Osteosarcoma: rare but problematic for those who experience it.

July is sarcoma & bone tumor awareness month.  While sarcomas only make up ~1% of total cancer diagnoses, osteosarcomas disproportionately affect young individuals more & can contribute to a significant amount of functional mobility issues.

We as physical therapists must understand what osteosarcoma is, how it’s treated, & how it thus affects our patients so we’re prepared to treat them effectively.  

What is osteosarcoma?

Osteosarcoma, aka osteogenic sarcoma, is a special subset of sarcomas, which are mesenchymal cancers.  Sarcomas are tumors of connective tissue.

So thinking back to anatomy here:

 Connective tissue includes muscle bone cartilage and other types of tissues. A sarcoma can affect any number of these tissues including muscle bone cartilage and other types and other soft tissues.

 Now as much as we’re talking about what osteosarcoma is we have to first address what osteosarcoma isn’t. You see we encounter bony metastasis frequently when working with patients who have cancer but this is different than osteosarcoma. Metastasis are a secondary bone cancer what this means is it is a cancer that has started in a different body region or tissue and then his bread to invade the bone. Osteosarcoma is a primary bone cancer meaning the tour started in the bone cells and it has now developed into a tumor Within These bone cells. 

Osteosarcomas primarily affect the extremities & the pelvic girdle.  

What causes osteosarcoma?

Most osteosarcomas don’t have a clear cause. The one exception here is radiation associated sarcomas that are linked to prior treatment for Hodgkin’s lymphoma and sometimes breast cancers. There’s some evidence to suggest that different environmental exposures could contribute to osteosarcomas, but we’re still learning a lot about that.

Additionally some patients may have familial syndromes that could contribute to the development of sarcomas for example Li fraumeni syndrome, hereditary retinoblastoma, Rothmund-Thomson syndrome, & others.

Who is typically affected by osteosarcoma?

Osteosarcomas tend to affect younger people including children, adolescents, and young adults. 

Osteosarcoma can technically affect any bone in the human body. However they tend to be more common in the distal femur, the proximal tibia, and the proximal humerus. 

For older adults, osteosarcoma may be more common in the pelvis, the shoulder, & the jaw bones.

What are the signs & symptoms?

Common symptom of osteosarcoma is pain in the bone where the tumor is located. This pain often gets worse with activity and can be worse at night. As we know, this is very common with malignant pain. Some patients may also experience swelling in the area of the tumor, but this may develop later in the disease process for some patients. 

How is osteosarcoma diagnosed?

Osteosarcomas are frequently diagnosed first with some kind of bone radiography, (for example X-rays). Patients may need further imaging, but ultimately need a biopsy. Patients with a suspected bone tumor will undergo a biopsy, which will help the medical team determine is this indeed cancer, what kind of cancer this is, and then to help plan the treatment.

How is osteosarcoma staged & graded?

Osteosarcomas are graded with the typical low grade intermediate grade high grade system that we tend to see with other cancers. Most osteosarcomas that develop in young people are high-grade meaning they are rapidly dividing into new cancer cells. 

What’s the treatment for osteosarcoma?

Many osteosarcomas are treated with neoadjuvant chemotherapy followed by surgery. Many patients will then go on to have adjuvant chemotherapy as well. Chemotherapy regimens commonly include methotrexate, doxorubicin, cisplatin, ifosfamide, & etoposide. 

When it comes to surgery for osteosarcomas, traditional management has been amputation. The goal for so long was to try and get the cancer out as best as possible and to get the widest margins, and this meant truly amputating the body part. Now that we’re getting better at treating cancer in general, including osteosarcoma, patients are more likely to undergo some kind of limb salvage surgery.

Treatment for advanced/distant osteosarcoma?

Some patients with very extensive disease may undergo radiation therapy if the surgeons were able to achieve clear margins after resection but this is very rare. Additionally radiation therapy could be used for palliative purposes but again this is very dependent on the patient case. 

Conclusion:

While osteosarcomas are not a very common type of cancer, they can result in significant functional mobility impairments for patients. In our next episode we’re going to talk about rehab implications that we as PT’s must be aware of when we’re working with the patient with an osteosarcoma.

We want to hear from you!

So now I want to hear from you: what did I miss? What else would you include in this episode about osteosarcomas? Message me on Instagram and let me know.

Until next time, this is Elise with TheOncoPT. And remember you are exactly the physical therapist that your patients with cancer need. So let’s get to work.

References:
  • Compston, Amy M. PT, DPT, CRT, CLT-LANA1; Zak, Jacqueline PT, DPT2; Alexander, John H. MD3; West, Julie M. MS, PA-C4; Scharschmidt, Thomas J. MD5; Valerio, Ian L. MD6; Mayerson, Joel L. MD7 Rotationplasty Rehabilitation Protocol: A Complex Case Report, Rehabilitation Oncology: April 2020 – Volume 38 – Issue 2 – p E32-E40 doi: 10.1097/01.REO.0000000000000182
  • https://www.cancer.org/cancer/osteosarcoma.html
  • Ambler, Steven B. PT, DPT, PhD, MPH1; Highsmith, M. Jason PT, DPT, PhD2; Alvero, Christine PT, DPT, MBA3; Binitie, Odion T. MD4 Functional Comparison of a Pediatric Patient With Osteosarcoma and Limb-Sparing Distal Femoral Endoprosthesis With an Identical Twin, Rehabilitation Oncology: October 2019 – Volume 37 – Issue 4 – p E1-E6 doi: 10.1097/01.REO.0000000000000148

More on Osteosarcoma:

Listen to Ep. 188 of TheOncoPT Podcast: What PTs Must Know About Osteosarcoma

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