Why don't cancer patients get entered into clinical trials? Experience of the Sheffield Lymphoma Group's collaboration in British National Lymphoma Investigation studiesBMJ 1997; 314 doi: http://dx.doi.org/10.1136/bmj.314.7073.36 (Published 04 January 1997) Cite this as: BMJ 1997;314:36
- B W Hancock, professora,
- M Aitken, research assistanta,
- C Radstone, clinical trials officera,
- G Vaughan Hudson, directorb
- a Yorkshire Cancer Research Campaign Department of Clinical Oncology, Weston Park Hospital, Sheffield S10 2SJ
- b British National Lymphoma Investigation, Middlesex Hospital, London W1N BAA
- Correspondence to: Professor Hancock
- Accepted 19 September 1996
By standardising treatment, often in collaboration with specialised centres, multicentre controlled clinical trials offer higher survival rates, particularly for less common cancers.1 Patients are generally willing to take part in such studies, 2 but in oncology generally few patients are entered into trials. Since 1981 the Sheffield Lymphoma Group, which sees patients by tertiary referral from district general hospitals in north Trent, has committed itself to entering patients into current British National Lymphoma Investigation studies. We looked at our record in doing so over 12 years.
Methods and results
We looked in detail at all patients referred to us in 1981-92, particularly to determine why patients were not entered into studies.
Of 1927 patients referred, 1813 were accepted by the group as having histologically proved lymphoma, and 822 (45%) of these patients were entered into studies. The annual recruitment rate varied from 25% in 1992 to 61% in 1984 (table 1). Reasons for non-entry were as follows.
Forty four per cent (804) were not eligible for current studies because they were too old (274), they were medically ineligible (365), no current study was available (55), they proved not to have lymphoma (73), or there was histological disagreement on their lymphoma type (37).
Ten per cent (187) were eligible but not entered into studies: 128 were considered but not entered by the clinician, 55 were missed by the clinician, and 4 refused.
The status of clinical trials has been under the spotlight recently.3 4 Stiller reviewed published data on survival rates for cancer in relation to patterns of organisation of medical care—specifically treatment by protocol, usually within the context of a clinical trial, and also treatment at specialist centres.1 Entry into trials (and centralised referral) was often associated with higher survival rates, particularly with less common cancers, and was never found to be associated with a lower survival rate. Patients themselves are usually willing to participate, attracted by being treated by a doctor with a specialist interest and encouraged by the promise of close monitoring of their progress.2 In our series only four refused to enter when asked.
Many patients are considered for studies but not entered on the clinician's decision. Even with our own group's positive attitude to trials and policy of putting as many patients as possible into studies, this explanation has consistently accounted for around 7% of patients. Almost half of our patients, however, were not considered for trials for genuine reasons: the eligibility criteria of particular trials excluded them on age or medical grounds or there was no appropriate current trial (old trials finished, new trials not yet started—as was the case in the last two years of our study period, when recruitment was temporarily lower). Such selection may be an important factor in determining the different outcomes between patients who take part in trials and those who do not. In particular, older and iller patients tend not to be entered into studies, and survival in this group will naturally be poor.
An increasing number of patients with cancer are eligible for relatively straightforward relevant clinical studies with less strict eligibility criteria, and these patients have the right to be fully informed about,4 and to have the opportunity to participate in, such trials. Major deterrents to involvement in trials by doctors are lack of time (to gain informed consent, to obtain ethics committee approval, to collect data) and lack of staff (many clinicians, particularly NHS staff in non-teaching hospitals, do not have access to dedicated research staff).5 Nevertheless, it should still be possible for motivated centres, actively encouraged and kept up to date by enthusiastic study teams, to recruit sizeable numbers of patients into large randomised clinical trials, hopefully to the benefit of the individual and to the disease group as a whole.
We thank the staff at the British National Lymphoma Investigation secretariat, the Trent Cancer Registry for providing details of tumour registrations, and all the clinicians who have cared for patients featured in this study.
Funding: Yorkshire Cancer Research Campaign and Weston Park Hospital Cancer Research Trust.
Conflict of interest: None.