Retrospective analysis of time to recurrence in the ATAC trial according to hormone receptor status: an hypothesis-generating study.

2.50
Hdl Handle:
http://hdl.handle.net/10541/76796
Title:
Retrospective analysis of time to recurrence in the ATAC trial according to hormone receptor status: an hypothesis-generating study.
Authors:
Dowsett, Mitch; Cuzick, Jack; Wale, Chris; Howell, Anthony ( 0000-0002-3879-5991 ) ; Houghton, Joan; Baum, Michael
Abstract:
PURPOSE: Arimidex, tamoxifen alone, or in combination (ATAC) trial of anastrozole (Arimidex) versus tamoxifen or a combination of the two in 9,366 postmenopausal patients with primary breast cancer found a significant improvement in disease-free survival and time to recurrence (TTR) for anastrozole compared with tamoxifen, that was restricted to patients with hormone receptor-positive (ie, estrogen receptor-positive [ER+] and/or progesterone receptor-positive [PgR+]) disease, the target population for these therapies. We retrospectively tested the hypothesis that this benefit might differ according to PgR status. PATIENTS AND METHODS: TTR was compared between the three treatment groups for subgroups defined by ER and PgR status using Cox's proportional hazards model, with and without adjustment for baseline variables. RESULTS: The unadjusted hazard ratio (HR) for anastrozole versus tamoxifen for TTR was 0.74 (95% CI, 0.64 to 0.87) for women with either ER+ or PgR+ tumors. In the ER+/PgR+ subgroup (n = 3,834) the HR was 0.84 (95% CI, 0.69 to 1.02) compared with 0.43 (95% CI, 0.31 to 0.61) in the ER+/PgR-negative (PgR-) subgroup (n = 880). In the adjusted model the HRs were 0.83 and 0.45, respectively. CONCLUSION: Time to recurrence was longer for anastrozole- than tamoxifen-treated patients in both ER+/PgR+ and ER+/PgR- subgroups, but the benefit was substantially greater in the PgR- subgroup. As this was an "exploratory" analysis, this effect should be considered as hypothesis generating and assessed prospectively in other trials comparing the adjuvant use of an aromatase inhibitor with tamoxifen.
Affiliation:
Royal Marsden Hospital London, SW3 6JJ United Kingdom. mitch.dowsett@icr.ac.uk
Citation:
Retrospective analysis of time to recurrence in the ATAC trial according to hormone receptor status: an hypothesis-generating study. 2005, 23 (30):7512-7 J. Clin. Oncol.
Journal:
Journal of Clinical Oncology
Issue Date:
20-Oct-2005
URI:
http://hdl.handle.net/10541/76796
DOI:
10.1200/JCO.2005.01.4829
PubMed ID:
16234518
Type:
Article
Language:
en
ISSN:
0732-183X
Appears in Collections:
All Christie Publications

Full metadata record

DC FieldValue Language
dc.contributor.authorDowsett, Mitch-
dc.contributor.authorCuzick, Jack-
dc.contributor.authorWale, Chris-
dc.contributor.authorHowell, Anthony-
dc.contributor.authorHoughton, Joan-
dc.contributor.authorBaum, Michael-
dc.date.accessioned2009-08-10T09:20:28Z-
dc.date.available2009-08-10T09:20:28Z-
dc.date.issued2005-10-20-
dc.identifier.citationRetrospective analysis of time to recurrence in the ATAC trial according to hormone receptor status: an hypothesis-generating study. 2005, 23 (30):7512-7 J. Clin. Oncol.en
dc.identifier.issn0732-183X-
dc.identifier.pmid16234518-
dc.identifier.doi10.1200/JCO.2005.01.4829-
dc.identifier.urihttp://hdl.handle.net/10541/76796-
dc.description.abstractPURPOSE: Arimidex, tamoxifen alone, or in combination (ATAC) trial of anastrozole (Arimidex) versus tamoxifen or a combination of the two in 9,366 postmenopausal patients with primary breast cancer found a significant improvement in disease-free survival and time to recurrence (TTR) for anastrozole compared with tamoxifen, that was restricted to patients with hormone receptor-positive (ie, estrogen receptor-positive [ER+] and/or progesterone receptor-positive [PgR+]) disease, the target population for these therapies. We retrospectively tested the hypothesis that this benefit might differ according to PgR status. PATIENTS AND METHODS: TTR was compared between the three treatment groups for subgroups defined by ER and PgR status using Cox's proportional hazards model, with and without adjustment for baseline variables. RESULTS: The unadjusted hazard ratio (HR) for anastrozole versus tamoxifen for TTR was 0.74 (95% CI, 0.64 to 0.87) for women with either ER+ or PgR+ tumors. In the ER+/PgR+ subgroup (n = 3,834) the HR was 0.84 (95% CI, 0.69 to 1.02) compared with 0.43 (95% CI, 0.31 to 0.61) in the ER+/PgR-negative (PgR-) subgroup (n = 880). In the adjusted model the HRs were 0.83 and 0.45, respectively. CONCLUSION: Time to recurrence was longer for anastrozole- than tamoxifen-treated patients in both ER+/PgR+ and ER+/PgR- subgroups, but the benefit was substantially greater in the PgR- subgroup. As this was an "exploratory" analysis, this effect should be considered as hypothesis generating and assessed prospectively in other trials comparing the adjuvant use of an aromatase inhibitor with tamoxifen.en
dc.language.isoenen
dc.subjectBreast Canceren
dc.subjectCancer Recurrenceen
dc.subject.meshAntineoplastic Combined Chemotherapy Protocols-
dc.subject.meshBreast Neoplasms-
dc.subject.meshChemotherapy, Adjuvant-
dc.subject.meshDisease-Free Survival-
dc.subject.meshDouble-Blind Method-
dc.subject.meshFemale-
dc.subject.meshHumans-
dc.subject.meshNeoplasm Recurrence, Local-
dc.subject.meshNitriles-
dc.subject.meshPostmenopause-
dc.subject.meshReceptors, Estrogen-
dc.subject.meshReceptors, Progesterone-
dc.subject.meshRetrospective Studies-
dc.subject.meshSurvival Rate-
dc.subject.meshTamoxifen-
dc.subject.meshTime Factors-
dc.subject.meshTreatment Outcome-
dc.subject.meshTriazoles-
dc.titleRetrospective analysis of time to recurrence in the ATAC trial according to hormone receptor status: an hypothesis-generating study.en
dc.typeArticleen
dc.contributor.departmentRoyal Marsden Hospital London, SW3 6JJ United Kingdom. mitch.dowsett@icr.ac.uken
dc.identifier.journalJournal of Clinical Oncologyen

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