As a cancer survivor my out of pocket cost was $70 parking pass for the hospital Parking lot. Transport to from hospital I did myself until the nausea and fatigue got bad, then a local church volunteered and arranged a driver for me.
Ongoing care for me has been buying a high fluoride toothpaste which is about twice the price.

So lost wages: I can see this being an issues. IF you are under a $ amount threshold previous tax year you can get income replacement through a cancer foundation fund. I earned too much the year before so did not qualify.

So for me it meant working anyway because I was supporting my family. Thankfully I had a WFH setup, so I could do 20 hours a week at whatever time of day I felt up to it, and in between vomiting. Some people may not have fortitude to do that and lose all their monthly income for several months.

One saving grace, Critical Illness Insurance. We had a line of credit that had a balance. The CII wiped the balance clean. So that was helpful during recovery.

Edit: I was self employed so had no disability insurance via work. However Canada Pension Plan has a disabilty plan you can tap into prior to retirement until you are back to normal. It only gives about $1000 a month currently I think