The Italian patient, who has not been named, was supposed to meet with doctors at a clinic in Switzerland to end their life.
But, according to pro-euthanasia campaigners Marco Cappato, treasurer of the Luca Coscioni Association and Mina Welby and Gustavo Fraticelli, promotors for the site www.soseutanasia.it, the person changed their mind the night before.
“This person, who is seriously ill, was able to consult with doctors specializing in end-of-life treatments to help them with medically-assisted death about whether it was their choice.
“However, they found out from these people that there were better alternatives for them and so will continue to live with their illness.”
The association added that the fact that the patient changed their mind proves that more must be done to campaign for euthanasia, in order to “give the ill person full freedom to make decisions about self-determination”.
The association said that it had supplied information, and in some cases logistic assistance and financial aid to people seeking euthanasia. Now it says it receives requests for information and help on a daily basis.
According to data from Italy's national statistics agency, Istat, the principal cause of 3,048 suicides in 2010 was physical or mental illness.
While euthanasia is still illegal in Italy, steps have been taken in France in recent months to ease up euthanasia legislation.
A 2005 French law already legalizes passive euthanasia, where treatment needed to maintain life is withheld or withdrawn.
But the proposed law goes further, allowing doctors to couple this with "deep and continuous sedation" for terminally ill patients.