Should breast surgery be considered for patients with de novo metastatic inflammatory breast cancer?

INTRODUCTION

We aimed to identify factors predicting surgery for de novo stage IV inflammatory breast cancer (IBC) and determine the association of surgery with overall survival (OS).

METHODS

Female patients with unilateral AJCC clinical stage IV IBC treated 2010-2018 in the NCDB were identified. Logistic regression and multivariable proportional Cox hazards regressions determined factors associated with treatment and OS.

RESULTS

Of 1049 patients, 29.1% underwent breast surgery (BS) and 70.9% had no surgery (NS). Increasing age and more recent treatment year were significantly associated with NS. 2-Year OS was superior in BS patients (71% vs 38% NS). Single-site and bone-only metastasis had no association with treatment type or OS.

CONCLUSION

Contrary to guidelines, 1/3 of de novo stage IV IBC patients underwent BS, and had an independent OS benefit irrespective of extent or site of metastasis. Further research is needed to determine which patients with stage IV IBC should undergo BS.

Using MammaPrint on core needle biopsy to guide the need for axillary staging during breast surgery

BACKGROUND

At present, the only opportunity to omit axillary staging is with Choosing Wisely criteria for women ages >70 y with cT1 2N0 estrogen receptor-positive/human epidermal growth factor receptor 2-negative breast cancer. However, many women are diagnosed when pathologic node status-negative, raising the question of additional opportunities to omit sentinel lymph node biopsy. We sought to investigate the association between MammaPrint, a genomic test that estimates estrogen receptor-positive breast cancer recurrence risk, and pathologic node status, with the aim that low-risk MammaPrint could be considered for omission of sentinel lymph node biopsy if associated with pathologic node status-negative.

METHODS

A single-institution database was queried for all women with cT1 2N0 estrogen receptor-positive/human epidermal growth factor receptor 2-negative invasive breast cancer with breast surgery as their first treatment and MammaPrint performed from 2020 to 2021. Patient and tumor factors, including MammaPrint score, were compared with axillary node status for correlation.

RESULTS

A total of 668 women met inclusion criteria, with a median age of 66 y. MammaPrint was low-risk luminal A in 481 (72%) and high-risk luminal B in 187 (28%). At the time of breast surgery, 588 (88%) had sentinel lymph node biopsy, 27 (4%) had axillary lymph node dissection, and 53 (7.9%) had no axillary staging. Most women in both the pathologic node status-negative and pathologic node status-positive cohorts had low-risk MammaPrint (355 [73.3%] pathologic node status-negative vs 91 [69.5%] pathologic node status-positive), and women with low-risk MammaPrint did not have a significantly lower risk of pathologic node status-positive (P = .377).

CONCLUSION

Low-risk MammaPrint does not predict lower risk of pathologic node status-positive breast cancer. Based on our results, genomic testing does not appear to provide additional personalization for the ability to omit sentinel lymph node biopsy for patients outside of the Choosing Wisely guidelines.

Abstract P2-14-05: Patient rather than tumor factors predict contralateral prophylactic mastectomy for inflammatory breast cancer

Introduction: Inflammatory breast cancer (IBC) is an aggressive form of breast cancer with best outcomes result-ing from trimodality therapy: neoadjuvant chemotherapy (NAC), modified radical mastectomy (MRM), and radiation (PMRT). Contralateral prophylactic mastectomy (CPM) is generally discour-aged at the time of MRM due to poor prognosis. Our aim was to identify factors associated with CPM for IBC and determine its relationship with overall survival (OS). Methods: The National Cancer Database was used to identify female patients with AJCC stage IIIC unilateral IBC (cT4d and inflammatory histology code) treated 2004-2018. Patients were stratified by mastec-tomy type: unilateral mastectomy (UM) was defined as MRM or simple mastectomy, and CPM was defined as UM + CPM. Logistic regression identified factors associated with mastectomy type, and multivariable proportional Cox hazards regression identified factors associated with OS. A subset analysis of patients receiving NAC compared complete pathologic response (pCR) between mastec-tomy groups. Results: Of the 2,837 patients with non-metastatic IBC, 2,013 (70.2%) underwent UM and 855 (29.8%) had CPM. The CPM group was significantly younger than the UM group (mean age 52 vs. 56.6 years, p=0.028), more frequently identified as Non-Hispanic White (79.7% vs. 70.1%, p< 0.001), and had private insurance (66.9% vs. 55.6%, p< 0.001). Nearly all patients received chemotherapy and over 80% were treated with NAC. Receipt of PMRT did not differ by mastectomy type (80% for UM and CPM). On multivariable logistic regression, patients age < 40 were more likely to undergo CPM than UM (OR 3.7, 95% CI 1.61-8.5, p< 0.002). Patients with age >70, Hispanic ethnicity, and public insur-ance were significantly less likely to receive CPM (all p≤0.002). On multivariable Cox regression ad-justed for patient, tumor, and treatment factors, CPM was not associated with OS benefit (HR 0.86, 95% CI 0.73-1.02, p=0.08). Higher histologic grade, node-positive disease, and greater co-morbidity were associated with poorer OS, while receipt of chemotherapy and PMRT improved OS. In the subset of NAC patients, overall pCR did not differ significantly by mastectomy type (CPM 22.3%, UM 19.4%, p=0.26). When included in multivariable models, pCR rates were not predictive of CPM de-spite being associated with improved OS. Conclusion: Nearly 30% of IBC patients undergo CPM despite discouragement by guidelines. Demographic char-acteristics – particularly age < 40 – predicted CPM, suggesting patient preferences and access to care affect surgical decisions. As expected, trimodality therapy and favorable NAC response im-proved oncologic outcomes, but CPM had no association with OS. While CPM may be chosen for risk reduction and symmetry, patients should be counseled that it does not improve survival for IBC.

Citation Format: Lauren M. Drapalik, Amanda L. Amin, Ashley Simpson, Lisa Rock, Mary Freyvogel, Robert Shenk, Megan E. Miller. Patient rather than tumor factors predict contralateral prophylactic mastectomy for inflammatory breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-14-05.

Abstract P6-01-02: Using MammaPrint on Core Needle Biopsy to Guide Neoadjuvant Chemotherapy for Invasive Breast Carcinoma

Introduction: MammaPrint, a 70-gene assay used to predict breast cancer recurrence, is typically obtained on the surgical specimen to guide the use of adjuvant chemotherapy. However, MammaPrint results obtained at the time of diagnosis on core biopsy specimen could allow consideration of neoadjuvant chemotherapy (NAC), particularly for tumors that may not traditionally be considered for NAC such as invasive lobular carcinoma (ILC). We hypothesized that MammaPrint scores correlate with pathologic complete response (pCR) and can predict NAC response independent of histology type.

Methods: The National Cancer Database was used to identify patients with AJCC Stage I-III unilateral HR+/HER2- breast cancer with MammaPrint scores treated 2010-2018. Patients were stratified by histology: invasive ductal carcinoma (IDC) and ILC; and by MammaPrint score for 5-year breast cancer recurrence: Low Risk (1%) and High Risk (12%). Descriptive statistics identified clinical and treatment differences between groups. Logistic regression was used to identify factors associated with chemotherapy receipt and sequence. A subset analysis of patients receiving NAC compared pCR rates by MammaPrint score and histology type.

Results: Of 10,999 patients, 9,351 (85%) were diagnosed with IDC and 1,648 (15%) with ILC. ILC were larger at presentation: 40% of ILC were cT2 or greater vs. 29% of IDC (p< 0.001). However, 90% of patients in both groups had cN0 disease. The majority of ILC were grade II (67% ILC vs. 52% IDC, p< 0.001). High Risk MammaPrint scores were significantly more common in IDC tumors: 44% IDC vs 25% ILC (p< 0.001). Mastectomy and axillary lymph node dissection (ALND) were performed more often for ILC than IDC (unilateral mastectomy 32% vs. 21%, bilateral mastectomy 17% vs. 12%, ALND 29% vs. 24%; all p< 0.001). Conversely, chemotherapy (38% vs. 30%, p< 0.001) and radiation (69% vs. 64%, p< 0.001) were more frequently used to treat IDC than ILC. In the subset analysis of patients who received NAC (n = 715), tumors with High Risk MammaPrint scores had more favorable in-breast and axillary responses than those with Low Risk scores for both ILC and IDC (Table 1). Furthermore, only tumors with High Risk Mammaprint scores achieved an overall pCR: 7% IDC and 5% ILC. There were no significant differences in pCR rates by histology type. On multivariable logistic regression, High Risk MammaPrint score was positively associated with the receipt of NAC (OR 4.3, p< 0.001) and adjuvant chemotherapy (OR 24.8, p< 0.001). NAC, adjuvant chemotherapy, and any chemotherapy were also strongly associated with node-positive disease and tumor size >2cm, but not IDC vs. ILC histology.

Conclusions: Superior response to NAC was observed in tumors with High Risk MammaPrint score regardless of histology type, indicating a correlation between pCR rates and genomic assay results. Greater use of NAC guided by High Risk Mammaprint score obtained on core needle biopsy may allow patients with invasive breast cancer to undergo less extensive breast and axillary surgery. Further prospective studies using MammaPrint testing on core biopsy specimens could validate these findings in clinical practice.

Table 1. Response to neoadjuvant chemotherapy by MammaPrint score for patients with Invasive breast carcinoma, NCDB 2010–2018

Citation Format: Lauren M. Drapalik, Rashi Singh, Ashley Simpson, Lisa Rock, Robert Shenk, Amanda L. Amin, Megan E. Miller. Using MammaPrint on Core Needle Biopsy to Guide Neoadjuvant Chemotherapy for Invasive Breast Carcinoma [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-01-02.

Disparities in treatment and survival for patients with isolated colorectal liver metastases

BACKGROUND

Surgical resection improves survival for patients with isolated colorectal liver metastasis. National studies on the disparities related to this topic are limited; therefore, we investigated factors that affect surgical treatment and survival.

METHODS

We queried the National Cancer Database (2010-2017) for patients with isolated synchronous colorectal liver metastasis. Multivariable logistic regression and Cox proportional hazard regressions were used to identify factors associated with surgical resection, treatment at high-volume facilities, and overall survival.

RESULTS

Of 34,050 patients with isolated colorectal liver metastasis, surgical resection (n = 7,810; 23.0%) was more likely among patients who were of high socioeconomic status (odds ratio = 1.16; 95% confidence interval, 1.04-1.31), traveled long distance for treatment (odds ratio = 1.48; 95% confidence interval, 1.31-1.66), and were treated at high-volume facilities (odds ratio = 4.86; 95% confidence interval, 14.45-5.30). Black patients were less likely to undergo resection (odds ratio = 0.75; 95% confidence interval, 0.69-0.82). Treatment at high-volume facility was more common among patients who were Black (odds ratio = 1.14; 95% confidence interval, 1.07-1.21), were of high socioeconomic status (socioeconomic status index 7: odds ratio = 1.21; 95% confidence interval, 1.11-1.31), and traveled long distance (odds ratio = 4.03; 95% confidence interval, 3.63-4.48) and less likely for nonmetropolitan residents and those of low socioeconomic status (P < .05). Patients of high socioeconomic status and those who traveled long distance, were treated at high-volume facilities, underwent surgical resection, and received perioperative chemotherapy had an associated survival advantage (P < .05 for all), whereas Black race was associated with poorer overall survival (P < .05).

CONCLUSION

Nonmedical patient factors, such as race, socioeconomic status, and geography, are associated with treatment and survival for isolated colorectal liver metastases. Disparities persist after adjusting for surgical resection and treatment facility. These barriers must be addressed to improve care for vulnerable cancer patients.

Guideline-Consistent Treatment for Inflammatory Breast Cancer Provides Associated Survival Benefit Independent of Age

BACKGROUND

Guideline-consistent treatment (GCT) for inflammatory breast cancer (IBC) includes neoadjuvant chemotherapy (NAC), modified radical mastectomy (MRM), and radiation. We hypothesized that younger patients more frequently receive GCT, resulting in survival differences.

METHODS

Using the National Cancer Database (2004-2018), female patients with unilateral IBC (by histology code and clinical stage T4d) were stratified by age (< 50, 50-65, > 65 years). Factors associated with NAC, MRM, radiation, and "GCT" (defined as all three treatments) were identified using multivariable logistic regression. Multivariable Cox proportional hazards regression identified predictors of overall survival.

RESULTS

Of 3278 IBC patients, 30% were younger than 50 years, 44% were 50-65 years of age, and 26% were older than 65 years. The youngest group comprised the greatest proportion of non-White patients ([35%] vs. [29%] age 50-65 years and [23%] age > 65 years, p < 0.001) and was most often treated at academic facilities ([33%] vs. [28%] age 50-65 years; and [23%] age > 65, p < 0.001). Patients older than 65 years received NAC, MRM, and radiation less frequently, and only 35% underwent GCT (vs. [57%] age 50-65 years and [52%] age < 50 years; p < 0.001). On multivariable logistic regression, age older than 65 years independently predicted omission of NAC (odds ratio [OR], 0.36), MRM (OR, 0.56), and radiation (OR, 0.56) (all p < 0.001), and patients older than 65 years also were less likely to undergo GCT than patients 50-65 years of age (OR, 0.65; p = 0.001). GCT was associated with superior overall survival in all three age groups ([hazard ratio {HR}, 0.61] age < 50 years, [HR, 0.62] age 50-65 years, [HR, 0.53] age > 65 years; all p < 0.001).

CONCLUSION

Advanced age alone should not limit receipt of GCT for IBC. Multimodal care should be performed for IBC patients of all ages to improve oncologic outcomes for this aggressive breast cancer subtype.