Cancers of the genitourinary system
Prostate cancer is the most common non-skin cancer diagnosed in men. Risk factors include increasing age and, less commonly, a family history of the disease. By far the most common pathological subtype is adenocarcinoma; grading is by the Gleason system; numbered from 1-5 (from well differentiated glandular structures to anaplastic) and the scoring of the two most common histological growth patterns is added together, i.e. 4+3 = 7. Grading is a strong predictor of prognosis. PSA is not recommended as a screening test for asymptomatic men as it results in over-diagnosis of many cases where survival would not be altered.
When localised, prostate cancer can be cured by surgery or radiation, but “watchful waiting” (observation) is a realistic management option, particularly when patients are elderly or have other co-morbidities, or the discovered tumour is low grade.
In a proportion of men, prostate cancer recurs, sometimes years after definitive therapy. At that stage, androgen deprivation, bilateral orchidectomy or LHRH (Leutinising Hormone Releasing Hormones) agonists are usually the first treatment options entertained. This is not curative, however, and around 3 years later on average, men develop rising PSA levels again, denoting castrate-resistant disease. Treatment options at that stage include chemotherapy and newer hormonal drugs targeting androgen receptors and androgen scavenging pathways. Complications of androgen deprivation therapy include osteoporosis, lack of libido, mood changes and metabolic syndrome, amongst others. Complications of prostatic surgery and radiation include impotence, incontinence and proctitis.
More correctly called urothelial carcinoma because the epithelium lining the bladder, ureter and the renal pelvis is the same, “bladder cancer” increases in incidence with age, smoking and exposure to dyes. The most common presenting symptom is painless, frank haematuria. Patients presenting with haematuria require evaluation, including a cystoscopy. The large majority of bladder cancer is superficial, and can be managed by local surgical techniques (e.g. resection, fulguration), assisted with intravesical drug therapy such as instillation of chemotherapy or BCG to control the disease. There is a small but real risk of disease progression to muscle invasive disease. In this instance, cystectomy or radiotherapy can be considered. For muscle invasive disease requiring cystectomy, neo-adjuvant chemotherapy improves survival by 5%. Chemotherapy for metastatic disease improves survival and can help maintain quality of life.
Most kidney cancers are now diagnosed incidentally, from imaging performed for other reasons. Clear cell carcinoma is the most common subtype. The disease is often silent clinically until cancers reach a size large enough to cause problems (e.g. haematuria, pain, inferior vena cava infiltration) or after it metastasises. For small cancers in anatomically favourable locations (e.g. upper or lower pole of the kidney), resection is curative; however, loss of nephrons leading to long term renal impairment has shifted thinking and careful observation with regular CT scans is increasingly employed in these situations, since some renal cancers grow very slowly. The prognosis for patients with metastatic disease is variable but has increased dramatically in recent years with the introduction of tyrosine kinase inhibitors and other targeted therapies. Patients who have solitary metastases may be considered for resection.
Germ cell cancer
Typically presenting in young men as a lump in the testis, germ cell (reproductive cell) tumours include a wide variety of histological subtypes (e.g. embryonal carcinoma, teratoma, yolk sac tumour and seminoma).
Management of germ cell tumours generally follows that of pure seminoma or non-seminoma; each is similar, but not exactly the same. An inguinal orchidectomy is necessary for tissue diagnosis as well as management of the primary site. If there is no evidence of metastatic disease on staging investigations (CT chest abdomen pelvis, normalizing beta HCG, alpha fetoprotein and LDH), most patients are now placed on surveillance (clinical, markers and CT scans) with systemic chemotherapy reserved for recurrence with cure rates approaching 100% In the past, seminomas were managed by para-aortic radiation with the long term risk of second tumours.
In the setting of metastatic disease, combination chemotherapy can still cure over 90% of patients, suggesting exquisite sensitivity of germ cell tumours to chemotherapy.
Given the risk of interstitial lung disease from bleomycin, monitoring of lung function is important. It is better to avoid high-flow oxygen supplementation for some time; the duration of which is debatable.
Since the risk of infertility is high after chemotherapy, all men should be offered semen cryopreservation.