RESUMEN
Defining predictive biomarkers for targeted therapies and optimizing anti-tumor immune response is a main challenge in ongoing investigations. Progastrin has been studied as a potential biomarker for detecting and diagnosing various malignancies, and its secretion has been associated with cell proliferation in the gastrointestinal tract that may promote tumorigenesis. Progastrin is a precursor molecule of gastrin, synthesized as pre-progastrin, converted to progastrin after cleavage, and transformed into amidated gastrin via biosynthetic intermediates. In cancer, progastrin does not maturate in gastrin and becomes a circulating and detectable protein (hPG80). The development of cancer is thought to be dependent on the progressive dysregulation of normal signaling pathways involved in cell proliferation, thus conferring a growth advantage to the cells. Understanding the interaction between progastrin and the immune system is essential for developing future cancer strategies. To that end, the present review will approach the interlink between gastrointestinal cancers and progastrin by exploring the underlying molecular steps involved in the initiation, evolution, and progression of gastrointestinal cancers. Finally, this review will focus on the clinical applications of progastrin and investigate its possible use as a diagnostic and prognostic tumor circulating biomarker for disease progression and treatment effectiveness, as well as its potential role as an innovative cancer target.
RESUMEN
BACKGROUND: Paragangliomas of the urinary tract are exceptionally uncommon, and sporadic case reports of primary paraganglioma of the prostate have been reported in the literature. METHODS: Systematic research in PubMed/Medline and Scopus databases concerning primary prostatic paraganglioma was performed by two independent investigators. RESULTS: This analysis included 25 adult males, with a mean age of 49.8 ± 22.4 years. 32% of included patients had a history of hypertension. Problems during urination (52%), blood loss (44%), either as hematuria or hemospermia, and catecholamine-related symptoms (36%) comprised the most frequently reported clinical manifestations. Digital rectal examination found a palpable nodule in 36% of patients, while prostatic specific antigen (PSA) was normal in all tested patients. Abdominal ultrasound (44%), computed tomography (44%) and magnetic resonance imaging (28%) helped to identify the primary lesion. 24-hour urine epinephrine, norepinephrine and vanillylmandelic acid (VMA) levels were elevated in 90%, 80% and 90% of included patients. Open surgical excision of the mass was performed in 40%, transurethral resection in 8%, open radical prostatectomy in 24%, transurethral resection of the prostate in 16% and robot-assisted radical prostatectomy in 4% of included patients. CONCLUSION: Due to atypical clinical manifestation and scarcity of prostatic paraganglioma, urologists should be aware of this extremely rare entity.