Baseline Characteristics of Patients
In this prospective single-center diagnostic study, 279 subjects with a median age of 71 years [interquartile range (IQR): 62–80] and median PSA of 10.04 ng/mL (IQR: 6.38–18.00) were enrolled from January 2017 to December 2020 irrespective of the biopsy history. Abnormal DRE was found in 74 men (26.52%). The patients’ demographics are given in Table 1.
Table 1
Patients’ baseline characteristics, TRUS findings and MRI findings.
Men, no.
|
279
|
Age, yr (IQR)
|
71 (65-77)
|
PSA, ng/mL (IQR)
|
10.04 (6.38-18.00)
|
Suspicious DRE findings, n (%)
|
74 (26.52)
|
TRUS prostate volume, mL (IQR)
|
57.00 (41.00-82.30)
|
Men with prior biopsy, n (%)
|
89 (31.90)
|
Men without biopsy history, n(%)
|
190 (68.10)
|
Abnormal TRUS findings, n (%)
|
139 (49.82)
|
Urologists’ biopsy experience, yr (IQR)
|
4 (4-5)
|
MRI suspicious lesions per patient, no. (IQR)
|
1 (1-1)
|
Total lesions, no.
|
353
|
PIRADS v2 score, n (%)
|
|
3
|
113 (32.01)
|
4
|
169 (47.88)
|
5
|
71 (20.11)
|
Location
|
|
Peripheral zone, n (%)
|
232 (65.72)
|
Transitional zone, n (%)
|
121 (34.28)
|
Values are presented as median (interquartile range [IQR]). Statistically significant at P<0.05. TRUS = transrectal ultrasound; MRI = magnetic resonance imaging; PSA = prostate-specific antigen; DRE = digital rectal examination; PIRADS = Prostate Imaging Reporting and Data System. |
Biopsy Cores
The median core of SB, TB, ipsi-SB + TB, and contra-SB + TB was 10, 2, 7, and 7, respectively; they all differed significantly from SB + TB (12, P < 0.001) (Table 2). Obviously, TB showed the best detection of csPCa for the total number of cores regardless of the definition (P < 0.001) and SB performed the worst (P < 0.001). A comparison of the csPCa positive core rates of ipsi-SB + TB and contra-SB + TB revealed that the former performed better irrespective of the definition of csPCa (P < 0.001) (Table 2).
Table 2
|
SB
|
TB
|
ipsi-SB+TB
|
contra-SB+TB
|
SB+TB
|
Biopsy cores, no.
|
10 (10-10)
|
2 (2-2)
|
7 (7-7)
|
7 (7-7)
|
12 (12-12)
|
Positive biopsy cores, no.
|
1 (0-4)
|
0 (0-2)
|
2 (0-5)
|
2 (0-3)
|
2 (0-6)
|
D1 positive core rate, n (%)
|
373 (10.69)
|
230 (29.72)
|
509 (20.21)
|
324 (12.86)
|
603 (14.14)
|
P
|
<0.001
|
<0.001
|
<0.001
|
0.017
|
-
|
D2 positive core rate, n (%)
|
678 (19.43)
|
357 (46.12)
|
817 (32.43)
|
575 (22.83)
|
1035 (24.27)
|
P
|
<0.001
|
<0.001
|
<0.001
|
0.051
|
-
|
Values are presented as median (interquartile range). Statistically significant at P<0.05. SB=systematic biopsy; TB=targeted biopsy; ipsi-SB=ipsilateral SB; contra-SB=contralateral SB; D1= definition 1 (EAU guidelines); csPCa=clinically significant prostate cancer; D2= definition 2 (Epstein criteria). |
csPCa Detection Rates
In the whole cohort, 104,146 csPCa and 90,146 csPCa were detected by ipsi-SB + TB and contra-SB + TB, respectively, on the basis of D1 (P = 0.042) and D2 (P = 1.000). SB could detect more patients with csPCa than TB when used alone; however, the difference was insignificant on the grounds of D1 (D1: 82 vs. 80, P = 0.302; D2: 143 vs. 118, P = 0.002). Compared with SB + TB, each remaining method detected significantly fewer patients with csPCa regardless of the definition of csPCa (P < 0.001) except ipsi-SB+TB, which achieved almost the same csPCa detection rate as that of SB + TB based on D1 (P = 0.066) (Table 3).
Table 3
Detection rates of csPCa.
|
SB
|
TB
|
ipsi-SB+TB
|
contra-SB+TB
|
SB+TB
|
Detected D1 csPCa cases, n (%)
|
82 (29.39)
|
80 (28.67)
|
104 (37.28)
|
90 (32.26)
|
106 (37.99)
|
P
|
<0.001
|
<0.001
|
0.066
|
<0.001
|
-
|
Detected D2 csPCa cases, n (%)
|
143 (51.25)
|
118 (42.29)
|
146 (52.33)
|
146 (52.33)
|
161 (57.71)
|
P
|
<0.001
|
<0.001
|
<0.001
|
<0.001
|
-
|
Statistically significant at P<0.05. csPCa=clinically significant prostate cancer; SB=systematic biopsy; TB=targeted biopsy; ipsi-SB=ipsilateral SB; contra-SB=contralateral SB; D1= definition 1 (EAU guidelines); D2= definition 2 (Epstein criteria); GS= Gleason score. |
GS Distribution, Concordance, and Upgrading
The distribution of the GS on each biopsy method could be seen in Fig. 3. It is worth noting that the number of PCa with a GS of 6 detected by SB was more than that by TB (P < 0.001), but the number of PCa with a GS of ≥7 detected by both of them was almost equal (P = 0.311). ipsi-SB + TB identified the same number of PCa as that of contra-SB + TB (P = 1.000) but higher number of patients with a GS of ≥7 (P < 0.001) and fewer patients with a GS of 6 (P < 0.001).
ipsi-SB detected 92 patients with a higher GS, and 38 patients were still detected after combining with TB. Of the 38 patients, 9 had a GS of 6, 14 had a GS of ≤6 on contra-SB + TB to ≥3+4 on ipsi-SB + TB, and the remaining 15 were concordant patients (Fig. 4a). The upgrading of a patient from a GS of ≤6 in one biopsy method to higher than a GS of ≤6 in another was considered as insignificantly upgraded. A patient upgrading from a GS of ≤6 in one biopsy method to a GS of ≥3+4 in another was considered as significantly upgraded. A patient upgrading from a GS of ≥3+4 in one biopsy method to higher than a GS of ≥3+4 in another was considered concordant. Details of the 38 upgrading patients on ipsi-SB are summarized in Supplement Table 1.
In contrast, 17 subjects were identified with a higher GS on contra-SB compared with ipsi-SB, and only 10 additional upgrades occurred after combining with TB. Among them, eight patients had a GS of 6, one had a GS of 6 on ipsi-SB + TB to a GS of 8 on contra-SB + TB, and one had a GS of 9 on ipsi-SB + TB to a GS of 10 on contra-SB + TB (Fig. 4b). Details of the 10 upgrading patients on contra-SB are summarized in Supplement Table 2.
Potential Predictors of GS Upgrading on ipsi-SB + TB and contra-SB + TB
We evaluated the potential predictors of GS upgrading on ipsi-SB + TB and contra-SB + TB. For all 38 patients with a higher GS on ipsi-SB + TB, decreased TRUS prostate volume, prior biopsy history, lesion located in the peripheral zone (PZ), and higher PSA level were associated with GS upgrading. Among them, prior biopsy history had the strongest association with GS upgrading [odds ratio (OR): 2.365; P = 0.008] (Table 4). In the 14 significantly upgrading patients on ipsi-SB + TB, decreased TRUS prostate volume and lesion located in the PZ remained significant (Table 4).
Table 4
Associated predictors of Gleason score upgrading on ipsi-SB+TB.
|
|
38 upgrading
|
|
|
|
14 significantly upgrading
|
|
|
OR
|
95% CI
|
P value
|
|
OR
|
95% CI
|
P value
|
TRUS prostate volume
(per 10 volume)
|
0.970
|
0.950-0.990
|
0.004
|
|
0.980
|
0.950-1.012
|
0.022
|
Biopsy history
(yes or no)
|
2.365
|
0.903-6.192
|
0.008
|
|
-
|
-
|
-
|
Location
(PZ or TZ)
|
1.949
|
0.713-5.324
|
0.019
|
|
8.424
|
1.201-59.065
|
0.032
|
PSA
(per ng/mL)
|
1.001
|
0.999-1.004
|
0.028
|
|
-
|
-
|
-
|
Statistically significant at P<0.05. SB=systematic biopsy; TB=targeted biopsy; ipsi-SB=ipsilateral SB; OR = odds ratio; CI = confidence interval; TRUS = transrectal ultrasound; PZ= peripheral zone; TZ= transitional zone; PSA = prostate-specific antigen. |
Prior biopsy history (OR: 3.148; P = 0.021) and inadequate biopsy experience (OR: 0.701; P = 0.032) were associated with a GS of 10 upgrading on contra-SB + TB (Table 5).The basic characteristics of the only patient with significant upgrading on contra-SB + TB were as follows: age 82 years, PSA 30.24 ng/mL, DRE (+), TRUS prostate volume 66.9 mL, prior biopsy history, abnormal TRUS findings, urologists’ biopsy experience 5, MRI suspicious lesions 1, maximum PI-RADS 5, and lesion position PZ.
Table 5
Associated predictors of 10 Gleason score upgrading on contra-SB+TB.
|
OR
|
95% CI
|
P value
|
Biopsy history
(yes or no)
|
3.148
|
0.527-18.802
|
0.021
|
Urologists’ biopsy experience
(per yr)
|
0.701
|
0.349-1.409
|
0.032
|
Statistically significant at P<0.05. SB=systematic biopsy; TB=targeted biopsy; contra-SB=contralateral SB; OR = odds ratio; CI = confidence interval. |