A leaked review into children’s cancer care in London indicates that the Royal Marsden unit in Sutton should close.

The report, which has remains unpublished, suggests that care should be condensed at one principal treatment centre for the capital.

NHS experts told national newspaper The Guardian the centre likely to take on the care is Great Ormond Street hospital in north London and said the Royal Marsden NHS Foundation Trust’s unit in Downs Road, Sutton, could face closure.

The review, chaired by Mike Stevens, professor of paediatric oncology at Bristol University, has not been officially shared with the Royal Marsden.

A spokeswoman from the trust said: “We are happy to consider the clinical evidence and affordability of proposed models to provide the best service and benefit for patients and their families.

“However, given the high standard of performance of the cancer specific model at the Royal Marsden any recommendation for change must be based on clear clinical evidence.”

London currently has two principal treatment centres for children’s cancer services, which both consist of two separate sites and trust partnerships.

The Royal Marsden and St George’s NHS Foundation Trust together provide cancer care for children in south London, Kent, Surrey and Sussex.

The Royal Marsden provides cancer diagnosis, treatment and non-surgical cancer therapy and admitted 600 children and young adults last year.

St George’s provides the paediatric specialist surgery and the intensive care unit for patients.

The other partnership comprises of Great Ormond Street and University College Hospital.

The sites are 1.3 miles apart, whereas the distance between St George’s and the Royal Marsden is 7.8 miles.

The report was requested by NHS London medical director Andy Mitchell and submited in February last year, however it has yet to emerge publicly.

A spokesperson from NHS London said: “There are good clinical arguments for ensuring cancer specialist services are co-located as they currently are, just as there are alternative views about combining children’s services regardless of speciality discipline.

“These are not black and white judgements and it’s important we take the time to get any future planning right.”

A 2011 report by the National Clinical Advisory Team, following the death of a child treated Royal Marsden and St George’s, concluded that areas of the decade-old partnership “required attention and development”.