I understand your argument: you're saying that by treating stage 1–3 patients early on, the stage 4 patients will have a shorter survival. But in the US, stage 4 patients also include many patients that would have been stage 1–3 in a different country, and because these cancers may not be quite as aggressive as the other stage 4 cancers, the 5-year survival will be higher. I'm on board with this part of your argument.
The part that doesn't hold up is patients regularly coming in to their doctors with symptomatic early stage cancer. In early stages, many cancers are completely asymptomatic. Even when we screen completely asymptomatic patients for early stage cancer in the US, we don't actually see clear cut overall mortality benefits. So how is it that these Australians are presenting to their doctors so early on with cancer symptoms?
EDIT: The holy grail of cancer screening has three features:
- Identifies dangerous cancers shortly after they form
- Perfectly separates cancer from non-cancer
- Patients live longer
Medical science itself (regardless of healthcare system and country) can't reliably meet the above three goals. So I'm skeptical that patients having easy access to medical care like in Australia would result in improved cancer survival.
This isn't a trivial problem. These patients are often asymptomatic, and objective physical exam findings are not easy to elicit or entirely non-existent. At this point, the only thing a doctor can do is screen every patient coming through the door for cancer via CT, MR, mammography, colonoscopy, etc., but this doesn't translate into clear cut clinically meaningful benefits that helps patients live longer. You often end up irradiating non-cancer patients and creating new cancers, or you selectively diagnose non-aggressive cancers (length-time bias) and unnecessarily put patients through surgery, chemotherapy, and radiation (i.e. over-treatment). Some fraction of these patients then go on to live shorter lives as a result of the over-treatment. This particular issue we're discussing is more of a medical science problem than a healthcare system problem.
Anecdote from med school: on my surgery rotation, I had a ~70 year-old patient recently diagnosed with early stage colon cancer on a screening colonoscopy. He had undergone chemotherapy and was now about to have the cancerous part of his colon removed. Surgery was a success, and the patient recovered in the hospital for a few days before we sent him home. The day after he goes home, we found out he died from a massive pulmonary embolism, likely a post-operative complication from surgery.
Alternatively, had this patient not had a screening colonoscopy, we never would have found his early stage cancer. Based on his cancer stage, he likely would've lived another 10–15 years without treatment (age ~85-90). Instead, our interventions killed him a few months after diagnosis.
> The records of all births, deaths, and surgeries are known.
Actually, this is not known (at least in the US). There is no central medical database or significant communication between hospital systems. As you can imagine, this is problematic for obtaining meaningful data. In order to answer the questions you raise, researchers have to begin collecting new data prospectively or look retrospectively at the incomplete records contained within their hospital system. The retrospective method is easier and probably more common, but there are serious biases with a retrospective approach, including small sample sizes and non-random sampling (many US hospitals serve specific demographics).
I find this somewhat astonishing and deeply troubling. How can patients or doctors truly make informed decisions if they are not in fact well informed? This is not right at all.
The other party responsible for the lack of centralized data is the EMR vendors (Epic being one of the largest). They're incentivized to lock-in their clients (i.e. hospitals) by making any kind of data sharing at best a pain in the ass and at worst entirely impossible. For large health systems, I've heard the cost of changing EMRs is in the tens to hundreds of millions (USD).
Besides the detriment to research, this does lead to real patient harms. Where I went to med school, there were two major hospitals systems about 5 mins from each other in a major city. I worked in the emergency department at one hospital where I would frequently see patients coming in after car accidents and heart attacks. But often, some of these patients had received all of their care at the hospital 5 mins away. We had zero records for these patients. Meaning, we had to work them up from scratch and any important medical history would be unbeknownst to us. This obviously led to poor care and duplication of medical tests, which can be harmful (e.g. radiation from CTs). And requesting medical records from the other hospital was infeasible in emergencies. Realistically, these records were only available 9a–5p on weekdays via fax at the other hospital's leisure.
I'm claiming that Australian citizens are more likely to bring cancer to their provider when it's still at stage 1, because the citizens do not risk bankruptcy when seeking diagnosis and treatment, resulting in treatment of cancers beginning prior to their reaching stage 4.
This would, if true, create a scenario where:
In Australia, the few stage 4 cancers seen are the cancers that failed treatment at stage 1, stage 2, and stage 3; they are extremely likely to be fatal, as they've already failed essentially every treatment available.
But in United States, the stage 1-2-3 "this is treatable" filtering out isn't occurring, because patients with cancer are waiting for age 65 to seek diagnosis, and so our stage 4 treatment success rate is higher because we didn't treat the treatable cancers earlier in the stages.
Do the above comparisons of AU vs US 'stage 4 survival rates' take into account the successful treatments at stages 1-3 that would presumably be occurring in AU? Do they take into account the incidences of 'this would have been treatable if diagnosed in stages 1-3' that are presumably occuring in US?
EDIT: Do they hold true for each individual type of cancer? Do they hold true when normalized for spending on a given type of cancer as a percentage of all cancer spending?
I'm aware that these are not easy things to compare or assess, and I understand that it's preferable to some to make no statement at all rather than make an approximation that doesn't hold up to a full-power statistical analysis. If someone does know of such a thesis, I suppose my most compact question would be:
"For each type of cancer: Does the Australian health care system tend to diagnose earlier than the United States health care system, provide care at a higher or lower total cost of treatment, with a higher or lower rate of success?"