LONDON, England (CNN)  -- An elderly British couple who died together at an assisted suicide clinic in Switzerland died "peacefully" after receiving "wonderful and humbling care" from their doctors, the couple's family said.



Peter and Penelope Duff from Bath, England, died in Zurich on February 27, according to a statement released Thursday by their family and reported by Britain's Press Association. Both had terminal cancer, the statement said.



"Penny had fought a rare cancer, GIST, since 1992 and Peter's colon cancer had spread to his liver," the statement said.



"Their decision in no way reflected on the wonderful and humbling care they have received from their consultant, doctors and nurses, for which the family, and they, were so appreciative."



Peter Duff, who was reported to be 80, was the executive chairman of Alcohol in Moderation, a nonprofit group that advocates a "sensible drinking ethos." His daughter, Helena Conibear, is executive director of AIM Digest, a monthly publication.



Conibear and AIM could not be reached for comment Friday.



The Press Association said Penelope Duff was 70. Her condition, GIST, stands for gastrointestinal stromal tumor, a rare type of cancer found in the digestive system.



Dignity in Dying, a British charity that advocates the choice of assisted death for terminally ill patients, said it was "extremely sad" that the Duffs had to travel abroad to die.



"Had they had the option of an assisted death in this country they may still be alive, as their physical ability to travel would not have been a factor," said Sarah Wootton, chief executive of Dignity in Dying.



Wootton called on Parliament to modernize laws on suicide to allow for assisted dying.



Phyllis Bowman, executive director of Right to Life, which opposes euthanasia, also said the Duffs' case was sad.



"I think it's very sad, particularly as they could have gone together into a hospice. A hospice with cancer -- there is not uncontrollable pain," Bowman told CNN. "I think that with the euthanasia lobby, they feed on despair and they encourage despair rather than hope."
Who died in Zurich on February 27? What type of illness did Peter have? What charity said it was extremely sad? What cancer did Penny suffer from? What did they want suicide laws to allow for? What type of cancer did she have? When did the Duffs die? What type of laws did they want changed?
Peter and Penelope Duff colon cancer Dignity in Dying, gastrointestinal stromal tumor, assisted dying. GIST, February 27, suicide
question: Who died in Zurich on February 27?, answer: Peter and Penelope Duff | question: What type of illness did Peter have?, answer: colon cancer | question: What charity said it was extremely sad?, answer: Dignity in Dying, | question: What cancer did Penny suffer from?, answer: gastrointestinal stromal tumor, | question: What did they want suicide laws to allow for?, answer: assisted dying. | question: What type of cancer did she have?, answer: GIST, | question: When did the Duffs die?, answer: February 27, | question: What type of laws did they want changed?, answer: suicide