I think it is but not sure. Single payer cant support catastrophic conditions in large amounts. You need a very healthy population to support it long term.
Medicare covers testing for cancer.
Medicaid covers some treatment and drugs.
Social Security, under disability coverage, covers treatments.
In addition to that there are programs like Charity Care that will pay the treatments.
In other words, crapcare was not needed. There was no need to destroy the insurance plans of 90% of the population to try cover 10%. Why didn't they come up with a separate plan for those 10%?