Table 1. General characteristics of the included studies (n=12).

First author (year)	Country	Study design	Aims	Participants		Sample size (n)
				Inclusion criteria	Exclusion criteria
Mohile (2007) [34]	USA	Cross-sectional study	To identify the prevalence of geriatric impairment in older patients with PC who were receiving ADT and evaluate the validity and reliability of the VES-13 compared with the CGA	- Having started ADT for a rising PSA level after local therapy, or asymptomatic, metastatic disease	- Severe cognitive impairment (SPMSQ: 5 errors)	50
				- Age ≥70 years	- Less than an 8th-grade education
					- Did not have a medical proxy for medical decision making
Bylow (2011) [35]	USA	Case-control prospective study	To examine the impact of ADT to frailty, objective physical performance, and falls in older PC patients with BCR.	- Diagnosis of PC	- Known diagnosis of dementia	134
				- Age ≥60 years			- Case: 63
					- Taking medications for dementia		- Control: 71
Cheung (2016) [20]	Australia	Case-control prospective study	To explore the relationships between insulin resistance and frailty with body composition and testosterone in ADT group and not in ADT group	- Diagnosis of localized non-metastatic PC	- Androgen deficiency	63
					- Significant renal, liver, cardiac, or neuromuscular disease		- Case: 34
				- No prior ADT			- Control: 29
				- Unrestricted activity with a normal ECOG performance statusa of 0
Mareschal (2017) [33]	Swiss	Quasi-Experimental study	To evaluate the effect of a multidisciplinary intervention program on QOL, the body composition, physical and psychological status of frail patients diagnosed with PC who received ADT combined to RT	- Diagnosis of non-metastatic locally advanced PC or aggressive intermediate disease treated with ADT and EBRT	- Expected survival <16 weeks	35
					- Incapacity for discernment
					- Judgment of the radiation oncologist expert in PC
				- Age ≥75 years and/or presenting with at least one out of the following functional or physiological frailty criteria (cardiovascular/pulmonary comorbidities with CCI≥3, VES-13≥3, balance unipedal stance test <5 seconds)
Winters-Stone (2017) [7]	USA	Cross-sectional study	To identify the relationship of ADT and frailty as well as frailty	Diagnosis of PC within the last 10 years (2005–2015)	N/A	280
Cheung (2018) [36]	Australia	Case-control prospective study	To identify gains in fat mass and loss of muscle mass improve after cessation of ADT and to compare insulin resistance, frailty, handgrip strength, and QOL of PC patients with ADT with non-ADT	- Diagnosis of localized non-metastatic PC	- Androgen deficiency (baseline total testosterone<10 nmol/L)	63
							- Case: 34
				- ADT-naïve			- Control: 29
				- ECOG performance statusa of 0	- Neuromuscular disease
				- Independently living in the community	- Limitation in their exercise tolerance
					- Active cardiac, respiratory, or joint disease
					- Requirements for a walking aid
Navarro-Martínez (2019) [39]	Spain	Case-control prospective study	To explore the contribution of peripheral inflammation in frailty syndrome in patients with PC receiving ADT	- Diagnosis of PC	- Severe cognitive impairment (MMSE score<21), severe psychiatric disorders	92
				- Prescription of ADT			- Case: 46
							- Control: 46
					- Blindness
					- Acute infections
Buigues (2020) [38]	Spain	Prospective observational study	To determine the relationship between progression (1 year follow up) of frailty syndrome and inflammatory markers	- Diagnosis of PC	- Severe cognitive impairment (MMSE score<21), severe psychiatric disorders	39
				- Prescription of ADT
					- Blindness
					- Acute infections
Couderc (2020) [27]	France	Prospective observational study	To examine the prevalence of sarcopenia in older PC patients before initiation of ADT and RT and identify the impact of ADT on the occurrence or aggravation of sarcopenia in this population	- Age ≥70 years	N/A	31
				- Referred for a CGA before initiation of ADT and RT for a localized or locally advanced PC
Momota (2020) [37]	Japan	Prospective observational study	To explore the relationship between frailty and RARP, radiotherapy, ADT alone, and metastatic diseases	- Localized PC patients treated by RARP, RT, or ADT-alone depending on eligibility for surgery or patient preference	- Not applicable for frailty evaluation using the G8	540
					- Insufficient treatment information
				- Metastatic PC patients with mHNPC or mCRPC were given a SOC treatment
Hamaya (2021) [40]	Japan	Retrospective study	To compare G8 with QOL scores between the localized diseases (M0 group) and mCSPC and examine the association of G8 and QOL scores in each group and the effect of frailty on worse QOL	- Diagnosis of Localized PC or mCSPC	N/A	409
				- Fulfilled frailty screening and HRQOL questionnaires with untreated status			- M0 group: 369
							- mCSPC: 40
Inglis (2021) [32]	USA	RCT	To evaluate the impact of vitamin D supplementation in a dose-dependent way on phase angle and physical function in PC patients receiving ADT	- Age ≥60 years	- Adequate vitamin D levels	59
				- Diagnosis of PC with no bone metastases	- Hypercalcemia, osteoporosis, stage IV kidney disease, or myocardial infarction within the past year		- Experimental: 29
							- Control: 30
				- Being within 6 months of starting ADT with an additional six more months planned
				- Suboptimal vitamin D levels (<32 ng/mL)
				- Total serum calcium ≤10.5 mg/dL
				- No contraindications for fitness testing

PC: prostate cancer, ADT: androgen deprivation therapy, VES: vulnerable elders survey, CGA: comprehensive geriatric assessment; PSA: prostate specific antigen; SPMSQ: short portable mental status questionnaire, BCR: biochemical recurrence, QOL: quality of life, EBRT: external beam radiotherapy, CCI: charlson comorbidity index, N/A: not applicable, MMSE: mini-mental state examination, RT: radiotherapy, RARP: robot assisted radical prostatectomy, mHNPC: metastatic hormone-naïve prostate cancer, mCRPC: metastatic castration-resistant prostate cancer, SOC: standard of care, G8: geriatric 8 screening tool, mCSPC: metastatic castration-sensitive prostate cancer, HRQOL: health related quality of life, M0: localized prostate cancer, RCT: randomized controlled trial.

^aECOG performance status: a scale for evaluating a person’s level of ability to care for oneself, daily activity, and physical ability.