There's nothing in the Australian health care system that precludes people with uncommon conditions seeking specialist treatments either in Australia or abroad.
> she will have a much higher chance of survival in the US.
Without a deep dive it looks ballpark the same, to be honest.
AU Cancer Survival Rates:
The 5-year survival for cancer in 1991–1995 was 55% and by 2016–2020, the rate had increased to 71%. Even with decreasing mortality rates and increasing survival, the number of deaths from cancer has been increasing.
US Cancer Survival Rates:
Five-year survival rates have also been increasing for an even longer period of time. The overall cancer survival rate was 49 percent in the mid-1970s. It currently sits at 68 percent