MD Anderson Cancer Center
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 the Chief of Orthopedic Oncology here at M. D. Anderson and our subject today is limb sparing surgery for pediatric patients who have had bone cancers. So Dr. Lewis, first of all, what are the types of bone cancer that affect children?
Dr. Valerae Lewis: Well, the two most common types of bone cancers that affect children is osteosarcoma and Ewing's sarcoma. So the majority of young patients that we see with sarcoma of the bone either have a osteosarcoma or Ewing's sarcoma.
Lisa Garvin: And the most common sites are the ends of the long bones, correct?
Dr. Valerae Lewis: Correct. So we say around the knee. So the distal femur and the proximal tibia, which really makes up your knee and then other common locations are in your proximal humerus and then in your pelvis kind of your hip bones.
Lisa Garvin: In the past, it seemed that a lot of pediatric patients did have to lose a limb, but we've come a long way since then.
Dr. Valerae Lewis: Absolutely. So I would say about 30 years ago the standard of care both in the pediatric population and in the adult population was amputation. It's really been the advent of chemotherapy that has allowed us as limb reconstructive doctors to really take our technology further. So at this time, there are excellent options for limb reconstruction for both children and adults. Children, however, do have a unique set of problems that you have to deal with when you're going to reconstruct the limb. One, children can be very, very small, so a 5, 6, 7-year-old, really the size of their bone is so small that it's hard to build a prosthesis that is durable that won't break, and in addition, you have to account for how much the child is going to grow. So can you save someone's limb who's about 3 feet and then you look at their parents and they're both 6 feet tall. No, we do not have a prosthesis that will grow that amount. So there're a lot of factors that you have to consider when you're first meeting a child who is a candidate for limb sparing surgery.
Lisa Garvin: So Dr. Lewis explain exactly what limb salvage surgery is?
Dr. Valerae Lewis: When it comes to bone tumors, limb salvage surgery consists of taking out the bone where the tumor resides and replacing that bone with either a prosthesis or with another type of bone. So when it comes to putting in prostheses and say a patient has a tumor in the distal femur, which is the big bone in your thigh, the surgeon cuts out the bone with the tumor in it and then reconstructs the bone by using a metal prosthesis. And a good way to think of it is kind of a fancy total knee replacement.
Lisa Garvin: Ewing's sarcoma is seen in sometimes very young children, correct?
Dr. Valerae Lewis: Absolutely.
Lisa Garvin: And so these issues come up fairly frequently?
Dr. Valerae Lewis: Yes, they come up very frequently for both Ewing's and osteosarcoma.
Lisa Garvin: How do you handle it going in with the parents? I mean you kind of have to lay out, you know, the possibilities. Is, is that tough trying to tell parents that their child's physical appearance may change dramatically?
Dr. Valerae Lewis: Well I think the first thing I have to do really or that we do with parents is to put them in the right perspective. I always say all my training, I'm two types of doctors, my training is such that my surgical training is at limb sparing surgery or limb reconstruction, but first and foremost, I'm an oncologist. So my goal say I'm with a mom and dad is really to get you grandkids, so that means your child has to get through high school, get through college, get through graduate school, get married, and then have grandkids. So my goal is to have your child live 30, 40, 50 years, and if they do that with their, with two legs or one leg, the most important thing is that they survive. And I think when you explain that to parents it gets them in the right mindset and that first conversation once they've kind of grasped that information, our next meeting we start talking about the different options. I start talking about the different options early, so they can explore what's right for them because say a prosthesis for one child may not be the right option for another, you know, for another child and another family.
Lisa Garvin: What are the options? I know that there are prostheses that can grow a little bit, but I guess they wouldn't be of use in a very young child.
Dr. Valerae Lewis: Well, the problem is depending on the age of the child, the options are amputation, Rotationplasty, which is a type of amputation, but generally leaves the child with a functioning knee and that's something we can come back to and then different types of prostheses or growing, growing bones. I say growing the bones like in the humerus, sometimes we take the fibula and tack it onto what we've taken out of the humerus and then the fibula will continue to grow, so the patient's arm will continue to grow. But that's not, that's not possible really in the lower extremity. So as far as growing prostheses in the lower extremity you have to consider both the patient's age, the patient's current size, how tall the patient will be, and you also have to take in consideration the family dynamics. Expandable prostheses are a huge undertaking for the patient, the family, and the physician. If you don't have a family who will buy into the rigorous physical therapy necessary then you're putting in an incredibly expensive not very durable prosthesis that they won't use, they won't get the benefits of because you have to have excellent knee range of motion before we can expand you again.
Lisa Garvin: Now, what is the, the upper limit of expansion in a prosthesis like this, a couple inches?
Dr. Valerae Lewis: Well it all depends on a, what type of really what manufacturer, what type of expandable prosthesis you're using, but with the new prostheses they can almost be indefinite because you can swap out the components. So you can expand it till it gets to a certain length. So say one prosthesis has you know two inches of expansion, then I can swap it out and then grow them again. So with the newest expandable prostheses, it's almost, almost infinite is the upside. Another upside is the expandable prostheses now are noninvasive. So the patient can either get expanded in the office or they can just go to the operating room and go to sleep and we expand them without opening them up. When we do have to open them up, that's when we're switching out the prostheses for another growing one. However, there is a downside because every time you operate on a prosthesis, the chance of getting infected is significant, small but significant and then once the prosthesis gets infected the child generally may ends up with an amputation.
Lisa Garvin: How many of these do you put in?
Dr. Valerae Lewis: At this point, it's too many to count.
Lisa Garvin: Oh, so people are, the parents are selecting that option then?
Dr. Valerae Lewis: Many parents do select the option. However, I think as a community, as an orthopedic oncology community we don't want to expand the indications too much because one of the things we're noticing or one of the things I'm noticing as I get, I hate to say older, but one of the things I'm noticing as I get more experience is the kids who have an amputation are done. They're done with their cancer, they can get back to their activities, they can go skiing, they can jump out of a plane, they can jump on a trampoline, they can do anything they want. Kids with these expandable prostheses really can't do anything. They can't run, I mean they could run if a bear is chasing them, but they can't use running as an activity. They can't play basketball, they can't go downhill skiing, they can't go waterskiing. Really their main activities are tennis and golf because you don't want to put wear and tear on the prosthesis, you don't want to put wear and tear on the prosthesis-bone junction because you know they're going to get another prosthesis later in their lives and you want this one to last as long as possible. So what I'm seeing really is as long, the longer I'm in practice what I'm seeing is and what I'm beginning to question is are we helping kids as much as we think we are by saving their limbs at ages, you know, 9 when I almost feel like we may be robbing them a little bit of their youth because they can't do all the activities they want.
Lisa Garvin: And I would think that amputation even a Rotationplasty as we're going to talk about in a minute would be a hard sell?
Dr. Valerae Lewis: I have quite a few patients who've come in and chosen amputation and he's a 10-year-old boy and he came in and said I want a amputation, I don't want to growing prosthesis because I want to jump on a trampoline tomorrow, you know, I want to be able to downhill ski. So, you know, here in Texas our patients come from all over and he is from, you know, an area where he can go skiing and he wants to ski, he wants to do karate. I'd a one child who chose Rotationplasty because he was big in karate and he want to continue the karate and continue the kicking and that type of thing. So I think kids are getting more savvy as well.
Lisa Garvin: Let's talk about the Rotationplasty. What is that?
Dr. Valerae Lewis: It was pioneered really kind of in the era of TB and what's most the name that it's most known under is kind of the Van Nes Rotationplasty because he popularized it. What you do is you take out the knee, and the tumor is either in the distal femur or the proximal tibia in this case and then you shorten, you reattach the tibia to the remaining femur. But when you do that you turn the foot around so it's pointing the opposite direction. So esthetically it may not be as pleasing as having a, you know, internal reconstruction when it looks like you have your two own legs. However, the activity possibilities are endless, essentially you're converting a patient who may have had an above-knee amputation to a below-knee amputation. The ankle acts as a knee so they're able to run, they're able to bike because they have that push off of their knee. They're able to ice skate, they're able to play soccer. So really they can do all activities very, very well because they have their own knee.
Lisa Garvin: So and then there's a prosthetic leg attached to the...
Dr. Valerae Lewis: Right, there's a pros.
Lisa Garvin: With the old foot.
Dr. Valerae Lewis: Exactly. There's a prosthetic, they still have to wear a prosthetic leg, but now they have a functioning knee versus a metal prosthetic knee. So as you said sometimes these can be a hard sell and we really veered away for these for a while, but I think it's really coming back because people are realizing, you know, the activity levels that can be achieved with the rotationplasties.
Lisa Garvin: And you really want to save that knee whenever possible?
Dr. Valerae Lewis: Right. You, a knee, a knee is incredibly important when it comes to kind of high impact or high functioning activities.
Lisa Garvin: So is there anything in the future? Are you looking at new surgical techniques or reconstructive techniques?
Dr. Valerae Lewis: Well the growing prostheses I think they're coming out with better growing prosthetic options that are a little bit more controlled. I think the main dilemma still remains in the young, the young children because you really, you know, it's difficult to make a durable prosthesis. You know, if you remember if you're 7 and you're going to live to 80 you're going to have a multitude of operations if you have a prosthesis by the time you're 80 because if you think grandma and grandpa their total knees and total joints only last 15 to 20 years, but they're 65. So these kids are much more active, but they're much younger. I mean the plus side is for the parents and these children, there's a plethora of options and they continue to grow, but you really have to consider really what's best for the child and the family dynamics when you're choosing these options. I have kids who are incredibly successful with their prostheses and then I have kids who are incredibly successful with their amputations. So it truly is a personal, you know, patient decision. I say we're going to make this together, you and your child and I will make this together and I also honor your wishes.
Lisa Garvin: How do children handle if they do have a Rotationplasty or an amputation? How do they handle it? How do your patients handle it?
Dr. Valerae Lewis: Well if they choose it, then they generally handle it well. I mean there are days when they're sad or they're mourning the loss of their leg, but then they put on their prostheses and go. I have one young patient who's been so active on his prostheses and never takes it off that he's really developed a big bursa, which means there's been a lot of, you know, activity and wear and tear on the limb and that's actually the best, I mean even though the downside is yes its bursa, it's a positive aspect because he's using his limb. I think when the children make educated decisions, and I think we have to remember that a child even as young as 7 can help make their own decision then they deal with it well. So if they're involved in the process to have an amputation, then I think they deal with it better than if it's, you know, forced on them. One thing I do always emphasize with parents is that the oncologic portion of the operation will always be the same. We're always going to do the procedure to get the cancer out and then after the cancer is out we have the options on how it's going to be reconstructed. So some patients worry, you know, if I choose an expandable prosthesis, if I choose Rotationplasty, you know, will my cancer operation be different. But your surgeon is always going to do the best thing for the cancer and then work from there on the reconstructive options.
Lisa Garvin: So children with bone cancers can lead full lives.
Dr. Valerae Lewis: Absolutely.
Lisa Garvin: Thank you very much. If you have questions about anything you've heard today on Cancer Newsline, contact Ask M. D. Anderson at 1877-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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