Adenoid Cystic Carcinoma of The Prostate Gland: A Review and Update

Kodzo-Grey Venyo A

Published on: 2023-08-24

Abstract

Adenoid cystic carcinoma (ACC) of the prostate gland is a very uncommon tumour of the prostate gland which has tended to be reported sporadically. Adenoid cystic carcinoma of the prostate gland does arise from the basal cells of prostate acini and which manifests with a portended aggressive biological behaviour and most often it is associated with poor prognosis for metastatic cases. Less than160 cases of adenomatoid carcinoma of the prostate had so far been reported and the general understanding is that the tumour is rare. Nevertheless, there is a possibility that due to its rarity, there has continued to be underreporting of the tumour or the tumour could have been misdiagnosed in the past due to the fact that many clinicians globally may not be aware of the tumour and may not have a high index of suspicion for the tumour. Another reason is that the commonest type of carcinoma that afflicts the prostate gland that is adenocarcinoma of the prostate gland does tend to be associated with raised serum prostate specific antigen (PSA) levels and the level of serum PSA and serum PSA doubling time generally are globally utilized for screening for early detection of prostate cancer apart from the finding of abnormal digital examination features of the prostate. Generally adenoid cystic carcinoma tends to be associated with low or normal serum PSA levels due to the fact that it develops from a different type of cell in comparison with the cell of origin of the common adenocarcinoma that most people know about. This could be one of the reasons why a number of cases of adenoid cystic carcinoma may be diagnosed late when the tumour has already metastasized. Some of these tumours tend to be diagnosed incidentally pursuant to the undertaking of trans-urethral resection of prostate for lower urinary tract symptoms or urinary retention that is presumed to be due to benign prostatic hypertrophy. Some patients manifest with metastatic disease at first presentation when it is too late to provide treatment of curative intent and they are then provided palliative treatment. Adenoid cystic carcinoma tends to manifest in younger individuals as well is in people who are old and at about similar ages of manifestation of adenocarcinoma of the prostate. There is no global consensus opinion regarding the best treatment options for localized tumours as treatment of curative intent as well there is no global consensus opinion related to the treatment of locally advanced as well as metastatic adenoid cystic carcinoma of the prostate gland. Multiple treatment options exist for different stages of prostate cancer that include the undertaking of radical prostatectomy, radiotherapy, combination chemotherapy and hormone therapy with gonadotrophin-releasing hormone (GnRH) agonists and antagonists for androgen receptor (AR)-positive cases. There is no global agreement on which chemotherapy medicaments that should be used in treating adenoid cystic carcinoma of the prostate. Considering the fact that the cell of origin of adenoid cystic carcinoma of the prostate gland is different from the cell of origin of adenocarcinoma of the prostate gland, it would be understood that adenoid cystic carcinomas would not respond well to the conventional chemotherapy medicaments that are used for pure adenocarcinoma of the prostate. For this reason, it would be important that the global rare disease societies in the world should negotiate with various governments and other societies to establish multi-centre global trials and research projects for the development of new chemotherapy medicaments that would effectively destroy adenoid cystic carcinomas of the prostate gland. For treatment of curative intent for some localized tumours as well as for locally advanced and some metastatic adenoid cystic carcinomas of the prostate gland some minimally invasive therapy can be undertaken with the aim of either eradicating the tumour or reducing the bulk of the tumour. Some of these options that could be tried as part of combination therapy regime could entail: Cryotherapy of the prostate plus or minus cryotherapy of a localized metastatic lesion; radiofrequency ablation of the prostate plus or minus radiofrequency ablation of a localized metastatic lesion; irreversible electroporation of the prostate plus or minus irreversible electroporation of a localized metastatic lesion; immunotherapy in addition to other treatment options through a global multicentre trial. Oncologists, urologists and pharmacology and pharmacy research workers should come together regularly at are cancer congresses to deliberate about the development of new chemotherapy medicaments that would effectively destroy the cancer cells but that would not destroy normal cells of the human being. Finally, clinicians need to be aware that if there is an abnormal digital examination finding of a prostate gland with a normal serum PSA level this could represent the possibility of a rare prostate cancer which is not associated with the production of PSA and an urgent prostate biopsy would be required to establish the diagnosis.