Original article
Routine bladder cancer treatment dictates divergence from trial-derived regimens: Results of treatment at 44 radiotherapy centers

https://doi.org/10.1016/j.urolonc.2017.09.010Get rights and content

Highlights

  • Almost 50% of bladder cancer patients are unsuitable for trial-derived regimens.

  • The aging population needs more practical options for bladder chemoradiation.

  • Bladder-preserving chemoradiation is appropriate in free-standing centers.

  • Medically inoperable bladder cancer patients should be offered chemoradiation.

  • Technology that permits higher radiotherapy dose may promise better cure rates.

Abstract

Purpose

To assess characteristics and outcome of patients treated with radiotherapy for muscle-invasive bladder cancer at 44 community-based radiotherapy centers and compare these to those on clinical trials.

Materials and methods

We reviewed 155 patients who had been treated from 2010 to 2014. Overall survival and progression-free survival were estimated using the Kaplan-Meier method. Results were compared to a pooled analysis of 6 Radiation Therapy Oncology Group (RTOG) protocols.

Results

What stood out was that our patients' characteristics were significantly inferior than those on RTOG studies: lower rate of complete transurethral resection of bladder tumor: 36.8% vs. 70% (P<0.0001), higher median age: 79 years vs. 66 (P<0.0001), more medically inoperable: (51.0%) vs. 0% in RTOG (P<0.001), and 46.9% had refused surgery. Fewer patients underwent concurrent chemotherapy: 56.1% vs. 100% (P<0.0001). It was also striking that at median follow-up 12.6 months (range: 3.1–49.2), the 36-month overall survival was 51.3% for those who refused surgery vs. 24.5% for medically inoperable (P = 0.009); 58.1% with complete transurethral resection of bladder tumor vs. 29.8% if incomplete (P = 0.07); 54.3% with chemoradiotherapy (CRT) vs. 17.2% without (P = 0.03); 66.3% for those who refused surgery and had CRT vs. 38.9% for medically inoperable who had CRT (P = 0.04).

Conclusions

The cohort at community-based centers was older, more medically inoperable, and less likely to receive CRT than clinical trial patients. This suggests that we may not be able to apply trial-derived regimens for many patients in this setting. There is a pressing need to find treatment options for such patients, especially given the aging population. Survival of medically operable CRT patients was comparable to results of RTOG protocols notwithstanding this study's smaller sample size, retrospective nature and suboptimal documentation of patient characteristics.

Introduction

Bladder-preserving trimodality chemoradiotherapy (CRT) is accepted as a first-line option in Europe [1], [2] and elsewhere since, compared to cystectomy it yields similar survival [3], [4], [5] and possibly improved outcome [6]. Only recently has it been included as a choice in the National Comprehensive Cancer Network Guidelines [7]. Instead, in the United States, it is common practice to offer definitive surgery to fit patients. Most of the data for CRT in the United States emerges from a few large academic centers [8] and Radiation Therapy Oncology Group (RTOG) trials. With the small volume of cases at most academic centers in the United States, the exposure of residents in training to this procedure may be limited, yet when practicing out in the community, radiation oncologists need to perform bladder CRT. We, therefore, examined the characteristics and outcome of patients who were treated for muscle-invasive bladder cancer (MIBC) at 44 community-based 21st Century Oncology radiotherapy (RT) centers in the United States and compared these to a pooled analysis of CRT from 6 RTOG protocols [9]. The incidence of treatment of this disease will continue to increase as life expectancy increases in developed countries [10] and as smoking becomes more prevalent in developing countries [11]. In 2012 an estimated 429,800 new cases of bladder cancer occurred worldwide [12].

Section snippets

Study type

We, retrospectively, reviewed the characteristics and outcome of patients with MIBC who were treated with RT at 44 centers that shared a single registry after ethical Institutional Review Board approval. The registry is a cancer registry that is used to report cases to each state within the United States. It is a comprehensive database that collects up to 815 fields of data that may be required by individual states in accordance with standards of the North American Association of Central Cancer

Comparison of patients against those on RTOG trials

There were 155 patients from August 2010 to June 2014 treated with RT whose characteristics listed in Table 1 alongside the respective values for patients of the RTOG pooled analysis.11 What is striking about the values in this table is that 51.0% were unfit for surgery in our study vs. 0% in RTOG (P<0.001); patients in the current study were older (P<0.0001), were more racially heterogeneous (P<0.0001), had poorer PS or more likely to be undocumented PS (P<0.0001), had less visibly complete

Practice of bladder chemoradiation outside of clinical trials

The 36-month OS for concurrent CT patients who refused surgery (66.3%) is comparable to the RTOG results. This reflects good performance of bladder CRT in community-based centers outside the academic setting. These results are respectable, especially given the high percentage of patients without a complete TURBT, a known adverse prognostic feature. It raises the question of the effect of major technological difference between this series and the techniques used in the patients of the pooled

Conclusions

Despite poorer patient characteristics, the 36-month OS of 66.3% for patients who refused surgery and received CRT is encouraging. It suggests that it is appropriate to offer bladder CRT in community free-standing centers. This good outcome may be related to improvement in techniques for planning and delivery of RT. The promising 36-month OS of 38.9% for patients who were unfit for surgery and received CRT suggests that patients with medical comorbidity should be considered for CRT instead of

Acknowledgment

We wish to thank April Mann, Writing Center Director, Senior Lecturer, College of Arts and Sciences, Department of English, University of Miami for her painstaking guidance in writing this article.

Presentations

An abstract of this article in part was published at the Annual Meeting of the American Society of Clinical Oncology 2017.

An abstract of this article in part was presented at the Annual Meeting of the American Society of Radiation Oncology, Boston MA, USA, 2016.

References (32)

1

The author has moved since this work described in this article was done.

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