Prostate Cancer – In A (Wal)nut Shell

A walnut best describes the shape and size of the prostate gland. The prostate is a round structure found between the bladder and the urethra, responsible for secreting prostate fluid, a constituent of semen. Interestingly, walnuts have also been associated with health benefits to males and slowing the progression of prostate cancer.

When the prostate gland grows during cancer or in Benign Prostatic Hyperplasia, it tightens the urethra and so greater force is needed to push urine out of the bladder. This causes Lower Urinary Tract Symptoms like poor urine stream, hesitancy or incomplete voiding. These symptoms however, are not always indicative of cancer, as some prostate cancer patients show no symptoms.

Prostate cancer is the most commonly diagnosed malignancy affecting men worldwide and incidence is on the rise, with a 1 in 9 lifetime risk for men in the UK (patient.co.uk). Despite its high incidence, prostate cancer is not the most common cause of cancer deaths among men (lung cancer is). This highlights the importance of early detection and management in improving a patient’s prognosis.

Age is an important risk factor for prostate cancer. The majority of new cases present in men over 50 and the incidence steeply rises amongst men over 65. Ethnic background also plays a role. Men of African descent are 56% more likely to develop prostate cancer compared to their white counterparts. Hispanic men also have a higher likelihood of developing prostate cancer, in relation to the general population.

Screening based on the Prostate Specific Antigen (PSA), an enzyme present in prostate fluid, was first introduced 28 years ago and is used to identify potential prostate cancer cases. Generally speaking, the higher the PSA value the higher the likelihood of prostate cancer. Yet it would be nutty to rely on PSA results alone. This assay is controversial; high values don’t always indicate prostate cancer, while low values do not necessarily mean no cancer, so it is used together with diagnostic tests such as a biopsy. Ever more sensitive detection techniques are always highly sought after and comparing such techniques is the focus of my research.

Currently the gold standard for prostate cancer detection is the Transrectal Ultrasound (TRUS) guided biopsy, followed by histological analysis. This means that a tissue sample is cut out from the prostate and a pathologist checks if cancer cells are present. Some cancers grow slowly and thus do not require urgent treatment, however these cancers still need regular monitoring through a process known as active surveillance.

For this purpose, UK National Institute for Health and Care Excellence recommended Multi-Parametric Magnetic Resonance Imaging (MP-MRI). This diagnostic test is ideal as it is less invasive, faster and cheaper than a biopsy. MP-MRI is considered reliable as detection is usually based on 4 different imaging exams that characterise the cancer by appearance, metabolism and aggressiveness. In spite of this, working out whether cancer detection is more sensitive using imaging or biopsies has been a hard nut to crack.

To date, we do not know enough about MP-MRI as a diagnostic tool to warrant a change in existing practice and biopsies remains the golden standard. But the possibility of a non-invasive, fast diagnosis highlights avenues for further research, which could drastically improve the diagnostic methods of numerous types of cancers! Nuts, isn’t it?

About the Author

Vanessa Otti - Getty ScienceVanessa Otti has just begun a Professional Training Year as part of her BSc Medical Sciences degree at the University of Exeter, UK. She is currently researching prostate cancer and the characterisation of tumours in this region through the use of multi-parametric MRI scanning. To advance her knowledge of medical science she has organised work placements which include The Harley Street Clinic, London and has carried out voluntary work at Kings College Hospital, London and The Royal Devon and Exeter Hospital. For leisure she enjoys playing netball and basketball and participating in the St John’s Ambulance society at university.

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