May 6, 1856 - September 23, 1939: Age 83
Freud loved a good cigar (whether just a cigar, or nothing more), and he smoked a lot of them: 20 a day. In 1923 he was diagnosed with mouth cancer, but he continued to smoke, even though he knew they were killing him (although the first breakthrough medical study linking tobacco smoking with health damage didn't come out until 1948, the link had been suspected since the 17th century).
The tumours started on his hard palate and metastasized to the upper part of the lower jaw and his cheek. He underwent more than 30 operations to try to halt the cancer and replace some of the affected tissue with prosthetics, but they seemed only to increase his discomfort.
In March 1938 the Nazis annexed Austria, and anti-Semitism in Vienna (including visits from the Gestapo and the cancellation of his passport) drove Freud and his family to flee to London in June 1938. His cancer advanced, and in March 1939, he wrote to Arnold Zweig, "There is no longer any doubt that we are dealing with a new outbreak of my dear old carcinoma with which I have shared my existence for the past 16 years. Who would turn out to be the stronger could not, of course, have been predicted." In June he wrote to Marie Bonaparte, "...the radium has once again begun to eat away at something...and my world is what it was previously, a small island of pain floating on an ocean of indifference."
In September he asked his friend, Dr. Max Schur, who had fled with him to London, to help him die. “My dear Schur, you certainly remember our first talk. You promised me then not to forsake me when my time comes. Now it is nothing but torture and makes no sense any more.” Schur administered three large doses of morphine in the space of several hours, and Freud died, an assisted suicide.
There is an interesting article on the website of the Freud Museum about Freud's attitude. A quote: “Freud did not just 'have' cancer, he formed a relationship with it which echoed the structure of numerous others in his life - from childhood playmates to later friends and colleagues.” Click here to read more, it’s worth your time.
Sources: BBC History, Jewish Virtual Library, Freud Museum