Prostate cancer complications may require palliative care, repeat intervention

Men with metastatic prostate cancer (mPCa) cancer present with morbidities and complications that are more common and debilitating than previously thought of, with some requiring immediate palliative treatments while others repeated intervention, according to a study from Singapore.

“With the incidence of mPCa likely to rise in tandem with an ageing world population and given the improving survivorship of patients with mPCa, both patients and clinicians alike will have to contend with significant morbidities during the course of the disease,” according to the investigators.

The present data show that factors such as prostate volume, baseline prostate-specific antigen (PSA), high volume bone metastasis, and poor Eastern Cooperative Oncology Group Performance (ECOG) performance status (PS) are prognostic of local obstructive urinary complications and skeletal fractures in mPCa, and that prompt “recognition of these predictive factors will guide clinicians in early detection that can lead to optimizing palliative treatment,” they added.

The analysis included 685 patients (median age at diagnosis, 73 years; 82.5 percent Chinese). At initial presentation, 82 (12.0 percent) had ECOG PS ≥2 while 480 (70.2 percent) had PSA levels >100 ng/mL. Most patients had distal metastasis to bone (85.4 percent). A total of 612 patients (89.3 percent) were symptomatic, with bone pain (81.2 percent), urinary obstruction (42.3 percent) and haematuria (27.0 percent) as the most common presentations. None of the patients progressed to metastatic disease after previous curative local treatments.

Local palliative treatments were needed in 237 patients (34.6 percent), among whom 88 (12.8 percent) presented with acute urinary retention. Another 23 patients (9.7 percent) required repetitive local palliative treatments. There were 118 patients (17.2 percent) who developed skeletal fractures. [BMJ Open 2020;10:e034331]

On multivariate analyses, PSA level >100 ng/mL (p=0.02) and prostate volume >50 g (p=0.03) predicted significant obstruction requiring palliative procedures. Prognostic factors for skeletal fractures included poor ECOG PS (p=0.01) and high-volume bone metastasis (p<0.01).

Overall, 653 (95.3 percent) patients received androgen deprivation therapy (ADT), with the median time to castrate resistance of 21.4 months. The median overall survival (OS) was 45 months, and prostate cancer mortality was 81.4 percent. OS improved from 41.6 months in 1995–1999 to 47.8 months in 2010–2014 (p<0.01).

“[O]ver these two decades, it was apparent that the incidence of de novo mPCa being referred to our institution had risen, from 129 (1999–2004) to 271 (2009–2014). This may reflect the changing referral patterns as our institution now represents the largest healthcare cluster within Singapore,” the investigators explained. “We hypothesized that improved health literacy may have translated to earlier health-seeking behaviours.”

Accordingly, better ADT compliance and initiation of chemotherapy in the treatment of advanced prostate cancer might have contributed to an increase in OS observed for over 20 years, they added.

Finally, prostate cancer patients at higher risks of developing skeletal fractures, should “be considered for routine baseline bone mass density screening, and earlier initiation of antiresorptive therapies might be beneficial in this particular subgroup,” the investigators said

The study had several limitations, including the absence of validated quality-of-life assessment tools, which may better reflect well-being, and the lack of data on the routine use of early systemic therapies in hormone-sensitive prostate cancer, which may affect the prevalence of local and systemic complications.