Radioactive seed localization is a safe and effective tool for breast cancer surgery: an evaluation of over 25,000 cases

Radioactive seed localization (RSL) provides a precise and efficient method for removing non-palpable breast lesions. It has proven to be a valuable addition to breast surgery, improving perioperative logistics and patient satisfaction. This retrospective review examines the lessons learned from a high-volume cancer center's RSL program after 10 years of practice and over 25 000 cases. We provide an updated model for assessing the patient's radiation dose from RSL seed implantation and demonstrate the safety of RSL to staff members. Additionally, we emphasize the importance of various aspects of presurgical evaluation, surgical techniques, post-surgical management, and regulatory compliance for a successful RSL program. Notably, the program has reduced radiation exposure for patients and medical staff.

Safety of a novel capecitabine dosing schedule when combined with lapatinib in patients with HER2-positive metastatic breast cancer refractory to trastuzumab

1131

Background: Capecitabine (C) is active in breast cancer and is usually dosed for 14 days (d) followed by a 7d rest (14 - 7). We described a mathematical method which predicts the optimal schedule for C to be 7d followed by a 7d rest (7 - 7) (Norton et al, Amer Assn Can Res. 2005). The MTD of C(7 - 7) is 2,000mg BID (Traina et al, J Clin Oncol. April 2008). Lapatinib (L) improves time to progression when added to C(14 - 7) in patients (pts) with HER-2-positive (+) metastatic breast cancer (MBC) that progressed after trastuzumab (T). To optimize this effective combination, we are testing C(7 - 7) + L in a phase II trial. Methods: Eligible pts have measurable, HER-2(+) MBC that has progressed after T. HER-2(+)=IHC 3+ or FISH>2. Pts have normal LVEF by MUGA, ECOG performance status (PS) <2 and normal organ function. <3 prior chemotherapy (CRx) regimens are permitted. Prior fluoropyrimidine is excluded. Therapy (tx) consists of C (2,000 mg BID, 7 - 7) and L (1,250 mg, daily). Cycle length = 4 wk. Pts are evaluated for toxicity q4 weeks (wk), for response q12wk; LVEF by MUGA q12wk. Primary endpoint: response rate (RR). Secondary endpoints: toxicity, stable disease >6 months, PFS. Using a Simon optimal 2-stage design, with alpha = 10%, power = 90% to discriminate between RR 10% and 25%, 21 pts will be accrued to the first stage. If >2 pts respond, 29 additional pts will be enrolled. If >7/ 40 pts respond, then C(7 - 7) + L will be considered worthy of further study. Results: As of January 5, 2008, 6 pts are enrolled and evaluable. Median (med) age 64 yrs (42–71), med ECOG PS 1 (0–1), ER/PR(+) 3, HER-2(+) 6, sites of MBC: bone (2), viscera (4), soft tissue (5). Med baseline LVEF 62% (51–68%). Prior tx: Adjuvant: CRx (5), hormone tx (3), T (3); MBC: CRx (2), hormone tx (1), T (3). After a med of 3 cycles (1–4), there were no grade 3, 4, or 5 events. Tx-related toxicity is: Gr 2 fatigue (1); Gr 1 AST (4), diarrhea (3), ALT (2), vomiting (1), hand-foot (1), fatigue (1). No withdrawls due to reduced LVEF. Two pts evaluable for response: PR = 1, SD<6 mo = 1. Conclusions: Capecitabine (7 - 7) + lapatinib appears well tolerated compared to C(14 - 7)+L (Geyer et al). Additional safety and efficacy data is anticipated prior to this meeting.

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Phase I study of a novel capecitabine schedule based on Norton-Simon mathematical modeling

1045

Background: We have previously described a mathematical method to optimize chemotherapy dose and schedule (Norton et al, AACR 2005). Capecitabine (C) has activity in breast cancer when conventionally dosed for 14 days (d) q3 weeks (14/7). However, the predicted optimal dosing schedule for C using our model is 7d followed by a 7d rest (biweekly, 7/7). We tested this hypothesis in a Phase I/II study described below. Methods: Eligible patients (pts) have measurable, metastatic breast cancer (MBC), ECOG performance status (PS) =2 and normal organ function. There is no limit to number of prior chemotherapy (CRx) regimens. Pts with prior fluoropyrimidine for MBC are excluded. HER2+ pts must not be candidates for trastuzumab. C is given in divided daily doses for 7d followed by a 7d rest. A standard “3+3” dose escalation scheme employs flat dosing which begins at 1,500mg BID and increases by 500mg/dose level. Primary endpoint is the maximum tolerated dose (MTD), defined as the highest dose for which the incidence of dose-limiting toxicity (DLT) is <33%. Results: 19 pts are now accrued; 17 pts have been treated, 2 withdrew prior to receiving C. Medians: age 47 y (range 34–62 y) and ECOG PS 0 (range 0–2). Sites of MBC: bone 8, viscera 16, soft tissue 11. ER/PR+ 11. HER2+ or unknown 2. Prior adjuvant tx: CRx 17, hormone tx 10. Six pts had adjuvant fluoropyrimidine-based tx. Three pts had 1 prior CRx for MBC; 12 pts received first-line hormone tx for MBC. Fifteen pts had prior anthracycline and taxane. Treatment-related toxicities after a median of 4 cycles (range 1–10) are shown in the table . The MTD has not been reached. Pts continue accrual to the 2500mg/2500mg dose level. Conclusions: Capecitabine 7/7 is well tolerated and allows for safe delivery of higher daily doses than routinely used in practice, as predicted by the mathematical model. Capecitabine 7/7 will be tested in a Phase II program at MSKCC in combination with targeted agents.

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No significant financial relationships to disclose.