgical treatment of the prostate involves laparoscopic radical prostactetomy (RP), the complete surgical removal of the prostate. Radical prostatectomy has better outcomes when performed robot-assisted. RP is only performed if one expects to achieve cure.

This surgery usually severs autonomic cavernous nerves which control erectile function, thereby almost always causing impotence as a side effect. Another common side effect is urinary incontinence, but this usually improves over time.

Radiotherapy

Radiotherapy is a potentially curative modality for prostate cancer, but prostate cancer requires a very high load of radiation for local control, up to 100 Gy total. Radiotherapy may be performed with external beam (EBRT) or high dose rate brachytherapy (HDBRT), but external therapy is most common.

Before radiotherapy, small seeds of gold are inserted into the prostate. Because these are clearly visible on imaging, this allows for more precise radiation planning.

Radiotherapy also has impotence as a common side effect.

Watchful waiting

Watchful waiting is different from active surveillance in that there is no routine evaluation for progression, and is an option for asymptomatic or mildly symptomatic prostate cancer. With watchful waiting, one undergoes no treatment but if symptoms occur or progress, one can consider palliative treatment.

Chemotherapy

Chemotherapy is indicated as palliation for metastatic prostate cancer. Commonly used drugs are docetaxel and cabazitaxel.

Castration/ADT

Castration, also known as androgen deprivation therapy (ADT), is the anatomical or functional loss of the testicals. It may be achieved by orchidectomy or by use of GnRH agonists or antagonists. ADT is usually combined with an antiandrogen like abiraterone or enzalutamide.

ADT is usually indicated as neoadjuvant therapy before curative radiotherapy as well as adjuvant therapy after. Hormones make the cancer cells more radiosensitive and decreases the tumour size. Common side effects include erectile dysfunction, as well as typical symptoms of menopause like hot flashes, night sweats, mood changes, and decreased libido. However, these side effects are reversible when hormonal therapy is finished. It may also be used as palliation for metastatic prostate cancer.

Screening

The efficacy of screening for prostate cancer is debated. The reason for this is that not all cases of prostate cancer are aggressive and fatal; many cases follow a very indolent course with few clinical symptoms. Screening (especially with PSA) can’t differentiate between prostate cancers that would become aggressive and those that wouldn’t, and so many people who would develop clinically indolent prostate cancer undergoes potentially life-changing treatment which may be worse than the symptoms of the cancer would have been. Indeed, prostate cancer is often found incidentally on autopsy, and more people die with prostate cancer than of prostate cancer.

In Norway, there is no national screening programme for prostate cancer. In Hungary, the lecture recommends annual DRE and PSA measurement for men older than 50, but there is no national screening programme (as far as I can see).