Unexpected costs for cancer treatment can amount to tens of thousands of dollars, a Newcastle researcher says.
Professor Christine Paul's research found more than a third of patients and carers had higher than expected out-of-pocket costs.
"These costs can vary from a few hundred dollars up to $70,000, or even more in some cases," said Professor Paul, co-deputy director of Hunter Cancer Research Alliance.
The University of Newcastle professor will speak at a public seminar on the matter at Hunter Medical Research Institute on Thursday.
Getting cancer can tax people physically and mentally and financially destroy them.
Those with private health insurance faced double the out-of-pocket expenses as those without it.
Such expenses in the private sector can relate to gap fees, while in the public sector they can be for things like the cost of chemotherapy drugs not covered by the PBS, along with travel, parking and accommodation.
Sometimes patients aren't aware that a treatment in the private system can be done in the public system for free.
The research shows that more than a third of patients and carers report problems paying bills due to the financial impost of cancer.
"Ninety percent of these people never had these kind of financial problems before the cancer diagnosis," Professor Paul said.
Cancer patients face the "double hit" of unexpected costs and being unable to work or having to work less.
"Two-thirds of patients who were employed when they were diagnosed reported their income was reduced," she said.
"Once people have used up their savings, they can find it very hard to find help and, when they do, it is still hard to manage if they need to rely on government support, the generosity of friends or charities."
Getting help from Centrelink was "very complicated".
A third of patients report a "moderate or heavy financial burden" over the cost of cancer-related medicines.
Those affected have described their experiences with comments like: "This continues to be a massive financial strain on our family", "It's as big a burden as the cancer itself" and "If the cancer comes back, I don't know what I'm going to do".
Some treatments, such as robotic surgery for prostate cancer, have "very high out-of-pocket costs". Often, people are not prepared for these costs.
These high and unexpected costs can lead to distress and anxiety, strained relationships and worry about the financial future. The professor said changes were needed, including greater disclosure of costs, reducing gap costs and changing the rules around safety-net support from Centrelink.