From Alexander Waugh's, The House of Wittgenstein: A Family at War, pp 275-276
After telling the story of Ludwig dying of prostate cancer; of his father, Karl, dying of cancer of the tongue and mouth; of Hermine, Ludwig's oldest sister, dying of gynecological cancer; and of Paul, Ludwig's brother, dying of prostrate cancer -- Waugh writes:
"If ever there were a case to show that cancer is a genetic disease, the Wittgenstein family should be submitted as the first exhibit of concluding proof. Eighteen months before Hermine's death Maria Salzer (Helene's daughter) was killed by cancer. [Helene is another of Ludwig's sisters -- sw] In time both Helene's daughters and several of her granddaughters as well as her great-granddaughters would be stricken by the same disease. Helene herself died of it in 1956. She had not seen her brother Paul since 1938."
Dr. Sean Wilson, Esq.