Abstract
Introduction: The aim of this study was to, based on the data collected, determine the right time for the application of bone scintigraphy in patients with breast cancer. Discovery of bone metastasis in their initial stages of development, before the occurrences of clinical signs, can completely alter treatment and improve prognosis of patients with breast cancer. Materials and methods: A retrospective study was conducted on three hundred consecutive patients with breast cancer in the period of 2005-2008. Patients without preliminary biochemistry analyses, radiological data and bone scintigraphy, were not included in the study, however, exceptions were made for Computer Aided Tomography and Magnetic Resonance Imaging examinations, because some patients didn’t make them. Bone scintigraphy was always performed after clinical examination of all patients, three hours after intravenous administration of 555-740 MBq activity of 99mTc MDP. Results: Two hundred ninety nine (99.67%) were female with breast cancer and only one case (0.33%) was male with breast cancer. Investigation group (IG) included 126 patients (42.0%) with breast cancer, before surgical treatment (positive clinical signs and laboratory findings for cancer) and in our control group (CG) were included 174 patients (58%) with breast cancer after surgical treatment. Unilateral mastectomy with removal of lymph nodes in the axillae was done in 97 patients (55.74%) whereas in 77 patients (44.26%) only mastectomy. Suspected lesions for bone metastases were found in 30 patients (23.8%) included in the investigation group and 65 patients (37.36%) included in the control group. Suspected bone lesions were found mainly in axial skeletal (vertebrae 57%, ribs 24%, pelvis 12%) and long other extremities (7%). Probability of bone metastases in patients ranged with stage three (III) and four (IV) of disease, was significantly higher (46.6% and 69.6%), in comparison with stage I and II (3.84% and 6.5% respectively), however bone metastases were found also in patients ranged with stage I and II. We noticed 8.7 higher probabilities of bone metastases for patients with lobular invasive breast carcinoma than for patients with invasive ductal breast carcinoma. The sensitivity of bone scintigraphy was 98%, its specificity 95%, resulting in a diagnostic efficiency of 98%. The positive predictive value was calculated to be 98% as compared to the negative predictive value of 95%. The concentrations of CA 15.3 were significantly higher in patients with bone metastasis than in those without bone metastasis (p<0.01). Conclusion: Our preliminary study results suggest that the application of bone scintigraphy in primary breast cancer, before surgical intervention is very useful to evaluate initial stage and to perform the follow up examination. y