Background: Pre-operative immune checkpoint blockade (ICB) with ipilimumab and nivolumab has shown encouraging pathological complete response (pCR) rates in stage III urothelial cancer (UC). A previous analysis of NABUCCO suggested that ipilimumab 3 mg/kg is more effective than ipilimumab 1 mg/kg. However, long-term progression-free and overall survival (PFS, OS) following pre-operative combination ICB are unknown. Methods: In NABUCCO, 54 patients received pre-operative ipilimumab plus nivolumab in different dosing regimens. PFS and OS were determined for the entire NABUCCO population and various clinically relevant subgroups. We explored ICB effects on the cellular composition of tumor-draining lymph nodes (tdLN) from ICB-treated patients (n = 5) and untreated or chemotherapy-treated patients (n = 5) using multiplex immunofluorescence for the PhenoCycler Fusion (Akoya). Results: With a median follow-up of 70 months, PFS and OS at 60 months were 67 % and 70 %, respectively, for the entire study. PFS and OS at 60 months were similar for patients with residual non-muscle invasive UC (NMIBC) and patients with a pCR. The presence of a nodal micrometastasis (<2 mm) after ICB, the development of grade ≥ 3 immune-related adverse events (irAE) and corticosteroids or antibiotics did not negatively impact survival. We observed smaller distances from CD20⁺ cells to CD14⁺ cells in tdLN following ICB compared to tdLN from untreated or chemotherapy-treated patients. Conclusions: Our data demonstrate a 5-year PFS of 67 % and OS of 70 % after pre-operative ICB in stage III UC. Survival was not impaired for patients with residual NMIBC, a nodal micrometastasis at resection, grade ≥ 3 irAE or corticosteroid use.

Purpose: In NABUCCO, the safety and efficacy of preoperative ipilimumab plus nivolumab were assessed in stage III urothelial cancer. Encouraging responses were achieved, and ipilimumab 3 mg/kg (ipilimumab-high) seemed more effective than ipilimumab 1 mg/kg (ipilimumab-low). We explored ipilimumab plus nivolumab response biomarkers and tumor microenvironment (TME) treatment dynamics. Patients and Methods: Baseline formalin-fixed, paraffinembedded tumor tissue was analyzed using PD-L1 IHC (n ¼ 51) and whole-exome and transcriptome sequencing (both n ¼ 53) and correlated with response. Baseline infiltration of CD8⁺ T cells (n ¼ 51) and at cystectomy (n ¼ 42) was examined. Single-cell RNA sequencing (scRNA-seq) of CD3⁺ T cells was conducted on on-treatment resection tissue of two responders to ipilimumab-high to explore the characteristics of CD8⁺ T cells within the TME. Results: High tumor mutational burden and PD-L1 positivity were associated with response to ipilimumab plus nivolumab. Nonresponding patients exhibited increased expression of a TGFβ signature. We observed increased transcription of the g2m checkpoint and e2f target in responders to ipilimumab-high and enhanced transcription of IFN-α and IFN-γ hallmarks in responders to ipilimumab-low. CD8⁺TCF7⁺ T cells accumulated in the TME of responders to ipilimumab-high. scRNA-seq of CD8A⁺TCF7⁺ T cells demonstrated enhanced expression of IL7R, CCR7, GPR15, XCL1, SELL, and LEF1. Conclusions: Our data indicate that tumor mutational burden, PD-L1, and TGFβ are potential biomarkers for response to ipilimumab plus nivolumab in stage III urothelial cancer. An inflammatory TME might be relevant for responding to ipilimumab-low. We found that in responders to ipilimumabhigh, TCF7⁺CD8⁺ T cells accumulated in the TME. scRNA-seq in two responders suggested that TCF7⁺CD8A⁺ T cells express genes associated with immunologic memory formation and T-cell homing.

Immune checkpoint inhibitors (ICI) can achieve remarkable responses in urothelial cancer (UC), which may depend on tumor microenvironment (TME) characteristics. However, the relationship between the TME, usually characterized by immune cell density, and response to ICI is unclear. Here, we quantify the TME immune cell densities and spatial relationships (SRs) of 24 baseline UC samples, obtained before pre-operative combination ICI treatment, using multiplex immunofluorescence. We describe SRs by approximating the first nearest-neighbor distance distribution with a Weibull distribution and evaluate the association between TME metrics and ipilimumab+nivolumab response. Immune cell density does not discriminate between response groups. However, the Weibull SR metrics of CD8⁺ T cells or macrophages to their closest cancer cell positively associate with response. CD8⁺ T cells close to B cells are characteristic of non-response. We validate our SR response associations in a combination ICI cohort of head and neck tumors. Our data confirm that SRs, in contrast to density metrics, are strong biomarkers of response to pre-operative combination ICIs.

Cisplatin-based neoadjuvant chemotherapy (NAC) followed by radical cystectomy is recommended for patients with muscle-invasive bladder cancer (MIBC). It has been shown that somatic deleterious mutations in ERCC2, gain-of-function mutations in ERBB2, and alterations in ATM, RB1, and FANCC are correlated with pathological response to NAC in MIBC. The objective of this study was to validate these genomic biomarkers in pretreatment transurethral resection material from an independent retrospective cohort of 165 patients with MIBC who subsequently underwent NAC and radical surgery. Patients with ypT0/Tis/Ta/T1N0 disease after surgery were defined as responders. Somatic deleterious mutations in ERCC2 were found in nine of 68 (13%) evaluable responders and two of 95 (2%) evaluable nonresponders (p = 0.009; FDR = 0.03). No correlation was observed between response and alterations in ERBB2 or in ATM, RB1, or FANCC alone or in combination. In an exploratory analysis, no additional genomic alterations discriminated between responders and nonresponders to NAC. No further associations were identified between the aforementioned biomarkers and pathological complete response (ypT0N0) after surgery. In conclusion, we observed a positive association between deleterious mutations in ERCC2 and pathological response to NAC, but not overall survival or recurrence-free survival. Other previously reported genomic biomarkers were not validated. Patient summary: It is currently unknown which patients will respond to chemotherapy before definitive surgery for bladder cancer. Previous studies described several gene mutations in bladder cancer that correlated with chemotherapy response. This study confirmed that patients with bladder cancer with a mutation in the ERCC2 gene often respond to chemotherapy.

The authors regret that the following statement regarding author contributions was missed: Kristan van der Vos is currently a Scientific Editor for Cell Reports Medicine, which is published by Elsevier. Dr van der Vos was not involved in the peer-review process or editorial discussions about this manuscript. The authors would like to apologise for any inconvenience caused.

PURPOSE: Patients with postpartum breast cancer diagnosed after cessation of breastfeeding (postweaning, PP-BCPW) have a particularly poor prognosis compared with patients diagnosed during lactation (PP-BCDL), or to pregnant (Pr-BC) and nulliparous (NP-BC) patients, regardless of standard prognostic characteristics. Animal studies point to a role of the involution process in stimulation of tumor growth in the mammary gland. However, in women, the molecular mechanisms that underlie this poor prognosis of patients with PP-BCPW remain vastly underexplored, due to of lack of adequate patient numbers and outcome data. EXPERIMENTAL DESIGN: We explored whether distinct prognostic features, common to all breast cancer molecular subtypes, exist in postpartum tumor tissue. Using detailed breastfeeding data, we delineated the postweaning period in PP-BC as a surrogate for mammary gland involution and performed whole transcriptome sequencing, immunohistochemical, and (multiplex) immunofluorescent analyses on tumor tissue of patients with PP-BCPW, PP-BCDL, Pr-BC, and NP-BC. RESULTS: We found that patients with PP-BCPW having a low expression level of an immunoglobulin gene signature, but high infiltration of plasma B cells, have an increased risk for metastasis and death. Although PP-BCPW tumor tissue was also characterized by an increase in CD8+ cytotoxic T cells and reduced distance among these cell types, these parameters were not associated with differential clinical outcomes among groups. CONCLUSIONS: These data point to the importance of plasma B cells in the postweaning mammary tumor microenvironment regarding the poor prognosis of PP-BCPW patients. Future prospective and in-depth research needs to further explore the role of B-cell immunobiology in this specific group of young patients with breast cancer.