Limitations in the Application of Clinicopathologic Factors Alone in Predicting Radiation Benefit for Women with Low-Risk DCIS after Breast Conserving Surgery: The Impact of a 7-Gene Biosignature Based on 10-Year Ipsilateral Breast Recurrence (IBR) Rates

PURPOSE/OBJECTIVE(S)

Most women diagnosed with ductal carcinoma in situ (DCIS) receive radiotherapy (RT) after breast conserving surgery (BCS); however, clinical trials show that over 70% of women with BCS alone will not have a recurrence and therefore not benefit from RT. Traditionally, clinicopathologic (CP) factors have been used to select for whom to de-escalate treatment, but prospective trials have failed to identify a low risk CP group that did not benefit from RT with respect to local control. This study assessed the re-classification of patients with low-risk CP into Risk groups defined by the 7-gene biosignature and compared to 10-yr IBR rates.

MATERIALS/METHODS

Women (n = 926) from four international DCIS cohorts treated with BCS had formalin-fixed paraffin embedded tissue samples analyzed at a CLIA lab (Laguna Hills, CA). CP low-risk patients were identified using a) RTOG-9804-like criteria [Nuclear Grade 1 or 2 & Size ≤2.5 cm & non-Palpable & Screen Detected & margin negative (no-ink on tumor)] and b) MSKCC-like criteria [low-risk score<220, determined using nomogram weighted factors (excluding: number of re-excisions and RT treatment), and using no-ink-on-tumor instead of close margin]. The 7-gene DCIS biosignature combined biomarkers with CP factors (age, size, palpability, and margin status) using an algorithm reporting a Decision Score (DS) and Residual Risk subtype (RRt). Women with low-risk CP were classified into biosignature Low Risk (DS≤2.8, no RRt) or High Risk (DS>2.8 +/- RRt) groups. 10yr in-breast event (IBR) rates with and without RT were assessed by Kaplan-Meier rates and Cox proportional hazard analyses.

RESULTS

Overall, 37% of all women were classified into the biosignature Low Risk group, while 51% and 34% were classified into CP low-risk groups (RTOG-9804-like, MSKCC-like, respectively). The biosignature Low Risk group (n = 338) had a 10-yr IBR risk of 5.6% after BCS and no significant RT benefit (absolute RT benefit = 0.8%, p = 0.70), 99% negative predictive value (NPV) for RT benefit. CP low-risk groups had 10-yr IBR rates of 12% and 8% after BCS without RT with absolute 6% (p = 0.04) and 4% (p = 0.1) IBR rate reductions with RT. The biosignature reclassified 51% and 63% of CP low-risk patients into the biosignature High Risk group. Importantly, these patients had higher IBR rates without RT (20% and 12%) and significant 13% (p = 0.005) and 8% (p = 0.01) absolute IBR rate reductions from RT. CP low-risk patients with concordant biosignature Low Risk demonstrated no significant RT benefit.

CONCLUSION

The 7-gene predictive biosignature more reliably identified patients with low 10-yr IBR rates and no significant RT benefit than the traditional CP low-risk criteria (RTOG-9804-like, MSKCC-like). Importantly, those CP low-risk patients who were re-classified as biosignature High Risk had increased 10-year IBR rates and significant RT benefit.

OS11.4.A Intrathecal delivery of dendritic cell vaccine eradicates tumor growth and protects against leptomeningeal disease re-inoculation in immunocompetent HER2+ and triple negative breast cancer leptomeningeal disease xenograft models

Background

Leptomeningeal disease (LMD) occurs in ~5% of patients with breast cancer (BC) and has a median survival of 2-4 months. We found a loss of the anti-HER2 and anti-HER3 CD4 Th1 immune responses in BC patients. In pre-clinical and clinical trials the administration of class II HER2 peptide-pulsed dendritic cell vaccine (HER2-DCV) partially restores anti-HER2 Th1 immune responses with pathologic complete responses in HER2+ BC patients. Here, we examined the intrathecal (IT) delivery of HER2/HER3-DCV in BC-LMD immunocompetent animal models.

Material and Methods

Luciferase-labeled HER2+ TUBO BCs were injected into the cisterna magna of BALB/c mice to produce LMD. We used our Murine Ommaya (mimics an Ommaya reservoir clinically in patients) for the IT administration of DCVs into the cerebral spinal fluid (CSF).

Results

BC-LMD mice were randomized into following groups: 1) HER2-DCV IT 2) HER3-DCV IT 3) HER2/HER3-DCV IT. The median survival of untreated (control) group was 15 days. All groups given DCV IT prolonged survival (p&lt;0.001). Interestingly, HER2-/HER3-DCV IT was able to rescue disease mice (71% in HER2+ BC-LMD and 28% in triple negative breast cancer-LMD) and showed complete tumor regression. Some surviving mice were immune to subsequent tumor rechallenge. In mice CSF, we found evidence of CD4+ and CD8+ T-cells infiltration, and robust IFN-gamma and IL18 response upon DCV treatment.

Conclusion

Our preclinical data supported a clinical trial (submitted) of the IT delivery of DCV in BC patients with LMD.

Abstract OT2-04-05: Phase II trial of pre-operative stereotactic ablative radiotherapy (SABR) in early-stage breast cancer

Background:

Post-operative accelerated partial breast irradiation (APBI) has demonstrated efficacy in preventing in-breast tumor recurrence. Pre-operative administration of APBI may be advantageous as an intact breast tumor is smaller than its corresponding lumpectomy cavity, is easier to distinguish on treatment-planning images, and results in smaller and more accurately delineated target volumes. Pre-operative APBI may reduce the incidence of positive margins following breast-conserving surgery (BCS). Investigation is needed in the correlation of MR imaging with pathologic response 6 weeks after SABR. Also, evidence suggests that SABR induces immune activation in the tumor microenvironment; evaluation of excised tumor tissue will give insight into these processes.

Trial Design:

Treatment Planning and Delivery: CT simulation and treatment are performed in the prone position. Diagnostic MRI is fused to planning CT. GTV is delineated on registered breast MRI and includes the intact breast tumor. CTV is 15mm expansion of GTV. PTV is 3 mm expansion of CTV. VMAT or IMRT are permitted. Daily image-guidance aligning to tumor and biopsy-fiducial is mandatory. All subjects undergo pre-operative SABR to 28.5 Gy in 3 fractions of 9.5 Gy on different days separated by ≤48 hours. CTCAE v4 is used to assess toxicity 4-5 weeks after SABR. Pre-operative diagnostic MRI is performed 5-6 weeks following SABR. Imaging parameters to be evaluated include changes in tumor size, enhancement, and tumor margin description. BCS will be 6-8 weeks following SABR.

Tissue pathology: Margin status and degree of pathologic response are recorded from breast-conserving excisions, specimens are archived for future analysis.

Eligibility Criteria:

Inclusion criteria are women age ≥50 with biopsy proven invasive breast adenocarcinoma with tumor size ≤2cm on MRI, cN0 M0, ER+/HER2-, without history of invasive malignancy or prior breast/thoracic radiotherapy.

Exclusion criteria are active scleroderma or lupus erythematosus with skin involvement, MRI defined tumor within 10 mm of skin, implanted hardware prohibiting appropriate treatment planning or delivery, neoadjuvant chemotherapy, carrier of BRCA1 or 2 gene mutation, pregnancy.

Specific Aims:

The primary endpoint is pathologic complete response (pCR) in the breast tumor, secondary endpoints are incidence of adequate surgical margins (defined as “no tumor on ink”) and MRI response following SABR. Analyses of tumor immune response and microenvironment on pathologic specimens following SABR will also be performed.

Statistical Methods:

Fisher's exact test will be performed to examine associations between patient/tumor characteristics and pCR and surgical margins; these associations will be explored with multivariable logistic and linear regressions.

Accrual:

Present accrual is 9 subjects.

Expected accrual is 22 subjects; if ≥3 pCR are noted in the initial cohort, accrual will be expanded to 40 subjects.

Citation Format: Liveringhouse CL, Diaz R, Ahmed KA, Lee MC, Czerniecki B, Laronga C, Khakpour N, Weinfurtner RJ, Rosa M, Montejo ME. Phase II trial of pre-operative stereotactic ablative radiotherapy (SABR) in early-stage breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-04-05.

Abstract OT2-07-01: Phase 1/2 trial of the oncolytic virus, talimogene laherparpvec, in combination with neoadjuvant chemotherapy in stage II/III triple negative breast cancer

Background: The host anti-tumor immune response plays an important role in determining natural history and therapy response for early stage breast cancer. Tumors with high levels of lymphocytic infiltration appear to have a superior prognosis and response rate to neoadjuvant chemotherapy. However, these tumors are in the minority so methods to enhance tumor lymphocyte infiltration should be identified. The oncolytic virus, talimogene laherparpvec (TVEC) is a genetically modified HSV1 virus which selectively replicates in transformed cells while sparing normal tissue. This leads to lysis of infected tumor cells along with co-expression of GM-CSF to elicit an enhanced anti-tumor immune response. Prior data has shown TVEC can be safely combined with chemotherapy in other indications, so we launched an investigator initiated study to determine the safety and efficacy of combining TVEC with neoadjuvant dose dense chemotherapy in stage II-III TNBC.

Study design: The study is a phase 1 (2 dose levels of TVEC, 3+3 design) and phase 2 single arm Simon two stage combination trial. Primary endpoints of phase 1 is safety of intratumoral TVEC (DL1=106 PFU x 5 injections, DL2=106 PFU x 1 then 108 PFU x 4 injections) administered q2-3 weeks concurrently with weekly paclitaxel followed by standard dose dense AC x 4 and local therapy as indicated. Phase 2 primary endpoint is pCR rate of the study treatment, secondary endpoints include DFS, OS, immune correlates in resected tumor specimens. Eligibility criteria includes females &gt;17 years old, newly diagnosed T2-3N0-3 TNBC, adequate organ function, primary tumor amenable to injection with TVEC, no immunosuppressive or autoimmune conditions, no inflammatory or bilateral/multifocal disease. Sample size is up to 49 patients (12 phase 1, 37 phase 2) with 80% power to detect increase in pCR rate from 30% to 50% with one sided p=.1 in phase 2.

Study status: This novel Amgen supported investigator initiated study activated to accrual 3/2017 and first patient on study was on 5/2017. The study is currently open only at the Moffitt Cancer Center. Target study completion date 8/2021. (NCT02779855)

Citation Format: Soliman HH, Hogue D, Han H, Lee C, Ismail-Khan R, Khong H, Niell B, Czerniecki B. Phase 1/2 trial of the oncolytic virus, talimogene laherparpvec, in combination with neoadjuvant chemotherapy in stage II/III triple negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT2-07-01.

Abstract P5-14-03: The Impact of Routine Cavity Margins on Reducing the Need for Re-Excision in Women Undergoing Breast-Conserving Surgery for Invasive or Non-Invasive Breast Cancer

Background: The goal of breast conserving surgery (BCS) in women with invasive breast cancer (IBC) or ductal carcinoma in situ (DCIS) is to remove all malignant cells from the breast or to reduce the residual tumor burden to a level that is likely to be eradicated by adjuvant radiation therapy and/or systemic therapy. Theoretical concerns exist that radiography of lumpectomy specimens and subsequent pathologic processing may lead to artifactually positive lumpectomy margins (LM), and the need for subsequent re-excision. To improve the chances of obtaining negative final margins (FM) (generally defined as 2 mm or greater), a number of surgeons in the US and abroad have adopted a technique in which 4-6 additional margins surrounding the main lumpectomy specimen, so-called “cavity margins” (CM), are routinely obtained. The purpose of this study was to assess the clinical utility of the routine use of CM in reducing the need for re-excision.

Methods: The surgical pathology records at our institution were searched for all cases of BCS with additional complete routine CM sampling performed by a single surgeon between May 2008 and April 2010. Patients in whom additional CM were obtained based on intraoperative findings of grossly close margins were excluded from the analysis. The demographic characteristics of the patients and the histological features of the tumor were recorded. We then tabulated the number of patients who had positive LM, CM, and FM, defined as either DCIS or invasive carcinoma at or less than 2 mm from inked specimen margin. The number needed to treat (NNT) to prevent one re-excision was calculated.

Results: We identified 97 women (74 with IBC and 33 with DCIS-only) who had undergone BCS with routine CM sampling during the study period. Mean patient age was 62. Median specimen volume was 178 cc3. 90% of the IBCs were ductal subtype. Mean IBC size was 1.5 cm. 63% of tumors were ER+, 58% PR+, and 7% HER2+. Of the 97 patients in this study, 64 had +LM and 33 had -LM. Of the 64 with +LM, 38 did not have tumor in the CM and 26 had tumor in the CM. Of these 26, 18 had +FM (re-excision needed) and 8 had -FM (no re-excision needed). The proportion of patients with actual tumor at ink (not just close margins) in the lumpectomy specimen was significantly higher among the group with tumor present in the CM than it was in the group with no tumor present in the CM (14/26 versus 7/38, p = 0.006). The NNT with routine CM compared with standard BCS to prevent one re-excision was 2.0 (95% CI, 1.5 — 2.1).

Discussion: In this study the routine use of CM reduced the need for reexcision in women undergoing BCS for IBC or DCIS; one re-excision was avoided for every two patients treated with this surgical approach. The absence of tumor in the CM in the majority of patients with positive LM suggests that specimen radiography and/or pathologic processing techniques may result in artifactually positive LM. Our results indicate that improved specimen imaging and pathological processing techniques are needed to increase the fidelity of margin assessment. In the meantime, the routine use of cavity margins may reduce the need for re-excision in women undergoing BCS.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-14-03.

Differentiation of benign and malignant breast lesions by in-vivo three-dimensional diffuse optical tomography

Abstract #805

Background: Diffuse optical tomography (DOT) uses near-infrared light to non-invasively image total hemoglobin concentration and blood oxygen saturation in the human breast. Given its low cost, ease of use, and possibility of repeated measured over time, DOT is a promising adjunctive imaging modality for screening, diagnosis and monitoring of neoadjuvant therapy. In this study we explored the performance of DOT to differentiate benign and malignant breast lesions.&#x2028; Method and Materials: Forty-seven women with clinical or mammographic abnormalities were prospectively recruited for DOT. Most patients underwent gadolinium-enhanced MRI examination. Three-dimensional oxy-, deoxy-hemoglobin, total hemoglobin concentration, blood oxygen saturation and scattering coefficient images of each breast were reconstructed. Tumor-to-normal (T/N) ratios of these parameters were computed by defining tumor regions with guidance from MRI and radiology reports. In addition, optical index was constructed based on these parameters to maximize the T/N contrast. Only the biopsy-proven lesions were selected (51 breast lesions) and classified into three groups: benign lesions (N=10), malignant lesions where DOT preceded core biopsy (N=20) and malignant lesions where DOT was performed after core-biopsy (N=21). We fit a mixed effects model that estimated the mean optical T/N ratios and optical index for each group, and using the resulting standard errors developed 95% confidence intervals and tested the hypothesis that each optical contrast parameter was unity.&#x2028; Results: Malignant cancers showed statistically significant higher total hemoglobin concentration, scattering, oxy-hemoglobin concentration and optical index (P=0.01-0.04) compared to normal tissue. Furthermore, malignant lesions exhibited a two-fold average increase in an optical index derived from the endogenous optical parameters (95% CI: 1.4 - 2.4). To test whether bleeding due to core biopsy influence DOT results, we compared if there was statistically significant differences between two groups measured before or after core-biopsy. There were no statistically significant differences in these groups, suggesting that post biopsy hemorrhage did not alter the DOT results. Benign tumors did not show statistical significance in all of the T/N ratios. AUC of total hemoglobin concentration, scattering, oxy-hemoglobin and optical index suggested good discriminatory power with values between 0.90 and 0.99.&#x2028; Discussion: The data demonstrates the feasibility of differentiating benign and malignant lesions by quantitative three-dimensional DOT when the tumor location information is provided by other imaging modality. The main drawback of this study is the small number of benign lesions, which warrants further study. DOT technology is still at its developing stage and needs more investigation to find its niche in breast imaging.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 805.

Cyclosporin A-induced fibroadenomas of the breast: report of five cases

Five female patients undergoing cyclosporin A therapy had newly developed breast masses. Masses were bilateral in three of the five patients and palpable in four patients. The imaging findings were suggestive of fibroadenomas, and biopsy results were used to confirm the diagnosis. With the development of new breast lesions in patients after transplantation surgery, the diagnosis of cyclosporin A-induced fibroadenomas should be considered.

MR imaging of the breast in patients with invasive lobular carcinoma

OBJECTIVE

Our objective was to assess the usefulness of MR imaging in patients diagnosed with invasive lobular carcinoma of the breast.

MATERIALS AND METHODS

Between July 1993 and September 1999, 32 women (33 cases) diagnosed with pure invasive lobular carcinoma of the breast underwent contrast-enhanced MR imaging examination. One woman was excluded because of lack of follow-up. Correlation was made between the mammographic and sonographic findings, the MR imaging findings, and the final pathology results for the remaining 32 cases.

RESULTS

In 18 women who did not undergo excisional biopsy before the MR imaging, MR imaging showed more extensive tumor burden or the detection of the primary lesion that was occult on conventional imaging in seven (38.9%) of 18 women. In nine (50%) of 18 women, MR imaging performed equally as well as mammography and sonography. In one case (5.6%), MR imaging and mammography underestimated disease extent. In another patient (5.6%), MR imaging overestimated tumor burden, although mammography failed to show the cancer. In 14 patients who had excisional biopsy before the MR imaging, residual tumor was shown in eight women (57.1%) with extensive tumor or additional separate foci in five of the eight patients. In two cases (14.3%) that were interpreted as equivocal, residual tumor was shown in both cases on reexcision. In three cases (21.4%), the MR imaging was interpreted as negative, but microscopic tumor was shown around seroma on reexcision. False-positive enhancement was seen in one case (7.1%).

CONCLUSION

MR imaging showed more extensive tumor than conventional imaging and affected the clinical management in 16 (50%) of 32 patients with invasive lobular carcinoma.

The role of free radicals in tumor promotion

A role has been suggested for free radicals and active states of oxygen in tumor promotion. There are a number of lines of support for this hypothesis, but no definitive evidence. The hypothesis has proven of value in leading to the development of models pertinent to understanding the mechanism of action of tumor promoters.

Inhalation of ozone produces a decrease in superoxide anion radical production in mouse alveolar macrophages

The potentiation of fatal bacterial pneumonia in mice by prior inhalation of ozone occurs at levels of this oxidant pollutant that are frequently present in ambient air. A likely mechanism for this effect is an ozone-induced inhibition in the ability of pulmonary alveolar macrophages (PAM) to produce superoxide anion radical (O2-) demonstrated in the present study. A 25% decrease in PAM O2- production, as measured by nitroblue tetrazolium reduction, occurred after exposure of Swiss-Webster mice to 0.11 ppm ozone for 3 h (p less than 0.05). After 1 ppm there was almost complete inhibition of O2- release. In contrast, the rat, which is highly resistant to the potentiation of bacterial infections by ozone, was less sensitive to inhibition of PAM O2- production, as measured by cytochrome c reduction (mouse IC50, 0.41 ppm; rat IC50, 3.0 ppm ozone for 3 h). The observed decrement in mouse PAM O2- production was not associated with any change in phagocytic ability, as measured by both latex bead ingestion and 51Cr-labeled sheep red blood cell ingestion. This decrease in O2- production in the presence of normal phagocytic activity is analogous to certain of the findings in the neutrophils of children with chronic granulomatous disease. A decrease in rat PAM membrane cytochrome b558 levels was observed after ozone exposure of 3 ppm for 3 h, preliminarily suggesting that the mechanism by which ozone interferes with PAM O2- production may be through interaction with this heme-containing electron carrier.

The development of contact hypersensitivity in mouse skin is suppressed by tumor promoters

The ability of tumor promoters to suppress the development of contact hypersensitivity (CHS) was assessed by the mouse ear swelling assay. Application of the complete or second stage tumor promoters phorbol-12-myristate-13-acetate (PMA, 2 micrograms), croton oil (1%), benzoyl peroxide (20 mg), mezerein (2 micrograms), or phorbol-12-retinoate-13-acetate (PRA, 2 micrograms) to the abdominal surface of CF-1 female mice for 1 week (three treatments) prior to the sensitization of the same location with 0.5% 1-chloro-2,4-dinitrobenzene (DNCB) resulted in a 50% suppression (p less than 0.05) of the CHS response to DNCB. The first stage tumor promoters 4-O-Me-PMA (80 micrograms), calcium ionophore A23187 (80 micrograms), hydrogen peroxide (15%) and the non-promoting analogs phorbol-12,13-diacetate (PDA, 20 micrograms), phorbol (80 micrograms) or acetone did not suppress the response. The suppression of the development of CHS caused by PMA was dependent on the promoter being applied at the site of induction and was inhibited by application of the phospholipase A2 inhibitor dibromoacetophenone (100 micrograms), the lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA, 100 micrograms), or the antiinflammatory steroid fluocinolone acetonide (2 micrograms). Application of PMA or mezerein 24 h prior to challenge with DNCB, to the ears of mice previously sensitized with DNCB resulted in a significant enhancement of the ear swelling response by 60% and 110%, respectively, compared with controls. The results demonstrate that tumor promoters suppress the development of CHS, and suggest the possibility that second stage promotion may involve suppression of the development of a tumor specific immune response.

Phorbol diacetate inhibits superoxide anion radical production and tumor promotion by mezerein

The ability of the non-promoter phorbol diacetate (PDA) to modulate superoxide anion radical production by the complete tumor promoter phorbol myristate acetate (PMA) or the second stage promoter mezerein was assessed. Superoxide anion radical production was measured by the superoxide dismutase inhibitable reduction of nitroblue tetrazolium (NBT) to a blue intracellular formazan precipitate. These studies demonstrated that superoxide anion radical production by murine peritoneal exudate cells (PEC) stimulated by i.p. injection with mezerein (100 ng) is inhibited in a dose-dependent manner by co-administration with PDA (1-1000 ng). There was no effect on the number of formazan-positive PEC when PDA was co-administered with PMA. In a two-stage tumor promotion bioassay in female SENCAR mice initiated with 25.6 micrograms dimethylbenz[a]anthracene (DMBA) followed by first stage promotion with PMA (4X, 2 micrograms), co-administration of mezerein (2 micrograms) with 2 micrograms or 20 micrograms PDA reduced the number of papillomas after 14 weeks by 38% and 44%, respectively, compared with mezerein treatment alone. PDA (20 micrograms) when co-administered with mezerein (2 micrograms) does not inhibit mezerein induced hyperplasia in mouse skin. These results suggest a correlation between the ability of PDA to inhibit both superoxide anion radical production and tumor promotion by mezerein.