PHILADELPHIA (May 30, 2023)—Patients with muscle-invasive bladder cancer who receive fewer than three cycles of chemotherapy prior to bladder removal surgery face higher risk of recurrence and worse survival outcomes. That’s according to research from Temple Health and Fox Chase Cancer Center that will be presented at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting.
“There really hasn’t been any research looking into less than three cycles of chemotherapy for these patients. Our study looked into the outcomes for these patients to see if we could find any differences compared to those who receive the standard treatment of full three cycles,” said Anumita Chakraborty, MD, lead author on the study and a second-year resident in internal medicine at Temple University Hospital.
Chakraborty will present her study, “Survival Outcomes in Patients with Muscle-Invasive Bladder Cancer Receiving Neoadjuvant Chemotherapy Stratified by Number of Cycles,” in a poster session during the 2023 ASCO Annual Meeting, which is being held June 2-6 in Chicago.
Standard of care for patients with muscle-invasive bladder cancer is to receive at least three cycles of chemotherapy prior to having their bladder, or a portion of their bladder, surgically removed. However, not all patients complete three cycles. Some stop chemotherapy after one or two cycles due to toxicity-related side effects such as nausea or low blood counts.
Chakraborty and her coauthors, including senior author Matthew Zibelman, MD, an associate professor in the Department of Hematology/Oncology at Fox Chase, set out to compare recurrence and survival rates between patients who received fewer than three cycles of neoadjuvant (i.e., presurgery) chemotherapy and those who received three or more cycles.
The researchers reviewed anonymous records for 195 Fox Chase patients who were diagnosed with muscle-invasive bladder cancer between 2004 and 2017. Thirty of those patients received fewer than three cycles of neoadjuvant chemotherapy while the other 165 received three or more cycles.
The researchers then compared three outcomes between the two patient groups: pathological response (the cancer was undetectable in the tissue that was removed during surgery, indicating that chemotherapy successfully eradicated the cancer), cancer recurrence (a measure of if the cancer came back and how quickly), and overall survival (if the patient was still alive after five years).
Patients who completed fewer than three cycles of chemotherapy were found to have worse outcomes than their standard-of-care counterparts on all three measures. These patients were less likely to have achieved pathologic or complete pathologic response — meaning they still showed evidence of disease in their bladder tissue — their cancer tended to recur more quickly, and they were 40% less likely to survive five years after treatment.
The researchers emphasized that while these findings have important implications for patients and clinicians, they need to be confirmed in prospective studies.
“If patients are able to tolerate the three cycles of neoadjuvant chemotherapy, clinicians should encourage and try to support patients to receive all three cycles,” said Chakraborty. She added that the study’s outcomes may also guide clinicians’ screening practices. “Patients who receive less than three cycles would need to be followed very closely after treatment to monitor for recurrence because they have a significantly higher recurrence rate.”