More than 10 years ago, Nora moved to London, where she works as a university professor. Nancy works for the U.S. government, and splits her time between Washington D.C. and New York City.

As identical twins, 67-year-old Nancy and Nora Groce share the same DNA. They also share a family history of breast cancer, and both had breast cancer treatment in the last five years. One thing they don't have in common is where they live.

Today, Nancy and Nora are both in remission. They took some time to speak with VICE about the very disparate paths they walked to get there. This interview has been lightly edited for length and clarity.

Nora didn't have to deal with any bills or insurance paperwork, while Nancy had to negotiate with her insurance providers, pay $14,000 out of pocket along with her $3,500 annual premium just to have insurance, fight mistake bills, like one for $40,000, and deal with extreme stress throughout the whole process—on top of dealing with cancer. Nancy's experience reflects larger trends in U.S. healthcare: In 2016, the U.S. spent almost twice as much as 10 other high-income countries on medical care, all while underperforming on health outcomes. Even with health insurance, being admitted to the hospital can result in bankruptcy.

Though their "study" is limited to two participants, it offers a view into how two people with the same disease and the same DNA can experience treatment in radically different ways.

In scientific research, studying twins can help compare how situations or environments affect an outcome since, genetically, the subjects are the same. Last week in The BMJ, Nancy and Nora wrote up a " comparative twin study " of their own. It's about what it's like to get cancer treatment in two remarkably different healthcare systems. Nora is covered through the National Health Service, the publicly funded healthcare system in England, and Nancy has private health insurance through her job.

They asked, "Do you have any health concerns?" And I said, "Well, you know, we have this history of breast cancer in the family," and I immediately got sent to a family genetics clinic to assess my risk. I was 55 at the time, so I was at the age where women in the U.K. regularly get mammograms. But, because of my history, I was told that I'd have a mammogram each year, which I had at a nearby hospital 15 minutes from my house, and I did that regularly for about four years.

I went in for an initial consultation with the local GP and I was very impressed. I went in on a Monday thinking I'd have to make an appointment and they said, "The doctor can't see you right away." I thought, "Oh, I've heard this about the NHS." And then they said, "Could we see you on Wednesday?" I wasn't expecting that.

I moved to the U.K. in 2008 and I could either go to a general practice and enroll in the national health insurance or I could get private insurance. My husband still works in the U.S. and so I could have also stayed on an American health plan.

Nora: We have a spectacular family history of breast cancer. Great-grandmother died of it. Our grandmother died of it. Our mother died of it. So, we knew we were at risk and we were getting regularly tested. Nancy actually got diagnosed in her early 40s for her first bout, but we have been careful about following up because we have such a strong history.

Nancy: When I had my first bout of cancer in 1994 I was about 40. I had a lumpectomy, chemotherapy for nine months, and radiation for two months. After I recovered, I was seen by my team at a major New York teaching hospital and I had a wonderful oncologist, so I liked my team there.

VICE: Nancy, in contrast, even before your second round of treatment, you were running into some issues, because of where you lived and the fact that you had cancer before.

Nora: I think when they were wheeling me in for the lumpectomies, I had to sign some sort of consent form. That's the only paperwork I ever got related to my cancer or anything else with the NHS. You get free medicine also: Since I'm over 60, all my medicine is free. Under age of 60 the most they can charge you is now £9 for any drugs. People in the U.K. sometimes are so unaware of what goes on elsewhere that they will grumble about the £9.

VICE: And during all of that, what kind of bills or paperwork were you getting?

Then they proceeded right on and scheduled a lumpectomy and another lumpectomy. That sometimes happens. They couldn't get ahead of it and they decided that what they really needed was a double mastectomy, and that all took place over the course of about four or five months.

One day, I went in for the annual screening, and they called me back about two weeks later and said that they wanted a biopsy. It was clear when I went back for the second screening—I was in the room with the counselors and they said there might be a risk of breast cancer given my family history.

Nora: Not really. They refer you based on where you live. I was referred to the local clinical breast service, but I live in central London, and the local clinical breast service actually is one of the university teaching hospitals for University College London. They took my medical history, and there was no problem with the preexisting condition. Nobody stopped while I was signing up for the NHS and said, "Oh, wait a minute, history of cancer ... we've got a problem," because, quite frankly, everybody gets taken—100 percent of people who live in the U.K. are eligible to sign up for the NHS. Nobody is excluded as long as they meet the requirements of having residency here.

VICE: Nora, did you have any choices like that to make when you signed up with the NHS—higher premiums for out of network, or pre-existing condition concerns?

I also pay a higher premium because it's termed within my insurance company as "high value medical insurance." It's a considerable percentage more than if I just went with in-network.

I worked in New York until about 2000 when I started to come down to Washington for jobs. At my present employer, I got the more expensive policy that allowed me to retain doctors outside of network so I could keep my oncological team in New York. Also, until Obamacare, I was not covered in Washington because my cancer was a preexisting condition. New York put in a statute saying that you couldn't be denied coverage because you had a preexisting condition, and that was one of the decisions for me to retain my place in New York, my apartment in New York.

Nancy: When I had to call a doctor's office or call the insurance company, I spoke to a lot of very pleasant people. They were very sympathetic. I probably called the insurance company two dozen times to try to clarify what a charge was for or why they were only paying a certain percentage of my claim to the doctors. I would say 90 percent of the people I spoke to were women, and I think they're used as frontline venters for people. They very rarely could resolve things. They were there for me to blow off steam to and be sympathetic, but they weren't in the position, usually, to make any major decisions.

Nora: And Nancy's doing this with a PhD. With a PhD, she's really struggling to sort this out. When we lived in the U.S., we would struggle at home with filling out forms even when my kids had earaches, we’d encounter the same sort of thing. I think that it's such a lugubrious system, it's designed not to be clear.

It's exhausting when you're in the middle of recovering from lumpectomies and MRIs and all sorts of things, but I realized that would drive me crazy later trying to reconstruct it.

Nancy: Almost everybody I know has had run-ins with their insurance company, strange billings, and paperwork. I found it totally exhausting and frustrating. Because I had had cancer before, one of the things I did initially is set up a chart, an Excel sheet, and I kept meticulous records about when I was going in, for what, and who I talked to. If I called an insurance company, I would take down the names of everybody I spoke with or needed to get back to, a nurse who was going to send someone something or confirmation of this or that.

Maybe if Nancy had a partner living with her who, on a day-to-day basis, was getting all the information, that partner could have been some help. But, for people who are on their own, which are millions and millions of people, this is just on top of whatever your illness is. This is like another disease.

Nora: First of all, I thought, "Thank God I'm in the NHS." I felt just terrible for Nancy. It was continuous stress and it went on for a month. Sometimes, I'd call up, and she'd obviously been just out of radiation and she was not feeling hot and she had to call up this place or that place.

Some departments would never negotiate. It seemed to be the whim of the person who answered the phone. Here I am: My employer is paying a large amount for insurance. I'm paying monthly into insurance. And then, you have to call up and negotiate as if you had nothing in place.

Nancy: Let's say a claim was processed, $300 for example, and they decided that I owed out of pocket. They would pay $200, but I owed out-of-pocket $100. Very often, if I called up, the lab or the doctor or the radiation department involved would say, "Oh, well, if you pay right away or if you give us your credit card number, we can lower it 20 percent or 10 percent." I was saying to Nora, "What is this, a post-Christmas sale?" How can they do these things? And, what happens to people who don't think to make that call?

VICE That inconsistency must be so frustrating too—feeling like the costs are somewhat negotiable or not set in stone.

Nancy: And I worked throughout this. There were days I’d go to radiation early in the morning, and then I'd go and work an eight-hour day. I'd come home, I'd open the mailbox, and there was yet another bill. I would sometimes just come up to my apartment and scream at the walls. I'd get really, really angry, and I tried not to call to negotiate things when I was really angry because I thought that was going to be counterproductive.

It was not good for my blood pressure, which apparently had already been raised by the lumpectomy. I used to have low blood pressure. Now, suddenly, I was having issues with high blood pressure.

VICE: Both of you are in remission, which means that you ultimately ended up at the same place, healthwise. But it sounds like the stress did take a physical toll?

Nora: We have a very small sample size. We can't say that there's a one-to-one correlation between Nancy's blood pressure and all the stress she went through. We think it's related, but a physician could say, "Well, it could have been other things."

Nancy: I just know as far as stress, it was something that was ever-present throughout, not only the time I was being treated, but for the months afterwards when I kept getting new bills or trying to resolve old bills. It wasn't like I finished treatment and I could go out and celebrate. I had to keep monitoring the situation.