I play at being a physician-scientist in rad onc academics, which for me personally has been a rollercoaster of highs and lows.
MD/PhD program average length is about 8 years, and it has been that long for many years now. The idea of a 6 year MD/PhD is very antiquated and 7 was even hard to pull off when I started an MD/PhD program almost 20 years ago.
Physician-scientist jobs that lead a research lab are supposed to be 20% clinical effort. That is basically the intent of MD/PhD training--to train leaders of research labs and/or enterprises. One day a week in clinic or a few weeks a year of hospital service is the model for research-oriented physician-scientists in most specialties. 75% research effort is required by K grants, as the NIH also views the physician-scientist as someone who has 25% clinical effort or less.
Most institutions aren't going to take you seriously for that kind of protected time and other startup resources to build a lab without at least a K level grant. For many institutions (including some big name places that supposedly want research), even a K isn't enough, and they're looking for R01 level funding or equivalent (hundreds of thousands per year committed for 5 years, transferable to their institution).
The average age for MD/PhDs to get their first R01 is 45 years old. That's not a typo. This is not 1980 when people like Ralph Weichselbaum finished their training and the average age for MD/PhDs to get their first R01 was 36 years old.
This means that today, if you start medical school at 22, finish MD/PhD training at 30, do a 5 year rad onc residency, you'll be done at age 35. Let's assume that you did not get major funding during residency, and frankly almost nobody does because an 18 month Holman isn't really enough time and the NIH and most other funding sources are not looking to give K08s or larger to residents.
Now you've got a choice if you're an MD/PhD who actually wants to do significant basic and/or translational research. You can either:
1. Go to a main center academic job like Wake Forest just posted at 80% clinical and work a lot of extra hours to prove yourself with grants and papers to claw back time.
2. Go to a research fellowship or instructor level position for at least 2-3 years to do more experiments, write papers, and write grants. If you're both lucky and good, you may end up with a real physician-scientist job somewhere once you get a solid grant. You may not succeed, and in this case you will end up back in position #1 or #3 below.
3. Just be screwed by the job market, have no option for 1 or 2 above, and end up in an academic satellite being a full-time clinician. Maybe they'll tell you that you might be able to work your way back to the main center. Maybe that will actually happen. What choice do you have?
There are shades of gray here. Maybe you got a 1-2 year grant as a resident that allows you to negotiate a 50% research position as faculty. Maybe you have a K08 written and/or submitted and your home institution or someone else powerful likes you enough that they make a case for you and give you a startup position anyway at 1-2 days of clinical effort and resources for 3 years assuming that you'll get the K grant. This is a select number of institutions willing to do this and happens for a small number of people every year.
The problem moving forward is that you have to sustain it. They're going to be expecting that R01 out of you within 5 years of starting, and probably sooner than that. Remember, you started your faculty job at 35, they're expecting that R01 by 40, and the average age for first R01 is 45. The selection pressure here is enormous, and most will fail to get their first or second R01s. The funding rates for R01 level grants are about 10% and as a new grad you'll be competing with career scientists and physician-scientists.
The physician-scientist pathway is straight up broken in this specialty. There are a very select few MD/PhDs who will succeed. The fellowship that's posted is for someone who really wants to take a shot at it. Or maybe they can't find any jobs besides academic satellites, and they are willing to take a shot at being a real academic because they never went into MD/PhD and rad onc to go be a generalist full time clinical rad onc at an academic satellite. There used to be plenty of high paying private jobs that would absorb MD/PhDs who didn't want to roll the dice or who weren't good and lucky enough to succeed. They would also absorb really strong productive clinical rad oncs in academic departments. But, there are very few of these jobs left, and they rarely want to take a chance on a seemingly academic MD/PhD when there are loads of "three A" graduates clamoring for them.
So in the end, this sort of fellowship just reflects the reality of a very difficult situation.