Cancer Res Treat.  2006 Jun;38(3):126-132.

Effects of the Expression of Leptin and Leptin Receptor (OBR) on the Prognosis of Early-stage Breast Cancers

• Kim Y
• Kim SY
• Lee JJ
• Seo J
• Kim YW
• Koh SH
• Yoon HJ
• Cho KS

Abstract

PURPOSE: Obesity-related leptin and leptin receptor (OBR) have a relation to the development of cancer and metastasis and also the low survival rate for breast cancer patients. Leptin has been associated with increased aromatase activity and it displays functional cross-talk with estrogen. This study was designed to determine the relationship between the expression of leptin and OBR in breast cancer tissue and the prognosis of early-stage breast cancer patients, and especially for the tamoxifen-treated patients.
MATERIALS AND METHODS
Ninety-five patients with early-stage breast cancer and who had undergone surgical treatment at Kyung Hee University Hospital between January 1994 and June 2004 were analyzed. The surgical specimens underwent immunohistochemical analysis for leptin and OBR. The patients' survival and clinical characteristics were obtained from the medical records.
RESULTS
Of the 95 patients, 79 (83%) and 32 (33.7%) showed the expression of leptin and OBR in breast cancer tissue, respectively. The expression of leptin and OBR in breast cancer tissue was not significantly related to the clinicopathological characteristics, including obesity, the expression of hormonal receptor, the HER-2/neu expression, menopause, stage and the nuclear grade. The expression of leptin and OBR was not significantly related to the overall disease-free survival (DFS). For the tamoxifen-treated postmenopausal obese patients, the DFS of the leptin-positive group was higher than that of the leptin-negative group (p=0.017).
CONCLUSION
The expression of leptin and OBR in breast cancer tissue may be not a prognostic factor for disease-free survival of breast cancer patients. In the future, further studies are needed to determine whether leptin expression could be a predictive factor for tamoxifen therapy in the postmenopausal obese subgroup among the early breast cancer patients.

Keyword

Leptin; OBR; Early breast cancer; Obesity; Postmenopause; Tamoxifen

MeSH Terms

Aromatase
Breast Neoplasms
Breast*
Disease-Free Survival
Estrogens
Female
Humans
Leptin*
Medical Records
Menopause
Neoplasm Metastasis
Obesity
Postmenopause
Prognosis*
Receptors, Leptin*
Survival Rate
Tamoxifen
Aromatase
Estrogens
Leptin
Receptors, Leptin
Tamoxifen

Figure

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  Fig. 1 Immunohistochemical staining of leptin (A, B) and OBR (C, D). (A) Positive staining of tumor tissue (×100). (B) Negatively stained tumor and positively stained adipose tissue (×200). (C) Positively stained tumor and negatively stained adipose tissue (×100). (D) Negatively stained tumor (×40).

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  Fig. 2 Disease-free survival for all patients according to the (A) leptin and (B) leptin receptor (OBR) expressions.

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  Fig. 3 Comparison of disease-free survival for patients with hormone (estrogen or progesterone) receptor expression between the groups with and without leptin/leptin receptor (OBR) expression.

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  Fig. 4 Disease-free survival for postmenopausal patients with a hormone receptor expression (estrogen receptor or progesterone receptor) and who were treated with tamoxifen according to the (A) leptin expression and (B) the OBR expression.

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  Fig. 5 Disease free survival for obese post-menopause patients with hormone receptor expression (estrogen or progesterone receptor) according to (A) the leptin expression and (B) the OBR expression.

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