An elderly cancer patient was injured at a Brooklyn cancer charity fundraiser Friday night when the porch she and several others were walking on suddenly collapsed, fire officials and a witness said.

The victim, a cancer patient in her early 70s, had just finished playing radio bingo at the Sheepshead Bay Yacht Club on Emmons Avenue near Brown Street at about 11:15 p.m. when the porch gave way, a witness told The Post.

The bingo event was a fundraiser for the Circle of Hope Cancer Foundation that started at 7 p.m. at the yacht club.

The woman and four other people dropped about five feet into a hole, said the witness, a 47-year-old woman who asked not to be named.

“The whole porch fell,” she said.

“I was screaming. I was a nervous wreck. I was shaking like a leaf,” she added.

The DJs at the event rushed over and were able to help most of the people climb out of hole, the woman said.

Firefighters arrived on the scene shortly after and rescued the elderly woman. She is in stable condition, fire officials said.

The Sheepshead Bay Yacht Club declined to comment.