I understand that medical authorities such as the American Association
for Cancer Research highlight leading medical centres that are
'leading the field' in the treatment of specific conditions;
 
i.e. Throat cancer:       Johns Hopkins Hospital - Boston USA (Oncology dept).
      Bowel cancer        Mayo Clinic - Rochester, Minnesota (Oncology dept)

I am seeking a site that has aggregated these types of recommendations
made by such medical authorities.

The site would ideally contain recommendations of  'treatment centres'
by a number of medical authorities on a wide range of medical
conditions.

I already am aware of America's Best Hospitals and equivalent sites
based on large lists of national hospitals.
 
I am instead looking for recommentations made by medical authorities,
based upon their specific expertise and access to research data being
undertaken around the world.