Survival rates with external beam radiation therapy in newly diagnosed elderly metastatic prostate cancer patients

Abstract

Background: The survival benefit of primary external beam radiation therapy (EBRT) has never been formally tested in elderly men who were newly diagnosed with metastatic prostate cancer (mPCa). We hypothesized that elderly patients may not benefit of EBRT to the extent as younger newly diagnosed mPCa patients, due to shorter life expectancy.Methods: We relied on Surveillance, Epidemiology and End Results (2004-2016) to identify elderly newly diagnosed mPCa patients, aged >75 years. Kaplan-Meier, univariable and multivariable Cox regression models, as well as Competing Risks Regression models tested the effect of EBRT versus no EBRT on overall mortality (OM) and cancer-specific mortality (CSM).Results: Of 6556 patients, 1105 received EBRT (16.9%). M1b stage was predominant in both EBRT (n = 823; 74.5%) and no EBRT (n = 3908; 71.7%, p = 0.06) groups, followed by M1c (n = 211; 19.1% vs. n = 1042; 19.1%, p = 1) and M1a (n = 29; 2.6% vs. n = 268; 4.9%, p < 0.01). Median overall survival (OS) was 23 months for EBRT and 23 months for no EBRT (hazard ratio [HR]: 0.97, p = 0.6). Similarly, median cancer-specific survival (CSS) was 29 months for EBRT versus 30 months for no EBRT (HR: 1.04, p = 0.4). After additional multivariable adjustment, EBRT was not associated with lower OM or lower CSM in the entire cohort, as well as after stratification for M1b and M1c substages. Conclusions:In elderly men who were newly diagnosed with mPCa, EBRT does not affect OS or CSS. In consequence, our findings question the added value of local EBRT in elderly newly diagnosed mPCa patients.

Rates of metastatic prostate cancer in newly diagnosed patients: Numbers needed to image according to risk level

“…Third, our analyses regarding subtypes of distant metastases revealed the highest prevalence when bone metastases (M1 b ) were considered: 3.8%. This proportion accounted for 78% (6971/8920) of all distant metastases (M1 a–c ), in accordance with other studies 5,10–13 . Specifically, M1 b substage was identified in 4.1% and 17.1% of high and very high‐risk PCa patients.…”

Influence of frailty and specific comorbidities on oncological outcomes in metastatic hormone-sensitive and castration resistant prostate cancer

“…Similarly, prior other cancer diagnosis or cardiovascular diseases (CVD) have been exclusion criteria for current practicing-changing phase III trials (12). Therefore, most evidence in frail, elderly or mHSPC/mCRPC patients with severe comorbidities are small numbered retrospective or epidemiological data (13)(14)(15)(16)(17).…”

Don't throw the baby out with the bath water

“…Use of PSMA PET-CT for primary staging results in substantial up-staging including 14.7% to N1% and 6.4% to M1 disease in one study. 7 The current study by Wenzel et al 1 appropriately behoves radiation oncologists to select elderly patients judiciously for local radiotherapy as per the evidence from the STAMPEDE trial as well as other factors including performance status, comorbidities, depth of response to systemic treatment; and of course, patient expectations. However, a return to the days of fixed (and un-fixable) pelvic recurrences in castrate-resistant men who were denied treatment to the primary (while hormone-sensitive) is unacceptable.…”