Tumors that metastasize to bone (mnemonic)
Citation, DOI & article data
- P: prostate
- B: breast
- K: kidney
- T: thyroid
- L: lung
For females, breast and lung are the most common primary sites ; nearly 80% of cancers that spread to the skeleton are from these locations. In males, prostate and lung cancers make up 80% of carcinomas metastasizing to bone. The other 20% of primary disease sites in both sexes are: kidney, thyroid, gastrointestinal tract and other locations.
Lytic vs blastic in "lead kettle" PB-KTL mnemonic
By knowing the typical behavior of the metastatic lesion - lytic or blastic - you can help sort between the types to make the mnemonic even more useful.
- prostate = blastic/sclerotic (induces bone growth)
- breast = mixed pattern
- kidney, thyroid, lung = lytic (induces bone destruction)
The spreading pathways of metastasis from the starting site to the bones are only partially understood, and some authors propose some bone metastasis via the Batson venous plexus, a two-way, valveless venous pathway that allows cancer cells, infection and emboli to travel freely both to cranial and caudal direction without passing through the main "tumor-catching" places: liver, lung, peritoneum and others.
Carcinoma metastases are the most common malignant tumors in the skeleton, with maybe somewhat vague symptoms or an acute onset, often with pain or pathological fractures. In people with breast and prostate cancer, the bone is often the first distant site of cancer spread. More than 2 out of 3 breast and prostate cancers that spread to other parts of the body spread to the bones. Of lung, thyroid, and kidney cancers that spread to other parts of the body, about 1 out of 3 will spread to the bones.
Basic knowledge of a simple mnemonic about the main types of bone metastases can be a handy tip in the medical routine: with a good history taking from the patient, clinical findings and sharp eyes on the images it is possible to nail a nice and elegant diagnostic hypothesis allowing a more specific investigation.
- 1. H Singh and JA Neutze (eds.), Radiology Fundamentals: Introduction to Imaging & Technology, DOI 10.1007/978-1-4614-0944-1_47,© Springer Science+Business Media, LLC 2012
- 2. RaioX do Trauma, 1 edição; Leão Henrique Záquia, Juan Zambon, Patrícia Comberlato; Editora da Ulbra, Canoas 2013
- 3. Orthopedic Secrets, 3rd edition; David E. Brown, Randall D. Neumann; Elsevier Health Sciences, 2004
- 4. Practical Surgical Neuropathology: A Diagnostic Approach; Arie Perry, Daniel J. Brat; Elsevier Health Sciences, 2010
- 4. Keene JS, Sellinger DS, McBeath AA et-al. Metastatic breast cancer in the femur. A search for the lesion at risk of fracture. Clin. Orthop. Relat. Res. 1986; (203): 282-8. Pubmed citation
- 6. Hung JJ, Jeng WJ, Hsu WH et-al. Prognostic factors of postrecurrence survival in completely resected stage I non-small cell lung cancer with distant metastasis. Thorax. 2010;65 (3): 241-5. doi:10.1136/thx.2008.110825 - Pubmed citation
- 7. Edwards J. Src kinase inhibitors: an emerging therapeutic treatment option for prostate cancer. Expert Opin Investig Drugs. Apr 5 2010;
- 8. Alarmo EL, Kallioniemi A. Bone morphogenetic proteins in breast cancer - dual role in tumourigenesis?. Endocr Relat Cancer. Mar 24 2010;
- 9 What are the key statistics about bone metastases? - American Cancer Society - http://www.cancer.org/treatment/understandingyourdiagnosis/bonemetastasis/bone-metastasis-key-statistics1
- 10. Edward Tobinick: The Cerebrospinal Venous System: Anatomy, Physiology, and Clinical Implications, Medscape General Medicine
- 11. Batson OV. The vertebral vein system. Caldwell lecture, 1956. Am J Roentgenol Radium Ther Nucl Med. 1957;78:195-212