Posted: Monday, February 28, 2022
Co-expression extrapolation (COXEN), a gene-expression model, was used to predict response to chemotherapy regimens in patients with muscle-invasive bladder cancer. For patients receiving platinum-based neoadjuvant treatment, the COXEN gemcitabine/cisplatin (COXEN GC) score showed some value in predicting survival. Thomas W. Flaig, MD, of the University of Colorado Cancer Center in Aurora, and colleagues presented these findings at the 2022 American Society of Clinical Oncology (ASCO) Genitourinary Cancers (GU) Symposium (Abstract 536).
This study enrolled 237 patients with stage T2 to T4 urothelial bladder cancer who were eligible for cisplatin and intended to undergo cystectomy. Patients were randomly assigned to receive neoadjuvant therapy consisting of either gemcitabine and cisplatin or dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC). MVAC was given every 14 days for four total cycles, and gemcitabine/cisplatin was given every 21 days for four cycles. A treatment-specific COXEN test was used for each of the two therapies to predict response to therapy (COXEN GC and COXEN MVAC).
There were 167 patients in this cohort who were included in the primary COXEN analysis. These patients had either undergone at least three cycles of chemotherapy and surgery within 100 days of their last chemotherapy dose or had disease progression while receiving chemotherapy. There was no significant association found between the COXEN GC score and overall survival or progression-free survival among the group receiving gemcitabine and cisplatin. The same was true for the COXEN MVAC scores in the MVAC group. When the investigators were looking at COXEN GC scores for both treatment groups combined, the COXEN GC score was a significant predictor of overall survival (hazard ratio = 0.45).
“The randomized, prospective design provides estimates of [overall survival] and [progression-free survival] for gemcitabine/cisplatin and [dose-dense] MVAC that appear comparable, but this phase II trial is underpowered for definitive comparisons,” noted the authors.
Disclosure: For a full list of authors’ disclosures, visit coi.asco.org.