Jan. 2 (Bloomberg) -- London's Royal Marsden Hospital was evacuated after a fire broke out, destroying part of the roof at a major European center for cancer treatment and research.

A section of the top floor of the six-story building in Chelsea was ablaze, and 75 firefighters were tackling the flames, Fire Brigade spokesman Martin Simpson said in a telephone interview.

All 79 in-patients, including two who were undergoing surgery when the fire broke out, were evacuated safely and taken to alternative hospitals, Chief Executive Cally Palmer said at a press conference outside the hospital. ``The most important thing is all patients and staff have been evacuated safely. The patients are being cared for in neighboring hospitals by our specialist teams,'' she said.

Non-resident patients who were being treated in clinics at the hospital were taken to a nearby church, St Paul's Onslow Square, ``to be supported until we can asses if they are fit to go home,'' she added.

``Operating theaters and at least two wards are very badly affected. We have five theaters and none are usable.'' She said patients would be able to continue to be treated by Royal Marsden staff at other hospitals.

Palmer said the fire had started in a plant room and had badly affected the newer part of the building. There was very little damage to the older part of the building, which was completed by the architect John Young in 1862.

No Casualties

There were no reports of casualties, according to ambulance crew who arrived at the scene, said London Ambulance Service spokeswoman Jenny Round in a telephone interview. Paramedics remained on standby at the hospital, where a hazardous-area response team was also in place, she added.

Kevin Harrington, a radiation oncologist who was working at the hospital when the alarm was raised, said all staff and patients had been evacuated in line with emergency procedures.

``My understanding is that everyone was safely evacuated from the building,'' he said in an interview with the British Broadcasting Corp.'s News 24 television channel. ``The fire was not in one of the treatment areas for radiation delivery and it's not near the main wards. It seems to be close to an area where a lot of the surgery takes place.''

Firefighters were called to the hospital in southwest London at 1:20 p.m. local time, the Fire Brigade said.

`Tremendous Blow'

Founded in 1851, the Royal Marsden was the world's first hospital dedicated to cancer treatment and research into the causes of cancer. It is Europe's largest comprehensive cancer center and sees more than 40,000 patients from the U.K. and abroad each year, the hospital said.

The oldest part of the site was completed in 1862 and has been added to since. The fire started in one of the newer parts of the hospital, which was extended in the 1980s to increase its capacity.

Karl Sikora, a cancer specialist at the nearby Hammersmith Hospital, said the fire was ``a tremendous blow'' to a center that is ``on the cutting edge of cancer research worldwide.''

``Picking up that work elsewhere in London is going to be very difficult,'' he said in an interview with the BBC. The Royal Marsden is ``a haven of education in British cancer'' and probably 30 percent of British cancer specialists have worked there, he added.

Sikora said the hospital's research is backed up elsewhere, including at a site in Sutton, Surrey.

To contact the reporter on this story: Thomas Penny in London tpenny@bloomberg.net.

Last Updated: January 2, 2008 12:47 EST