Bladder Cancer: improved survival with adjuvant chemotherapy

Bladder Cancer: improved survival with adjuvant chemotherapy

21 Jan 2016

Adjuvant chemotherapy following cystectomy was associated with improved overall survival compared with cystectomy alone in patients with locally advanced bladder cancer, according to a large observational study of patients in the National Cancer Database (NCDB).

Although radical cystectomy has the potential to cure patients with muscle-invasive bladder cancer, the disease metastasizes and proves fatal in about 50% of patients, lead author Matthew D. Galsky, MD, of Mount Sinai School of Medicine and Tisch Cancer Institute in New York City, and colleagues wrote. Despite the poor outcomes with surgery alone, perioperative chemotherapy is underutilized generally, and particularly in older patients.

Applicable findings to contemporary patients

The cohort included patients with bladder cancer treated from 2003 through 2006. Of those that met inclusion criteria, 51% were over age 70. Investigators noted that there have been no changes in adjuvant chemotherapy regimens commonly used since that time period, thus the findings remain applicable to contemporary patients. "These findings do provide added confidence that our older patients that are deemed sufficiently fit to proceed with chemotherapy derive benefit comparable to younger patients," Galsky commented.

Of 5,653 patients that met study inclusion criteria:

• 23% received adjuvant combination chemotherapy (those receiving monotherapy were excluded), which was initiated a median of 52 days (interquartile range 28 days) after surgery
• Median follow-up for patients in the adjuvant chemotherapy group was 6.8 years versus 6.7 years in the observation group.

Factors associated with adjuvant chemotherapy were identified. Patients who received this treatment were younger and more likely to have private insurance, live in areas with a higher median income and a higher percentage of high school -- educated residents, and have lymph node involvement and positive surgical margins.

Adjuvant chemotherapy was linked to improved overall survival

Stratified analyses indicated an improvement in overall survival with adjuvant chemotherapy. Subset analyses demonstrated the same positive effect of adjuvant chemotherapy on survival, and this was not affected by poor performance status.

In patients with pathologic T3-4 and/or pathologic node-positive bladder cancer after cystectomy, the 5-year overall survival rate was 37.0% among patients who received adjuvant chemotherapy compared with 29.1% for those who did not receive adjuvant chemotherapy, reported Galsky.

Study limitations

"Although neoadjuvant chemotherapy remains the preferred approach based on level I evidence, these data lend further support for the use of adjuvant chemotherapy in patients with locally advanced bladder cancer post-cystectomy who did not receive chemotherapy preoperatively," the authors wrote.

Potential issues concerning study limitations included:

• the lack of detailed information concerning specific combination adjuvant treatment regimens used (i.e., whether they were cisplatin-based, and at what dose or intensity);
• potential use of salvage therapy in the observation group; and
• the possibility that findings may have been biased due to missing data and/or variations in patient characteristics across treatment arms. Cancer recurrence and cancer-specific survival could not be assessed since these data are not captured in the NCDB.

Noting the existing "evidence gap" created by the lack of robust prospective data for adjuvant chemotherapy in bladder cancer, Galsky and colleagues suggested that their use of a large database that includes approximately 70% of all newly diagnosed cancer patients in the U.S. offers an advantage in terms of real-world generalizability of their findings.

Source: MedPage Today