Table 1.
Characteristic and primary findings of the presented studies
| Reference | Design | No. of patients | Tumours (NMIBC) |
BCG course | Analysed cell population | Assay* | PD-L1 positivity threshold, % | Pre-treatment positive PD-L1 expression, % | Findings |
|---|---|---|---|---|---|---|---|---|---|
| Martínez et al., [6] | R | 22 | T1 high-grade | Induction and maintenance | TCs, tumour infiltrating ICs | SP142 | ≥1 | TCs: 9 ICs: 77 |
No significant difference in the expression pattern of PD-L1 was identified between the BCG responders and BCG non-respondersa. |
| Delcourt et al., [7] | R | 186 | High-risk | Induction | TCs, tumour infiltrating ICs | E1L3 N | ≥1 | TCs: 18.1 ICs: 58.1 |
Early recurrenceb was not significantly more frequent in the PD-L1-positive patients vs the PD-L1-negative patients. PD-L1 expression was significantly increased on ICs after BCG therapy. |
| Kates et al., [8] | R | 63 | High-risk | Induction | TCs, tumour infiltrating ICs | SP142, 22C3 | ≥5 | CPS: SP-142: 25 22C3: 28 |
PD-L1 was significantly increased in the pre-treatment samples collected from BCG non-respondersb vs BCG responders. BCG treatment did not increase PD-L1 expression. |
| Aydin et al. [9] | R | 117 | High grade | At least induction | TCs, tumour infiltrating ICs | SP142 | ≥1 | TCs: 8.5 ICs: 77 |
Positive pre-treatment PD-L1 expression (on ICs) was significantly associated with refractory tumour recurrencec but not with relapsing recurrencec and progressionc. RFS and PFS did not correlate with positive PD-L1 expression. Post-treatment PD-L1 expression levels on ICs were significantly decreased in patients who had refractory recurrence. |
| Pierconti et al., [10] | R | 60 | Primary CIS | At least induction | TCs, tumour infiltrating ICs | SP263, 22C3, SP142 | Low (0–5) High (>5) | TCs: 16.7 ICs: 38.3 |
PD-L1 expression on TCs and on ICs was higher in BCG-unresponsivec patients vs BCG responders, but only the PD-L1 22C3 expression in TCs was associated with recurrence of disease. |
CPS, combined positivity score; R, retrospective.
* In all studies PD-L1 expression was evaluated by IHC.
aDefined as patients without a recurrence or progression based on follow-up cystoscopy and urinary cytology ≥30 months after BCG treatment initiation.
bDefined by IBCG and GU ASCO definitions
cDefined according to criteria specified in EAU Guidelines,