Salvage systemic therapy for advanced urothelial carcinoma: on the cusp of a sea change?

Association of tumour microRNA profiling with outcomes in patients with advanced urothelial carcinoma receiving first-line platinum-based chemotherapy

Background:

Tumour expression of selected microRNAs (miRs) correlates with cisplatin efficacy in multiple cancers. We investigated the role of selected miRs in patients receiving cisplatin-based therapy for advanced urothelial carcinoma (UC).

Methods:

RNA was extracted from formalin-fixed paraffin-embedded tumour from 83 advanced UC patients who received cisplatin. A miR panel based on relevance for platinum sensitivity and UC was studied by quantitative reverse transcription quantitative PCR (RT–qPCR). Association of progression-free survival (PFS) with miR expression was analysed using cox regression. Selected TFs were chosen by association with the panel of miRs using the Transcription Regulation algorithm (GeneGo MetaCore+MetaDrug version 6.23 build 67496). Bladder cancer (BC) cell lines were used to investigate the previously described role of miR-21 mediating cisplatin sensitivity.

Results:

The 83 patients had a median PFS of 8 months. In multivariate analysis, higher levels of E2F1 (P=0.01, HR: 1.95 (1.14, 3.33)), miR-21 (P=0.01, HR: 2.01 (1.17, 3.45)) and miR-372 (P=0.05, HR: 1.70 (1.00, 2.89)) were associated with a shorter PFS. In the 8 BC cell lines, miR-21 was not shown to be necessary nor sufficient for modulating cisplatin sensitivity.

Conclusions:

In metastatic UC patients treated with cisplatin-based therapy, high primary tumour levels of E2F1, miR-21 and miR-372 are associated with poor PFS independent of clinical prognostic factors. The in vitro study could not confirm miR-21 levels role in modulating platinum sensitivity.

Single-agent Taxane Versus Taxane-containing Combination Chemotherapy as Salvage Therapy for Advanced Urothelial Carcinoma

BACKGROUND

Single-agent taxanes are commonly used as salvage systemic therapy for patients with advanced urothelial carcinoma (UC).

OBJECTIVE

To study the impact of combination chemotherapy delivering a taxane plus other chemotherapeutic agents compared with single-agent taxane as salvage therapy.

DESIGN, SETTING, AND PARTICIPANTS

Individual patient-level data from phase 2 trials of salvage systemic therapy were used.

INTERVENTIONS

Trials evaluating either single agents (paclitaxel or docetaxel) or combination chemotherapy (taxane plus one other chemotherapeutic agent or more) following prior platinum-based therapy were used.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Information regarding the known major baseline prognostic factors was required: time from prior chemotherapy, hemoglobin, performance status, albumin, and liver metastasis status. Cox proportional hazards regression was used to evaluate the association of prognostic factors and combination versus single-agent chemotherapy with overall survival (OS).

RESULTS AND LIMITATIONS

Data were available from eight trials including 370 patients; two trials (n=109) evaluated single-agent chemotherapy with docetaxel (n=72) and cremophor-free paclitaxel (n=37), and six trials (n=261) evaluated combination chemotherapy with gemcitabine-paclitaxel (two trials, with n=99 and n=24), paclitaxel-cyclophosphamide (n=32), paclitaxel-ifosfamide-nedaplatin (n=45), docetaxel-ifosfamide-cisplatin (n=26), and paclitaxel-epirubicin (n=35). On multivariable analysis after adjustment for baseline prognostic factors, combination chemotherapy was independently and significantly associated with improved OS (hazard ratio: 0.60; 95% confidence interval, 0.45-0.82; p=0.001). The retrospective design of this analysis and the trial-eligible population were inherent limitations.

CONCLUSIONS

Patients enrolled in trials of combination chemotherapy exhibited improved OS compared with patients enrolled in trials of single-agent chemotherapy as salvage therapy for advanced UC. Prospective randomized trials are required to validate a potential role for rational and tolerable combination chemotherapeutic regimens for the salvage therapy of advanced UC.

PATIENT SUMMARY

This retrospective study suggests that a combination of chemotherapy agents may extend survival compared with single-agent chemotherapy in selected patients with metastatic urothelial cancer progressing after prior chemotherapy.