The authors determined the significance of prostate specific antigen (PSA) levels in determining survival in prostate cancer patients with bone tumors after hormone therapy

Hormone therapy is a common treatment for prostate cancer. It targets the male sex hormones active in prostate cancer, such as testosterone. Hormone therapy can be used to treat patients with advanced prostate cancer (stage III/ IV – cancer spreads out from the prostate). In some patients, prostate cancer can spread to the bones and form tumors. PSA can be used as a predictor to determine cancer spread and growth. PSA is a protein elevated in the blood when prostate cancer is present. The time taken to achieve the lowest (nadir) level of PSA is known as time to the prostate-specific antigen nadir (TTPN). The role of TTPN in predicting survival in prostate cancer patient has been investigated.

Further research is needed in this aspect to evaluate the significance of TTPN in predicting survival of prostate cancer patients with bone tumors beyond TTPN. 

The authors aimed to evaluate the benefit of using PSA to determine survival in prostate cancer patients with bone tumors.

Data from 419 patients were analyzed in this study with a median (midpoint) follow-up of 38 months. All patients had bone tumors.

Patients with high PSA levels had a 63% increased risk of experiencing shorter progression-free survival after PSA increased from the lowest level. Patients with high PSA levels had a 96% increased risk of experiencing shorter overall survival after PSA increased from the lowest level. Patients who had a longer time from treatment until PSA increased from the lowest value (beyond TTPN) had a 28% reduced risk of cancer progression. They also had a 35% reduced risk of dying from the disease.

In patients with a progression-free survival of less than 3 months and an overall survival of less than 6 months survival beyond TTPN increased with TTPN. In patients with a progression-free survival of 3 to 17 months and an overall survival of 6 to 20 months survival beyond TTPN remained relatively static. In patients with a progression-free survival of more than 17 months and an overall survival of more than 20 months survival beyond TTPN increased largely with TTPN. 

The authors concluded that TTPN was a good predicting factor for survival outcomes beyond TTPN in prostate cancer with bone tumors following hormone therapy.