You still have access to any sales and attendee details for any tickets that have been cancelled in an event.
To find a list of your events cancelled tickets navigate to the manage attendees > attendees report.
Click the filter next to the search bar and select cancelled under order status.
Cancelled tickets are removed from the attendees report as they are no longer considered 'attending' the event.
However, any unrefunded sales amounts will still count towards your earnings
You can also use the orders/refunds > orders report to track the financial overview of each order including tickets cancelled and remaining earnings.