The responses came in addition to news specials on Friday's killing of 27 people, most of them school children, in Newtown, Conn., by a gunman who later took his own life.
Showtime gave its viewers a special warning Sunday before the season finales of the thriller series "Homeland," and "Dexter," a series about a serial killer.
"In light of the tragedy that has occurred in Connecticut, the following program contains images that may be disturbing," said the disclaimer before both programs.
Another cable network, HBO, postponed airings of the 2012 crime thriller "Contraband" over the weekend. The film with Mark Wahlberg and Kate Beckinsale was replaced by airings of "Crazy, Stupid Love" and the remake of "Arthur," the network said.
The Film Society of Lincoln Center in New York canceled Monday's screening of Tom Cruise's violent new movie, "Jack Reacher," that was to include a conversation with the actor. A scheduled premiere of the movie in Pittsburgh had also been postponed over the weekend.
In Los Angeles, the Weinstein Co. canceled Tuesday's planned premiere of the violent movie "Django Unchained."
The TLC network postponed a Dec. 27 special, "Best Funeral Ever," about a colorful Dallas funeral home. The show, considered a pilot for a potential series, will instead air during the first week of January.
In one of the odder substitutions, NBC pulled a Blake Shelton holiday special at the last minute Friday and replaced it with one starring Michael Buble. That's because the Shelton special had an animated segment about a reindeer killing, which NBC would be removed from any future showings of the special.
It's a ritual for entertainment companies in the wake of national tragedies, noted Chris Ender, CBS entertainment spokesman: The network's series and promos are all looked at carefully with an eye toward whether any of them could be considered insensitive with the news still fresh in mind. CBS has made no changes other than doing two prime-time news specials, he said.
Fox on Sunday night replaced new episodes of its animated comedies "Family Guy" and "American Dad" with repeats amid worries they could be seen the wrong way. The "American Dad" episode featured a demon who punished naughty children at Christmas.
Several daytime talk shows, including "Katie," ''Dr. Oz," ''Dr. Phil," and "The Doctors," responded with shows Monday that were dedicated to Friday's shootings. That's unusual for these shows, which are usually taped much further in advance.
Katie Couric's show featured interviews with two families that had lost children in the shootings. In one interview, Couric asked the sobbing brother of one child killed, "Is there something you want people to know about your little brother?"
News reporters had been criticized in the immediate aftermath of the coverage for interviewing children who had been in the Newtown school during the shooting.
Both Couric and "Dr. Oz" featured interviews with spiritual leader Joel Osteen.
Talk show host Phil Graham, in addition to devoting his own program on the shooting, also appeared in Monday's episode of "The Doctors."
"Doctor's orders: Hug your family a little bit tighter today," said Travis Stork of "The Doctors."
"The View" invited ABC News' Chris Cuomo and forensic psychiatrist Michael Welner to talk about the incident. One of the show's co-hosts, Elisabeth Hasselbeck, asked Welner with tears in her eyes, "How can this happen?"
Associated Press writer Nicole Evatt contributed to this report.