02.22 Bone Cancer (Osteosarcoma, Chondrosarcoma, and Ewing Sarcoma)

All right. Hi guys, we’re talking today about bone cancer. So just an overview here of sarcoma. This is a tumor that forms in any bone or connective tissue, and actually primary bone cancers are pretty rare, but they can occur at any age. In fact, one of the most common childhood cancers is bone cancer, but again, it can occur at any age. Metastasis- So this is important to talk about. Usually, as I said, bone cancer, cancer in the bones usually spreads from another site and goes to the bones. However, if it’s a primary bone cancer it can also spread to other places and it most often goes to the lungs, we don’t know exactly why this happens, but that’s just the most common sites of metastasis. And then it does go into the bone marrow often for the specific type of ewing sarcoma.  Survivability- This is exciting to talk about as an oncology nurse, because we have made huge advances in the treatment of bone cancer and survivability has significantly increased because of that.

There are 3 main types of bone cancers and they have a lot of similarities, but we want to talk now about what makes these different types of cancers, unique. Osteosarcoma forms in the osteoblasts. So those are those bone-forming cells, right? And this cancer often occurs in children and young adults, 

Chondrosarcoma forms in the cartilage. And this most often affects adults. And then ewing sarcoma can form in soft tissue or bones. And this is actually most common in teenagers. And this one is more of an aggressive spreader. It spreads more aggressively. So this is the one that we see goes to the bone marrow, as I mentioned before, and it’s treated more with chemo and radiation versus just local surgery. We’ll talk more about that in treatments, but no matter what, they all commonly form in long bones, they can form anywhere in the body though. So risk factors for any type of bone cancer, an important thing to mention is a lot of them are non-modifiable. So it’s not something that we can change, right? Unlike skin cancer, where we can say, don’t go in the sun or lung cancer, we can say don’t smoke. 

There’s not really anything we can change. If they have genetic mutations, they can be at risk if they’ve radiation treatment in the past. And so this would be a modifiable one, but necessary, right? We’re talking about radiation like to treat cancer, actual radiation treatment for something not, x-rays not that sort of radiation exposure. We’re talking about high dose radiation exposure, and then fast-growing bones. Again, we can’t really change this, but we’re talking about that age group, right? Well, fast-growing bones, adolescents. And then also if they have some bone growth disorder that causes their bones to grow more frequent, one of those is called Pickett’s disease. Let's talk about the way that these patients usually present. They come in with pain, almost always a dull ache. That’s worse at night, and usually, that’s just because they’re at rest and they notice it more since they’re not moving, they notice the pain more. And this is because the tissue is damaged right around the bone. Of course, it’s going to hurt or cause swelling because of the tumor growth, right? You might even feel the tumor or you might feel a crazy thing is even a bruit from increased blood flow to that site. And just a reminder, a bruit that’s what you hear with these patients who have dialysis, from their dialysis fistula- underneath their skin and you put your stethoscope on that, you can hear it. So that’s what a bruit is. And you can kind of sometimes hear that with these tumors growing on the bones or in the joints- decreased range of motion. This again is from swelling in the joint, right? If there’s a tumor, this is a bone and this is our joint, a ball and socket. Right? Of course, they’re not going to be able to have the same range of motion if this tumor’s going to get in the way.  And then pathologic fractures-  they can sometimes present this way. Like they broke their femur without even falling or that sort of thing. So that would be a pathologic fracture. It just happened. And we don’t know why, not caused by injury, but it’s caused by weakened bones. So these are often oftentimes bone lesions or tumors are found by x-rays. Even from just going to the dentist and getting a routine, x-ray sometimes it’s found even there. And then we get a CT or an MRI for a more specific picture and to look for metastasis, then they’ll do a biopsy of the tumor and also a bone marrow biopsy. Again, that is with Ewing sarcoma- those usually go hand in hand because we want to see if it spread to the bone marrow and then lab values. We’re looking at a few important ones. So CBC, and again, that’s a complete blood count. We’re looking at our white blood cells,  platelets, and red blood cells. So these are all gonna be decreased if we have bone marrow involvement because these are created within the bone marrow. So if the bone marrow is not working, these are all going to be reduced. And then also the chemo they go through also causes this pancytopenia or reduction in all of these numbers here. So that’s why we monitor the CBC. We also monitor the CMP to help us show the kidney function. 

We’ll look at LFTs to assess the liver function, to see how they can tolerate treatment. And then an important one specific for this cancer is an ALP, and that is a byproduct of the osteoblast activity. So as bone is formed, this ALP goes up in anyone. But in this case, we’re talking about the tumor activity sometimes releases this, so it will be increased and the treatment. So this is where we’ve been doing multimodal approaches. We don’t only do surgery for these patients or only chemotherapy often it’s a combination and that’s what has caused an increase in patient survival or disease-free time. We used to just say, if they present with bone cancer, we’ll cut off the limb and send them on their way. But then we found that 80 to 90% of people were coming back later in life with the cancer again, or if it had spread to the lungs, for example. 

So now in addition to doing the surgery, which is still the number one treatment and most effective, we also will do chemo or radiation and we’ll talk about why we do those. So for the surgeries- often we can do limb-sparing. Now, unlike in the past where it was more amputations. Sometimes we still do amputations, but often we can do limb-sparing. And in this case they would often have a bone graft that we need to do a lot of education about their weight-bearing status and stuff as this bone graft is growing. And then there’s also a surgery called a rotationplasty. And this is just a very unique surgery. We’re going to talk more about this on the next slide: chemotherapy- So this can be before or after surgery if it’s before surgery it’s called Neoadjuvant. And if it’s after it’s called adjuvant. So neoadjuvant would be to reduce the tumor burden before surgery usually, or sometimes a primary treatment, especially in the ewing sarcoma. And then after surgery, the adjuvant chemo is to kill the micro Mets, micrometastasis that we didn’t really know about until all these patients started coming back with more cancer. So now we’re taking out the main tumor and also treating these little undetectable, micrometastasis with chemo to prevent it from coming back. And then radiation is used in the same way to kind of treat the micrometastasis or as a local treatment to reduce the tumor size, or it is sometimes used as palliative treatment. If we don’t think we can resect the tumor or it’s not something that we can treat we'll give palliative radiation to reduce the size of the tumor for pain management. Radiation is also often used more in ewing sarcoma. 

We’re going to talk more about the rotationplasty excuse my drawing, but I want you to kind of get a picture of what this is. So we have someone who comes in, these are two legs here, right? They have cancer like right here. So here’s their cancer. So they need to be amputated above the knee because we have to get enough clear margins are cancer, free zones to amputate. But, they still have this healthy foot down here. Right. Um, and then their other leg is fine. Right? Okay. So for this surgery, we’re cutting the leg off right here, but we’re also making a cut right here, leaving enough healthy tissue. So there’s not a risk of there being cancer down here or down here, but they cut off this section of the leg and then here’s this healthy leg, right? They reattach this part of the leg. They’ll reattach it so that this heel becomes their new knee joint. So they have this knee joint over here and they have a knee joint right here from the heel. So they reattached this portion of the leg up here on this above the knee amputation. So when these people are walking, their heel is what you’ll see above their prosthetic. So they can wear a prosthetic and get around a lot better with this type of surgery. So this is just so shocking to see. It was one of the most surprising things I ever saw as a new oncology nurse. When I went to do my assessment for a patient. And I saw a foot when I expected the knee, not only a foot, but a backwards foot. It was just very surprising. I had never heard of this surgery. So I hope that I can save you from that shocking experience. Luckily, the patient was fantastic and you can always Google this rotationplasty um, and there are some good videos patients have put out about how they get around. There’s this really great. One of someone swimming and even directly bearing weight on the repaired limb. All right, guys, we covered a lot about bone cancer today. I hope you can apply this information in your clinical practice. We love you guys go out and be your best self today and as always happy nursing.