C5aR2 Regulates STING-Mediated Interferon Beta Production in Human Macrophages

The complement system mediates diverse regulatory immunological functions. C5aR2, an enigmatic receptor for anaphylatoxin C5a, has been shown to modulate PRR-dependent pro-inflammatory cytokine secretion in human macrophages. However, the specific downstream targets and underlying molecular mechanisms are less clear. In this study, CRISPR-Cas9 was used to generate macrophage models lacking C5aR2, which were used to probe the role of C5aR2 in the context of PRR stimulation. cGAS and STING-induced IFN-β secretion was significantly increased in C5aR2 KO THP-1 cells and C5aR2-edited primary human monocyte-derived macrophages, and STING and IRF3 expression were increased, albeit not significantly, in C5aR2 KO cell lines implicating C5aR2 as a regulator of the IFN-β response to cGAS-STING pathway activation. Transcriptomic analysis by RNAseq revealed that nucleic acid sensing and antiviral signalling pathways were significantly up-regulated in C5aR2 KO THP-1 cells. Altogether, these data suggest a link between C5aR2 and nucleic acid sensing in human macrophages. With further characterisation, this relationship may yield therapeutic options in interferon-related pathologies.

Multi-Institutional Phase II Trial Using Dose Escalated Five Fraction Stereotactic Partial Breast Irradiation (S-PBI) with GammaPodTM for Early-Stage Breast Cancer

PURPOSE/OBJECTIVE(S)

We report on our early experience of a multi-institutional phase II study of dose escalated five fraction stereotactic partial breast irradiation (S-PBI) for early-stage breast cancer after partial mastectomy using the GammaPodTM stereotactic radiation system.

MATERIALS/METHODS

Patient eligibility included DCIS or invasive epithelial histologies, AJCC clinical stage 0, I, or II with tumor size < 3 cm, and negative margins. Prior safety of Phase I dose escalation has been reported. Dose was 40 Gy delivered in 5 fractions to the CTV, and minimum dose 30 Gy in 5 fractions to the PTV. CTV margin was 1 cm and PTV margin 3 mm. For PTV cavities larger than 100cc, dose was reduced to 35Gy in 5 fractions to the CTV and 30 Gy in 5 fractions to the PTV. Primary endpoint of the study is to determine the 3-year patient global cosmesis score (4-point scale excellent, good, fair, or poor) and adverse cosmesis using a dose escalated approach with smaller PTV margins than conventional methods. Both patients and physicians completed baseline and subsequent cosmesis outcome questionnaires. Treatment related toxicity was graded using the NCI version 4.0 and RTOG/EORTC late radiation scale.

RESULTS

From 3/2019-10/2021, 74 patients were treated respectively. Of these, 38 were treated to 40Gy and 36 were treated to 35 Gy. Median follow up (f/u) was 24 months (mo), range (r) 3-39mo. Median age was 63 years (r 43-77). Histology included 28 DCIS, and 46 invasive carcinomas. 45/46 invasive tumors were ER+. 60/74 (81%) patients received endocrine therapy, and 7/74 patient received chemotherapy. There were 221 acute grade 1 toxicities, and 28 Grade 2 toxicities. No grade 3 or higher acute toxicities were reported (< 90 days). The most common Grade 2 toxicities were radiation dermatitis (10), breast pain (8), blister (4), skin infection (2), nipple discharge (2), and fatigue (2). In the late period, there were 54 Grade 1 late toxicities, 4 Grade 2 late toxicities, and no Grade 3 or higher late toxicities. Grade 2 toxicities included fibrosis (2), and pain (2). Two patients developed grade 1 asymptomatic nonpalpable fat necrosis both diagnosed at 12 months after radiation treatments. The most common grade 1 late toxicities were breast pain (14), hyperpigmentation (8), fibrosis (10), and fatigue (5). Physicians scored cosmesis excellent or good 70/73 (95.8%), 58/60 (96.7%), 36/36 (100%),17/17(100%) respectively at baseline, 12 months, 24 months, and 36months post SBRT, while patients scored the same periods 62/71 (83.7%), 53/59 (89.8%), 33/36 (91.6%), 17/18 (94.4%). There have been no reports of disease recurrences.

CONCLUSION

Results at 24-month median follow-up, of our dose escalated stereotactic partial breast 5 fraction regimen, has low acute and late toxicity, while maintaining high proportion of excellent/good cosmetic outcomes. Continued analysis of all cohorts is in progress.

CLINICAL TRIALS

gov identifier is NCT03581136.

Abstract P4-10-18: Patterns of failure in a predominately black, inner city cohort of triple negative breast cancer patients at a single institution

Introduction: Triple negative breast cancer (TNBC) accounts for 12-17% of breast cancer (BC) in the US, but behaves much more aggressively. It occurs more commonly in younger, black women and death within two years of diagnosis is more common in this subset of BC compared to hormone receptor positive BC. At the University of Maryland Greenebaum Comprehensive Cancer Center, we see a higher proportion of TNBC and present our comprehensive evaluation of the patterns of failure in women with TNBC treated at our urban breast center.

Materials/Methods: A retrospective review of TNBC patients treated from 2005-2017 identified 198 patients with Stage I (33%), Stage II (47%), Stage III (16%) and Stage IV (4%) TNBC. The patients were all female, median age of 54 years (range 22-86 years), 64% black, 40% married, 7% BRCA mutated, and 3% HIV positive. Tumor characteristics revealed 93% infiltrating ductal carcinoma, 68% grade 3, and 18% with lymphovascular space invasion. Self-palpation of the lesion occurred in 76% of women, and the lesion was in the upper outer quadrant 62% of the time. Thirty percent of pts had neoadjuvant and 67% adjuvant chemotherapy. Ninety-eight percent of pts underwent surgical resection, 55% had lumpectomy and 61% sentinel lymph node biopsy. Adjuvant radiation was given in 56% of patients with a median dose of 60 Gy (range 16-70 Gy). Chi-square testing was used to compare variables, while logistic regression with Kaplan-Meier estimate was used to calculate overall survival (OS) and freedom from recurrence (FFR).

Results: With a median follow up of 45 months, 33 (17%) documented failures occurred. At time of first documented failure, 30% were local (L), 6% regional (R), 22% distant (D), 6% combination of L/R, 12% combination of L/R/D, 9% L/D, and 15% R/D, with a total combined failure pattern in 42% of pts. There was no significant difference in failure patterns between white and black pts (p=0.50, Table 1). The 2 and 5 year OS was 88% and 80%, respectively. Median survival was not reached in our cohort. The 2 and 5-year FFR was 90% and 84%, respectively with a median time to any failure of 16 months after initiation of therapy and median OS of 29 months for these pts.

Conclusion: Our work shows that with modern BC therapies treatment outcomes for pts with TNBC are improved and 84% are free of disease at 5 yrs after the initial diagnosis. The patterns of failure in TNBC are complex, did not vary by race, and showed the largest proportion of our pts (58%) failing in distant and locoregional sites simultaneously, while an additional 30% of pts fail locally only. These failure patterns did not differ significantly based on race. Future efforts will identify pts most at risk for treatment failure for consideration of treatment intensification, as salvage options are limited when treatment failure occurs.

Comparison of Failure Patterns Between White and Black PatientsFailure PatternWhite (n,%)Black (n,%)p-valueLocal only2 (22.5)8 (33) Regional only1 (11)1 (4) Distant only2 (22.5)5 (21)p=0.496Local and Regional0 (0)2 (8) Local and Distant0 (0)3 (13) Regional and Distant3 (33)2 (8) Local, Regional and Distant1 (11)3 (13) 

Citation Format: Rice SR, Cherng H-R, Hamza M, Murali S, Rosenblatt P, Bellavance E, Cheston S, Amin N, Nichols EM. Patterns of failure in a predominately black, inner city cohort of triple negative breast cancer patients at a single institution [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 P4-10-18.

Abstract OT2-03-03: Delivery of a single fraction lumpectomy cavity boost using a novel immobilization device and treatment delivery system

Background: The lumpectomy cavity (LPC) boost has been shown in 2 randomized studies to improve local control in breast cancer. Hypofraction is now being used for delivery of the LPC boost in some early-stage patients. This trial delivers the LPC boost in a single fraction using a novel breast immobilization device/treatment delivery system.

Trial design: Patients are enrolled in this trial after standard resection with lumpectomy/sentinel lymph node biopsy (as appropriate) and chemotherapy (as indicated per standard of care). At the time of CT simulation for whole-breast radiation therapy (RT), the radiation oncologist evaluates breast size and LPC position. If consented for treatment, the patient receives a single fraction “boost” treatment of 8 Gy in 1 fraction followed by standard whole-breast RT to start within 7 days of completion of the boost. Whole-breast radiation is delivered in the supine or prone position with the following fractionation schemes: 4005 cGy in 15 fractions or 5000 cGy in 25 fractions.

On the day of the boost treatment, the patient is fitted with the breast immobilization device, with a plastic inner cup that is fitted so that the breast fills all or most of the cup. A rigid outer cup with a built-in stereotactic fiducial system is attached. Moderate negative pressure is applied to immobilize the breast within the cup system. Patients then undergo CT simulation in the prone position. Clip placement and LPC cavity location must meet eligibility criteria before proceeding with treatment planning and delivery.

Eligibility criteria:

Eligibility criteria: age &gt;60 yo; female only; dx of invasive ductal or lobular carcinoma or ductal carcinoma in situ; estrogen receptor positive; successful completion of lumpectomy ± sentinel lymph node biopsy with negative margins for invasive or noninvasive cancer; greatest tumor dimension &lt;4 cm before surgery; weight &lt;330 lb; height &lt;76 inches; nonlactating and nonpregnant. Various additional dosimetric factors must be met prior to treatment. If these are unable to be met, the patient will become ineligible for treatment.

Specific aims: The aim of this study is to demonstrate the feasibility and safety of delivering the LPC boost RT using a single fraction with a novel immobilization device/treatment delivery system while ensuring coverage of the target volume with appropriate dose homogeneity and conformity. Secondary aims are evaluation of patient comfort, acute toxicity (1 month), and late toxicity (1 year).

Statistical methods: A Simon 2-stage design is utilized for this trial. After evaluating the device and treatment on 8 patients in the first stage, the trial was designed to be terminated and device rejected if the dose distribution was acceptable for ≤5 patients. The first stage was completed in spring 2017 and progressed to the second stage, designed to include a total of 17 patients.

Accrual and target accrual: Target accrual for this study is 14 patients successfully treated while meeting all protocol constraints. As of 6/2017, 16 patients have been enrolled, of whom 13 have been successfully treated while meeting all protocol constraints.

Citation Format: Nichols EM, Becker S, Hong J, Cohen RJ, Mishra MV, Citron W, Cheston SB, Niu Y, Mutaf Y, Yu CX, Feigenberg SJ. Delivery of a single fraction lumpectomy cavity boost using a novel immobilization device and treatment delivery system [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 OT2-03-03.

Abstract OT3-01-07: Phase II study of trastuzumab and pertuzumab alone and in combination with hormonal therapy or chemotherapy with eribulin in women aged ≥60 with HER2/neu overexpressed locally advanced and/or metastatic breast cancer

Her2 overexpression is both a predictive and prognostic marker with tumors overexpressing Her2 having an aggressive natural history, but also responding to targeted therapy. The standard of care for Her2 positive metastatic cancer is docetaxel paired with combined antibody therapy of pertuzumab (P) and trastuzumab (T). Older patients are known to have more difficulty tolerating traditional cytotoxic chemotherapy. Neoadjuvant studies have shown a proportion of patients have pathologic complete responses (pCR) with dual Her2 targeted therapy without chemotherapy. The NEOSPHERE trial demonstrated at 17% pCR after 3 cycles of T+P. The Translational Breast Cancer Research Consortium has shown 12-28% pCR with the combination of estrogen deprivation, trastuzumab, and lapatinib (TBCRC 006 and 023). We have designed a phase II study of T+P alone and then in combination with hormonal or chemotherapy after progression in women age ≥ 60 with Her2 overexpressed locally advanced or metastatic breast cancer (BC). As a primary endpoint, this study seeks to evaluate the overall response rate (ORR) of dual Her2 targeted therapy with T+P without chemotherapy in older patients with locally advanced or metastatic Her2 positive BC (cohort 1). At progression,depending on tumor characteristics and disease status, chemotherapy with eribulin or hormone therapy with anastrozole plus fulvestrant will be added (cohort 2 – A and B). ORR for cohorts 1, 2A and 2B will be determined. Secondary end points will evaluate clinical benefit, progression free survival, overall survival, tolerability, safety, and quality of life. Translational studies involving circulating tumor cells identified through OncoCEE – Biocept system and glycoprotein 88 expression will be performed. Eligibility includes patients' age ≥60 with locally advanced or metastatic Her2 positive BC treated with 0-3 lines of chemotherapy. Patients must have an ejection fraction &gt;50% and meet set hematologic and metabolic lab criteria. Her2 status is per ASCO/ACP guidelines. Excluded patients include patients with active brain metastasis, second malignancies, anticancer treatment &lt;3 weeks prior to the start of therapy. Patients must have not received pertuzumab, eribulin, anastrozole, or fulvestrant in the metastatic setting. A true ORR of 40% will be considered active. The study was designed assuming 25% of patients initially respond to T+P and 75% progress to cohort 2. With a type I error rate of 0.05 and power of 0.90, 40 patients will need to enroll in order to have 30 patients in cohort 2 (15 per arm). Data will be analyzed after eight patients are enrolled. If there are no responders in cohort 1 and 2, the accrual will be stopped and declared inefficient. After 15 patients are enrolled, if no more than 3 of the 15 respond, the therapy will be considered not promising and halted. Currently there are two patients enrolled at the University of Maryland. We are in negotiations to expand to additional sites. Questions can be directed to prosenblatt@umm.edu.

Citation Format: Rosenblatt PY, Kesmodel SD, Bellavance E, Nichols EM, Feigenberg SJ, Tait N, Lewis J, Sivisailam SS, Couzi R, Goloubeva O, Tkaczuk KHR. Phase II study of trastuzumab and pertuzumab alone and in combination with hormonal therapy or chemotherapy with eribulin in women aged ≥60 with HER2/neu overexpressed locally advanced and/or metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT3-01-07.

Abstract P4-11-11: Preoperative Radiotherapy Increases Eligibility for Partial Breast Irradiation by Significantly Reducing Normal Tissue Exposure

Introduction: External-beam accelerated partial breast irradiation (EB-APBI) is the most common technique used on NSABP B-39 primarily due to the non-invasive nature of the treatment. Many patients thought to be eligible for EB-APBI become ineligible at the time of planning due to inability to meet dose-volumetric constraints. EB-APBI in the preoperative setting will reduce the volume of normal tissue treated potentially increasing the number of patients eligible for APBI. This study tested the hypothesis that pre-operative EB-APBI will not only decrease target volumes but will decrease normal tissue exposure significantly increasing eligibility for APBI.

Materials and Methods: Forty patients with 41 previously treated early stage breast cancers (tumors ≥4 cm) were retrospectively analyzed from a prospective cohort. Imaging studies (MRI, US and mammogram) were utilized to create a spherical pre-op tumor volume using the largest reported dimension centered within the previously contoured lumpectomy cavity (LPC). Plans were created and optimized for each patient using the pre-operative tumor volume (pre-op) and LPC (post-op) using NSABP B-39 guidelines. Dose-volumetric constraints were analyzed between the cohorts using a t-test analysis. The primary end-point was to evaluate for differences in patient eligibility and normal tissue exposure.

Results: The median tumor volume was 93 cc (range 24-570 cc) and 250 cc (range 46-879 cc) in the pre-and post-operative setting respectively. This reduction in tumor volume translated into an increase in patient eligibility for EB-APBI with 35/41 (85%) cases being eligible for EB-APBI in the preop setting versus 18/41 (44%) cases in the post-op setting (p=0.0002). In the pre-op setting 6 cases were ineligible due to violation of one constraint by 5% and no case violated multiple constraints. In the post-op setting, 12 cases had 1 and 11 cases multiple reasons for ineligibility due to exceeding dose constraints by 5%. The most common reason for ineligibility in both groups was &gt; 60% of the ipsilateral breast volume receiving 50% of the dose. The mean volume of ipsilateral breast receiving 50% of the dose was 42% and 63% in the pre-and post-op groups respectively. The mean contralateral breast dose and ipsilateral lung V20 in the pre-and post-op groups were 1 versus 4% and 3 versus 9%. All DVH criteria were statistically significantly improved in the pre-op setting including heart V5 and V40, ipsilateral breast V5, V20, V50 and V80, contralateral breast dose, chest wall V5, V10 and V20; ipsilateral lung V5, V10, V20 and volume of skin receiving 50% of the dose. Contralateral lung dose and thyroid max dose were not significantly different between plans.

Conclusions: Administration of EB-APBI in the pre-op setting decreases the size of the target volume which significantly increases the utility of APBI nearly doubling the eligibility for APBI in this cohort. The largest benefit is seen by reducing the volume of breast receiving 50% of the dose. This decreased dose to normal tissues will potentially result in decreased morbidity and improved cosmesis.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-11-11.

Comparative analysis of the post-lumpectomy target volume versus the use of pre-lumpectomy tumor volume for early stage breast cancer: implications for the future

Abstract #5134

Purpose: Accelerated partial breast irradiation (APBI) is increasingly being utilized for the treatment of early stage breast cancer. Planning target volume (PTV) generation with this approach is based on the post-lumpectomy cavity volume (post-LPC) and is often associated with treatment of large amounts of normal breast tissue which can result in patient ineligibility for external beam APBI (EB-APBI). In malignancies such as soft tissue sarcomas, neoadjuvant radiation therapy (RT) has been shown to be associated with smaller volumes of tissue irradiated compared to adjuvant RT. However, neoadjuvant RT has not been attempted in the setting of APBI. We hypothesized that a PTV generation based on an expansion of the pre-lumpectomy (pre-LP) intact tumor volume would result in a significant reduction in the volume of irradiated normal breast tissue compared to the current approach of using the post-LPC. We further hypothesize that the use of EB-APBI utilizing the pre-LP tumor will result in greater patient eligibility for APBI.&#x2028; Materials and Methods: 40 patients with 41 early stage breast cancers previously treated with breast conserving lumpectomy and RT were analyzed. Pre-operative imaging and pathology reports were used to determine a pre-LP tumor volume. A sphere, the diameter of which was the largest determined radiographic dimension, representing the pre-LP tumor volume was placed in the center of the previously contoured and treated lumpectomy cavity. PTVs were developed for the pre-LP tumor volume and the post-LPC volume as per the NSABP-B39 protocol guidelines. The pre-LP and post-LPC PTV volumes were compared. Suitability for APBI was analyzed using criteria set forth by NSABP-B39 guidelines.&#x2028; Results: For all patients, the pre-LP PTV was smaller than the post-LPC PTV. The median volume for the pre and post-LPC PTVs were 93 cc (range 24 – 570 cc) and 250 cc (range 45 – 879 cc), respectively. Paired t-test analysis demonstrated the pre-LP PTV to be significantly smaller than the post-LPC PTV, p &lt; 0.001. The average difference between pre-LP and post-LPC PTVs represented 173 cc (range 21 – 482 cc) or 18% (range 3 - 42%) of the whole breast volume. Based on our analysis, only 3 of 41 cases were ineligible for EB-APBI when using the pre-LP tumor volume, (2 based on pathologic criteria and 1 based on dose/volume constraints) while 13 of 41 cases were ineligible when using the post-LPC PTV (2 based on pathologic criteria and 11 based on dose/volume constraints).&#x2028; Conclusion: PTVs based on the pre-LP tumor expansion are likely to be associated with a significantly reduced amount of normal breast tissue irradiated compared to post-LPC PTVs potentially leading to improved breast cosmesis, decreased dose to critical structures and decreased toxicities. Additionally, eligibility for EB-APBI would potentially increase if administered in the pre-lumpectomy setting. The findings from this study support future investigation as to the implications and feasibility of neoadjuvant APBI.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5134.

Control of methicillin-resistant Staphylococcus aureus in a burn unit: role of nurse staffing

We investigated retrospectively the spread of methicillin-resistant Staphylococcus aureus (MRS) in a burn unit. During 8 months, 34% of the patients acquired MRS, and transmission continued despite barrier isolation precautions and treatment of colonized personnel with topical intranasal antibiotics. Several findings suggested MRS was spread primarily by contact transmission involving personnel: case-control comparison showed burn size to be the major host risk factor for colonization; correlation analysis of environmental factors revealed a significant (p = 0.001) association of new cases with increased patient load and with staffing by overtime or temporary nurses; and environmental sampling yielded few colonies of MRS. The outbreak halted following implementation of control measures, among which assignment of separate nurses to colonized patients appeared to be essential. The association of different nurse staffing variables with persistence then eradication of MRS suggests nurse staffing may have been an important factor in staphylococcal transmission.