From the Guidelines
In bone cancer, alkaline phosphatase (ALP) should be checked in addition to Lactate Dehydrogenase (LDH). ALP is a crucial biomarker for bone cancer as it is produced by osteoblasts and elevated levels often indicate increased bone turnover or destruction, which occurs in primary bone tumors like osteosarcoma or in metastatic bone disease. While LDH is a non-specific marker of tissue damage and cellular turnover that increases in many cancers, ALP provides more specific information about bone involvement, as supported by a study published in the Journal of the National Comprehensive Cancer Network 1. The combination of these markers offers complementary information - LDH reflecting overall tumor burden and cellular damage, while ALP specifically indicates bone involvement.
Other useful markers may include bone-specific alkaline phosphatase (BSAP), which is more specific than total ALP, and in certain bone cancers, additional markers like CA-125, PSA, or CEA might be relevant if metastasis from other primary sites is suspected. A comprehensive review of current evidence and recommendations for the monitoring of bone health in patients with cancer, published in Cancer Treatment Reviews in 2017, highlights the importance of bone markers such as ALP and BSAP in assessing bone metastases and guiding treatment decisions 1. Regular monitoring of these markers can help track disease progression and treatment response in bone cancer patients.
Key points to consider when using biomarkers for bone cancer include:
- ALP is a sensitive predictive marker of bone turnover and bone metastases in patients with advanced solid tumors
- BSAP is more specific than total ALP for assessing bone involvement
- Other markers such as CA-125, PSA, or CEA may be relevant in certain cases of bone cancer
- Regular monitoring of biomarkers can help track disease progression and treatment response.
From the Research
Bone Cancer Markers
In addition to Lactate Dehydrogenase (LDH), other markers should be checked in bone cancer, including:
- Alkaline Phosphatase (ALP) 2, 3, 4
- Bone Alkaline Phosphatase (BAP) 5, 6, 3
- Bone-specific alkaline phosphatase (BSAP) 4
Rationale
These markers are associated with bone turnover and metastasis, and their levels can provide valuable information about the presence and extent of bone involvement in cancer patients. For example:
- Elevated serum ALP and BAP levels have been observed in patients with bone metastases 2, 3
- BAP levels are correlated with the extent of bone uptake at scintigraphy 5
- High N-telopeptide (Ntx) levels, a marker of bone resorption, are associated with an increased risk of skeletal complications and disease progression 6
Diagnostic Value
The diagnostic value of these markers can be enhanced by combining them with other markers, such as:
- Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) 4
- Carbohydrate antigen 19-9 (CA 19-9) 4
- LDH isozymes levels 4
Clinical Implications
The use of these markers can help identify patients with bone metastases and monitor their response to treatment. For example: