Rahu in Cancer
Rahu is enemy to Moon, lord of cancer, moreover, Rahu is totally materialistic planet, highly illusive and complicated. Whereas Moon is soft and emotional planet related to good things such as mother, family, emotions etc. Rahu is too heavy for Moon to handle and Rahu will overshadow Moon with its negativity or illusion. Cancer is water sign which knows no boundaries. From kundli perspective position of Moon will be critical to decide Rahu behavior.
These people may suffer from unfluctuating and unstable mindset, always worrying, struggling to cope up with their emotions. They are very vulnerable to get influenced by anyone who can convince them to do something. They lack practicality. There could be mother and family related issues as well; physical problems related to chest/lungs/heart. The native could be day-dreamer or always thinking about setting unrealistic goals to gain materialism.
These guys can do well in the medical profession as it relates to the care.