An osteolytic lesion (from the Greek words for "bone" (ὀστέον), and "to unbind" (λύειν)) is a softened section of a patient's bone formed as a symptom of specific diseases, including breast cancer and multiple myeloma. This softened area appears as a hole on X-ray scans due to decreased bone density, although many other diseases are associated with this symptom.[1] Osteolytic lesions can cause pain, increased risk of bone fracture, and spinal cord compression.[2] These lesions can be treated using biophosphonates or radiation, though new solutions are being tested in clinical trials.

Osteolytic lesion at the bottom of the radius, diagnosed by a darker section that indicates a loss of bone density

Cellular causes

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Bone lesions are caused by an imbalance of regulatory factors, characterized by an increased depletion and resorption of old bone tissue and a decrease in bone rebuilding, known as bone remodeling. This imbalance is due to a flooding of regulatory factors released by specific tumors, thus overwhelming the tissue repair system and resulting in these lesions. The over-activity of osteoclasts can also cause hypercalcemia, which can cause damage to the kidneys and requires additional medication and monitoring.[1]

In multiple myeloma, an increased number of myeloma cells block osteoblasts from creating new bone, while these cancerous cells also release factors that cause an upregulation on osteoclasts, causing an increasing in bone tissue resorption and an overall breakdown of bone integrity. This breakdown often begins in the bone marrow near tumor sites and spreads outward to the surface of the implicated bone.[1]

The most common cancers that metastasize to form osteolytic lesions are thyroid, lung, kidney, gastrointestinal, malignant melanoma and breast, though any cancer can cause bone lesions. Lesions are most often found in larger bones, such as the skull, pelvis, radius, and femur.[3][4]

Potential treatments

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Bisphosphonates

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Bisphosphonates are drugs that are used to prevent bone mass loss and are often used to treat osteolytic lesions. Zoledronic acid (Reclast) is a specific drug given to cancer patients to prevent the worsening of bone lesions and has been reported to have anti-tumor effects as well.[5] Zoledronic acid has been clinically tested in conjunction with calcium and vitamin D to encourage bone health.[6] Denosumab, a monoclonal antibody treatment RANKl inhibitor that targets the osteocyte apoptosis regulatory RANKL gene, is also prescribed to prevent bone metastases and bone lesions.[7][8] Most biophosphonates are co-prescribed with disease-specific treatments, such as chemotherapy or radiation for cancer patients.

Radiation

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Bone lesions in multiple myeloma patients may be treated with low-dose radiation therapy in order to reduce pain and other symptoms.[7] Used in combination with immunochemotherapy, radiation therapy can be used to treat certain cancers when aimed at areas of bone lesion and softened bone.[9]

References

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  1. ^ a b c "Myeloma Bone Lesions - Lytic Bone Lesions - Bone Lesion Myeloma". Multiple Myeloma Research Foundation. Retrieved 2017-03-14.
  2. ^ Matsumoto, Toshio; Kido, Shinsuke; Inoue, Daisuke; Oshima, Takashi; Abe, Masahiro (2004). "Myeloma-Bone Interaction for the Development of Myeloma Bone Disease". Journal of Bone and Mineral Research. 19 (9): 1559–1600 – via Wiley.
  3. ^ "Round 2 : Treatment of Metastatic Bone Disease • Arthritis Information". Arthritis Information. Archived from the original on 2020-04-04. Retrieved 2017-04-10.
  4. ^ Kumar, Vinay (2014). Pathologic Basis of Disease. p. 1207. ISBN 978-1-4557-2613-4.
  5. ^ Kawai, Sadayuki; Yamaura, Gengo; Yasuda, Katsuhiro; Suzuki, Takao (2012-05-10). "Remarkable Regression of an Osteolytic Lesion of Large Cell Lung Cancer Treated with Zoledronic Acid: A Case Report". Case Reports in Oncology. 5 (2): 233–237. doi:10.1159/000339125. ISSN 1662-6575. PMC 3369252. PMID 22679429.
  6. ^ "Therapy With Zoledronic Acid in Patients With Multiple Myeloma Stage I - Full Text View - ClinicalTrials.gov". clinicaltrials.gov. Retrieved 2017-04-10.
  7. ^ a b "Multiple Myeloma Bone Disease Treatment - Bone Disease Treatments". Multiple Myeloma Research Foundation. Retrieved 2017-03-14.
  8. ^ "Denosumab Compared to Zoledronic Acid in the Treatment of Bone Disease in Subjects With Multiple Myeloma - Full Text View - ClinicalTrials.gov". clinicaltrials.gov. Retrieved 2017-03-14.
  9. ^ Ahmad, Irfan; Chufal, Kundan Singh; Goyal, Nidhi; Bhatt, Chandi Prasad (2017-03-01). "Case of polyostotic primary bone lymphoma successfully treated with immunochemotherapy and consolidation radiotherapy". BMJ Case Reports. 2017: bcr2016218832. doi:10.1136/bcr-2016-218832. ISSN 1757-790X. PMC 5353460. PMID 28249886.