Serum endostatin and bFGF as predictive factors in advanced breast cancer patients treated with letrozole.
BACKGROUND
To investigate the value of baseline serum levels of VEGF, bFGF, endostatin and their ratio as predictive factors of response to endocrine therapy in patients with metastatic breast cancer (MBC) and positive ER treated with letrozole after tamoxifen failure.


METHODS
The serum levels of endostatin, VEGF and bFGF were determined in postmenopausal patients with progressing MBC from serum samples obtained before initiation of letrozole. The relation between serum angiogenic factor levels and TTP was investigated.


RESULTS
Seventy-six patients (45.2%) presented a high endostatin level (> 24.6 ng/ml), 40% low bFGF levels (0 pg/ml) and 50.4% low VEGF (=/< 187 ng/ml). With a median follow-up of 22 months, the median TTP was 12.3 months. Median TTP was worse in patients with high endostatin concentration as well as in the low bFGF group, but was not affected when VEGF was considered. When the two factors were combined, the median TTP of patients with endostatin > 24.6 ng/ml and bFGF equal 0 pg/ml was 9.5 months versus 19.5 months in patients with endostatin =/< 24.6 ng/ml and bFGF > 0 pg/ml.


CONCLUSIONS
The baseline levels of bFGF and endostatin are predictive factors of efficacy in patients with MBC treated with letrozole and can select groups with different TTP.
Alba
Emilio
E
Hospital Clínico Universitario, Málaga, Spain. oncologia98@yahoo.com
Llombart
Antonio
A
Ribelles
Nuria
N
Ramos
Manuel
M
Fernández
Roberto
R
Mayordomo
José Ignacio
JI
Tusquets
Ignasi
I
Gil
Miguel
M
Barnadas
Agustí
A
Carabante
Francisco
F
Ruiz
Manuel
M
Vera
Ruth
R
Palomero
Isabel
I
Soriano
Vicente
V
González
Jesús
J
Colomer
Ramón
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000097:blood* / Q000188:drug therapy* / Q000473:pathology; D018567:Breast Neoplasms, Male / Q000097:blood / Q000188:drug therapy / Q000473:pathology; D018450:Disease Progression; D043169:Endostatins / Q000097:blood*; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000097:blood*; D006801:Humans; D000077289:Letrozole; D008297:Male; D008875:Middle Aged; D009570:Nitriles / Q000627:therapeutic use*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D014230:Triazoles / Q000627:therapeutic use*
D000970:Antineoplastic Agents; D043169:Endostatins; D009570:Nitriles; D014230:Triazoles; D016222:Fibroblast Growth Factor 2; D000077289:Letrozole