Conservative talk show host Rush Limbaugh, 69, announced on air Monday that he's been diagnosed with advanced lung cancer and that he may miss upcoming episodes of his show while seeking treatment.

Why it matters: Limbaugh has been one of the most high-profile conservative media personalities in the country over the past three decades. His show has often featured influential guests, including President Trump.

Limbaugh has also served as an election surrogate and campaigned alongside Trump during the final stretch of the 2018 midterms.

Go deeper: How right-wing radio honed Trump's feel for the Republican base