PSMA in circulating tumor cells is a new poor prognostic marker for castration-resistant PCa - Plos One - Published: January 27, 2020

[cujoe]

From the sudy Introduction:

"More than 90% of patients with metastatic treatment-naive prostate cancer initially respond to androgen deprivation therapy (ADT). However, most patients eventually progress to castration-resistant prostate cancer (CRPC), which is then treated with sequential therapy [1]. Several drugs available for sequential therapy of CRPC, such as enzalutamide (ENZ), abiraterone (ABI), docetaxel (DOC), cabazitaxel (CBZ) and radium-223, have been shown to prolong the survival of CRPC patients [2]. However, approximately 30% of CRPC patients show primary resistance to novel androgen receptor (AR)-targeted agents such as enzalutamide and abiraterone [3, 4]. Since tissue biopsy is invasive and cannot be performed for all tumors, liquid biopsy is drawing attention as a new testing option to overcome these shortcomings. Liquid biopsies are the blood-based analyses of non-solid biological tissues such as exosomes, cell-free DNA and circulating tumor cells (CTCs). CTCs are characterized as cancer cells that intravasate into the circulatory system from primary locations.[5]. In CRPC patients, androgen receptor splice variant 7 (AR-V7) in CTCs has the possibility to be a biomarker to predict the development of drug resistance to enzalutamide and abiraterone [6, 7]. In contrast, taxane-based chemotherapies are effective against CRPC irrespective of AR-V7 status [8, 9]. In lung cancer, genetic information of CTCs facilitates the delivery of personalized medicine [10, 11]. To optimize treatment selections and avoid unwanted adverse events, genetic analysis of CTCs would provide useful information."

"Prostate-specific membrane antigen (PSMA) is a type II transmembrane glycoprotein with several enzymatic functions. Although the mechanism by which PSMA stimulates proliferation of prostate cancer remains to be elucidated [12], its expression in prostate cancer tissue correlates with cancer aggressiveness [13, 14]. Recently, the utility of PSMA PET-CT as a diagnostic tool came under the spotlight [15]. Also, PSMA is drawing attention as a target for radionuclide therapy and immunotherapy of CRPC [16–19]. Here, we investigated the PSMA expression in CTCs from CRPC patients and explored its potential as a biomarker of treatment response for CRPC."

Abstract and Full Report available here:

journals.plos.org/plosone/a...

Be Well - K9

[NPfisherman]

Great find, K9,

Indeed , the expression of PSMA on CTC's showed higher resistance to treatment and specific mutations were more prevalent...That is the question, how do we overcome resistance.???... the second line drugs are coming and there has been some success in clinical trials on overcoming resistance to these mutations with the addition of those drugs... Give it 5 years and we shall see some success in overcoming resistance...The problem is the ability to mutate by cancer, but these new drugs will buy us a precious commodity.... TIME !!!

Don Pescado

[cujoe in reply to NPfisherman]

Thanks for the input, Señor Pescado. There is no doubt that PCa is one sneaky SOB.

Yet, someday day, some way, we will find a way to wipe that SOB out for all time.

In the meantime, Stay Strong & Be Well - Captain K9