Kim Kardashian Stays Mum on Kate Middleton's Cancer Diagnosis After Joking Online

Kim Kardashian stayed mum about Kate Middleton's shocking cancer revelation Friday ... this after the reality star created controversy over her recent flippant comments about the princess.

Kim and her son, Saint, tried to make a fast getaway as they were leaving his basketball game in Thousand Oaks, CA -- but they couldn't escape the lenses of the paparazzi.

As they dashed inside their waiting SUV, one of the shutterbugs hurled a question at Kim, asking her for a comment about Kate. Kim didn't even acknowledge the photog before disappearing inside the vehicle with Saint and being driven away.

As you may recall ... Last Sunday, Kim got herself in some hot water when she posted an Instagram image, showing her standing next to her ride while making a small wisecrack about Kate. In the caption, Kim lightly joked that she was on her way to find the Princes of Wales.

This all happened after Kate vanished from the public eye amid her then-secret cancer crisis.

But it didn't matter ... Kim caught heat from commenters, accusing her of trolling Kate for flying under the radar. Now Kim is getting really roasted after Kate's big cancer reveal Friday. The reason? Kim hasn't taken down her Kate post from IG.

Pissed-off people wrote in Kim's comment section ... "You should take this down!" "Kate Middleton has cancer Kim." "She’s having cancer treatment… this didn’t age well."

A few other KK critics advised, "I would take this down and apologize, she has cancer" and 'take your s***ty post about Kate down!"