Lecturer of Clinical oncology department Menoufia university- Egypt Study of Distribution of bone metastases in metastatic breast cancer patients compared to other major cancer Presenting author: Dr. Suzy.F. Gohar Lecturer of Clinical oncology department Menoufia university- Egypt

Introduction Any malignant tumor can metastasize to bone. Mainly breast cancer in females and prostate cancer in males and lung cancer in both. Bone scan is a sensitive but not specific method for evaluation of bone metastases. However, the clinical data and the pattern of bone scan findings help the physician to narrow the diagnostic differentials.

Aim of the work Evaluation of pattern of distribution of skeletal metastases in patients with breast carcinoma compared to other common cancers . Explore if there is a specific distribution of bony deposits in breast cancer patients compared to all other major malignancies to reduce diagnostic differentials.

Method Positive bone scan films were collected and studied regarding number and sites of metastatic lesions. The involved areas were divided into nine portions: skull, sternum, spine, ribs, pelvic bones, sacrum, humeri , scapulae, femora and clavicles. Based on number of metastatic lesions patients were divided into three categories: few metastatic lesions (≤ 3lesions), intermediate metastatic lesions (4-≤9 lesions) extensive metastatic lesions (≥10 lesions).

Results We collected 134 patients who were histologically proved to have malignancies and whom bone scans were positive for bone deposits.

Distribution of the studied patients regarding their demographic characteristics: % Age Mean ±SD Range   53.88±11.98 28-90 Sex Male Female 85 89 33.6 66.4 Type of cancer Breast HCC Prostate Lung Bladder Head and neck 81 8 24 12 6 3 60.4 6.0 17.9 9.0 4.5 2.2

Distribution of the studied group according number of metastatic lesions (few, intermediate and extensive).   Cancer Breast (n=81) HCC (n=8) Prostate (n=24) Lung (n=12) Bladder (n=6) Head and neck (n=3) no % Metastasis Few Intermediate Extensive 37 29 15 45.7 35.8 18.5 7 1 87.5 12.5 4 8 12 16.7 33.3 50.0 3 2 58.3 25.0 6 100.0 66.7

Distribution of the studied group according to Frequency of involved sites   Cancer Breast (n=81) HCC (n=8) Prostate (n=24) Lung (n=12) Bladder (n=6) Head and neck (n=3) no % Ribs 18 22.2 1 12.5 10 41.7 4 33.3 0.0 Scapula 3 3.8 8.3 Skull 7 8.6 5  20.8 Sternum 11 13.6 Spine 68 84.0 37.5 21 87.5 9 75.0 Spine site Cervical Thoracic Lumber only Cer+Th Th+Lumb Cer+Th+Lumb 19 25 1.5 27.9 36.8 4.4 2 66.7 6 8 4.8 28.6 38.1 23.8 11.1 55.6 Sacrum 14 17.3

Cancer Breast (n=81) HCC (n=8) Prostate (n=24) Lung (n=12) Bladder   Cancer Breast (n=81) HCC (n=8) Prostate (n=24) Lung (n=12) Bladder (n=6) Head and neck (n=3) no % Pelvis 30 37.0 4 50.0 16 66.7 3 25.0 2 33.3 1 Iliac 13.3 7 43.8 100.0 Pubic 3.3 Ischium Hip 6 20.0 6.2 Iliac +pubic Iliac + ischium 6.7 Iliac+ hip 9 30.0 Iliac + obturator Hip+ ischium 12.5 Acetabulum (Ischium+ ileum+ acetabulum+ hip) (Ischium+ ileum+ acetabulum+ pubis) Pubic+ acteabulum

  Cancer Breast (n=81) HCC (n=8) Prostate (n=24) Lung (n=12) Bladder (n=6) Head and neck (n=3) no % Humeri 13 16.0 2 25.0 7 29.2 3 4 66.7 Site humeri Upper shaft Lower shaft Whole length 11 84.6 15.4 1 50.0 6 85.7 14.3 100.0 75.0 Femuri 25 30.9 10 41.7 16.7 33.3 Site femuri 20 80.0 12.0 8.0 9 90.0 10.0 Tibii 2.5 Site tibii

Distribution of the studied group regarding Frequency of involved sites   Cancer Breast (n=81) HCC (n=8) Prostate (n=24) Lung (n=12) Bladder (n=6) Head and neck (n=3) no % Ribs 18 22.2 1 12.5 10 41.7 4 33.3 0.0 Scapula 3 3.8 8.3 Skull 7 8.6 5  20.8 Sternum 11 13.6 Spine 68 84.0 37.5 21 87.5 9 75.0 Spine site Cervical Thoracic Lumber only Cer+Th Th+Lumb Cer+Th+Lumb 19 25 1.5 27.9 36.8 4.4 2 66.7 6 8 4.8 28.6 38.1 23.8 11.1 55.6 Sacrum 14 17.3

  Cancer Breast (n=81) HCC (n=8) Prostate (n=24) Lung (n=12) Bladder (n=6) Head and neck (n=3) no % Pelvis 30 37.0 4 50.0 16 66.7 3 25.0 2 33.3 1 Iliac 13.3 7 43.8 100.0 Pubic 3.3 Ischium Hip 6 20.0 6.2 Iliac +pubic Iliac + ischium 6.7 Iliac+ hip 9 30.0 Iliac + obturator Hip+ ischium 12.5 Acetabulum (Ischium+ ileum+ acetabulum+ hip) (Ischium+ ileum+ acetabulum+ pubis) Pubic+ acteabulum

  Cancer Breast (n=81) HCC (n=8) Prostate (n=24) Lung (n=12) Bladder (n=6) Head and neck (n=3) no % Humeri 13 16.0 2 25.0 7 29.2 3 4 66.7 Site humeri Upper shaft Lower shaft Whole length 11 84.6 15.4 1 50.0 6 85.7 14.3 100.0 75.0 Femuri 25 30.9 10 41.7 16.7 33.3 Site femuri 20 80.0 12.0 8.0 9 90.0 10.0 Tibii 2.5 Site tibii

Comparison between breast cancer patients and other malignancies regarding number and site of involved sites.   Cancer χ2 Test P- value Breast (N=81) Others (N=53) No % Origin Primary Secondary 46 35 56.8 43.2 15.34 <0.001 Number of Metastasis Few Intermediate Extensive 37 29 15 45.7 35.8 18.5 26 11 16 49.1 20.8 30.2 4.39 0.111 Ribs 18 22.2 1.07 0.300 Scapula 3 3.8 1 1.9 0.35 0.550 Skull 7 8.6 5 9.4 0.02 0.875 Sternum 13.6 *5.37 0.028(S) Spine 68 84.0 33 62.3 8.11 0.004(S) Spine site Cervical Thoracic Lumber Cer+Th Th+Lum Cer+Th+Lumb 19 25 1.5 27.9 36.8 4.4 6 3.0 18.2 21.2 33.3 Z 0.25 0.81 1.35 0.33 2.30 0.800 0.415 0.176 0.745 0.021(S)

  Cancer χ2 Test P- value Breast (N=81) Others (N=53) No % Pelvis 30 37.0 26 49.1 1.90 0.168 Iliac Pubic Ischium Hip Iliac +pubic Iliac + ischium Iliac+ hip Iliac + obturator Hip+ ischium Acetabulum (Ischium+ ileum+ acetabulum+ hip) (Ischium+ ileum+ acetabulum+ pubis) Pubic+ acteabulum 4 1 6 2 9 13.3 3.3 20.0 6.7 30.0 0.0 10 3 38.5 3.8 7.7 11.5 Z 3.17 0.33 2.44 1.70 3.51 0.70 2.02 1.52 0.73 1.04 0.001(S) 0.473 0.014(S) 0.089 0.743 0.740 0.0004(S) 0.481 0.043(S) 0.128 0.462 0.297

conclusion In breast cancer patients, spine especially (lumbar region) is the most frequent site of involvement followed by pelvic bones and then axial skeleton(especially upper third of femur). Compared to other malignancies Spine , sternal and iliac bone involvement were significantly more frequent in breast cancer patients.