mCRPC: Monitoring Patients

Video

An expert in prostate cancer discusses the typical follow-up and monitoring approaches for a patient with metastatic CRPC.

Matthew R. Smith, MD, PhD: In my practice, the main state of monitoring is a serial measurement of PSA. Typically, serum PSA is measured every 3 months while [a patient is] on androgen deprivation therapy. Then, in a patient with an appropriate response, as in this case, we would repeat imaging after 1 year to establish a new baseline and to exclude the remote possibility of cancer progression despite a lower, undetectable PSA.

There are a number of metrics that we use to inform decision-making about addition or changes in systemic treatment. Rise in PSA on primary androgen deprivation therapy is the leading indicator of progression to castration-resistant disease, but there's quite a spectrum of what that means with different patients. We consider the time from initiation of ADT [androgen deprivation therapy] to progression as an important indicator about the necessity of adding or intensifying systemic treatment. We consider the rate of PSA rise, or so-called PSA doubling time, in subsequent decisions about adding systemic treatment. PSA doubling time is an established part of decision-making in non-metastatic castration-resistant prostate cancer, where the 3 pivotal studies in that disease state included patients who are at higher risk for progression based on a PSA doubling time of less than 10 months.

Transcript edited for clarity.

Case: A 82-Year-Old Man with Metastatic Castration-Resistant Prostate Cancer

Sept. 2016

Initial presentation

  • A 82-year-old man with nocturia

Clinical workup

  • Abnormal digital rectal exam, PSA 31 ng/mL
  • No family history of prostate cancer
  • Diabetes and hypertension, both of which are managed with medications, neuropathy and uses a cane for long distances
  • Prostate biopsy confirms advanced adenocarcinoma of the prostate and Gleason score of 8 (4 + 4)
  • Bone scans show no detectable spread to bone, abdominal pelvic CT scan shows enlarged pelvic and retroperitoneal nodes consistent with metastatic prostate cancer.
  • His ECOG PS is 1

Treatment

  • Patient starts continuous ADT in October 2016.
  • PSA levels go down to undetectable levels within 3 months after start of treatment. Levels are checked every 3 months thereafter.
  • Patient undergoes repeat abdominal pelvic CT scan after completing a year of therapy which show resolution of pelvic and retroperitoneal nodes.

April 2018

  • An increase in PSA is seen and PSA levels are 2.7 ng/ml, with PSA doubling time of 6 months
  • Patient undergoes conventional imaging with bone scan and CT that show no detectable prostate cancer.
  • PSMA PET scan shows multiple areas of increased uptake in pelvis and retroperitoneum, consistent with previously identified sites of metastasis.
  • Lab tests are normal and patient has adequate liver, renal and bone marrow function.
  • Patient is treated with enzalutamide (160 mg/day) and PSA levels decline
  • After some time on enzalutamide, patient decides to discontinue treatment due to fatigue and problems with gait.
  • Symptoms resolve on their own after going off treatment for a few months
  • Patient is started on darolutamide and continued ADT (leuprolide depot) and remains on this treatment
  • PSA levels stay undetectable on treatment
Related Videos
Experts on prostate cancer
Expert on prostate cancer
Experts on prostate cancer
Expert on prostate cancer
Experts on prostate cancer
Experts on prostate cancer
Experts on prostate cancer
Related Content