An overview on BPH (Benign Prostatic Hyperplasia)

Written by Jasim Siddiqui, MBBS, Urology Registrar at Our Lady of Lourdes Hospital & Mr Ronan Long, MB, BCh, BAO, MCh, MMed SCI, FRCS(Urol), Consultant Urologist at Our Lady of Lourdes Hospital, Louth County Hospital and Mater Private Outreach Clinic Drogheda.

Definition:

BPH (benign prostatic hyperplasia) refers to the non-malignant growth or hyperplasia of prostate tissue. A benign prostatic enlargement (BPE) can cause bladder Outflow Obstruction (BOO) and is a common cause of lower urinary tract symptoms (LUTS)in men.

Epidemiology:

The prevalence of histological BPH increases with age, affecting approximately 42% of men between the ages of 51 and 60 years and 82% of men between the ages of 71 and 80 years. 1 The global lifetime prevalence of BPH is around 25%. 2

Aetiology & Pathophysiology:

Hyperplasia in the prostate is stimulated by androgens. The main androgen is dihydrotestosterone, which is converted from testosterone by the enzyme 5-alpha reductase. Lower urinary tract symptoms resulting from hyperplasia are mainly due to 2 components: a static component related to an increase in benign prostatic tissue mainly at the transitional zone, narrowing the urethral lumen and a dynamic component related to an increase in prostatic smooth muscle tone mediated by alpha-adrenergic receptors. 3

The aetiology is multifactorial with advancing age, endogenous androgens and prostate volume increasing the risk of developing symptoms. Black men appear to have a higher risk and Asian men have a lower risk. 4 Potential causal risk factors include Obesity, smoking, male pattern baldness, family history of BPH & metabolic syndrome.

Progression from pathologic BPH to clinical BPH (i.e., the presence of symptoms) may require additional factors such as prostatitis, vascular effects, and changes in the glandular capsule. 5

Making the Diagnosis:

The diagnosis of benign prostatic hyperplasia (BPH) can often be suggested based on the history alone. In men above the age of 50, history and symptoms suggestive of BPH include possible voiding and storage symptoms. Voiding symptoms include hesitancy, intermittency, weak stream, straining, incomplete emptying & post void dribbling. Storage symptoms include urinary frequency, nocturia, and urgency

A small proportion of men present with the inability to pass urine and is associated with suprapubic pain and a palpable bladder, which is a complication of untreated BPH. This is a urological emergency and the bladder requires immediate drainage. Men presenting under the age of 50 with voiding LUTS are unlikely to have BPH.

Examination:

Examination for BPH begins with abdominal, digital rectal examination(DRE) and a focused neurological examination. The DRE should assess perianal sensation, anal tone, prostate size and for any prostatic irregularity. A prostate nodule on DRE should prompt PSA levels. Decreased anal sphincter tone or the lack of a bulbocavernosus muscle reflex may indicate an underlying neurological disorder.

Investigations:

All patients should have a urine dipstick and/or culture and sensitivity to rule out a UTI or haematuria. NICE guidelines recommend that all patients with LUTS suggestive of renal impairment should have a serum creatinine and eGFR. If renal impairment is present, an ultrasound scan should be requested to assess for hydronephrosis and post-void residual.

Patients should be advised to record a frequency/volume chart voiding diary for a few days, which is a useful tool to objectify symptoms and detect polyuria. 6

Assessment of the severity of the patient’s symptoms and the impact on their quality of life is done using the IPSS (International Prostate Symptom Score), a selfadministered questionnaire with 8 questions. 7

Investigations may include a urinary flow rate and post-void residual estimation. Post-void residuals greater than 200ml may indicate a less favourable response to treatment.

Urodynamic or Pressure flow studies provide the most complete means of determining the presence of outlet obstruction, but its use is optional. 7

A transrectal or abdominal ultrasound & cystoscopy is considered in assessing Prostate size, shape & morphology, which play an important role in decision-making for the treatment and differential diagnosis of male LUTS/BPH.

Role of PSA in BPH

PSA has a useful role in the assessment of LUTS by acting as a surrogate marker in benign disease for an enlarged prostate. The weight of evidence suggests that men with a PSA >1.4ng/ml should be considered at increased risk of disease progression of BPH. 8,9 A note of caution should remain that a PSA test cannot replace a DRE and should not be done in its absence.

The presence of BPH symptoms does not predispose to prostate carcinoma and therefore it is not essential in men with BPH unless an abnormal prostate is felt on DRE or the patient is specifically concerned about or has a family history of prostate carcinoma [10]. The NICE guidelines also recommend that a PSA test is offered only after full counselling. One must also exclude a UTI prior to a PSA test and not perform the test within a month of a proven UTI.

Approach To Treatment:

The aim of treating BPH with LUTS is to relieve symptoms and improve quality of life, as well as to attempt to prevent progression of disease and the development of complications.

These aims need to be balanced against the potential side-effects of treatment. Therefore, watchful waiting is an option recommended for many men.

Watchful waiting is the recommended strategy for patients with BPH who have mild symptoms (International Prostate Symptom Score ≤7) and for those with moderate-to-severe symptoms (IPSS score ≥8) who are not bothered by their symptoms and are not experiencing complications of BPH. In patients with mild symptoms, medical therapy is not likely to improve their quality of life. 11

These Patients may also benefit from behavioural and lifestyle modifications including reducing fluids at night, limiting caffeinated and alcoholic beverages, avoiding, or modifying the timing of diuretics or medications that increase urinary retention, and use of techniques to help control bladder symptoms.

Patients managed expectantly with watchful waiting are re-evaluated annually.

Conservative & Interventional Treatment:

In general, medical therapy is offered as first-line management for patients with moderate to severe symptoms of BPH who do not require surgery. 7

An alpha-blocker is considered as initial therapy for most patients and a 5-alpha reductase inhibitor can be added for those patients at risk of progression. 7

Patients are evaluated 4 to 12 weeks after starting medical therapy. Patients need to be assessed using the IPSS; further evaluation may include a post-void residual (PVR) and uroflowmetry. Modification in treatment is required where patients do not show improvement in symptoms and/or experience intolerable side effects.

Interventional therapy (e.g., Transurethral resection of prostate [TURP]) – For patients with moderate-to-severe LUTS and those who have developed acute urinary retention, or other complications of BPH.

TURP is accepted as the criterion standard for relieving bladder outlet obstruction (BOO) secondary to BPH. 11

In current clinical practice, most patients with BPH do not present with obvious surgical indications; instead, they often have milder lower urinary tract symptoms (LUTS) and, therefore, are initially treated with medical therapy. Several minimally invasive treatments for BOO are also available.

Counselling & patient education play important role in determining intervention, which can include behavioural/lifestyle modifications, medical therapy, and/or surgical options.

Summary:

BPH is hyperplasia of both epithelial and stromal prostatic components. A key characteristic of BPH is increased stromal: epithelial ratio. Prostatic hyperplasia can eventually result in bladder outlet obstruction. Obstruction has both a static component due to increased volume of tissue, particularly in a transition zone, and a dynamic component due to increases in stromal smooth muscle tone. A large number of alpha-adrenergic receptors are present in the prostate capsule, stroma, and the bladder neck. The predominant alpha-1 receptor in prostatic stromal tissue is the alpha-1A receptor. Treatment of symptomatic BPH is mainly accomplished through relaxation of smooth muscle tone with alpha blockers and the reduction of the size of the glandular component following inhibition of the formation of dihydrotestosterone by 5-alpha-reductase inhibitors.

Select surgical intervention (e.g., transurethral resection) alleviate symptoms of urinary obstruction by reduction of prostatic bulk. 12

References:

1. Berry SJ, Coffey DS, Walsh PC, et al. The development of human benign prostatic hyperplasia with age. J Urol. 1984 Sep;132(3):474-9.
2. Lee SW, Chan EM, Lai YK. The global burden of lower urinary tract symptoms suggestive of benign prostatic hyperplasia: a systematic review and meta-analysis. Sci Rep. 2017 Aug 11;7(1):7984.
3. D’Ancona C, Haylen B, Oelke M, et al. The International Continence Society (ICS) report on the terminology for adult male lower urinary tract and pelvic floor symptoms and dysfunction. Neurourol Urodyn. 2019 Feb;38(2):433-77.
4. Masumori N, Tsukamoto T, Kumamoto Y, et al. Japanese men have smaller prostate volumes but comparable urinary flow rates relative to American men: results of community-based studies in 2 countries. J Urol. 1996 Apr;155(4):1324-7.
5. Isaacs JT, Coffey DS. Etiology and disease process of benign prostatic hyperplasia. Prostate. 1989;15(S2):33- 50.
6. Nickel JC, Aaron L, Barkin J, et al. Canadian Urological Association guideline on male lower urinary tract symptoms/benign prostatic hyperplasia (MLUTS/BPH): 2018 update. Can Urol Assoc J. 2018 Oct;12(10):303-12.
7. Lerner LB, McVary KT, Barry MJ et al. Management of lower urinary tract symptoms attributed to benign prostatic hyperplasia: AUA guideline. 2021 [internet publication].
8. Bartsch G, Fitzpatrick JM, Schalken JA et al. BJU Int 2004; 93 Suppl 1: 27-
9. Roehrborn CG, McConnell J, Bonilla J et al. J Urol 2000; 163: 13-20.
10. Hewitson P, Austoker J. BJU Int 2005; 95 Suppl 3: 16-32
11. [Guideline] Parsons JK, Dahm P, Köhler TS, Lerner LB, Wilt TJ. Surgical Management of Lower Urinary Tract Symptoms Attributed to Benign Prostatic Hyperplasia: AUA Guideline Amendment 2020. J Urol. 2020 Oct. 204 (4):799-804.
12. Patel AK, Chapple CR. Benign prostatic hyperplasia: treatment in primary care. BMJ. 2006 Sep 9;333(7567):535-9.

Read the Latest Magazine: HPN June 2022

Read our Latest News