The latest UK Thyroid Cancer Clinical Trial IoN is well underway, with more than 110 patients who are already taking part in this important study of thyroid cancer.

The UK HiLo study results were reported in the top medical journal, the New England Journal of Medicine, in May 2012. It showed that selected patients with well-differentiated thyroid cancer could now be given a low dose of radioactive iodine for ablation, instead of the usual high dose, if the whole thyroid gland has been removed by a specialist surgeon.

This highly successful trial was the first national thyroid study in the UK, and it would not have been possible without the great support of all 438 patients who took part.

The next step is to look at thyroid cancer patients carefully selected by experts in whom the risk of the cancer coming back is even lower than those in the HiLo Trial. In these patients the risk of dying from thyroid cancer is zero or negligible. There is no reliable evidence for giving radioactive iodine ablation to these low risk patients, especially because thyroid cancer is now being detected at an earlier stage than before and specialist surgeons can perform optimal surgery.

Several international experts believe that these particular patients are likely to be cured by high quality surgery alone and thyroid hormone replacement therapy, and having radioactive iodine in addition to these two treatments has no extra benefit. But patients have to stay in hospital for one to two days and there are side effects, including a small risk of having a second cancer in the future.

The IoN (Iodine or Not) study is the next national study in the UK. We would like to see whether these low risk patients need radioactive iodine (RAI) ablation to reduce the chance of the cancer coming back, when they have already had the two other upfront usual treatments for thyroid cancer, which are total thyroidectomy (whole thyroid gland removed) and thyroid stimulating hormone suppression (TSHS) therapy.

In the IoN study, all patients would have these two upfront treatments, then half of them would also receive RAI ablation, and the other half would not.

Like the HiLo Trial, the whole thyroid gland would have been removed by a specialist surgeon. In addition, patients are followed up regularly and more closely (every six months for five years) using a combination of clinical examination, modern sensitive blood tests, and neck scans. Other tests and scans would be performed when required.

The chance of the cancer coming back in these patients is low, less than 5% over five years and almost always in the neck (in fact, published research indicates that it is <2%). Even if the cancer does come back in this small number of cases, they are readily detected early by the tests and scans used in the IoN study, and are adequately treated and almost always cured. This avoids unnecessary treatment of up to 98% of patients with upfront radioiodine.

If the chance of the cancer coming back is similar between patients who had RAI ablation and those who did not, then future patients can avoid this therapy, and its side effects.

IoN has been approved and funded by Cancer Research UK.

About 30 hospitals across the UK are taking part in the trial, and the following clinicians and hospitals are already recruiting patients:

Bristol – Bristol Haematology & Oncology Centre (Dr Matthew Beasley)
Cambridge – Addenbrooke’s (Dr Sarah Jeffries)
Canterbury – Kent and Canterbury Hospital (Dr Elena Macias Fernandez)
Cardiff – Velindre Cancer Centre (Dr Laura Moss)
Chelmsford – Broomfield Hospital (Dr Abdel Hamid)
Cheltenham – Cheltenham General Hospital (Dr Charles Candish)
Edinburgh – Royal Infirmary Edinburgh (Dr Mark Strachan)
Exeter – Royal Devon & Exeter Hospital (Wonford) (Dr Andy Goodman)
Glasgow – Beatson Oncology Centre (Dr Nicholas Reed)
Guildford – Royal Surrey County Hospital (Dr Stephen Whitaker)
Ipswich – Ipswich Hospital (Dr Christopher Scrase)
Leeds – St James’s Hospital (Dr Georgina Gerrard)
Leicester – Leicester Royal Infirmary (Dr David Peel)
London – Royal Marsden Hospital (Dr Kate Newbold)
London – St Mary’s Hospital (Dr Danielle Power)
London – Guy’s Hospital (Dr Hosahalli Mohan)
Maidstone – Kent Oncology Centre (Dr Nick Rowell)
Manchester – The Christie (Prof Nicholas Slevin)
Middlesbrough – James Cook University Hospital (Dr John Hardman)
Newcastle – Freeman Hospital (Dr Ujjal Mallick)
Norwich – Norfolk & Norwich University Hospital (Dr Tom Roques)
Nottingham – Nottingham Hospital (Dr Sally Morgan)
Poole – Poole Hospital (Dr Perric Crellin)
Portsmouth – Queen Alexandra Hospital – (Dr Dae Kim)
Sheffield – Weston Park Hospital (Dr Jonathan Wadsley)
Southend-on-Sea – Southend Hospital (Dr Krishnaswamy Madhavan)
Wolverhampton – New Cross Hospital (Dr Mano Joseph)

If you would like to take part in this trial please speak to your clinician.