The research, led by the Pathology Department of Bellvitge University Hospital (HUB), has established that when amyloidosis is incidentally detected in the prostate, it almost always happens to be the systemic TTR variant of the disease, which is related to ageing
This type of amyloidosis has a specific treatment that, if started early, improves survival and quality of life
Amyloidoses are a group of diseases in which different types of proteins fold abnormally, deposit in tissues and eventually compromise their function. These deposits can be local or systemic.
Although little known only 25 years ago, TTR (Transthyretin deposition) amyloidosis is now considered to be the most common form of systemic amyloidosis associated with ageing. Formerly known as senile cardiac amyloidosis, we now know that deposits can be found in various organs and tissues, years before the onset of potentially severe heart symptoms.
Early diagnosis of this form of systemic amyloidosis is difficult because its main symptoms often overlap and are confused with common manifestations of ageing.
A research led by Dr Maria Pané and Dr Enric Condom, from the HUB’s Pathological Anatomy Service and IDIBELL researchers, in which also participated the hospital’s Radiology, Urology and Internal Medicine services, has shown that the prostate is one of the tissues where amyloid is deposited in cases of systemic amyloidosis (especially TTR type). This fact was little known until now.
The authors incidentally found minimal amyloid deposits in prostate biopsies from 40 patients out of thousands of biopsies performed for suspected prostate cancer between 2001 and 2022. Immunohistochemical study confirmed the finding and determined the type of amyloid in more than 80% of cases. Most of them were TTR amyloid. Only four of the patients had a previous diagnosis of systemic amyloidosis (all of them non-TTR).
In reviewing the medical records of patients in whom amyloid deposition had been detected, the authors of the study, published in the journal Histopathology, found that all had at least one of the symptoms described as usually related to systemic TTR amyloidosis: bilateral carpal canal syndrome, hearing loss and osteoarticular problems (tendinopathies, lumbar canal stenosis, osteoarthritis), among others.
This is the largest series published to date of patients diagnosed with amyloidosis in the prostate. As Dr Maria Pané, principal investigator of the study, explains, "the potential clinical impact and the benefit we can obtain from this incidental diagnosis is big, because an undetermined percentage of patients with systemic TTR amyloidosis end up developing a heart disease. If the disease is diagnosed and treated early, a significant improvement in the quality of life and survival of patients is possible".
In addition to highlighting that the prostate is a target tissue for amyloid deposits, the HUB study also aims to help raise awareness among professionals of the systemic TTR amyloidosis clinical features, mainly musculoskeletal- and neurosensory-related symptoms, emphasising that not all patients with this type of amyloidosis have heart affectations.
In addition, it is stressed the usefulness of reviewing any biopsy samples in patients with suspected symptoms of systemic amyloidosis, in order to try to detect amyloid deposits that may have gone unnoticed, explains Dr Pané.
Reference article
Clinical relevance of amyloid in prostate samples: a report on 40 patients
Histopathology, July 5th 2022 https://doi.org/10.1111/his.14717