LONDON , England -- John Symons lost his wife Jo to a mysterious cancer two years ago . But he is n't done battling the disease . The CUP Foundation was founded in memory of Jo Symons , who died in 2006 of the mysterious disease . Jo suffered from cancer of unknown primary , or CUP , a diagnosis that is given when doctors find cancer in the body but are n't able to identify where it began . That inevitably complicates treatment , as doctors are at a loss as to whether they are dealing with breast , lung or countless other types of cancer . `` Any cancer diagnosis is devastating for patients and loved ones . But not knowing where in the body the cancer has originated and what type of cancer we are dealing with is a double blow , it 's double agony , '' Symons told CNN . After his wife died in 2006 , Symons abandoned his career as a business school professor to set up the Cancer of Unknown Primary Foundation , also known as `` Jo 's friends . '' The charity aims to raise awareness of CUP and campaigns for more research in the hope that it will lead to better treatment . Symons said he also wanted to help others faced with the challenging diagnosis . People from 35 countries visit the foundation 's Web site . `` Most of them say there 's nowhere else [ for them to turn to ] , '' he said . It is unclear how many people are faced with the cancer of unknown primary worldwide , but according to Symons , 3 to 5 percent of all cancers are CUP . The CUP Foundation estimates that in the UK alone , more than 10,000 people are diagnosed with the mystery disease annually , giving it a higher incidence than pancreatic and ovarian cancers . Find out more about rare conditions » . Cancer needs to be treated by identifying the anatomical location of where the cancer has started , and therapy is always based on where that cancer starts in the body , Symons explained . In the case of CUP , the cells lose their unique features as the cancer spreads . `` So if you do n't know where the cancer has started , it is very difficult to treat it , '' he told CNN . Many CUP sufferers have just weeks or months to live after the cancer has spread . Jo died at the age of 46 , only eight months after being diagnosed . Jo discovered she had cancer when she developed a lump in her neck , according to Symons . But it was only a secondary tumor , and doctors believed the primary tumor was too small to locate or possibly had already disappeared . At first , the Symons were hopeful : `` We kept thinking it 's only a matter of time before someone figures out where this comes from and are able to treat it , that we 'd have good news and that while she might not be cured , she would be able to live with the cancer . '' But as time went by , they realized this was n't going to be possible . Doctors first thought Jo might have ovarian cancer , but ruled that out after several tests . Subsequently they thought it might be breast cancer , so Jo underwent grueling chemotherapy treatment for several months . That did n't help , and further tests were conducted to try and identify the genetic profile of the tumor where the cancer originated . These tests suggested Jo might be suffering from pancreatic cancer . For the last months of her life , Jo was treated for pancreatic cancer . `` But sadly , that was too late , even if it had been the correct diagnosis , to turn the tables , '' Symons recalled . He never found out what cancer his wife had suffered from . `` It has been difficult for me , '' Symons said . But faced with the choice of putting the ordeal behind him or trying to do something about it , he picked the latter . `` In a sense this charity has been therapeutic . '' But at the same time , `` I 'm living daily with a reminder of what it is like for people to go through this terrible disease . ''
`` Cancer of unknown primary , '' or CUP , is a mystery disease . It's not known why it occurs in some people and not others. CUP Foundation casts light on the challenging diagnosis .