Comment on the paper entitled “high serum concentration of estradiol may be a risk factor of prostate enlargement in aging male in China”

Dear Editor,

With the great interest in the recent-online article entitled “High serum concentration of estradiol may be a risk factor of prostate enlargement in aging male in China”, we found some significant question that need to discuss [1].

The authors in the paper found that serum estradiol (E2) levels in the patients with larger prostate volume was also significantly high than these with smaller prostate volume [1]. As we know, E2 can promote prostatic proliferation in vitro study and animal experiment yet [2]. Nevertheless, the link between E2 and BPH in human-body study remain controversial. We reviewed some similar research reports and found most of studies do not support the opinion. All analogous results were shown in Table 1. Even, there was negative relationship between serum E2 levels and prostate volume [3,4]. It was possible due to the difference among race or measurement method in different comparative groups in these studies. According to the current evidence in human body involving the relationship between E2 and prostate volume, we consider that more high-quality, well-design study is needed to solve the issue.

Table 1. Comparison in E2 and prostate volume.

Study ID	Country	No. of patient (BPH/Control)	PV (ml) among different groups	Measurement assay of serum E2	Estradiol (larger/smaller PV) (pg/ml)	Statistic value	Is E2 related with PV?
Xu et al. [1]	China	168/71	>50/≤505	ELISA	177.78/147.71(pmol/l)	0.019	Positive correlation
Liao et al. [3]	Taiwan	258/247	≥20/<20	RA	35.3/43.3	<0.001^a	Negative correlation
Zhang et al. [4]	China	15/15	112.94/30.44	RA	40.46/63.47	0.0058^a	Negative correlation
Joseph et al. [5]	USA	369	–	ELISA	–	0.09^b	NO
Zeng et al. [6]	China	949	–	RA	–	0.0192^b	NO
Nukui et al. [7]	Japan	126/101	>25/≤25	ELISA	29.6/29.5	0.094	NO
Asiedu et al. [8]	Chana	30/30	99.3/–	ELISA	29.4/29.18	0.029^a	Positive correlation
Neuzillet et al. [9]	France	16/16	≥50/<50	GC-MS	26.2/28.7	0.35	NO

ELISA: enzyme-linked immunosorbent assay; E2: estradiol; PV: prostate volume; RA: radioimmunoassay.

^a p value from comparative analysis.

^b r value from spearman correlation statistics.

Disclosure statement

No potential conflict of interest was reported by the authors.