Markers of Toxicity and Response to Radiation Therapy in Patients With Prostate Cancer

Abstract

The main treatment modalities for localized prostate cancer are surgery and radiation. Surgery removes the whole prostate gland, whereas with radiation therapy the irradiated prostate remains within the patient's body. Biomarkers specific to the prostate gland should become undetectable after surgery, but this is not the case when radiation therapy is used, as residual prostate cells may still be metabolically active. Here, we review the role of tumor markers of toxicity and response to radiation therapy in patients with prostate cancer, including prostate specific antigen, human kallikrein 2, osteopontin, prostate cancer associated 3, citrulline, and others.

Quantification of biochemical PSA dynamics after radioligand therapy with [177Lu]Lu-PSMA-I&T using a population pharmacokinetic/pharmacodynamic model

“…Though exact mechanisms of the radiation-induced bystander effect are very complex, the interaction of irradiated cells with the immune system is likely to play an important role [ 65 , 66 ]. A delayed effect on PSA levels is also described after external beam radiation therapy, since the average time to nadir PSA after radiotherapy is approximately fifteen months [ 67 ]. It is important to mention that this delay in PSA effect does not per se reflect a similar delayed effect on overall tumor treatment response.…”

“…It is important to mention that this delay in PSA effect does not per se reflect a similar delayed effect on overall tumor treatment response. The estimated delay is probably also partly related to PSA being our PD measure, because changes in PSA are likely to occur somewhat after treatment [ 67 , 68 ]. This could be partly due to occurrence of a PSA-flare phenomenon after start of treatment, which was previously hypothesized before for radioligand therapy with [ 177 Lu]Lu-PSMA-617 [ 68 , 69 ].…”

Administering Docetaxel for Metastatic Hormone-Sensitive Prostate Cancer 1–6 Days Compared to More Than 14 Days after the Start of LHRH Agonist Is Associated with Better Clinical Outcomes Due to Androgen Flare

“…Sleep-related erections were investigated in prostate cancer patients treated with bicalutamide monotherapy, and there were no significant modifications in the number of nocturnal penile tumescence episodes, maximum penile circumference and rigidity time before and after therapy [ 35 ]. Prostate-specific antigen [ 2 , 3 ] decreases under treatment with bicalutamide, and thus it is often regarded as a “castrating” medication, despite that most patients maintain erections under antiandrogen monotherapy [ 36 ]. A large study that randomized more than 8000 patients with locally advanced prostate cancer to bicalutamide 150 mg plus standard care vs. standard care alone found that impotence was similar in both treatment groups, 9.3% (375/4022) with bicalutamide, and 6.5% (263/4031) with standard care alone [ 36 ].…”

“…Prostate cancer is the most prevalent non-cutaneous malignancy among men [ 1 , 2 , 3 ]. In 1941, Charles Huggins and Clarence V. Hodges published a series of eight patients with carcinoma of the prostate metastatic to bone who underwent bilateral orchiectomy, with estrogen or androgen injections provided daily before castration [ 4 ].…”