Microscopic view of bladder cancer cells targeted by chemotherapy.

Bladder Cancer Breakthrough: Can Chemoablation Replace Surgery?

Elliot Brynn in Health & Wellness August 2025 • 4 min read.

"A new study explores whether chemoablation, a less invasive treatment, could be a viable alternative to surgery for low-risk non-muscle invasive bladder cancer."

Non-muscle invasive bladder cancer (NMIBC) is characterized by frequent recurrence, necessitating ongoing monitoring through cystoscopic surveillance. Mitomycin C (MMC) chemotherapy, recognized for its established safety profile, has been a mainstay in NMIBC treatment for over two decades.

A recent study, CALIBER, has explored the potential of chemoablation, utilizing intravesical chemotherapy, as an alternative for tumor ablation. The study seeks to determine if this approach demonstrates sufficient activity against low-risk NMIBC, warranting further investigation as a potential management strategy in this specific clinical context.

The study aims to provide patients and healthcare providers with valuable information regarding alternative treatment options, potentially reducing the need for more invasive procedures and improving overall patient well-being.

CALIBER Trial: Assessing Chemoablation's Feasibility

Microscopic view of bladder cancer cells targeted by chemotherapy.

The CALIBER trial employed a Simon two-stage design to evaluate the efficacy and feasibility of chemoablation compared to surgery for low-risk NMIBC. The study incorporated a surgical control group to accurately assess patient acceptability and the feasibility of randomization. Patients diagnosed with recurrent low-risk NMIBC were randomized in a 2:1 ratio to receive either chemoablation (four weekly intravesical instillations of 40mg) or undergo surgery (standard of care).

The primary endpoint of the study was to determine the complete response (CR) rate to chemoablation, assessed through visual examination and histological biopsy three months post-treatment. Secondary endpoints encompassed treatment compliance, time to recurrence in patients who were disease-free at three months, rates of transurethral resection and biopsy, progression-free survival, toxicity (CTCAE v4), quality of life, and health service utilization.

Participants: 82 participants (54 chemoablation, 28 surgery) from 37 UK centers.
Feasibility: Randomization demonstrated with 55% acceptance.
Patient Profile: Median age 70.7 years, 76.8% male, 63.4% current or former smokers.

The trial initially aimed to reach a 60% complete response rate in the chemoablation arm to proceed to the second stage. However, the independent trial oversight committees recommended closing the trial to recruitment because this threshold was not met.

Chemoablation: A Promising Alternative?

The study found that chemoablation resulted in a visual and histologically confirmed complete response rate of 37% in patients with low-risk NMIBC. While surgery proved more effective overall, nearly 20% of patients in the surgical arm still exhibited histological evidence of disease at three months, suggesting that surgical management alone may not always be optimal.

These findings suggest that chemoablation could be a safe and potentially effective alternative for certain patients with low-risk NMIBC. While surgery remains the standard of care, the study highlights the need for further research to determine the specific role of neoadjuvant intravesical chemotherapy in managing this condition.

Further research is needed to refine patient selection criteria and optimize chemoablation protocols to improve outcomes and minimize recurrence rates. This could lead to more personalized treatment strategies that balance efficacy with quality of life for individuals with low-risk NMIBC.

About this Article -

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This article is based on research published under:

DOI-LINK: 10.1016/s1569-9056(18)31571-9, Alternate LINK

Title: Results Of Caliber: A Phase Ii Randomised Feasibility Trial Of Chemoablation Versus Surgical Management In Low Risk Non-Muscle Invasive Bladder Cancer

Subject: Urology

Journal: European Urology Supplements

Publisher: Elsevier BV

Authors: H. Mostafid, J. Cresswell, T. Griffiths, J. Kelly, A. Knight, J. Catto, K. Davenport, A. Feber, M. Knowles, J. Mcgrath, P. Cooke, S. Masood, A. Goubar, S. Penegar, N. Porta, L. Wiley, R. Lewis, E. Hall

Published: 2018-03-01

Everything You Need To Know

What is Non-muscle invasive bladder cancer (NMIBC) and why is it important?

Non-muscle invasive bladder cancer (NMIBC) is a type of bladder cancer that hasn't spread into the muscle layer of the bladder wall. Its significance lies in its high recurrence rate, which means the cancer often comes back after treatment. Because of this, ongoing monitoring through cystoscopic surveillance is necessary. Understanding NMIBC helps to appreciate the need for less invasive treatment options like chemoablation.

What was the goal of the CALIBER trial and what was its significance?

The CALIBER trial aimed to determine if chemoablation, using intravesical chemotherapy, could effectively treat low-risk NMIBC. The significance of this is that chemoablation could potentially offer a less invasive alternative to surgery. It included a surgical control group to assess patient acceptance and the feasibility of randomization. The implications are that if successful, chemoablation could improve patient well-being and reduce the need for more invasive procedures, but the trial did not meet its goals.

What is Mitomycin C (MMC) chemotherapy and why is it significant in this context?

Mitomycin C (MMC) chemotherapy is a type of chemotherapy used in the treatment of NMIBC. Its importance stems from its established safety profile, having been used for over two decades. This chemotherapy is delivered intravesically, which means it is instilled directly into the bladder. The implications are that MMC provides a well-established and trusted treatment option for NMIBC, forming a foundation upon which newer treatments like chemoablation are built.

What is chemoablation and what were the results of the CALIBER trial?

Chemoablation is a treatment approach using intravesical chemotherapy to ablate (destroy) tumors in the bladder. In the CALIBER trial, it involved four weekly instillations of 40mg of Mitomycin C. The significance of chemoablation is that it offers a less invasive alternative to surgery, which has implications on improved patient quality of life, with less recovery time. The trial found a 37% complete response rate, indicating that chemoablation is not as effective as surgery.

What were the key outcomes that the CALIBER trial measured, and what is the significance of these measurements?

The CALIBER trial evaluated the effectiveness of chemoablation versus surgery for low-risk NMIBC. The study's endpoints included the complete response rate, time to recurrence, progression-free survival, and quality of life. The significance of these endpoints is that they provide a comprehensive assessment of the treatment's success, considering not only cancer control but also patient well-being. Although the study did not progress as planned, the trial generated significant data, but did not meet its goal, indicating the need for further research to fully understand the role of chemoablation.