Auxiliary Bishop Reverend Francis Kane filled in for the ailing cardinal.
During the Mass, which was held at Holy Family Church, participants took time to pray for the cardinal and wish him a quick recovery.
"I talked with him earlier, and it's difficult, but he's very upbeat," Kane said. "I was happy to see that. And, you know, I think we're all there to support him, all the bishops, so it'll be good."
Kane said he believes the cardinal is due to undergo more extensive testing this week, and then he is expected to start cancer treatment.