Abstract P5-12-03: Withdrawn

This abstract was withdrawn by the authors.

Abstract P5-14-08: Prospective phase II study of concurrent capecitabine and radiation demonstrates futility in triple negative chemo-resistant breast cancer

Background: Capecitabine is an established radiosensitizer in rectal and other cancers. We conducted a prospective single arm phase II study to examine the response rate of gross chemo-refractory breast cancer treated with concurrent capecitabine and radiotherapy.

Methods: Patients who had inoperable or marginally operable gross disease in the breast and/or lymph node(s) after chemotherapy or gross disease on the chest wall or in the regional lymphatics after mastectomy were eligible. Patients 1-9 received capecitabine 825 mg/m2 BID daily beginning on the first day of radiotherapy. Excess grade 3 toxicity (%) was observed; the protocol was amended and subsequent patients received drug only on radiation treatment days. Radiation dose was at the discretion of the treating physician (50Gy-72 Gy, with no more than 2.5 Gy/fraction). Response was assessed by a single physician using paired radiation planning CTs (pretreatment and on-treatment after 45 Gy). Clinical correlation to all other available imaging was also made. Kaplan-Meier curves were used to estimate overall survival (OS) and local recurrence-free survival (LRFS). Circulating tumor cells (CTCs) in blood were examined in consenting patients.

Results: The trial was stopped early after an unplanned interim analysis prompted by slow accrual suggested futility independent of response. From 2009-2012, 32 patients were accrued; 26 completed protocol specific treatment (17 post-mastectomy radiation with gross nodes, 4 pre-op, 5 aggressive palliation) and are included in this analysis. Median follow up was 7.3 months (interquartile range 6.7 – 17.4). Nineteen patients (73%) had a partial or complete response. Fourteen patients (53.9%) experienced at least one grade 3 non-dermatitis toxicity including 7/9 treated with continuous dosing. Four inoperable patients were treated with pre-op radiation therapy and 3 converted to operable. None achieved a pCR or near pCR. One-year actuarial OS was 52%. There was no difference in OS comparing among PMRT vs. preoperative or palliative RT (P = 0.90). One-year actuarial local recurrence free survival among PMRT patients was 38%. Ten patients had triple negative (TN) receptor status. There was no difference in radiation response by receptor status (P = 0.56); however, treatment was deemed subjectively futile (i.e., converted to operable but death secondary to new widespread M1 disease immediately post-op) in 9 of the 10 patients with TN disease versus 6 of the 16 patients with non-TN disease (P = 0.014). Median OS and 1-yr actuarial OS, among non-TN vs. TN patients were not reached vs. 6.1 months and 77% vs. 10% (P < 0.001), respectively. Eight/fifteen patients tested were positive for CTCs. CTCs did not correlate to receptor status, futility of RT or OS.

Conclusions: Capecitabine can be safely administered as a daily concurrent chemoradiation regimen with weekend holidays. However, in this small, prospective and selected cohort, concurrent chemoradiation with capecitabine was futile among patients with TN breast cancer. Alternative strategies are urgently needed in TN patients.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-14-08.

Pleomorphic Calcifications, Tumor Markers, and Response to Therapy

IntroductionMany breast cancers are initially identified by pleomorphic calcifications (PC) on mammography (MG). We hypothesized that presence of PC correlates with primary tumor markers and with response to systemic therapy.MethodsMammograms of women with Stage I-III breast cancer were evaluated for the presence of PC. Only patients with biopsy proven invasive carcinoma in association with PC were included. Primary tumor markers (ER, PgR, and HER2) were determined in the standard manner at the time of core biopsy and correlated with presence or absence of PC on MG. We also evaluated cyclooxygenase-2 (COX2), based on data showing a role in tumor progression and possible interaction with HER2 and/or ER. Primary tumors were immunostained with an anti-COX2 monoclonal antibody, and staining of ≥ 5% or more of tumor cells was considered as positive. For response to therapy analyses, complete pathologic response (pCR) was defined as lack of any residual invasive disease in primary tumor and regional lymph nodes. We used chi-square and Fischer's exact test for the statistical analysis.ResultsWe prospectively enrolled 239 patients. Median age was 51.2 years and the median follow up was 26 months. Pleomorphic calcifications were more often found in HER2 positive patients (22/37) vs. HER2 negative (71/202), P = 0.005, as well as in COX2 positive patients (28/57), P = 0.044. There were no significant associations between PC and ER or PgR. PC were less prevalent in triple receptor negative patients (11/55)[20%] as compared to receptor positive patients (84/188), P = 0.001. We found PC predicted DCIS to be associated with invasive cancers (27/51)[53%] compared to those who showed no DCIS associated with their invasive breast cancer (57/157) [36%] (P=0.035).When evaluating response to therapy, patients with PC on MG were more likely to have a pCR (6/18) [33%] as compared to those who showed absence of pleomorphic calcifications (2/34)[ 6%], following neoadjuvant chemotherapy, P= 0.015.ConclusionsPleomorphic calcifications were significantly associated with HER2 and COX2 positive primary tumors. Patients with PC were also more likely to have a pCR after systemic therapy. Information regarding PC on MG may be helpful in predicting tumor marker status and response to therapy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2027.

Clinicopathologic factors associated with involved margins following breast conserving surgery for invasive lobular carcinoma (ILC)

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Background: ILC is characterized by a diffusely infiltrative growth pattern making it difficult to accurately assess disease extent prior to surgical resection. This has resulted in difficulty obtaining negative margins at the time of breast conserving surgery. We evaluated patients undergoing surgery for ILC to determine if there were specific clinicopathologic factors influencing the ability to obtain negative margins. Methods: We identified 211 patients with ILC treated between 1994 and 2004. Clinical data including radiographic appearance, biopsy method, initial surgical procedure (segmental vs. total mastectomy), and use of neoadjuvant chemotherapy were noted. Pathologic data included margin status (negative (>2mm), close (0–2mm), or positive), multifocality, multicentricity, ILC subtype, grade, associated LCIS or DCIS, hormone receptor status and HER2 status. Factors associated with close or positive margins were determined using univariate and multivariate analyses. Subset analysis was performed on patients whose initial surgery was segmental mastectomy. Results: 110 (52%) patients underwent total mastectomy and 101 (48%) underwent segmental mastectomy as their initial procedure. For patients undergoing segmental mastectomy, 50 (50%) had positive or close margins requiring re-excision. Patients with close or positive margins were more likely to have distortion on ultrasound (vs. mass, p=.05), to have undergone an excisional biopsy (vs. core or FNA, p=.008), and to have associated DCIS (p=.02). On multivariate analysis, only biopsy method retained significance (p = .006). Having an excisional biopsy for diagnosis was also associated with need for multiple surgeries (p < .0001). Breast conserving surgery was ultimately successful in 86 patients (85%). Conclusions: The majority of patients with ILC can undergo successful breast conserving surgery. Patients with distortion rather than a mass on imaging and those with DCIS are more likely to have close or positive margins. Diagnosis by excisional biopsy makes subsequent imaging less reliable and results in the need for multiple surgeries to ensure adequate excision.

No significant financial relationships to disclose.