Physician use of perioperative chemotherapy (POC) for muscle-invasive bladder cancer (MIBC) increased by 35% from 2006 to 2010, following the 2003 landmark SWOG-8710 trial favoring the treatment. The shift was driven mainly by neoadjuvant chemotherapy administration, which almost doubled. Adjuvant chemotherapy usage changed little.
“Although a rising trend in guideline adherence is reassuring, the optimal rate of POC administration for MIBC is not known,” stated the researchers led by Zachary D. Reardon, MD, of Vanderbilt University Medical Center in Nashville. “In an era where physicians are subject to performance measures contingent on both quality-of-care metrics and patient outcomes, reconciliation of guideline adherence, patient selection, and execution of appropriate therapy in the setting of MIBC will become increasingly complex. It is clear that shared decision making between individual patients and physicians as well as a risk-stratified approach to the administration of POC will optimize outcomes.”
For the study, the investigators analyzed data on 5,692 patients from the National Cancer Database with no prior malignancy who ultimately underwent radical cystectomy for stage 2 MIBC or greater without node involvement or metastases.
POC administration increased significantly from 29.5% of cases in 2006 to 39.8% of cases in 2010, according to results published in European Urology. Neoadjuvant chemotherapy usage rose from 10.1% to 20.8% over the same period. Adjuvant chemotherapy use remained stable between 18.1% and 21.3%.
Increasing age beyond 59 years was negatively associated with POC receipt. Comorbidities were another factor. For example, prior analyses show that 30% to 50% of patients with MIBC are ineligible for standard chemotherapy due to poor performance status and impaired renal function.
The researchers also confirmed several other nonclinical patient factors associated with lack of chemotherapy, including no insurance, residing outside the northeastern United States, and increasing distance from treatment facilities. By contrast, increasing income above $35,000 a year predicted a greater likelihood of chemotherapy receipt.
“Certainly, the significant toxicities noted in the standard methotrexate, vinblastine, doxorubicin, cisplatin regimen used in the SWOG-8710 trial tempered enthusiasm for the ubiquitous use of [neoadjuvant chemotherapy],” the researchers added. Claims data have shown considerable declines in methotrexate and vinblastine use coupled with increased administration of paclitaxel, gemcitabine, and carboplatin since the mid-1990s due to their more favorable toxicity profiles.