Humphrey Bogart as Rick Blaine in "Casablanca" (1942)Time magazine called Humphrey Bogart “one of a handful of old-timers whose acting reputation and box office value is indestructible, and whose Hemingwayish philosophy tends to make him morally indestructible in that nothing he does or says will surprise or scandalize anyone —an enviable spot these days when high-earners in Hollywood are afraid to spit on the sidewalk lest they cut industry grosses by a third”.
Not surprisingly, Bogart’s legend has overshadowed all of his image-conscious contemporaries. For good reason. As actor Rod Steiger pointed out, “Bogart has endured because in our society the family unit has gone to pieces. And here you had a guy about whom there was no doubt. There is no doubt that he is the leader. There is no doubt that he is the strong one. There is no doubt with this man that he can handle himself, that he can protect the family. This is all unconscious, but with Bogart you are secure, you never doubt that he will take care of things.”Bogart was diagnosed with cancer of the esophagus in January of 1956. He underwent nine hours of surgery then convalesced for months.
Humphrey Bogart as 'Rip' Murdock in "Dead Reckoning" (1947)True to his code, he never spoke of the disease that made his body waste away, and he never stopped drinking. As soon as he got back from the hospital he climbed off the wagon, although he did switch from scotch to martinis.
The cancer returned and Humphrey Bogart died January 4, 1957 at the age of fifty seven, with nothing left to prove. His last words were about drinking: “I never should have switched from scotch to martinis.” Source: www.drunkard.com
"In "The Harder They Fall", Bogie is in even worse shape, pale, shaky, pasty and puffy. He was dying of throat cancer and the insidious disease would claim his life nine months after the film was released. In the movie, Bogart plays a down on-his-luck sports writer who, due to unemployment, takes on a job as a publicity man for a Panamanian boxer named Toro Moreno. 
Pangs of conscience finally hit Bogie and he helps the fighter escape back to his home in South America and begins writing a tell-all expose on the dirty business of pro boxing. It is a wonderful, soul-searching performance by Bogie with Rod Steiger perfectly villanous as a crooked manager. As stated above, Bogart was dying and he was aware of it. 
This adds an additional level of pathos to the film as we see a clearly in-pain Bogie doing his best to right the wrongs that he has wrought. We know he'll take a turn for the better, but in the classic Bogart tradition, we also know he'll do it slowly and with a certain bewilderment. The pain in his eyes is as much from the cancer eating away at him as it is from the character's reluctant involvement in what he clearly knows is wrong. Mark Robson's direction is spare, but that's fitting. This film noir doesn't require anything fancy". Source: www.nndb.com
