DaBlaCa-13 Study: Oncological Outcome of Short-Term, Intensive Chemoresection With Mitomycin in Nonmuscle Invasive Bladder Cancer: Primary Outcome of a Randomized Controlled Trial

PURPOSE

This study aimed to assess long-term follow-up after chemoresection with mitomycin (MMC), a nonsurgical treatment modality for recurrent nonmuscle invasive bladder cancer (NMIBC). At the time of recurrence, chemoresection has previously been shown to reduce the number of patients requiring a procedure (transurethral resection of bladder tumors [TURBT] or office biopsy) by more than 50%. This study investigated the number of patients requiring a procedure during initial treatment and 2-year follow-up in patients treated with short-term, intensive chemoresection with MMC compared with patients undergoing standard surgical treatment of recurrent NMIBC.

METHODS

A randomized, controlled trial was conducted in two urological departments in Denmark from January 2018 to August 2021. In total, 120 patients with a history of Ta low- or high-grade NMIBC were included upon recurrence. The intervention group received intravesical MMC (40 mg/40 mL) three times a week for 2 weeks and TURBT or office biopsy only if the response was incomplete. The control group received TURBT or office biopsy and 6 weekly adjuvant instillations. The primary outcome was the number of patients undergoing a procedure within 2 years from inclusion, which was compared between groups using the chi-squared test. Recurrence-free survival was analyzed using the Kaplan-Meier method.

RESULTS

Significantly fewer patients were in need of a procedure in the intervention group than in the control group: 71% (95% CI, 57 to 81) and 100% (95% CI, 94 to 100), P < .001. The 12-month recurrence-free survival was 36% (95% CI, 24 to 50) and 43% (95% CI, 30 to 56) in the intervention and control groups, respectively (P = .5).

CONCLUSION

Short-term intensive chemoresection is an effective treatment strategy for recurrent NMIBC that leads to a reduced number of required procedures without compromising long-term oncological safety.

The DaBlaCa-13 Study: Short-term, Intensive Chemoresection Versus Standard Adjuvant Intravesical Instillations in Non-muscle-invasive Bladder Cancer-A Randomised Controlled Trial

BACKGROUND

Instillation therapy for non-muscle-invasive bladder cancer (NMIBC) reduces recurrences but is associated with side effects. Preoperative instillation of chemotherapy could potentially be associated with fewer side effects compared with adjuvant instillations and in some patients make tumour resection (transurethral resection of the bladder tumour [TURBT]) superfluous.

OBJECTIVE

To investigate tumour response and adverse events related to short-term, intensive chemoresection with mitomycin C compared with adjuvant instillations in patients with recurrent NMIBC.

DESIGN, SETTING, AND PARTICIPANTS

A randomised, controlled trial was conducted in two urological departments in Denmark from January 2018 to June 2019. In total, 120 participants with a history of Ta bladder tumours, low grade or high grade, were included upon recurrence.

INTERVENTION

Intravesical mitomycin C (40 mg/40 ml) three times a week for 2 wk in the intervention group (59 patients) was compared with TURBT and six weekly adjuvant instillations in the control group (61 patients).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Tumour response was evaluated in the intervention group by flexible cystoscopy after 4 wk. Side effects were prospectively registered in both groups using the National Cancer Institute's Common Terminology Criteria for Adverse Events. Groups were compared using χ² or Fisher's exact test.

RESULTS AND LIMITATIONS

Complete tumour response was seen in 33 participants (57%) in the intervention group. Fewer adverse events were reported in the intervention group than in the control group. Two patients in each group ceased instillation treatment due to adverse events. The main limitation is the current lack of long-term follow-up.

CONCLUSIONS

Short-term, intensive chemoresection yields a tumour response of 57%. Hence, only half of those treated with chemoresection needed TURBT. The treatment was furthermore associated with fewer clinically significant side effects. Owing to small numbers, further investigations on Ta high-grade tumours are needed.

PATIENT SUMMARY

We compared a nonsurgical treatment with standard treatment in patients with superficial bladder tumours. We found it to be safe and able to avoid surgery in more than half of the patients.