Organ Replacement Progress - Pancreas?

[DoggerDan]

Organ Replacement Progress - Pancreas?

We've successfully replaced heart parts (valves) for decades.

Artificial heart recipients have lived for decades.

Kidney failure folks have lived for decades.

Jobs' pancreas fails; he dies. Where are we on this? Gall bladders are removed all the time. Liver failures can sometimes have their own regrown in time enough to self-replant. At least they can take a third of another's and survive.

What's so complicated about the pancreas? Apparently, it does more than just regulate insulin.

 

[f95toli]

It is possible to transplant the pancreas, this is done from time to time on people with severe diabetes.
The issue here is that Jobs had pancreatic cancer; and you can't cure that by simply transplanting the organ; presumably because it would make the cancer spread even faster, and it would come back in the pancreas as well.

Note that people who die of cancer often do so because many organs are affected; I might be wrong here but I seriously doubt many women die because of cancer in their breasts, the reason they die is that the cancer spreads to other vital organs.

 

[Ryan_m_b]

We've successfully replaced heart parts (valves) for decades.

Artificial heart recipients have lived for decades.

This is a bit misleading; heart valves are either synthetic mechanical devices or more recently regenerative medicine products from decelluarised animal scaffolds. This is not the same as an entire organ.

Kidney failure folks have lived for decades.

I'm not sure about the decades figure but these patients need regular dialysis and are not in good health.

Jobs' pancreas fails; he dies. Where are we on this? Gall bladders are removed all the time. Liver failures can sometimes have their own regrown in time enough to self-replant. At least they can take a third of another's and survive.
What's so complicated about the pancreas? Apparently, it does more than just regulate insulin.

The pancreas is an organ and as such is made from multiple interacting tissue types, that's a hell of a lot of complexity. This poses a problem because trying to mimick the pancreas requires establishing an artificial environment for pancreatic tissues to operate in, this is a daunting task in most avenues of regenerative medicines. The other organs/tissues you mention are not comparable; the gall bladder can be considered vestigial, the filter action of kidneys can be mimicked to some extent and the liver is capable of partial regeneration.

Having said all that there is a http://scholar.google.co.uk/scholar...pancreas&hl=en&as_sdt=0&as_vis=1&oi=scholart" some years ago that inspired me to pursue regenerative medicine.

EDIT: On the subject of Steve Jobs he died from pancreatic cancer which is one of the most lethal types of cancer. Treatment is not as simple as removing the pancreas and installing a new one because most pancreatic cancers show no or little symptoms until they have already undergone metastasis.

 

[bobze]

EDIT: On the subject of Steve Jobs he died from pancreatic cancer which is one of the most lethal types of cancer. Treatment is not as simple as removing the pancreas and installing a new one because most pancreatic cancers show no or little symptoms until they have already undergone metastasis.

Bingo. Pancreatic cancers are extremely, extremely aggressive and invasive. Like Ryan points out, by the time you catch them they normally have undergone metastasis already--Which is why survival rates are so dismal. The 1 year survival rate is on the order of a whopping 25% and 5 years out the estimates are all under 5% or so.

One of my first clinical rotations was through the oncology ward and we had a family with a known history of pancreatic cancer. One of the sons in the family, who's father had died pancreatic cancer, was monitored via imaging very often. Even with a constant monitoring of imaging it wasn't enough. He simply came in one day and had infiltrates in his lungs and liver, after no overt sign of pancreatic cancer in prior and recent imaging.

Normally there is an ebb and flow to how cancer grows. Certain mutations that allow more mutations. Followed by mutations that promote escape from tissues. Followed by those that promote vascular or lymphatic movement, etc. I suspect with pancreatic cancers (though I haven't looked into it) the "normal" ebb and flow of metastasis is different from other cancers--and factors promoting motility and tissue colonization occur early on in them.

Anyway, this is why simply monitoring (even with a positive family history) and transplant of the pancreas probably isn't enough. Maybe once the offending genes are isolated in the case of familia pancreatic cancer then removal and replacement maybe clinically indicated. However, for the majority of pancreatic cancer (non-familia, ie; spontaneous) the best hope really lays in better targeted chemotheraputics with high toxicity to those metastatic pancreatic cells.

 

[DoggerDan]

It is possible to transplant the pancreas, this is done from time to time on people with severe diabetes.
The issue here is that Jobs had pancreatic cancer; and you can't cure that by simply transplanting the organ; presumably because it would make the cancer spread even faster, and it would come back in the pancreas as well.

Yet if one catches it early, before it has spread, then replacement prior to it spreading would solve the problem, no?

Note that people who die of cancer often do so because many organs are affected; I might be wrong here but I seriously doubt many women die because of cancer in their breasts, the reason they die is that the cancer spreads to other vital organs.

Well, yes. That's why early detection is so important.

I think you may be right, f95toli. However, if PC is so devastating and yet reversible in it's early stages, why isn't it tested for on a regular basis?

 

[Ryan_m_b]

Yet if one catches it early, before it has spread, then replacement prior to it spreading would solve the problem, no?

Well, yes. That's why early detection is so important.

I think you may be right, f95toli. However, if PC is so devastating and yet reversible in it's early stages, why isn't it tested for on a regular basis?

I think part of the problem is that there is no efficient and cheap mechanism to easily test for pancreatic cancer. As Bobze related even with regular testing it is possible that from one test to the next a patient can go from seemingly healthy to suffering from multiple cancers. What we need, as always, is better imagining/diagnostic techniques and better treatments.

 

[Ms Music]

Yet if one catches it early, before it has spread, then replacement prior to it spreading would solve the problem, no?

Unfortunately, the cancer cells are still typically in the blood after transplants, and the tumor regrows at twice the rate each time the organ is transplanted, or even with resection. Transplants don't necessarily remove the cancer, neither does resection.