Adjuvant RT Plus Chemo Improves Local Control in Bladder Cancer

An Egyptian study found that bladder cancer patients who underwent radical cystectomy had better local recurrence-free survival with adjuvant radiotherapy (RT) and chemotherapy combined, compared with chemotherapy alone. Results were presented at the 2016 American Society of Clinical Oncology (ASCO) Genitourinary Cancers Symposium, held January 7-9 in San Francisco (abstract 356).

The trial was conducted by Mohamed S. Zaghloul, MD, in Cairo, in collaboration with researchers at the University of Pennsylvania. UPenn’s Brian C. Baumann, MD, presented the results.

The study initially randomized bladder cancer patients after radical cystectomy to either adjuvant radiotherapy totaling 45 Gy (78 patients) or to a “sandwich approach” of gemcitabine and cisplatin followed by RT and then another round of chemotherapy (75 patients). Because adjuvant RT is not the standard of care in many countries outside of Egypt, another group of adjuvant chemotherapy alone was added later (45 patients).

The median age in the trial was 54 years, and histology was divided between urothelial carcinoma, squamous cell carcinoma, and others.

The first comparison pitted adjuvant RT against the combination of RT and chemotherapy. There were no significant differences between the groups with regard to disease-free survival (DFS); the 3-year DFS rate was 63% with RT alone and 68% with the combination (P = .29). The 3-year local recurrence-free survival (LRFS) rates were 87% with RT alone and 96% with the combination (P = .13). Similarly, neither distant metastasis–free or overall survival rates were different between the groups.

A second comparison was then done between the combination group and the adjuvant chemotherapy alone group. There was a trend toward improved 3-year DFS rates with the combination, at 68% vs 56% (P = .10).

A significant benefit was seen with regard to 3-year LRFS, at 96% with the combination and 69% with adjuvant chemotherapy alone (P < .0001). Again, there were no differences with regard to distant metastasis-free or overall survival rates.

There was a small increase in risk of late grade 3 or higher gastrointestinal toxicity in both groups involving RT compared with chemotherapy alone (8% RT alone, 7% combination, 2% chemotherapy alone).

Baumann noted some limitations to the trial, including its small size and imbalanced accrual. “We think the results favoring chemotherapy and radiation are intriguing, but the trial design and limited sample size does not allow for definitive conclusions,” he said.

Elizabeth R. Plimack, MD, of Fox Chase Cancer Center in Philadelphia, was the discussant for the session, and agreed that the trial design presents a problem with these results. She noted that the histologies were grouped together, though they probably do represent differing biologies. Also, she questioned the importance of LRFS improvements if metastasis and overall survival are not affected. “We really need to embed quality-of-life endpoints in future trials,” she said, in order to determine if local control has clinically relevant effects.