title: High expression of leptin receptor mRNA in breast cancer tissue predicts poor prognosis for patients with high, but not low, serum leptin levels.
abstract: The association of mRNA expression levels of leptin receptors (long isoform: Lep-R(L) and short isoform: Lep-R(S)) in breast cancer tissue with patient prognosis was studied with special reference to the serum leptin level or the leptin mRNA level in tumor tissue. Lep-R(L), Lep-R(S) and leptin mRNA levels in breast cancer tissue (n = 91) were determined with a real-time PCR assay, and serum leptin levels in breast cancer patients (n = 67) with an enzyme-linked immunosorbent assay. Neither Lep-R(L) nor Lep-R(S) mRNA levels in tumor tissue were significantly associated with patient prognosis, but both intratumoral Lep-R(L) and Lep-R(S) mRNA high tumors were significantly (p < 0.01) associated with a poor prognosis. Multivariate analysis showed that a high level of both Lep-R (L) and Lep-R (S) mRNA in tumor tissue was a significant risk factor, independent of other risk factors. The subset analysis demonstrated that both intratumoral Lep-R(L) and Lep-R(S) mRNA high tumors were significantly associated with a poor prognosis for the subset of patients with high serum leptin or high intratumoral leptin mRNA levels but not in the subset of patients with low serum leptin or low intratumoral leptin mRNA levels. The association between both intratumoral Lep-R(L) and Lep-R(S) mRNA high tumors and a poor prognosis in the presence of high serum leptin or high intratumoral leptin mRNA levels seems to suggest that the leptin and Lep-R(L)/Lep-R(S) pathways are implicated in the growth stimulation of breast tumors. The well-established finding that obesity serves as a risk factor for relapse in breast cancer patients may thus be partially explained by the high serum leptin level seen in obese women.
authors.affiliation: Department of Surgical Oncology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Miyoshi
authors.forename: Tohru
authors.initials: T
authors.lastname: Funahashi
authors.forename: Sachiyo
authors.initials: S
authors.lastname: Tanaka
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Taguchi
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tamaki
authors.forename: Iichiro
authors.initials: I
authors.lastname: Shimomura
authors.forename: Shinzaburo
authors.initials: S
authors.lastname: Noguchi
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000097:blood / Q000235:genetics / Q000628:therapy*; D018572:Disease-Free Survival; D004358:Drug Therapy; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D020738:Leptin / Q000097:blood* / Q000235:genetics; D008408:Mastectomy; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000235:genetics*; D054411:Receptors, Leptin
chemical_list: C515448:LEPR protein, human; D020738:Leptin; D020033:Protein Isoforms; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin