Step 1 : Introduction to the question "Which TV show holds the Guinness World Record for longest-running soap opera?"
..."Guiding Light" was cancelled in 2009 after a run of 72 years. As its popularity grew from its radio spot, the show transitioned into a half-hour television show in 1952. Over the years, it would take on social issues such as alcoholism, teen pregnancy and cancer. It was also the first network-televised soap opera to feature regular African-American characters. Like most soap operas, "Guiding Light" was struggling by the 2000s. Despite the show's best efforts, CBS cancelled the show 2009. Source: SmithsonianMag.com