Laboratory Tests for Suspected Lower Extremity Bone Cancer

Prognostic Markers

The National Comprehensive Cancer Network (NCCN) recommends that alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) levels should be measured at baseline for patients with suspected bone cancer, as elevated levels correlate with adverse outcomes in osteosarcoma 1, 2, 3, 4, 5, 6, 7, 8
Elevated LDH levels are associated with higher disease burden and poorer outcomes in bone sarcomas, and are predictive of skeletal metastases in osteosarcoma patients 9
Elevated ALP levels are associated with adverse outcomes in osteosarcoma, and should be carefully evaluated to distinguish between benign bone turnover and malignant processes 1, 2, 3, 4, 5, 6, 7, 8

A complete blood count with differential should be performed to assess baseline hematologic status 1, 2, 3, 4, 5
Blood group typing is required for potential transfusions during surgery 1, 2, 3, 4, 5
A coagulation profile should be evaluated to assess bleeding risk before biopsy and surgery 1, 2, 3, 4, 5
Serum electrolytes, including magnesium and phosphate, should be assessed for baseline monitoring of chemotherapy 1, 2, 3, 4, 5
Renal function tests are critical, as chemotherapy can cause renal dysfunction 1, 2, 3, 4, 5
Liver function tests should be performed for baseline hepatic assessment 1, 2, 3, 4, 5

The NCCN guidelines recommend that all staging investigations, including laboratory tests, should be completed before biopsy to avoid contamination of tissue planes and ensure accurate baseline assessment 6, 7, 8, 12
Any patient with radiographic suspicion of bone malignancy should be quickly referred to a cancer center or bone sarcoma reference center for multidisciplinary evaluation before further workup 6, 7, 8, 12