Patients face a difficult choice when prostate cancer is detected early, at a stage where it has not spread to other parts of the body. Aggressive treatment like surgery or radiation reduces the chance of progression. But it also risks urinary, sexual, and bowel side effects impacting the quality of life.

Active monitoring involves regular prostate-specific antigens (PSA) screening and biopsies, only treating if the cancer shows signs of growth. It spares immediate treatment harm but has a higher progression risk.

What option offers the best balance? The ProtecT study set out to find out.

Balancing act: Treatment choices in prostate cancer

The treatment options for prostate cancer include:

• Active monitoring

• Prostatectomy (surgical removal of prostate gland)

• Radiation therapy

• Hormone therapy

• Chemotherapy

For metastatic (cancer spread to other parts of the body) disease, more aggressive options are preferred. These include prostatectomy or radiation therapy along with hormone therapy called androgen deprivation therapy (ADT) which lowers the amount of testosterone (a major male hormone) in the body to castration levels [1]. The cancer cells are either surgically removed or killed using radiation or chemotherapy drugs to avoid further worsening of the condition.

But when prostate cancer is diagnosed while still at the localized stage, the choice of treatment option can be difficult. The more aggressive options offer a better degree of control over the disease and prevention of disease progression in the future. However aggressive treatment comes with risks of severe adverse effects and long-term complications [2].

On the other hand, the less aggressive option is active monitoring during which the prostate cancer is closely monitored. Intervention is given only when the cancer shows signs of growth. However, this approach increases the chances of disease progression which may lead to a high mortality rate. Therefore, the selection treatment strategy in localized prostate cancer is a clinical challenge.

Tracking over 1600 prostate cancer patients for 15 years

Researchers conducted a lengthy clinical study to help clarify this medical puzzle [3], [4]. From 1999 to 2009, over 1600 men in the UK with screen-detected localized prostate cancer joined the ProtecT study.

Patients were randomly assigned to:

• Active monitoring (545 men)

• Prostatectomy (553 men)

• Radiotherapy (545 men)

After a median 15-year follow-up, researchers compared prostate cancer deaths and overall survival. Metastases, disease progression, and eventual treatment rates were also analyzed.

Low prostate cancer deaths across the board

In every group, long-term prostate cancer survival was excellent:

• Active monitoring - 97%

• Prostatectomy - 98%

• Radiotherapy - 97%

Overall, only 45 men (2.7%) died from prostate cancer. The numbers were similar between the groups. Active monitoring stacked up well against immediate radical treatments for this outcome.

Higher metastases with active monitoring

However, active monitoring did see more eventual metastases and disease progression:

• Metastases - 9.4% with active monitoring versus 4.7-5% with surgery/radiation.

• Treatment initiation - 61% with active monitoring versus 90-92% with surgery/radiation.

Still, these differences did not translate to better 15-year prostate cancer survival with aggressive early treatment.

In a nutshell

The ProtecT study provides unique long-term data showing that prostate cancer deaths remain low at 15 years, even with conservative initial management.

There are valid reasons some patients may still prefer early radical treatment. But for most of the cases, active monitoring appears to be a reasonable option to avoid treatment harms without sacrificing survival.

In the end, treatment choice involves weighing individual trade-offs. The ProtecT trial offers reassurance on prostate cancer outcomes with multiple management approaches.

References

1. “Prostate Cancer Treatment - NCI.” Accessed: Oct. 18, 2023. Available: https://www.cancer.gov/types/prostate/patient/prostate-treatment-pdq

2. M. D. Michaelson, S. E. Cotter, P. C. Gargollo, A. L. Zietman, D. M. Dahl, and M. R. Smith, “Management of complications of prostate cancer treatment,” CA Cancer J Clin, vol. 58, no. 4, pp. 196–213, 2008, doi: 10.3322/CA.2008.0002.

3. University of Oxford, “The ProtecT Trial - Evaluating the Effectiveness of Treatments for Clinically Localised Prostate Cancer,” clinicaltrials.gov, Clinical trial registration NCT02044172, Nov. 2022. Accessed: Jan. 01, 2023.

4. F. C. Hamdy et al., “Fifteen-Year Outcomes after Monitoring, Surgery, or Radiotherapy for Prostate Cancer,” N Engl J Med, vol. 388, no. 17, pp. 1547–1558, Apr. 2023, doi: 10.1056/NEJMoa2214122.