M. D. Anderson Cancer Center
Date: April 9, 2012
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Lisa Garvin: Welcome to Cancer Newsline, a podcast series from the University of Texas M.D. Anderson Cancer Center. Cancer Newsline helps you stay current with the news on cancer research, diagnosis, treatment, and prevention, providing the latest information on reducing your family's cancer risk. I'm your host, Lisa Garvin. Today, our guest is Dr. Valerae Lewis. She's Chief of Orthopedic Oncology here at M.D. Anderson and we're going to be talking about the bone reconstruction for adults who have had bone cancer. First of all Dr. Lewis, what are the types of cancers that do affect bone in adults?
Dr. Valerae Lewis: In adults the really, the most common lesion or tumor that is in bone is actually metastasis which is a type of cancer that starts somewhere else like breast or lung or prostate that moves to bone. That being said, your adult population is also afflicted with chondrosarcoma and osteosarcoma.
Lisa Garvin: Dr. Lewis, where are the most common sites where we see bone cancer occurring in adults?
Dr. Valerae Lewis: As far as metastatic disease, the spine and about the hip are most commonly affected. As far as primary bone cancers really your long bones and your pelvis are very commonly affected.
Lisa Garvin: So, typically in the past and we're talking maybe 20, 30 years ago, limb salvage was kind of in its infancy, are more patients able to keep their limbs these days?
Dr. Valerae Lewis: Absolutely, especially with primary, you know, primary tumors of bone, osteosarcoma, chondrosarcoma, those are treated surgically with resection and reconstruction and I would say the majority of patients actually are able to keep their limb and we perform what's called the limb salvage surgery.
Lisa Garvin: Are there different types of limb salvage surgery? Let's talk about the different techniques.
Dr. Valerae Lewis: Absolutely and like real estate, it's location, location, location. So, in the distal femur which is the big bone in your body, the bottom portion, the patients do very well with resection and endoprosthetic or megaprostheses reconstruction. So, that's what I actually talk to patients as a PMC in large total knee replacement. So, we take out part of the diseased bone, actually, we take out all of the diseased bone in the distal femur and then replace it with a metal prosthesis. However, there are other areas where you can use a combination of allograft bone; that's bone that has been harvested from a cadaver and a prosthesis together. These reconstructions are called alloprosthetic composites. The benefit of this reconstruction is that you generally get better tendinous attachments and thus, they have a potential for better motion. These are used generally in the shoulder or proximal humerus and the proximal femur and the proximal tibia.
Lisa Garvin: Now, explain the allograft, you say you take a piece of bone from a cadaver, how do you create the graft?
Dr. Valerae Lewis: Well, there are actually companies that are certified to harvest allografts from the cadavers and then what we do is we match them to the patient in size. Then that's sent to us essentially in the Operating Room and after the tumor or the patient's bone has been resected, we implant the same amount of bone from the cadaver that has been size-matched, but before implanting the bone we resurface it with metal. So, we put it in. There are routine, you know, total humerus, or have a hip replacement such as a hemiarthroplasty or a proximal tibia. So, it's as if we're recreating the patient's entire bone with the allograft and then resurfacing it with metal.
Lisa Garvin: Now, do you have problems with graft versus host disease with allografts or the same issues with implanting other tissue?
Dr. Valerae Lewis: You don't have problems with graft versus host disease, but with allograft, you do have a high risk of infection, so the patient has to be very cognizant about sites and signs of infection. So, our patients essentially, you know, they take antibiotics when they go to the dentist, if they get any boils or sores on their toes or legs, we really address those quickly because the allografts do have a propensity to get infected over that of the metal prosthesis.
Lisa Garvin: Now, with the allograft and endoprosthesis versus just the endoprosthesis, which are we doing more of?
Dr. Valerae Lewis: Well, it's really depends on the patient and location. So, I have a patient who flies an airplane and it was very important for him to put his arms straight up in the air so he could turn on and off knobs in the cockpit above him. Really that is best done with the alloprosthetic composite because they regain excellent range of motion. But then I have patients who don't necessarily require that extreme of motion and do very well with just an all prosthetic replacement. This is in the shoulder. There are downsize of allografts and that's why the patient and the physician weigh the choices carefully. The allografts have an increased chance of infection and in addition, they take a long time to heal to the patient's own bone or to the host bone. This is especially true if you get chemotherapy after surgery as you do with osteosarcoma or Ewing's sarcoma.
Lisa Garvin: So, during that healing time where the allograft grafts to your real bone, they would probably have to make significant changes in their lifestyle during that time.
Dr. Valerae Lewis: Exactly, so in the upper extremity, it's not heavy lifting and you really babying your arm until it's healed and then in lower extremity, you can't bear weight on it until it's healed. So, for some patients that can be up to 18 months.
Lisa Garvin: Wow!
Dr. Valerae Lewis: Right.
Lisa Garvin: So, were they having to literally stay off their feet?
Dr. Valerae Lewis: Well, they have to stay on crutches. So, I tell my patients you can do whatever you want as long as you're on crutches and not putting weight on the reconstructed limb, so that you could see why some patients would choose an all metal prosthesis because the day after surgery on an all metal prosthesis, you begin walking on your leg.
Lisa Garvin: And I think in some cases, some like osteosarcoma we tend to see it in younger adults like primary bone cancers if I'm not mistaken, but don't prostheses have a shelf life? I mean, if you were a young person who got prosthesis, wouldn't you theoretically have to have it replaced down the line as you age?
Dr. Valerae Lewis: Yes, most prostheses do have a limited shelf life, be at 15 or 20 years, so the younger you are, the more surgeries you will have. And osteosarcoma, the most common age group is about 18, but it does have a second peak in the fifth to seventh decade. So, as patients are living longer we're seeing that second peak. In addition, as patients survive their original diagnosis, such as breast cancer or lymphoma or cervical cancer, we're seeing a rise in the post-radiation sarcomas. So once again, that's a type of osteosarcoma that is more prevalent in the older age group that seem to be on the rise could patients are surviving their first cancer.
Lisa Garvin: Now, we talked about, well, you've done a previous podcast about bone reconstruction in children and one of the options for children was what's called the rotationplasty. Let's catch our audience up and explain what that is again.
Dr. Valerae Lewis: So, rotationplasty is when you take out, say the knee joint and it shortens the limb, but you leave the neurovascular bundle which is the nerves and the vessels intact with the remaining foot. Then you bring the lower part of the tibia and attach it to the femur, but you turn the foot backwards so that the foot and the toes are actually pointing behind the person and what you're doing is changing the ankle to a knee. So, they wear a prosthesis, but the foot now fits down into the prosthesis and they have a functioning knee.
Lisa Garvin: Do you do less of those in adults than you do in children?
Dr. Valerae Lewis: We do do less of those in adults than in children mostly because the ankle is different in adult, so your range of motion isn't as good.
Lisa Garvin: So, it sounds like with all these treatment options that amputation would actually be a last resort?
Dr. Valerae Lewis: Well, it's interesting. It's a little different from kids than in adults, but amputation--essentially, amputations can be done anytime, so if you get a limb salvage and it fails, you can then get an amputation. That being said, with an amputation you're done with surgery. The chance of recurrence is zero because the part that had the cancer is no longer present and you're up and moving. So, I have patients who had amputations who three months later were up walking around with their prosthesis and were really done. They're actually very happy with their choice. So, even though amputations aren't done as frequently, because of the new generation of limb salvage techniques, they still are very, very good option for people.
Lisa Garvin: Do you find that adults are choosing amputation if they have that as a choice?
Dr. Valerae Lewis: I don't think they're choosing it as much. I think it's more of a personal decision, but you know, people were born with two legs. They do generally like to keep them.
Lisa Garvin: But do we find the body image issues different in children as opposed to adults? I mean, I would think that maybe adults might be more sensitive about their body image because they've had a whole life time to kind of graft it.
Dr. Valerae Lewis: I think adults are more sensitive about their body image because they're more attached to their limbs. That being said, they actually can think through the process a little bit more. So, once you explain to them the need, if it is a need for an amputation, I think they do grasp it somewhat quickly even if they have to leave your office and then come back. This is if there's a need, but I actually think children do better with the amputations because they can re-train their brains and you know, I always say that children are like bangles from Rudolph the red nosed reindeer, they bounce. So, they do their surgery and even if they have an amputation, they bounce back and they're running around.
Lisa Garvin: Do you have many elderly patients that you have to deal with and are there specific issues with them, somebody like over 60, 65?
Dr. Valerae Lewis: Well, the second peak for osteosarcoma is in the fifth to seventh decade, so we do have those individuals who are mostly in their 50's and 60's who have limb salvage surgeries, yes and they actually do quite well.
Lisa Garvin: So, Dr. Lewis, are there any kind of new techniques or refinement of traditional techniques on the horizon, are you doing any research in this area?
Dr. Valerae Lewis: I think the main emphasis at this point is for tendon reattachment. So, for the areas where we use the alloprosthetic composite in the shoulder, in the tibia, in the hip, I think people are working towards getting and developing better tendinous attachments so you could have better range of motion.
Lisa Garvin: Great! Thank you very much. If you have questions about anything you've heard today on Cancer Newsline, contact askMDAnderson at 1-877-MDA-6789 or online at www.mdanderson.org/ask. Thank you for listening to this episode of Cancer Newsline, tune in for the next podcast in our series.
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