A multicenter study to determine the optimum duration of neoadjuvant letrozole on tumor regression to permit breast-conserving surgery: Final analyses.

Carpenter, R; Doughty, JC; Cordiner, C.; Moss, N. Henry; Gandhi, Ajeet Kumar; Wilson, Christopher R.; Andrews, Chris; Gui, Gerald; Skene, Anthony

doi:10.1200/jco.2010.28.15_suppl.670

Cited by 3 publications

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“…Only three groups have explored longer (>6 months) administration and the overall response rate (Krainick-Strobel et al , 2008; Dixon et al , 2009; Carpenter et al , 2010). Dixon et al (2009), in their prospective study assessing the response to 3–12 months neoadjuvant treatment with letrozole, showed tumour shrinkage continuing up to 12 months in responders.…”

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confidence: 99%

Increased pathological complete response rate after a long-term neoadjuvant letrozole treatment in postmenopausal oestrogen and/or progesterone receptor-positive breast cancer

et al. 2013

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Background:The objective of this study was to determine the optimal scheduling of 2.5 mg daily letrozole in neoadjuvant breast cancer patients to obtain pathological complete response (pathCR) and assess Ki-67 expression as an early predictor of response.Patients and methods:This single institution study comprised 120 oestrogen receptor (ER)-positive postmenopausal women with primary breast cancer (clinical stage ⩾T2, N0–1), from three sequential cohorts (cohort A of 40, cohort B of 40 and cohort C of 40 patients, respectively) based on different duration of the neoadjuvant letrozole. Biological markers such as ER, progesterone receptor, HER2 and Ki-67 expression were tested at diagnosis and at definitive surgery.Results:A total of 89 patients (75.4%) achieved an objective response with 44 (37.3%) clinical CRs and 45 (38.1%) partial responses. The clinical CRs were significantly observed in cohort C (23 out of 40 patients, 57.5%) and B (16 out of 38 patients, 42.1%) compared with cohort A (5 out of 40 patients, 12.5%) (P-value for trend <0.001). Letrozole induced a similar significant reduction in Ki-67 index after treatment in all cohorts. The pathCR rate was significantly more frequent in cohort C (7 out of 40 patients, 17.5%) than in cohort A (1 out of 40 patients, 2.5%) and B (2 out of 40 patients, 5.0%) (P-value for trend <0.04).Conclusion:One-year neoadjuvant letrozole therapy leads to a higher pathCR rate and may be the optimal length of drug exposure.

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Increased pathological complete response rate after a long-term neoadjuvant letrozole treatment in postmenopausal oestrogen and/or progesterone receptor-positive breast cancer

et al. 2013

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“…It is now appreciated that longer durations of neoadjuvant endocrine therapy produce continued response and increase the numbers of women suitable for BCS, as described above [18]. In a single-arm, open-label, non-comparative study, Carpenter et al [31] followed 139 PMW with primary invasive ER ? and/or PR ?…”

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confidence: 97%

Invasive lobular carcinoma: response to neoadjuvant letrozole therapy

Renshaw

Dixon

Thomas

2011

Breast Cancer Res Treat

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Invasive lobular cancer (ILC) responds poorly to neoadjuvant chemotherapy but appears to respond well to endocrine therapy. We examined the effectiveness of neoadjuvant letrozole in postmenopausal women (PMW) with estrogen receptor (ER)-rich ILC. PMW were considered for treatment with neoadjuvant letrozole if they had ER-rich, large operable, or locally advanced cancers, or were unfit for surgical therapy. Tumor volume was estimated at diagnosis and at 3 months using calipers (clinical), ultrasound, and mammography. At 3 months, if physically fit, women were assessed for surgery. Responsive women with cancers too large for breast-conserving surgery continued with letrozole. Patients had surgery or were switched to alternative therapy if tumor volume was increasing. Sixty-one patients (mean age, 76.2 years) with 63 ILCs were treated with letrozole for ≥ 3 months. The mean reduction in tumor volume at 3 months was 66% (median, 76%) measured clinically, 61% (median, 73%) measured by ultrasound, and 54% (median, 60%) measured by mammography. Surgery was possible at 3 months in 24 cancers in 24 patients, and all but two of the remaining patients continued with letrozole therapy for a median duration of 9 months. At the time of this publication, 40 patients with a total of 41 cancers have undergone surgery. The rate of successful breast conservation was 81% (25/31). Twenty-one patients have continued with letrozole monotherapy, and 19 remain controlled on letrozole at a median of 2.8 years. There is a high rate of response to letrozole in PMW with ER-rich ILC.

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Preoperative Endocrine Therapy: Preferred Therapy for Whom?

Macaskill

Dixon

2011

Curr Breast Cancer Rep

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Neoadjuvant endocrine therapy is safe and can be effective in many postmenopausal women with estrogen receptor positive breast cancer. There are limited data available for premenopausal women taking aromatase inhibitors in combination with estrogen suppression. Letrozole, anastrozole, and exemestane have all been shown to be equivalent or superior to tamoxifen in relatively small neoadjuvant trials in postmenopausal women. Tumor factors that appear to have good response are estrogen receptor positivity, characteristics consistent with the so-called Luminal A subtype and lobular carcinomas. Response to neoadjuvant treatment may inform decision making regarding adjuvant treatment, which should include radiotherapy following breast-conserving surgery, or mastectomy, made feasible by neoadjuvant treatment to maintain low local recurrence rates. Chemotherapy may also be required in some cases based on the biological characteristics of the residual tumor and the extent of residual disease.

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A multicenter study to determine the optimum duration of neoadjuvant letrozole on tumor regression to permit breast-conserving surgery: Final analyses.

Cited by 3 publications

References 0 publications

Increased pathological complete response rate after a long-term neoadjuvant letrozole treatment in postmenopausal oestrogen and/or progesterone receptor-positive breast cancer

Increased pathological complete response rate after a long-term neoadjuvant letrozole treatment in postmenopausal oestrogen and/or progesterone receptor-positive breast cancer

Invasive lobular carcinoma: response to neoadjuvant letrozole therapy

Preoperative Endocrine Therapy: Preferred Therapy for Whom?

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