Update - Hepatopancreaticobiliary.

For my first month at Memorial, I was on the HPB service, the focus of which is liver and pancreas.  Rotating on HPB as a student is a very good learning experience because it is one of the more extreme areas of oncology.  The surgical cases in HPB tend to be on the longer side.  The pancreas in particular, while being a relatively small organ, is notoriously hard to get to.  It also shares blood supply with other organs.  The end result is that operations involving the pancreas tend to be long and complex, and usually include removing other organs as well (the duodenum on one end, the spleen on the other).

The classic pancreas operation is the "whipple procedure" which takes 4-8 hours depending on the patient.  Surgeons perform a whipple if there is a tumor in the head of the pancreas.  The duodenum also must come out, since the head of the pancreas and the duodenum share a common blood supply.  The problem with taking out the duodenum is that it connects the stomach to the rest of the small intestine, and it also is where the bile from the liver and pancreatic juices drain into.  So once the duodenum is removed, the stomach must be joined to the rest of the small intestine, and the plumbing from the liver and the remnant of the pancreas must also be re-attached.

Other times we do a "distal pancreatectomy", most commonly for small lesions in the tail of the pancreas (more to the left) which can be pre-cancerous (IPMN).  Distal pancreatectomies are not easy either, and since the splenic artery runs right under the pancreas they often involve splenectomy as well.

The liver is also a major component of HPB surgical oncology.  We do surgery on the liver if there is a primary liver tumor (that is, the cancer started in the liver) or there are metastases to the liver.  The liver is where nutrients from digestion are processed by the body.  When we eat or drink, the nutrients, toxins, vitamins, and water are absorbed in the stomach, intestine, colon.  Those organs then immediately drain into the liver in what is called the "hepatic portal vein".  That is why a cancer that originates in the GI tract is so likely to spread to the liver.  Not all veins in the lower body drain immediately to the liver, however.  Some of them skip the liver and go right to the lungs.  That is why cancer so commonly spreads to the liver and lungs.

Anyway, so on HPB we see patients with colon cancer who have metastases in the liver.  A general rule of cancer is that the presence of distant metastases generally means the cancer cannot be cured by surgery, but there are exceptions to this rule, and colon cancer is one of them.  If a patient has a colon cancer removed, and then a year later they have a liver tumor, we often will try to take out that liver tumor.  Liver surgery is challenging because the organ is so vital, and variable.  The surgeon must be very aware of the anatomy and ready to avoid major bleeding, but without compromising other major vessels.  Liver surgery can turn catastrophic really quickly without extra caution.

In the hands of an experienced surgeon, liver surgery is very safe.  Additionally, the organ is the only in the body that is capable of regenerating, so you can remove a huge chunk of a patient's liver and the rest will grow right back.  My attending on HPB is working on a project with some engineers that maps the internal blood networks of a patient's liver before hand.  Then during the case, the engineers use lasers to scan the outside and contours of the liver and they match the internal blood network to the real-time layout of the liver.  When the project is perfected, a surgeon should be able to take a probe and point it to any spot on the patient's liver and look at a real-time 3-dimensional screen to see where the blood vessels below are running.  Right now we can get some idea with ultrasound (so don't worry, the surgeon's are not flying blind), but this would be a big improvement.

The other reason why HPB is a good service for students in oncology is that we are exposed to the less rosy side of surgical oncology.  In HPB we commonly see pancreatic adenocarcinoma, cholangiocarcinoma, and hepatocellular carcinoma.  All of these cancers carry a very poor prognosis.  Even with complete surgical resection, negative lymph nodes, and negative margins, these cancers more likely than not will come back, and quickly.

I finished HPB last week and now I have started my second rotation, GMT (gastric and mixed tumors), which include sarcoma and melanoma.  This month I am seeing a great diversity of very rare cancers and learning more about melanoma (which is not so rare).  I'll update about that soon.