Body mass index and circulating oestrone sulphate in women treated with adjuvant letrozole.
BACKGROUND
Obesity is an independent adverse prognostic factor in early breast cancer patients, but it is still controversial whether obesity may affect adjuvant endocrine therapy efficacy. The aim of our study (ancillary to the two clinical trials Gruppo Italiano Mammella (GIM)4 and GIM5) was to investigate whether the circulating oestrogen levels during treatment with the aromatase inhibitor letrozole are related to body mass index (BMI) in postmenopausal women with breast cancer.


METHODS
Plasma concentration of oestrone sulphate (ES) was evaluated by radioimmunoassay in 370 patients. Plasma samples were obtained after at least 6 weeks of letrozole therapy (steady-state time). Patients were divided into four groups according to BMI. Differences among the geometric means (by ANOVA and ANCOVA) and correlation (by Spearman's rho) between the ES levels and BMI were assessed.


RESULTS
Picomolar geometric mean values (95% confidence interval, n=patients) of circulating ES during letrozole were 58.6 (51.0-67.2, n=150) when BMI was <25.0 kg m(-2); 65.6 (57.8-74.6, n=154) when 25.0-29.9 kg m(-2); 59.3 (47.1-74.6, n=50) when 30.0-34.9 kg m(-2); and 43.3 (23.0-81.7, n=16) when ≥35.0 kg m(-2). No statistically significant difference in terms of ES levels among groups and no correlation with BMI were observed.


CONCLUSIONS
Body mass index does not seem to affect circulating oestrogen levels in letrozole-treated patients.
1] Medical Oncology Unit, Sacro Cuore Don Calabria Hospital, Via Sempreboni, 5, 37024 Negrar (Verona), Italy [2] Oncology Unit, Surgical and Medical Department of Clinical Sciences, Sant'Andrea Hospital, via di Grottarossa, 1035, 00189 Rome, Italy.
V
V
Sini
Medical Oncology Unit, Sacro Cuore Don Calabria Hospital, Via Sempreboni, 5, 37024 Negrar (Verona), Italy.
G
G
Lunardi
Medical Oncology Unit, Sacro Cuore Don Calabria Hospital, Via Sempreboni, 5, 37024 Negrar (Verona), Italy.
M
M
Cirillo
Medical Oncology Unit, Sacro Cuore Don Calabria Hospital, Via Sempreboni, 5, 37024 Negrar (Verona), Italy.
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M
Turazza
Medical Oncology Department, IRCSS AOU San Martino, IST, L.go R. Benzi, 10, 16132 Genoa, Italy.
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C
Bighin
Medical Oncology Department, IRCSS AOU San Martino, IST, L.go R. Benzi, 10, 16132 Genoa, Italy.
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S
Giraudi
Medical Oncology Department, IRCSS AOU San Martino, IST, L.go R. Benzi, 10, 16132 Genoa, Italy.
A
A
Levaggi
Medical Oncology Department, IRCSS AOU San Martino, IST, L.go R. Benzi, 10, 16132 Genoa, Italy.
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P
Piccioli
Department of Oncology, Azienda Ospedaliera ASMN, viale Risorgimento, 80, 42123 Reggio Emilia, Italy.
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Bisagni
Department of Oncology, Azienda Ospedaliera ASMN, viale Risorgimento, 80, 42123 Reggio Emilia, Italy.
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R
Gnoni
Department of Oncology, Azienda Ospedaliera ASMN, viale Risorgimento, 80, 42123 Reggio Emilia, Italy.
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G
Stridi
University Department of Gynecology and Obstetrics, S.Anna Hospital, Corso Spezia, 60, 10126 Turin, Italy.
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M
Porpiglia
University Department of Gynecology and Obstetrics, S.Anna Hospital, Corso Spezia, 60, 10126 Turin, Italy.
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E
Picardo
Gynecological Oncology, Institute for Cancer Research and Treatment, Strada Provinciale 142, Km 3.95, 10060 Candiolo (Turin), Italy.
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R
Ponzone
1] Gynecological Oncology, Institute for Cancer Research and Treatment, Strada Provinciale 142, Km 3.95, 10060 Candiolo (Turin), Italy [2] Gynecology and Obstetrics, Santa Croce Hospital, Piazza Amedeo Ferdinando, 3, 10024 Moncalieri (Turin), Italy.
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D
Marenco
Oncology Department, University Hospital of Udine, Piazzale Santa Maria della Misericordia, 15, 33100 Udine, Italy.
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M
Mansutti
Oncology Department, University Hospital of Udine, Piazzale Santa Maria della Misericordia, 15, 33100 Udine, Italy.
F
F
Puglisi
Medical Oncology Department, IRCSS AOU San Martino, IST, L.go R. Benzi, 10, 16132 Genoa, Italy.
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L
Del Mastro
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D047072:Aromatase Inhibitors / Q000627:therapeutic use; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000097:blood* / Q000188:drug therapy* / Q000473:pathology; D017024:Chemotherapy, Adjuvant / Q000379:methods; D004970:Estrone / Q000031:analogs & derivatives* / Q000097:blood; D005260:Female; D006801:Humans; D000077289:Letrozole; D008875:Middle Aged; D009570:Nitriles / Q000627:therapeutic use*; D017698:Postmenopause / Q000097:blood; D014230:Triazoles / Q000627:therapeutic use*
D000970:Antineoplastic Agents; D047072:Aromatase Inhibitors; D009570:Nitriles; D014230:Triazoles; D004970:Estrone; D000077289:Letrozole; C017296:estrone sulfate