If you are the meeting organizer, then there are times when you have to cancel a meeting. Here are some sentences you can use for this situation.

"There are four people who will not be able to attend the meeting tomorrow. I am going to reschedule the meeting to a more convenient time."
"The director asked that we postpone the finance meeting until the quarterly report comes out. So I'll send an update with the new date and time later this week."

Some meetings are weekly meetings that occur at the same time. It is common that these meetings are canceled when there is nothing to talk about.

"There is nothing new to discuss this week, so we are going to cancel this week's agenda meeting."

"I am running late this morning. Let's postpone the meeting until the afternoon."
"I can't make it in tomorrow, so let's cancel this week's meeting. I'll email everyone if something new comes up."