Cancer Metastatic to Bone

WHEN cancer cells become detached from the primary growth to circulate in the blood and lymph, it is quite logical to expect that some of them will lodge in bony structures. Autopsy reports lead one to believe that this actually occurs much more frequently than we once supposed. The fact that the condition is often unrecognized antemortem is probably due to several factors, some of which are as follows: 1. Considerable proliferation of the transplanted cancer is usually necessary before signs or symptoms appear. 2. Small lesions of bone are difficult to detect in the roentgenogram. 3. In advanced cases of cancer, with general metastases, it often seems superfluous to search for bony invasion. A wide variance of percentages of incidence for bone invasion would be obtained by a clinic which searched the skeleton for purposes of confirming the diagnosis, and by an institution which observed cases in the late stages of the disease. This study, therefore, makes no attempt to gauge the incidence of metastases to bone. It merely attempts to point out the favorite locations for transplants in bone by various types of cancer and to show that practically any type will grow in bony tissue in some patients. The appended table presents 259 cases of carcinoma, 28 cases of other types of cancer, and 21 unidentified types that showed roentgen evidence of metastasis to bone.2 A comparison with some of the reports from other sources is instructive. Sutherland, Decker, and Cilly (1) reported 1,032 cases of cancer, observed at the Mayo Clinic, which showed metastatic lesions in bones (Series I). Copeland (2) reported 334 cases of cancer with bone metastasis, observed at the Johns Hopkins Hospital (Series II). In Table I, some of the more important observations of the above mentioned observers are compared with ours (Series III). The following are among the more interesting cases of our series. Case 1. Sarcoma, primary, in the rib of a 25-year-old male, with metastasis to skull, pelvis, ulna, and other long bones. This was a slow-growing tumor. Several metastatic foci in the lungs were calcified. Microscopic sections from autopsy material suggested angio-sarcoma in some tissues and fibro-chondro-sarcoma in others. Case 2. Carcinoma of the breast with only one bone metastasis—in the mandible, with fracture. Case 3. Carcinoma of the breast with one bone metastasis—in the clavicle, with fracture. Cases 4, 5, 6. Three cases of congenital hemolytic jaundice, with widespread bone lesions (see Table I). Two of these were in the same family.3 Case 7. Malignant melanoma, primary in the skin of the deltoid region, with metastasis to the third lumbar vertebra. The sections of this growth were those of sarcoma, but there was some dispute as to type. Case 8. Adamantinoma, with large solitary metastasis to the pelvis. There was a pathologic fracture through the acetabulum. Autopsy revealed a few small lesions in the ribs. No other metastases were found.