Clinicogenomic characterization of inflammatory breast cancer

Background

Inflammatory breast cancer (IBC) is a rare and poorly characterized type of breast cancer with an aggressive clinical presentation. The biological mechanisms driving the IBC phenotype are relatively undefined-partially due to a lack of comprehensive, large-scale genomic studies and limited clinical cohorts.

Patients and Methods

A retrospective analysis of 2457 patients with metastatic breast cancer who underwent targeted tumor-only DNA-sequencing was performed at Dana-Farber Cancer Institute. Clinicopathologic, single nucleotide variant (SNV), copy number variant (CNV) and tumor mutational burden (TMB) comparisons were made between clinically confirmed IBC cases within a dedicated IBC center versus non-IBC cases.

Results

Clinicopathologic differences between IBC and non-IBC cases were consistent with prior reports-including IBC being associated with younger age at diagnosis, higher grade, and enrichment with hormone receptor (HR)-negative and HER2-positive tumors. The most frequent somatic alterations in IBC involved TP53 (72%), ERBB2 (32%), PIK3CA (24%), CCND1 (12%), MYC (9%), FGFR1 (8%) and GATA3 (8%). A multivariate logistic regression analysis revealed a significant enrichment in TP53 SNVs in IBC; particularly in HER2-positive and HR-positive disease which was associated with worse outcomes. Tumor mutational burden (TMB) did not differ substantially between IBC and non-IBC cases and a pathway analysis revealed an enrichment in NOTCH pathway alterations in HER2-positive disease.

Conclusion

Taken together, this study provides a comprehensive, clinically informed landscape of somatic alterations in a large cohort of patients with IBC. Our data support higher frequency of TP53 mutations and a potential enrichment in NOTCH pathway activation-but overall; a lack of major genomic differences. These results both reinforce the importance of TP53 alterations in IBC pathogenesis as well as their influence on clinical outcomes; but also suggest additional analyses beyond somatic DNA-level changes are warranted.

Preoperative Risk Factors for Lymphedema in Inflammatory Breast Cancer

BACKGROUND

 Prophylactic lymphatic bypass or LYMPHA (LYmphatic Microsurgical Preventive Healing Approach) is increasingly offered to prevent lymphedema following breast cancer treatment, which develops in up to 47% of patients. Previous studies focused on intraoperative and postoperative lymphedema risk factors, which are often unknown preoperatively when the decision to perform LYMPHA is made. This study aims to identify preoperative lymphedema risk factors in the high-risk inflammatory breast cancer (IBC) population.

METHODS

 Retrospective review of our institution's IBC program database was conducted. The primary outcome was self-reported lymphedema development. Multivariable logistic regression analysis was performed to identify preoperative lymphedema risk factors, while controlling for number of lymph nodes removed during axillary lymph node dissection (ALND), number of positive lymph nodes, residual disease on pathology, and need for adjuvant chemotherapy.

RESULTS

 Of 356 patients with IBC, 134 (mean age: 51 years, range: 22-89 years) had complete data. All 134 patients underwent surgery and radiation. Forty-seven percent of all 356 patients (167/356) developed lymphedema. Obesity (body mass index > 30) (odds ratio [OR]: 2.7, confidence interval [CI]: 1.2-6.4, p = 0.02) and non-white race (OR: 4.5, CI: 1.2-23, p = 0.04) were preoperative lymphedema risk factors.

CONCLUSION

 Patients with IBC are high risk for developing lymphedema due to the need for ALND, radiation, and neoadjuvant chemotherapy. This study also identified non-white race and obesity as risk factors. Larger prospective studies should evaluate potential racial disparities in lymphedema development. Due to the high prevalence of lymphedema, LYMPHA should be considered for all patients with IBC.

Partial Breast Irradiation for Patients With Early-Stage Invasive Breast Cancer or Ductal Carcinoma In Situ: An ASTRO Clinical Practice Guideline

PURPOSE

This guideline provides evidence-based recommendations on appropriate indications and techniques for partial breast irradiation (PBI) for patients with early-stage invasive breast cancer and ductal carcinoma in situ.

METHODS

ASTRO convened a task force to address 4 key questions focused on the appropriate indications and techniques for PBI as an alternative to whole breast irradiation (WBI) to result in similar rates of ipsilateral breast recurrence (IBR) and toxicity outcomes. Also addressed were aspects related to the technical delivery of PBI, including dose-fractionation regimens, target volumes, and treatment parameters for different PBI techniques. The guideline is based on a systematic review provided by the Agency for Healthcare Research and Quality. Recommendations were created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength.

RESULTS

PBI delivered using 3-dimensional conformal radiation therapy, intensity modulated radiation therapy, multicatheter brachytherapy, and single-entry brachytherapy results in similar IBR as WBI with long-term follow-up. Some patient characteristics and tumor features were underrepresented in the randomized controlled trials, making it difficult to fully define IBR risks for patients with these features. Appropriate dose-fractionation regimens, target volume delineation, and treatment planning parameters for delivery of PBI are outlined. Intraoperative radiation therapy alone is associated with a higher IBR rate compared with WBI. A daily or every-other-day external beam PBI regimen is preferred over twice-daily regimens due to late toxicity concerns.

CONCLUSIONS

Based on published data, the ASTRO task force has proposed recommendations to inform best clinical practices on the use of PBI.

HER2 heterogeneity and treatment response-associated profiles in HER2-positive breast cancer in the NCT02326974 clinical trial

BACKGROUNDHER2-targeting therapies have great efficacy in HER2-positive breast cancer, but resistance, in part due to HER2 heterogeneity (HET), is a significant clinical challenge. We previously described that in a phase II neoadjuvant trastuzumab emtansine (T-DM1) and pertuzumab (P) clinical trial in early-stage HER2-positive breast cancer, none of the patients with HER2-HET tumors had pathologic complete response (pCR).METHODSTo investigate cellular and molecular differences among tumors according to HER2 heterogeneity and pCR, we performed RNA sequencing and ERBB2 FISH of 285 pretreatment and posttreatment tumors from 129 patients in this T-DM1+P neoadjuvant trial. A subset of cases was also subject to NanoString spatial digital profiling.RESULTSPretreatment tumors from patients with pCR had the highest level of ERBB2 mRNA and ERBB signaling. HER2 heterogeneity was associated with no pCR, basal-like features, and low ERBB2 expression yet high ERBB signaling sustained by activation of downstream pathway components. Residual tumors showed decreased HER2 protein levels and ERBB2 copy number heterogeneity and increased PI3K pathway enrichment and luminal features. HET tumors showed minimal treatment-induced transcriptomic changes compared with non-HET tumors. Immune infiltration correlated with pCR and HER2-HET status.CONCLUSIONResistance mechanisms in HET and non-HET tumors are distinct. HER2-targeting antibodies have limited efficacy in HET tumors. Our results support the stratification of patients based on HET status and the use of agents that target downstream components of the ERBB signaling pathway in patients with HET tumors.TRIAL REGISTRATIONClinicalTrials.gov NCT02326974.FUNDINGThis study was funded by Roche and the National Cancer Institute.

TBCRC 039: a phase II study of preoperative ruxolitinib with or without paclitaxel for triple-negative inflammatory breast cancer

BACKGROUND

Patients with inflammatory breast cancer (IBC) have overall poor clinical outcomes, with triple-negative IBC (TN-IBC) being associated with the worst survival, warranting the investigation of novel therapies. Preclinical studies implied that ruxolitinib (RUX), a JAK1/2 inhibitor, may be an effective therapy for TN-IBC.

METHODS

We conducted a randomized phase II study with nested window-of-opportunity in TN-IBC. Treatment-naïve patients received a 7-day run-in of RUX alone or RUX plus paclitaxel (PAC). After the run-in, those who received RUX alone proceeded to neoadjuvant therapy with either RUX + PAC or PAC alone for 12 weeks; those who had received RUX + PAC continued treatment for 12 weeks. All patients subsequently received 4 cycles of doxorubicin plus cyclophosphamide prior to surgery. Research tumor biopsies were performed at baseline (pre-run-in) and after run-in therapy. Tumors were evaluated for phosphorylated STAT3 (pSTAT3) by immunostaining, and a subset was also analyzed by RNA-seq. The primary endpoint was the percent of pSTAT3-positive pre-run-in tumors that became pSTAT3-negative. Secondary endpoints included pathologic complete response (pCR).

RESULTS

Overall, 23 patients were enrolled, of whom 21 completed preoperative therapy. Two patients achieved pCR (8.7%). pSTAT3 and IL-6/JAK/STAT3 signaling decreased in post-run-in biopsies of RUX-treated samples, while sustained treatment with RUX + PAC upregulated IL-6/JAK/STAT3 signaling compared to RUX alone. Both treatments decreased GZMB+ T cells implying immune suppression. RUX alone effectively inhibited JAK/STAT3 signaling but its combination with PAC led to incomplete inhibition. The immune suppressive effects of RUX alone and in combination may negate its growth inhibitory effects on cancer cells.

CONCLUSION

In summary, the use of RUX in TN-IBC was associated with a decrease in pSTAT3 levels despite lack of clinical benefit. Cancer cell-specific-targeting of JAK2/STAT3 or combinations with immunotherapy may be required for further evaluation of JAK2/STAT3 signaling as a cancer therapeutic target.

TRIAL REGISTRATION

www.

CLINICALTRIALS

gov , NCT02876302. Registered 23 August 2016.

Impact of Prepectoral vs. Subpectoral Tissue Expander Placement on Post-mastectomy Radiation Therapy Delivery: A Retrospective Cohort Study

Background

Implant-based reconstruction is the most common method of postmastectomy reconstruction. Many patients require postmastectomy radiation (PMRT). Tissue expanders (TEs), typically inserted as a first stage, have historically been placed subpectorally. More recently, prepectoral reconstruction has gained popularity, but its impact on PMRT is unknown. Prior studies focus on complication rates and aesthetic outcomes. This study examines whether there is a difference in radiation dosimetry among patients undergoing prepectoral versus subpectoral TE reconstruction.

Methods

Electronic medical records and radiation plans of 50 patients (25 prepectoral, 25 subpectoral) who underwent mastectomy with immediate TE reconstruction at our institution or affiliate site were reviewed. Pectoralis major muscle and chest wall structures were contoured and mean percentage volumes of these structures receiving less than 95%, 100%, and more than 105% target radiation dose were calculated, as were heart and ipsilateral lung doses. Welch two sample t test, Fisher exact test, and Pearson chi-squared tests were performed.

Results

The groups had comparable patient and tumor characteristics and underwent similar ablative and reconstructive procedures and radiation dosimetry. Subpectoral patients had larger mean areas receiving less than 95% target dose ("cold spots"); prepectoral patients had larger mean areas receiving greater than 105% ("hot spots") and 100% target doses. There were no differences in chest wall, heart, and lung doses.

Conclusions

Our results demonstrate an increased mean percentage area of pectoralis cold spots with subpectoral reconstruction and increased area of hot spots and 100% dose delivery to the pectoralis in prepectoral patients. Larger studies should analyze long-term effects of prepectoral reconstruction on radiation dosing and recurrence rates.

Intraoperative Pathology Assessment May Lead to Overtreatment of the Axilla in Clinically Node-Negative Breast Cancer Patients Undergoing Upfront Mastectomy

BACKGROUND

Randomized trials have established the safety of observation or axillary radiation (AxRT) as an alternative to axillary lymph node dissection (ALND) in patients with limited nodal disease who undergo upfront surgery. Variability remains in axillary management strategies in cN0 patients undergoing mastectomy found to have one to two positive sentinel lymph nodes (SLNs). We examined the impact of intraoperative pathology assessment in axillary management in a national cohort of AMAROS-eligible mastectomy patients.

METHODS

The National Cancer Database was used to identify AMAROS-eligible cT1-2N0 breast cancer patients undergoing upfront mastectomy and SLN biopsy (SLNB) and found to have one to two positive SLNs, from 2018 to 2019. We constructed a variable defining intraoperative pathology as 'not performed/not acted on' if ALND was either not performed or performed at a later date than SLNB, or 'performed/acted on' if SLNB and ALND were completed on the same day. Adjusted multivariable analysis examined predictors of treatment with both ALND and AxRT.

RESULTS

Overall, 8222 patients with cT1-2N0 disease underwent upfront mastectomy and had one to two positive SLNs. Intraoperative pathology was performed/acted on in 3057 (37.2%) patients. These patients were significantly more likely to have both ALND and AxRT than those without intraoperative pathology (41.0% vs. 4.9%; p < 0.001). On multivariate analysis, the strongest predictor of receiving both ALND and AxRT was use of intraoperative pathology (odds ratio 8.99, 95% confidence interval 7.70-10.5; p < 0.001).

CONCLUSIONS

We advocate that consideration should be made for omission of routine intraoperative pathology in mastectomy patients likely to be recommended postmastectomy radiation to minimize axillary overtreatment with both ALND and AxRT in appropriate patients.

Looking Back: International Practice Patterns in Breast Radiation Oncology From a Case-Based Survey Across 54 Countries During the First Surge of the COVID-19 Pandemic

PURPOSE

The COVID-19 pandemic has profoundly affected cancer care worldwide, including radiation therapy (RT) for breast cancer (BC), because of risk-based resource allocation. We report the evolution of international breast RT practices during the beginning of the pandemic, focusing on differences in treatment recommendations between countries.

MATERIALS AND METHODS

Between July and November 2020, a 58-question survey was distributed to radiation oncologists (ROs) through international professional societies. Changes in RT decision making during the first surge of the pandemic were evaluated across six hypothetical scenarios, including the management of ductal carcinoma in situ (DCIS), early-stage, locally advanced, and metastatic BC. The significance of changes in responses before and during the pandemic was examined using chi-square and McNemar-Bowker tests.

RESULTS

One thousand one hundred three ROs from 54 countries completed the survey. Incomplete responses (254) were excluded from the analysis. Most respondents were from the United States (285), Japan (117), Italy (63), Canada (58), and Brazil (56). Twenty-one percent (230) of respondents reported treating at least one patient with BC who was COVID-19-positive. Approximately 60% of respondents reported no change in treatment recommendation during the pandemic, except for patients with metastatic disease, for which 57.7% (636/1,103; P < .0005) changed their palliative practice. Among respondents who noted a change in their recommendation during the first surge of the pandemic, omitting, delaying, and adopting short-course RT were the most frequent changes, with most transitioning to moderate hypofractionation for DCIS and early-stage BC.

CONCLUSION

Early in the COVID-19 pandemic, significant changes in global RT practice patterns for BC were introduced. The impact of published results from the FAST FORWARD trial supporting ultrahypofractionation likely confounded the interpretation of the pandemic's independent influence on RT delivery.

Clinical outcomes of de novo metastatic HER2-positive inflammatory breast cancer

Inflammatory breast cancer (IBC) is a rare, aggressive form of breast cancer that presents as de novo metastatic disease in 20-30% of cases, with one-third of cases demonstrating HER2-positivity. There has been limited investigation into locoregional therapy utilization following HER2-directed systemic therapy for these patients, and their locoregional progression or recurrence (LRPR) and survival outcomes. Patients with de novo HER2-positive metastatic IBC (mIBC) were identified from an IRB-approved IBC registry at Dana-Farber Cancer Institute. Clinical, pathology, and treatment data were abstracted. Rates of LRPR, progression-free survival (PFS), overall survival (OS), and pathologic complete response (pCR) were determined. Seventy-eight patients diagnosed between 1998 and 2019 were identified. First-line systemic therapy comprised chemotherapy for most patients (97.4%) and HER2-directed therapy for all patients (trastuzumab [47.4%]; trastuzumab+pertuzumab [51.3%]; or trastuzumab emtansine [1.3%]). At a median follow-up of 2.7 years, the median PFS was 1.0 year, and the median OS was 4.6 years. The 1- and 2-year cumulative incidence of LRPR was 20.7% and 29.0%, respectively. Mastectomy was performed after systemic therapy in 41/78 patients (52.6%); 10 had a pCR (24.4%) and all were alive at last follow-up (1.3-8.9 years after surgery). Among 56 patients who were alive and LRPR-free at one year, 10 developed LRPR (surgery group = 1; no-surgery group = 9). In conclusion, patients with de novo HER2-positive mIBC who undergo surgery have favorable outcomes. More than half of patients received systemic and local therapy with good locoregional control and prolonged survival, suggesting a potential role for local therapy.

Incidence, characteristics, and management of central nervous system metastases in patients with inflammatory breast cancer

BACKGROUND

Patients with inflammatory breast cancer (IBC) have a high risk of central nervous system metastasis (mCNS). The purpose of this study was to quantify the incidence of and identify risk factors for mCNS in patients with IBC.

METHODS

The authors retrospectively reviewed patients diagnosed with IBC between 1997 and 2019. mCNS-free survival time was defined as the date from the diagnosis of IBC to the date of diagnosis of mCNS or the date of death, whichever occurred first. A competing risks hazard model was used to evaluate risk factors for mCNS.

RESULTS

A total of 531 patients were identified; 372 patients with stage III and 159 patients with de novo stage IV disease. During the study, there were a total of 124 patients who had mCNS. The 1-, 2-, and 5-year incidence of mCNS was 5%, 9%, and 18% in stage III patients (median follow-up: 5.6 years) and 17%, 30%, and 42% in stage IV patients (1.8 years). Multivariate analysis identified triple-negative tumor subtype as a significant risk factor for mCNS for stage III patients. For patients diagnosed with metastatic disease, visceral metastasis as first metastatic site, triple-negative subtype, and younger age at diagnosis of metastases were risk factors for mCNS.

CONCLUSIONS

Patients with IBC, particularly those with triple-negative IBC, visceral metastasis, and those at a younger age at diagnosis of metastatic disease, are at significant risk of developing mCNS. Further investigation into prevention of mCNS and whether early detection of mCNS is associated with improved IBC patient outcomes is warranted.

HER2-low inflammatory breast cancer: Clinicopathologic features and prognostic implications

BACKGROUND

HER2)-low expression is a predictive biomarker for novel anti-HER2 antibody-drug conjugates. However, little is known about its clinical significance in inflammatory breast cancer (IBC).

METHODS

Patients diagnosed with HER2-negative IBC between December 1999 and December 2020 were identified from the Dana-Farber Cancer Institute IBC registry. Patients were divided into HER2-low (IHC 1+ or 2+/ISH-) and HER2-zero (IHC 0), comparing clinicopathologic features and disease outcomes between the two subgroups.

RESULTS

The study included 276 patients. Among patients with stage III (n = 209) and stage IV (n = 67) IBC, 54% and 39% had HER2-low tumours, respectively. Oestrogen receptor (ER)-expressing tumours were more common in patients with HER2-low versus HER2-zero stage III IBC (65% versus 38%, p < 0.01). Among stage III patients undergoing surgery (n = 182), pathologic complete response (pCR) rates were higher for HER2-zero versus HER2-low IBC (11% versus 6%, OR: 1.8, 95%CI:0.6-5.3), but minimal differences persisted when separately analysing pCR by ER status. Similar invasive disease-free survival (iDFS) outcomes were observed among ER-positive HER2-zero versus HER2-low IBC (48-month iDFS: 63% versus 63%, HR: 1.10, 95%CI:0.57-2.13) and ER-negative HER2-zero versus HER2-low IBC (48-month iDFS: 28% versus 25%, HR: 1.19, 95%CI:0.69-2.04). Differences in overall survival (OS) were small, both among ER-positive HER2-zero versus HER2-low IBC (48-month OS: 80% versus 81%, HR: 0.82, 95%CI:0.39-1.73) and ER-negative HER2-zero versus HER2-low IBC (48-month OS: 34% versus 47%, HR: 1.34, 95%CI: 0.74-2.41).

CONCLUSIONS

Marginal differences in clinicopathologic features and outcomes were observed in HER2-low versus HER2-zero IBC when controlling for ER status, not supporting the definition of HER2-low as a distinct subtype of IBC.

Local Therapy Outcomes and Toxicity From the ATEMPT Trial (TBCRC 033): A Phase II Randomized Trial of Adjuvant Trastuzumab Emtansine Versus Paclitaxel in Combination With Trastuzumab in Women With Stage I HER2-Positive Breast Cancer

PURPOSE

Human epidermal growth factor receptor 2 (HER2)-directed therapy improves local control among women with HER2-positive breast cancer. This retrospective analysis evaluates the safety and efficacy of radiation therapy (RT) among patients receiving adjuvant trastuzumab emtansine (T-DM1) or paclitaxel (T) plus trastuzumab (H) in the ATEMPT (Adjuvant Trastuzumab Emtansine Versus Paclitaxel in Combination With Trastuzumab) trial; Translational Breast Cancer Research Consortium (TBCRC) 033.

METHODS AND MATERIALS

Patients with stage I HER2-positive breast cancer were randomized 3:1 to receive adjuvant T-DM1 or TH after mastectomy or breast-conserving surgery (BCS). Breast RT was required after BCS and permitted after mastectomy. Patients receiving T-DM1 began RT after 12 weeks of therapy and received RT concurrently with T-DM1. Patients receiving TH began RT after paclitaxel, but concurrent with trastuzumab. RT records were retrospectively reviewed to determine details of radiation delivery and acute RT-related toxicity.

RESULTS

Protocol therapy was initiated by 497 patients. Among the 299 BCS patients, 289 received whole breast RT (WBRT) and 10 partial breast. Among WBRT patients, 40.2% in the T-DM1 arm and 41.5% of TH patients received hypofractionated (≥2.5 Gy/fraction) RT. Eight mastectomy patients received RT, all conventional fractionation. Skin toxicity (grade ≥2) was seen in 33.9% of patients in the T-DM1 arm and 23.2% in the TH arm (P = .11). In conventionally fractionated WBRT patients, 44.7% had a grade ≥2 skin toxicity compared with 17.9% of patients receiving hypofractionation (P < .001). Five patients experienced pneumonitis after RT (T-DM1: n = 4, 1.0%; TH: n = 1, 0.9%). Three-year invasive disease-free survival was 97.8% for T-DM1 (95% confidence interval, 96.3-99.3) and 93.4% for TH (95% confidence interval, 88.7-98.2). Among the 18 invasive disease-free survival events, 7 were isolated locoregional recurrences (2, T-DM1; 5, TH).

CONCLUSIONS

RT was well-tolerated when given concurrently with either T-DM1 or TH. Among BCS patients, hypofractionation resulted in lower grade ≥2 acute skin toxicity even with concurrent anti-HER2 therapy. Although follow-up was short, local recurrences were uncommon, attesting to the efficacy of HER2-directed therapy combined with RT.

MRI Changes in Breast Skin Following Preoperative Therapy for Patients with Inflammatory Breast Cancer

RATIONALE AND OBJECTIVES

Preoperative systemic therapy (PST) followed by mastectomy and radiation improves survival for patients with inflammatory breast cancer (IBC). Residual disease within the skin post-PST adversely impacts surgical outcome and risk of local-regional recurrence (LRR). We aimed to assess magnetic resonance imaging (MRI) breast skin changes post-PST with pathologic response and its impact on surgical resectability.

MATERIALS AND METHODS

We retrospectively reviewed 152 baseline and post-PST breast MRIs of 76 patients with IBC. Using the ACR-BIRADS MRI lexicon, we correlated skin thickness, qualitative enhancement, and kinetic analysis with pathologic response in the skin at mastectomy.

RESULTS

Baseline MRI showed skin thickening in all 76 patients, 75/76 (99%) showed skin enhancement, 54/75 (72%) had medium/fast initial kinetics, usually with persistent delayed kinetics in 49/54 (91%). Following PST, 66/76 (87%) had residual skin thickening with 64/76 (84%) showing a decrease; 33/76 (43%) had persistent enhancement. The median thickness post-PST was 4.7 mm with residual tumor in the skin, and 3.0 mm without residual tumor (p = 0.008). Regardless of pathologic response, the majority of patients had persistent skin thickening on MRI following PST (100% [14/14] with residual tumor and 84% [52/62] without residual tumor). There was no association between post-PST skin thickness on breast MRI and rate of LRR.

CONCLUSION

Patients with IBC have skin thickening and enhancement on baseline breast MRI, with a statistically significant reduction in skin thickness following successful PST. Despite persistent skin changes on MRI, patients achieving a partial or complete parenchymal response to PST may proceed to mastectomy with low LRR rates.

CALGB 40603 (Alliance): Long-Term Outcomes and Genomic Correlates of Response and Survival After Neoadjuvant Chemotherapy With or Without Carboplatin and Bevacizumab in Triple-Negative Breast Cancer

PURPOSE

CALGB 40603 (NCT00861705), a 2 × 2 randomized phase II trial, demonstrated that adding carboplatin or bevacizumab to weekly paclitaxel (wP) followed by doxorubicin and cyclophosphamide significantly increased the pathologic complete response (pCR) rate in stage II-III triple-negative breast cancer. We now report long-term outcomes (LTOs) and correlative science end points.

PATIENTS AND METHODS

The Kaplan-Meier method was used to estimate LTOs in 443 patients who initiated study treatment. Log-rank tests and Cox proportional hazards models evaluated the impact of clinical characteristics, pathologic response, calculated residual cancer burden (RCB) in patients with residual disease (RD), treatment assignment, and dose delivery during wP on LTOs, including event-free survival (EFS). Genomic predictors of treatment response and outcomes were assessed on pretreatment tumor samples by mRNA sequencing.

RESULTS

Among baseline characteristics, only the clinical stage was associated with LTOs. At a median follow-up of 7.9 years, LTOs were not significantly improved with either carboplatin or bevacizumab, overall or in patients with basal-like subtype cancers by genomic analysis. Patients with pCR (n = 205, 46.3%) had significantly higher 5-year EFS (85.5% v 56.6%, log-rank P < .0001) and overall survival (87.9% v 63.4%, P < .0001) rates compared with patients with RD, even those with RCB class I. Among clinical and genomic features, evidence of immune activation, including tumor-infiltrating lymphocytes and low B-cell receptor evenness, was associated with pCR and improved EFS.

CONCLUSION

Despite higher pCR rates, neither carboplatin nor bevacizumab appeared to improve LTOs although the study was not powered to assess these secondary end points. pCR was associated with superior LTOs even when compared with minimal RD. Markers of immune activation in pretreatment tumor biopsies were independently associated with higher pCR rates and improved survival.

Should Everyone With Ductal Carcinoma in Situ Receive Adjuvant Radiation?

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

Optimizing Axillary Management in Clinical T1-2N0 Mastectomy Patients with Positive Sentinel Lymph Nodes

BACKGROUND

Following publication of the AMAROS trial, we sought to optimize axillary lymph node dissection (ALND) or postmastectomy radiation therapy (PMRT) + axillary radiation (AxRT) utilization in cT1-2N0 patients with 1-2 positive sentinel lymph nodes (SLNs) after mastectomy.

METHODS

In November 2015, our multidisciplinary group implemented a protocol to omit intraoperative SLN evaluation for mastectomy patients with cT1-2N0 breast cancer likely to be recommended PMRT if found to have 1-2 positive SLNs (age ≤ 60 years and/or high-risk features defined as estrogen receptor-negative and/or positive for lymphovascular invasion). We prospectively evaluated axillary management, short-term complications, and oncologic outcomes in patients with 1-2 positive SLNs.

RESULTS

From November 2015 to December 2018, 479 of 560 (85%) cT1-2N0 breast cancers treated with mastectomy were potential candidates for PMRT. Intraoperative SLN evaluation was omitted in 344 (72%), thus following the protocol. Overall, 121 cases had 1-2 positive SLNs: 17 (14%) were managed with observation, 5 (4%) PMRT alone, 59 (49%) PMRT + AxRT, 16 (13%) ALND alone, and 24 (20%) ALND + PMRT. Protocol compliance resulted in less ALND (8% vs. 24%) and less ALND + PMRT (9% vs. 41%, p < 0.01). At median follow-up of 24 months, there was one regional and four distant recurrences, with no regional recurrences or differences in disease-free survival in patients treated with ALND versus PMRT + AxRT (100% vs. 98%, p = 0.67). Similarly, there were no differences in complication rates (p = 0.18).

CONCLUSIONS

Omitting intraoperative SLN evaluation in cT1-2N0 mastectomy patients who would be candidates for PMRT if found to have positive nodes decreased rates of ALND and minimized use of ALND + PMRT without compromising outcomes.

Time-Driven Activity-Based Costing in Breast Cancer Care Delivery

BACKGROUND

Accurate measurement of healthcare costs is required to assess and improve the value of oncology care.

OBJECTIVES

We aimed to determine the cost of breast cancer care provision across collaborating health care organizations.

METHODS

We used time-driven activity-based costing (TDABC) to calculate the complete cost of breast cancer care-initial treatment planning, chemotherapy, radiation therapy, surgical resection and reconstruction, and ancillary services (e.g., psychosocial oncology, physical therapy)-across multiple hospital sites. Data were collected between December 2019 and February 2020. TDABC steps involved (1) developing process maps for care delivery pathways; (2) determine capacity cost rates for staff, medical equipment, and hospital space; (3) measure the time required for each process step, both manually through clinic observation and using data from the Real-Time Location System (RTLS); and (4) calculate the total cost of care delivery.

RESULTS

Surgical care costs ranged from $1431 for a lumpectomy to $12,129 for a mastectomy with prepectoral implant reconstruction. Radiation therapy was costed at $1224 for initial simulation and patient education, and $200 for each additional treatment. Base costs for chemotherapy delivery were $382 per visit, with additional costs driven by chemotherapy agent(s) administered. Personnel expenses were the greatest contributor to the cost of surgical care, except in mastectomy with implant reconstruction, where device costs equated to up to 60% of the cost of surgery.

CONCLUSION

The cost of complete breast cancer care depended on (1) treatment protocols; (2) patient choice of reconstruction; and (3) the need for ancillary services (e.g., physical therapy). Understanding the actual costs and cost drivers of breast cancer care delivery may better inform resource utilization to lower the cost and improve the quality of care.

Weathering the Storm: Managing Older Adults With Breast Cancer Amid COVID-19 and Beyond

Caring for older patients with breast cancer presents unique clinical considerations because of preexisting and competing comorbidity, the potential for treatment-related toxicity, and the consequent impact on functional status. In the context of the COVID-19 pandemic, treatment decision making for older patients is especially challenging and encourages us to refocus our treatment priorities. While we work to avoid treatment delays and maintain therapeutic benefit, we also need to minimize the risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposures, myelosuppression, general chemotherapy toxicity, and functional decline. Herein, we propose multidisciplinary care considerations for the aging patient with breast cancer, with the goal to promote a team-based, multidisciplinary treatment approach during the COVID-19 pandemic and beyond. These considerations remain relevant as we navigate the “new normal” for the approximately 30% of breast cancer patients aged 70 years and older who are diagnosed in the United States annually and for the thousands of older patients living with recurrent and/or metastatic disease.

Abstract P26: Re-analyzing randomized trials with incorporation of COVID-19 risk associated with cancer therapy

Background: Cancer therapy may put patients at risk of mortality from COVID-19. The impact of abbreviated treatment courses on outcomes in the setting of COVID-19 is unknown. We incorporated COVID-19-associated risks in re-analysis of practice-defining randomized trials in oncology that compared different radiation therapy (RT) regimens. Methods: We extracted individual patient level data (IPLD) from published survival curves from randomized trials in rectal cancer (Dutch TME, TROG 01.04), early stage breast cancer (CALGB 9343, OCOG hypofractionation trial, FAST-Forward, NSABP B-39), and localized prostate cancer (CHHiP, HYPO-RT-PC). Trials were simulated with incorporation of varying risk of SARS-CoV-2 infection and mortality associated with receipt of therapy. Results: IPLD from 14,170 patients were re-analyzed. In scenarios with low COVID-19-associated risks (0.5% infection risk per fraction [IRF], 5% case fatality rate [CFR]), fractionation did not significantly affect outcomes. In locally advanced rectal cancer, short-course RT appeared preferable to long-course chemoradiation (TROG 01.04) or RT omission (Dutch TME) in most settings. While moderate hypofractionation in early stage breast cancer (OCOG hypofractionation trial) and prostate cancer (CHHiP) was not associated with survival benefits in the setting of COVID-19, more aggressive hypofractionation (FAST-Forward, HYPO-RT-PC) and accelerated partial breast irradiation (NSABP B-39) were associated with improved survival in higher risk scenarios (≥5% IRF; ≥ 20% CFR). In settings where RT can be omitted, such as favorable early stage breast cancer in the elderly (CALGB 9343), RT was associated with worse survival in higher risk pandemic scenarios (≥5% IRF, ≥ 20% CFR). Conclusions: Our framework, which can be adapted to dynamic changes in COVID-19 risk, provides a flexible, quantitative approach to assess the impact of treatment recommendations across oncology. The magnitude of potential benefit from abbreviated RT courses depends on the degree of hypofractionation and local COVID-19-associated risk. Abbreviated RT courses should be prioritized when possible and are increasingly beneficial in higher risk pandemic settings. With increased understanding and precautions against COVID-19 that can minimize risks for patients, our results support the continued use of evidence-based treatments for cancer patients in the COVID-19 era.

Citation Format: Shervin Tabrizi, Lorenzo Trippa, Daniel Cagney, Ayal A. Aizer, Shyam Tanguturi, Steffen Ventz, Geoffrey Fell, Jennifer R. Bellon, Harvey Mamon, Paul Nguyen, Anthony V. D'Amico, Daphne Haas-Kogan, Brian M. Alexander, Rifaquat Rahman. Re-analyzing randomized trials with incorporation of COVID-19 risk associated with cancer therapy [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2021 Feb 3-5. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(6_Suppl):Abstract nr P26.

Assessment of Simulated SARS-CoV-2 Infection and Mortality Risk Associated With Radiation Therapy Among Patients in 8 Randomized Clinical Trials

IMPORTANCE

During the COVID-19 pandemic, cancer therapy may put patients at risk of SARS-CoV-2 infection and mortality. The impacts of proposed alternatives on reducing infection risk are unknown.

OBJECTIVE

To investigate how the COVID-19 pandemic is associated with the risks and benefits of standard radiation therapy (RT).

DESIGN, SETTING, AND PARTICIPANTS

This comparative effectiveness study used estimated individual patient-level data extracted from published Kaplan-Meier survival figures from 8 randomized clinical trials across oncology from 1993 to 2014 that evaluated the inclusion of RT or compared different RT fractionation regimens. Included trials were Dutch TME and TROG 01.04 examining rectal cancer; CALGB 9343, OCOG hypofractionation trial, FAST-Forward, and NSABP B-39 examining early stage breast cancer, and CHHiP and HYPO-RT-PC examining prostate cancer. Risk of SARS-CoV-2 infection and mortality associated with receipt of RT in the treatment arms were simulated and trials were reanalyzed. Data were analyzed between April 1, 2020, and June 30, 2020.

EXPOSURES

COVID-19 risk associated with treatment was simulated across different pandemic scenarios, varying infection risk per fractions (IRFs) and case fatality rates (CFRs).

MAIN OUTCOMES AND MEASURES

Overall survival was evaluated using Cox proportional hazards modeling under different pandemic scenarios.

RESULTS

Estimated IPLD from a total of 14 170 patients were included in the simulations. In scenarios with low COVID-19-associated risks (IRF, 0.5%; CFR, 5%), fractionation was not significantly associated with outcomes. In locally advanced rectal cancer, short-course RT was associated with better outcomes than long-course chemoradiation (TROG 01.04) and was associated with similar outcomes as RT omission (Dutch TME) in most settings (eg, TROG 01.04 median HR, 0.66 [95% CI, 0.46-0.96]; Dutch TME median HR, 0.91 [95% CI, 0.80-1.03] in a scenario with IRF 5% and CFR 20%). Moderate hypofractionation in early stage breast cancer (OCOG hypofractionation trial) and prostate cancer (CHHiP) was not associated with survival benefits in the setting of COVID-19 (eg, OCOG hypofractionation trial median HR, 0.89 [95% CI, 0.74-1.06]; CHHiP median HR, 0.87 [95% CI, 0.75-1.01] under high-risk scenario with IRF 10% and CFR 30%). More aggressive hypofractionation (FAST-Forward, HYPO-RT-PC) and accelerated partial breast irradiation (NSABP B-39) were associated with improved survival in higher risk scenarios (eg, FAST-Forward median HR, 0.58 [95% CI, 0.49-0.68]; HYPO-RT-PC median HR, 0.60 [95% CI, 0.48-0.75] under scenario with IRF 10% and CFR 30%).

CONCLUSIONS AND RELEVANCE

In this comparative effectiveness study of data from 8 clinical trials of patients receiving radiation therapy to simulate COVID-19 risk and mortality rates, treatment modification was not associated with altered risk from COVID-19 in lower-risk scenarios and was only associated with decreased mortality in very high COVID-19-risk scenarios. This model, which can be adapted to dynamic changes in COVID-19 risk, provides a flexible, quantitative approach to assess the potential impact of treatment modifications and supports the continued delivery of standard evidence-based care with appropriate precautions against COVID-19.

Abstract PD13-06: Incidence and management of central nervous system metastases in patients with inflammatory breast cancer

Background: Patients (pts) with inflammatory breast cancer (IBC) have a high risk of central nervous system (CNS) metastasis (mets) with their associated impact on longevity and quality of life. Given evolving CNS-directed treatments, including focal radiation (RT), we compared the proportion of pts diagnosed with asymptomatic CNS mets before and after 2012 as data from Phase III trials in the preceding years (yr) increasingly supported the use of stereotactic radiosurgery (SRS). Specific attention was paid to pts treated with tri-modality therapy (TMT), defined as preoperative systemic therapy, surgery, and RT to determine whether screening for asymptomatic CNS mets would be beneficial. Methods: We retrospectively reviewed the records of pts diagnosed with IBC 1997-2019 and enrolled in an IRB-approved registry at a dedicated IBC center. CNS met-free survival time was defined as the time from IBC diagnosis to date of CNS mets. Alive CNS met-free pts were censored at their latest survival date and death was treated as a competing risk. Cumulative CNS mets incidence was computed. Analyses were stratified based on stage at diagnosis (III vs. de novo IV) and receipt of TMT. For pts completing TMT, the completion date was the starting point for cumulative incidence calculations. Overall survival (OS) was estimated as the time from CNS mets diagnosis to death, with censoring for pts who were still alive. Results: A total of 531 pts were identified; 372 (70%) with stage III; 159 (30%) with de novo Stage IV disease. The median follow-up for pts presenting with stage III and stage IV disease at diagnosis was 5.6 yr and 1.8 yr, respectively. 124 pts had CNS mets; 5 of them at diagnosis. CNS was the first site of mets or progression in 50 pts (9.4%). The cumulative incidence of CNS mets stratified by stage at diagnosis and receipt of TMT is seen in Table 1. Among the 50 de novo Stage IV pts who completed TMT, 4 developed CNS mets prior to surgery. The median overall survival (mOS) after CNS mets was 0.6 yr (IQR: 0.2 - 1.4). Results stratified by tumor subtype were: HER2+ disease (n=51) 1.4 yr (IQR: 0.6 - 3.7); hormone receptor+/HER2- (n=27) 0.6 yr (IQR: 0.2 - 1.2); triple negative (n=40) 0.2 yr (IQR: 0.1 - 0.5). Most pts with CNS mets (87/124, 70%) had neurologic symptoms prompting imaging. There was no difference in the proportion of asymptomatic pts diagnosed with CNS mets prior to or after 2012. Management of CNS mets was as follows: 47 pts (38%) received whole brain RT (WBRT) alone, 22 (18%) SRS alone, 15 WBRT + SRS (12%), 6 resection + WBRT (5%), and 5 resection + SRS (4%). The remaining pts received several of these modalities with or without intrathecal chemotherapy (13, 11%) or CNS treatment was not documented (16, 13%). A total of 258/531 pts have died (49%). Of these pts, 103 (40%) had CNS mets. 67/103 (65%) died due to CNS mets. Conclusions: Among pts with IBC completing TMT, the incidence of CNS mets is as high as 20% both in de novo Stage IV pts at 1 yr and in Stage III pts within 5 yrs, supporting routine surveillance brain MRI among pt with Stage IV disease. The majority of pts continue to receive WBRT with its resultant toxicities. Efforts should be made to identify CNS mets early to facilitate more focal therapy. Future research on systemic therapy with CNS penetrance for IBC patients should be pursued. These data support an ongoing prospective study of screening brain MRI in pts with Stage III IBC to quantify the incidence of CNS mets, utilization of WBRT and impact on neurologic quality of life (NCT04030507).

Cumulative Incidence of CNS MetsNo.1 year (95% CI)2 year (95% CI)3 year (95% CI)Stage III (All)3725% (3-7)9% (6-12)18% (14-23)Stage IV (All)15417% (12-24)30% (22-37)42% (32-51)Stage III (TMT)3045% (3-8)11% (8-16)19% (14-24)Stage IV (TMT)4621% (10-34)28% (16-43)35% (20-50)

Citation Format: Laura Warren, Samuel M Niman, Marie Claire Remolano, Jean Landry, Faina Nakhlis, Jennifer R Bellon, Meredith M Regan, Beth A Overmoyer. Incidence and management of central nervous system metastases in patients with inflammatory breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD13-06.

ATM Variants in Breast Cancer: Implications for Breast Radiation Therapy Treatment Recommendations

PURPOSE

Advances in germline genetic testing have led to a surge in identification of ataxia-telangiectasia mutated (ATM) variant carriers among breast cancer patients, raising numerous questions regarding use of breast radiation therapy (RT) in this population.

METHODS

A literature search using PubMed identified articles assessing association(s) between the germline ATM variant status and the risk of toxicity after breast RT. An expert panel of breast radiation oncologists, genetic counselors, and basic scientists convened to review the association between ATM variants and radiation-induced toxicity or secondary malignancy risk and to determine any impact on breast RT recommendations.

RESULTS

Carriers of pathogenic variants in ATM have a 2- to 4-fold increased risk for developing breast cancer. ATM variants do not consistently increase risks of toxicities after RT, except possibly among patients with the single nucleotide variant c5557G>A (rs1801516), in whom a small increased risk for the development of both acute and late radiation effects has been identified. In most breast cancer patients with ATM variants, the excess 5-year absolute risk of developing a secondary contralateral breast cancer (CBC) after radiation is extremely low. The exception is in women younger than 45 years old with deleterious rare ATM missense variants, who may be at higher risk for developing a radiation-induced CBC over time.

CONCLUSIONS

Adjuvant radiation is safe for most breast cancer patients who harbor ATM variants. The possible exceptions are patients with the variant c5557G>A (rs1801516) and patients younger than 45 years old with certain rare deleterious ATM variants, who may be at higher risk for developing CBC. These latter patients should be counseled regarding this potential risk, and every effort should be made to minimize the contralateral breast dose. However, the inconsistency of published data limits precise recommendations, magnifying the need for further prospective studies and the development of a centralized database cataloging RT outcomes and genetic status.

Optimizing Radiation Therapy to Boost Systemic Immune Responses in Breast Cancer: A Critical Review for Breast Radiation Oncologists

Immunotherapy using immune checkpoint blockade has revolutionized the treatment of many types of cancer. Radiation therapy (RT)-particularly when delivered at high doses using newer techniques-may be capable of generating systemic antitumor effects when combined with immunotherapy in breast cancer. These systemic effects might be due to the local immune-priming effects of RT resulting in the expansion and circulation of effector immune cells to distant sites. Although this concept merits further exploration, several challenges need to be overcome. One is an understanding of how the heterogeneity of breast cancers may relate to tumor immunogenicity. Another concerns the need to develop knowledge and expertise in delivery, sequencing, and timing of RT with immunotherapy. Clinical trials addressing these issues are under way. We here review and discuss the particular opportunities and issues regarding this topic, including the design of informative clinical and translational studies.

A Phase II Study of Pembrolizumab in Combination With Palliative Radiotherapy for Hormone Receptor-positive Metastatic Breast Cancer

BACKGROUND

The purpose of this study was to investigate whether combining pembrolizumab with palliative radiation therapy (RT) improves outcomes in patients with hormone receptor-positive (HR⁺) metastatic breast cancer (MBC).

PATIENTS AND METHODS

Eligible patients had HR⁺/human epidermal growth factor receptor 2-negative MBC; were candidates for RT to ≥ 1 bone, soft tissue, or lymph node lesion; and had ≥ 1 lesion outside the RT field. Patients received 200 mg pembrolizumab intravenously 2 to 7 days prior to RT and on day 1 of repeating 21-day cycles. RT was delivered to a previously unirradiated area in 5 treatments each of 4 Gy. The primary endpoint was objective response rate. The study used a 2-stage design: 8 women were enrolled into the first stage, and if at least 1 of 8 patients experienced an objective response, 19 more would be enrolled. Secondary endpoints included progression-free survival, overall survival, and safety. Exploratory endpoints included association of overall response rate with programmed death-ligand 1 status and tumor-infiltrating lymphocytes.

RESULTS

Eight patients were enrolled in stage 1. The median age was 59 years, and the median prior lines of chemotherapy for metastatic disease was 2. There were no objective responses, and the study was closed to further accrual. The median progression-free survival was 1.4 months (95% confidence interval, 0.4-2.1 months), and the median overall survival was 2.9 months (95% confidence interval, 0.9-3.6 months). All-cause adverse events occurred in 87.5% of patients, including just 1 grade 3 event (elevation of aspartate aminotransferase).

CONCLUSIONS

RT combined with pembrolizumab did not produce an objective response in patients with heavily pre-treated HR⁺ MBC. Future studies should consider alternative radiation dosing and fractionation in patients with less heavily pre-treated HR⁺ MBC.

Understanding Yeast Impact on 1,1,6-Trimethyl-1,2-dihydronaphthalene Formation in Riesling Wine through a Formation-Pathway-Informed Hydrolytic Assay

The occurrence in Riesling wine of the potent odorant 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) is dependent upon vineyard and winemaking conditions, and TDN can have a prominent impact on the attributes of a wine after years in a bottle. As such, immediately assessing the impact of vineyard or winery treatments on future TDN formation requires forced creation of the aroma compound under non-wine-like conditions from other precursors. Here, we use a Box-Behnken approach and known TDN end points in commercial wines to optimize the conditions (pH, temperature, and time) of a "total TDN" hydrolytic assay for Riesling wine, which was intended to not interfere with yeast-derived formation pathways. The new assay (75 °C, pH 1.7, and 60 min) was used to determine the role of industry-relevant commercial yeasts as well as novel hybrid yeast strains on total TDN concentrations in young Riesling wines. While significant differences were observed between some yeasts, the impact of defoliation as a viticultural intervention outweighed yeast effects, suggesting that elevated TDN concentrations in wine are likely due to grape growing conditions and cannot be readily reduced or compensated for in the winery.

Contemporary Issues in Breast Cancer Radiotherapy

A series of landmark studies have increasingly emphasized the role of adjuvant radiotherapy for the definitive management of breast cancer. Although regional nodal irradiation, including the internal mammary nodes, was typically reserved for high-risk patients, there is now evidence of benefit to this approach even for those with a limited nodal disease burden. Similarly, low-risk disease has historically been treated with whole-breast tangents, although contemporary studies now support accelerated partial breast irradiation or the omission of radiotherapy in select cases. This article presents recent data informing these contemporary developments in the radiotherapeutic management of breast cancer.

Patterns of breast reconstruction in patients diagnosed with inflammatory breast cancer: The Dana-Farber Cancer Institute's Inflammatory Breast Cancer Program experience

Inflammatory breast cancer (IBC) exhibits dermal lymphatic involvement at presentation, and thus, the standard surgical approach is a nonskin-sparing modified radical mastectomy (MRM) without breast reconstruction (BR). In this study, we evaluated immediate and delayed BR receipt and its outcomes in IBC. Using an IRB-approved database, we retrospectively evaluated stage III IBC patients who received trimodality therapy (preoperative systemic therapy, followed by MRM and postmastectomy chest wall/regional nodal radiation). Patients with an insufficient response to preoperative systemic therapy and/or who required preoperative radiotherapy were excluded. BR receipt, timing, and morbidity were evaluated. Among 240 stage III IBC patients diagnosed between 1997 and 2016, 40 (17%) underwent BR. Thirteen (33%) had immediate, and 27 (67%) had delayed BR. Four patients had complications (1 [8%] immediate BR and 3 [11%] delayed BR); only 1 BR (delayed) was unsuccessful. From the MRM date, the median time to recurrence was 35 months (<1-212) and median overall survival was 87 months (<1-212). In this cohort of stage III IBC patients, only 11% pursued delayed BR following trimodality therapy, possibly attributable to the observed high recurrence rates hindering BR. Further studies addressing BR outcomes in IBC are needed for better counseling patients regarding their reconstructive options.

Local-regional recurrence in women with small node-negative, HER2-positive breast cancer: results from a prospective multi-institutional study (the APT trial)

PURPOSE

Women with HER2-positive breast cancer treated prior to effective anti-HER2 therapy have higher rates of local-regional recurrence (LRR) than those with HER2-negative disease. Effective systemic therapy, however, has been shown to decrease LRR. This study examines LRR in women with HER2-positive breast cancer treated on a single-arm prospective multicenter trial of adjuvant trastuzumab (H) and paclitaxel (T).

METHODS

Patients with HER2-positive tumors ≤ 3.0 cm with negative axillary nodes or micrometastatic disease were eligible. Systemic therapy included weekly T and H for 12 weeks followed by continuation of H to complete 1 year. Radiation therapy (RT) was required following breast-conserving surgery (BCS), but dose and fields were not specified. Disease-free survival (DFS) and LRR-free survival were calculated using the Kaplan-Meier method.

RESULTS

Of the 410 patients enrolled from September 2007 to September 2010, 406 initiated protocol therapy and formed the basis of this analysis. A total of 272 (67%) had hormone receptor-positive tumors. Of 162 patients undergoing mastectomy, local therapy records were unavailable for two. None of the 160 for whom records were available received RT. Among 244 BCS patients, detailed RT records were available for 217 (89%). With a median follow-up of 6.5 years, 7-year DFS was 93.3% (95% CI 90.4-96.2), and LRR-free survival was 98.6% (95% CI 97.4-99.8).

CONCLUSION

LRR in this select group of early-stage patients with HER2-positive disease receiving effective anti-HER2 therapy is extremely low. If confirmed in additional studies, future investigational efforts should focus on de-escalating local therapy.

A Novel Approach to Isolating Improved Industrial Interspecific Wine Yeasts Using Chromosomal Mutations as Potential Markers for Increased Fitness

Wine yeast breeding programs utilizing interspecific hybridization deliver cost-effective tools to winemakers looking to differentiate their wines through the development of new wine styles. The addition of a non-Saccharomyces cerevisiae genome to a commercial wine yeast can generate novel phenotypes ranging from wine flavor and aroma diversity to improvements in targeted fermentation traits. In the current study we utilized a novel approach to screen isolates from an evolving population for increased fitness in a S. cerevisiae × S. uvarum interspecific hybrid previously generated to incorporate the targeted phenotype of lower volatile acidity production. Sequential grape-juice fermentations provided a selective environment from which to screen isolates. Chromosomal markers were used in a novel approach to identify isolates with potential increased fitness. A strain with increased fitness relative to its parents was isolated from an early timepoint in the evolving population, thereby minimizing the risk of introducing collateral mutations and potentially undesirable phenotypes. The evolved strain retained the desirable fermentation trait of reduced volatile acidity production, along with other winemaking traits of importance while exhibiting improved fermentation kinetics.

Concurrent Veliparib With Chest Wall and Nodal Radiotherapy in Patients With Inflammatory or Locoregionally Recurrent Breast Cancer: The TBCRC 024 Phase I Multicenter Study

Purpose Locoregional control for inflammatory breast cancers and chest wall recurrences is suboptimal, which has motivated interest in radiosensitization to intensify therapy. Preclinical studies have suggested a favorable therapeutic index when poly (ADP-ribose) polymerase inhibitors are used as radiosensitizers; clinical investigation is necessary to establish appropriate dosing and confirm safety. Patients and Methods We conducted a multi-institutional phase I study of veliparib and concurrent radiotherapy (RT) to the chest wall and regional lymph nodes in 30 patients with inflammatory or locally recurrent breast cancer after complete surgical resection. RT consisted of 50 Gy to the chest wall and regional lymph nodes plus a 10-Gy boost. A Bayesian time-to-event continual reassessment method escalated dose through four levels, with a 30% targeted rate of dose-limiting toxicity (DLT) measured during the 6 weeks of treatment plus 4 weeks of follow-up. DLTs were defined as confluent moist desquamation > 100 cm², nonhematologic toxicity grade ≥ 3, toxicity that requires an RT dose delay > 1 week, absolute neutrophil count < 1,000/mm³, platelet count < 50,000/mm³, or hemoglobin < 8.0 g/dL if possibly, probably, or definitely related to study treatment. Results Five DLTs occurred: Four were moist desquamation (two each at 100 and 150 mg twice a day), and one was neutropenia (at 200 mg twice a day). The crude rate of any grade 3 toxicity (regardless of attribution) was 10% at year 1, 16.7% at year 2, and 46.7% at year 3. At year 3, six of 15 surviving patients had severe fibrosis in the treatment field. Conclusion Although severe acute toxicity did not exceed 30% even at the highest tested dose, nearly half of surviving patients demonstrated grade 3 adverse events at 3 years, which underscores the importance of long-term monitoring of toxicity in trials of radiosensitizing agents.