Predicting benefit from fulvestrant in pretreated metastatic breast cancer patients.
Fulvestrant use in pretreated metastatic breast cancer patients is associated with variable response rates. This study aimed to characterize these responses and to develop a prediction model to identify those patients who could potentially derive the most clinical benefit. A nationwide review of patients enrolled in a Canadian compassionate use program from 1999 to 2006 was performed. Prior therapy with tamoxifen, steroidal, and nonsteroidal aromatase inhibitors was mandatory. The dependent variable in the analysis was the proportion of patients requiring chemotherapy at 3 months following the start of fulvestrant. General Linear Mixed modeling was used to identify factors significantly associated with this dependant variable and to subsequently develop the prediction model. Three hundred and five women received at least one dose of fulvestrant; 207 went on to receive chemotherapy (68%). Median duration of fulvestrant treatment was 4.1 months (range 0.8-63.1). Factors predictive of being chemotherapy free at 3 months included older age, no prior adjuvant hormonal therapy, and the absence of lung or brain metastases at the start of therapy. A receiver operating characteristic (ROC) curve analysis had an area under the curve of 0.70 (95% CI 0.60-0.80). This model was able to identify risk information that could be helpful in assessing which patients would most likely benefit from fulvestrant as an intervention with the objective being a delay in chemotherapy.
Freedman
Orit
O
Division of Medical Oncology, Princess Margaret Hospital, Suite 5-205, 610 University Avenue, Toronto, ON, M5G 2M9, Canada.
Amir
Eitan
E
Dranitsaris
George
G
Napolskikh
Julie
J
Kumar
Ritu
R
Fralick
Michael
M
Chia
Stephen
S
Petrella
Teresa
T
Dent
Susan
S
Tonkin
Katia
K
Ahmad
Imran
I
Rayson
Daniel
D
Clemons
Mark
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D019540:Area Under Curve; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D002986:Clinical Trials as Topic; D004958:Estradiol / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D000077267:Fulvestrant; D006801:Humans; D008875:Middle Aged; D015233:Models, Statistical; D009362:Neoplasm Metastasis; D010166:Palliative Care; D012372:ROC Curve; D018570:Risk Assessment / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult
D018931:Antineoplastic Agents, Hormonal; D000077267:Fulvestrant; D004958:Estradiol