The role of technetium-99m-labeled octreotide acetate scintigraphy in suspected breast cancer and correlates with expression of SSTR

Wang, Feng; Wang, Zizheng; Wu, Jie; Qu, Wei; Yao, Weixuan; Zhao, Jianhua; Liu, Zijun

doi:10.1016/j.nucmedbio.2008.04.010

« Previous Next »Nuclear Medicine and Biology
Volume 35, Issue 6 , Pages 665-671, August 2008

The role of technetium-99m-labeled octreotide acetate scintigraphy in suspected breast cancer and correlates with expression of SSTR

Feng Wang
- Department of Nuclear Medicine, Nanjing First Hospital affiliated to Nanjing Medical University, Nanjing 210006, China
- Corresponding author. Tel.: +86 25 52271491 or 13851702760; fax: +86 25 52254223.
- These authors contributed equally to this study.
Zizheng Wang
- Department of Nuclear Medicine, Nanjing First Hospital affiliated to Nanjing Medical University, Nanjing 210006, China
- These authors contributed equally to this study.
Jie Wu
- Department of Nuclear Medicine, Nanjing First Hospital affiliated to Nanjing Medical University, Nanjing 210006, China
Wei Qu
- Department of Nuclear Medicine, Nanjing First Hospital affiliated to Nanjing Medical University, Nanjing 210006, China
Weixuan Yao
- Department of Nuclear Medicine, Nanjing First Hospital affiliated to Nanjing Medical University, Nanjing 210006, China
Jianhua Zhao
- Department of Pathology, Nanjing First Hospital affiliated to Nanjing Medical University, Nanjing 210006, China
Zijun Liu
- Department of General Surgery, Nanjing First Hospital affiliated to Nanjing Medical University, Nanjing 210006, China

Received 26 January 2008; received in revised form 17 April 2008; accepted 30 April 2008. published online 01 July 2008.

Abstract

Purpose

To evaluate the value of ^99mTc-octreotide acetate (hereafter, ^99mTc-octreotide) somatostatin receptor (SSTR) scintigraphy in the detection of primary breast cancer and to correlate with expression of SSTRs.

Materials and Methods

Fifty-four female and 1 male patients (range, 17–77 years; mean age, 48 years) with palpable breast lesion were included in this study. ^99mTc-octreotide and ^99mTc-MIBI scintigraphy were undertaken in all patients, and the region of interest was drawn around each lesion. Tumor uptake was measured and expressed as the ratio of tumor to normal tissue activity (T/NT). Final clinical diagnosis was confirmed by histopathological analysis. Expression of SSTR1–5 mRNA was measured with RT-PCR in 15 patients with malignant neoplasm, and protein level of SSTR-2 and SSTR-5 was measured using immunohistochemical staining in 15 patients with malignant neoplasm and 18 patients with benign lesion.

Results

Thirty-five patients were confirmed to have infiltrative ductal breast carcinoma, 1 patient with cellular cancer, 1 patient with adenocarcinoma and 18 patients had benign lesions. The sensitivity, specificity, positive predictive value and negative predictive value of ^99mTc-octreotide in detection of primary lesion were 91.8%, 22.2%, 71.8% and 57.1%, respectively. No significant correlation was observed between T/NT of ^99mTc-octreotide and ^99mTc-MIBI. SSTR mRNA subtypes were variably expressed. SSTR3 was the most highly expressed, followed by SSTR1, SSTR2 and SSTR5; SSTR4 was the least expressed in the level of mRNA of SSTR. Significant correlation was shown between T/NT and the expression of SSTR2 mRNA (r=0.73, P<.01).

Conclusion

^99mTc-octreotide acetate scintigraphy was sensitive for the detection of primary lesion of breast cancer; however, nonspecific breast tissue uptake hampered the specificity and clinical value in the detection of lymph node metastasis. Five subtypes of SSTR mRNA and protein SSTR2 and SSTR5 were expressed variably in breast cancer due to tumor heterogeneity. ^99mTc-octreotide imaging may hold promise in the evaluation of the level of SSTR2 in vivo.

Keywords: Breast cancer, Somatostatin receptor, Scintigraphy, mRNA