The challenge of equipoise in trials with a surgical and non-surgical comparison: a qualitative synthesis using meta-ethnography

BACKGROUND

Randomised controlled trials in surgery can be a challenge to design and conduct, especially when including a non-surgical comparison. As few as half of initiated surgical trials reach their recruitment target, and failure to recruit is cited as the most frequent reason for premature closure of surgical RCTs. The aim of this qualitative evidence synthesis was to identify and synthesise findings from qualitative studies exploring the challenges in the design and conduct of trials directly comparing surgical and non-surgical interventions.

METHODS

A qualitative evidence synthesis using meta-ethnography was conducted. Six electronic bibliographic databases (Medline, Central, Cinahl, Embase and PsycInfo) were searched up to the end of February 2018. Studies that explored patients' and health care professionals' experiences regarding participating in RCTs with a surgical and non-surgical comparison were included. The GRADE-CERQual framework was used to assess confidence in review findings.

RESULTS

In total, 3697 abstracts and 49 full texts were screened and 26 published studies reporting experiences of patients and healthcare professionals were included. The focus of the studies (24/26) was primarily related to the challenge of recruitment. Two studies explored reasons for non-compliance to treatment allocation following randomisation. Five themes related to the challenges to these types of trials were identified: (1) radical choice between treatments; (2) patients' discomfort with randomisation: I want the best treatment for me as an individual; (3) challenge of equipoise: patients' a priori preferences for treatment; (4) challenge of equipoise: clinicians' a priori preferences for treatment and (5) imbalanced presentation of interventions.

CONCLUSION

The marked dichotomy between the surgical and non-surgical interventions was highlighted in this review as making recruitment to these types of trials particularly challenging. This review identified factors that increase our understanding of why patients and clinicians may find equipoise more challenging in these types of trials compared to other trial comparisons. Trialists may wish to consider exploring the balance of potential factors influencing patient and clinician preferences towards treatments before they start recruitment, to enable issues specific to a particular trial to be identified and addressed. This may enable trial teams to make more efficient considered design choices and benefit the delivery of such trials.

MRE11 expression is predictive of cause-specific survival following radical radiotherapy for muscle-invasive bladder cancer

Radical radiotherapy and surgery achieve similar cure rates in muscle-invasive bladder cancer, but the choice of which treatment would be most beneficial cannot currently be predicted for individual patients. The primary aim of this study was to assess whether expression of any of a panel of DNA damage signaling proteins in tumor samples taken before irradiation could be used as a predictive marker of radiotherapy response, or rather was prognostic. Protein expression of MRE11, RAD50, NBS1, ATM, and H2AX was studied by immunohistochemistry in pretreatment tumor specimens from two cohorts of bladder cancer patients (validation cohort prospectively acquired) treated with radical radiotherapy and one cohort of cystectomy patients. In the radiotherapy test cohort (n = 86), low tumor MRE11 expression was associated with worse cancer-specific survival compared with high expression [43.1% versus 68.7% 3-year cause-specific survival (CSS), P = 0.012] by Kaplan-Meier analysis. This was confirmed in the radiotherapy validation cohort (n = 93; 43.0% versus 71.2%, P = 0.020). However, in the cystectomy cohort (n = 88), MRE11 expression was not associated with cancer-specific survival, commensurate with MRE11 being a predictive marker. High MRE11 expression in the combined radiotherapy cohort had a significantly better cancer-specific survival compared with the high-expression cystectomy cohort (69.9% versus 53.8% 3-year CSS, P = 0.021). In this validated immunohistochemistry study, MRE11 protein expression was shown and confirmed as a predictive factor associated with survival following bladder cancer radiotherapy, justifying its inclusion in subsequent trial designs. MRE11 expression may ultimately allow patient selection for radiotherapy or cystectomy, thus improving overall cure rates.