Introduction: Metastatic bone disease is frequent in patients with advanced breast cancer. Although it is not specific for the detection of metastatic bony lesions, bone scan is a sensitive method. The pattern of distribution of bone metastases as detected by bone scan combined with clinical data may help in reaching diagnosis.
Methods: Technetium-99m-methylene diphosphonate skeletal scintigraphy was used for evaluation of distribution pattern of skeletal metastases in patients with breast carcinoma compared to other common cancers.
Results: Out of 134 patients with positive bone scan for skeletal deposits, the primary cancer was breast cancer in 81 patients, prostate in 24, lung in 12, liver in 8, urinary bladder in 6, and head and neck in 3.
Few metastases (≤ 3 deposits) were common in breast cancer, while extensive metastatic lesions (≥10 deposits) were more common in prostate cancer (50%). The most common locations of bone metastases in patients with breast cancer were the spine, pelvic bones, femora, and ribs, respectively.
In prostate cancer patients, spine was the most common site of metastases, especially the lumber region. In lung cancer patients, thoracic spine was the most common site of metastases, while pelvic bones were the most common site in liver cancer patients.
Conclusion: In breast cancer, the most frequent sites of involvement are the spine (especially lumber region), pelvis and axial skeleton, respectively. Spinal and sternal involvements are significantly more in breast cancer than in other malignancies.