Neoadjuvant cisplatin-based chemotherapy in nonmetastatic muscle-invasive bladder cancer: A systematic review and pooled meta-analysis to determine the preferred regimen

OBJECTIVE

To determine whether neoadjuvant gemcitabine and cisplatin (GC) versus dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin (ddMVAC) before radical cystectomy improves overall survival (OS), progression-free survival (PFS), and pathologic complete response (pCR) for patients with muscle-invasive bladder cancer (MIBC) with secondary analyses of pathological downstaging and toxicity.

MATERIALS AND METHODS

This systematic review and meta-analysis identified studies of patients with MIBC treated with neoadjuvant GC compared to ddMVAC from PubMed, Web of Science, and EMBASE. Random-effect models for pooled log-transformed hazard ratios (HR) for OS and PFS and pooled odds ratios (OR) for pCR and downstaging were developed using the generic inverse variance method and Mantel-Haenszel method, respectively.

RESULTS

Ten studies were identified (4 OS, 2 PFS, and 6 pCR clinical endpoints). Neoadjuvant ddMVAC improved OS (HR 0.71 [95% CI 0.56; 0.90]), PFS (HR 0.76 [95% CI 0.60; 0.97]), and pathological downstaging (OR 1.34 [95% confidence interval 1.01; 1.78]) as compared to GC. There was no significant difference between regimens for pCR rates (odds ratio 1.38 [95% confidence interval 0.90; 2.12]). Treatment toxicity was greater with ddMVAC. Limitations result from differences in number of ddMVAC cycles and patient selection between studies.

CONCLUSIONS

Neoadjuvant ddMVAC is associated with improved overall survival and progression-free survival versus gemcitabine/cisplatin for patients with muscle-invasive bladder cancer prior to radical cystectomy. Although rates of pathological complete response were not significantly different, pathological downstaging correlated with overall survival. Dose-dense MVAC should be preferred over gemcitabine/cisplatin for patients with muscle-invasive bladder cancer who can tolerate its greater toxicity.

Outcomes of Second-Line Therapies in Patients With Metastatic de Novo and Treatment-Emergent Neuroendocrine Prostate Cancer: A Multi-Institutional Study

BACKGROUND

De novo neuroendocrine prostate cancer (NEPC) and treatment-emergent neuroendocrine prostate cancer (T-NEPC) are rare diseases with a poor prognosis. After first-line platinum chemotherapy, there is no consensus on second-line treatments.

PATIENTS AND METHODS

Patients with a pathologic diagnosis of de novo NEPC or T-NEPC between 2000 and 2020 who received first-line platinum and any second-line systemic therapy were selected and standardized clinical data was collected via the electronic health record at each institution. The primary endpoint was overall survival (OS) based on second-line therapy. Secondary endpoints included objective response rate (ORR) to second-line therapy, PSA response, and time on treatment.

RESULTS

Fifty-eight patients (32 de novo NEPC, 26 T-NEPC) from 8 institutions were included. At de novo NEPC or T-NEPC diagnosis, the overall cohort had a median age of 65.0 years (IQR 59.2-70.3) and median PSA of 3.0 ng/dL (IQR 0.6-17.9). Following first-line platinum chemotherapy, 21 patients (36.2%) received platinum chemotherapy, 10 (17.2%) taxane monotherapy, 11 (19.0%) immunotherapy, 10 (17.2%) other chemotherapy, and 6 (16.2%) other systemic therapy. Among 41 evaluable patients, the ORR was 23.5%. The mOS after start of second-line therapy was 7.4 months (95% CI 6.1-11.9).

CONCLUSIONS

In this retrospective study, patients with de novo NEPC or T-NEPC who received second-line therapy were treated with wide variety of treatment regimens, reflecting the lack of consensus in this setting. Most patients received chemotherapy-based treatments. Overall prognosis was poor and ORR was low in the second line regardless of treatment choice.

Effectiveness and durability of benefit of mTOR inhibitors in a real-world cohort of patients with metastatic prostate cancer and PI3K pathway alterations

BACKGROUND

Alterations in the PTEN/PI3K/AKT/mTOR pathway are prevalent in prostate cancer. In this retrospective study, we evaluated the clinical effectiveness of mTOR inhibitors (mTORi) in patients with metastatic prostate cancer (mPCA) and tissue assessed phosphatidyl-3-inositol kinase (PI3K) pathway alterations.

METHODS

This study used a nationwide (US-based) de-identified PCA clinico-genomic database, originating from approximately 280 US cancer clinics (~800 sites of care). We evaluated treatment data for patients with PCA from October 2014 to February 2020. In a cohort of 2301 PCA patients with 7208 evaluable treatment lines, we selected 17 mPCA patients (2 hormone-sensitive, 15 castrate-resistant) with tissue assessed PI3K pathway alterations by comprehensive genomic profiling who received mTORi treatment.

RESULTS

Patients had a median age of 72 years (IQR 68.0, 76.0) and were heavily pretreated with a median 3 lines of therapy prior to mTORi use (range 0-6). The PI3K pathway alterations included PTENdel (10 patients, 58.8%), AKT1mut (4 patients, 23.5%), PTENmut (2 patients, 11.8%), and dual PTENmut and PIK3CAmut (1 patient, 5.9%). Most (15 patients, 88.2%) were treated with everolimus monotherapy. Among 10 patients with on treatment PSA available, 2 patients had a PSA decrease ≥10% at week 12 and 5 patients overall had a subsequent PSA decrease. For those on mTORi, the median time to next treatment was 3.62 months (range 0, 8.52).

CONCLUSIONS

In this small cohort of mPCA patients with tissue assessed PI3K pathway alterations, mTORi therapy was not effective with few PSA responses and short duration of therapy.