Factors associated with improved outcomes for metastatic inflammatory breast cancer patients

Immune checkpoint inhibitors for patients with metastatic triple-negative inflammatory breast cancer (INCORPORATE): An international cohort study

BACKGROUND

Inflammatory breast cancer (IBC) is the most aggressive clinical presentation of breast cancer, recapitulating a specific biology with more immune-vulnerability than non-IBC. Patients with metastatic, triple-negative IBC (mTN-IBC) receive immune checkpoint inhibitors (ICIs) and chemotherapy, similarly to patients with triple-negative non-IBC. However, the benefit derived from ICI incorporation in this rare type of breast cancer is unknown.

METHODS

We conducted a multicenter, international, retrospective, cohort study to evaluate the activity of ICIs in patients with metastatic, triple-negative, primary IBC, who received ICIs plus first line chemotherapy from January 2015 to April 2023. A sample size of 42 patients allowed to detect an increase in 6-months real-world progression-free survival (rwPFS) rate from 40 % with only chemotherapy to 60 % with ICI and chemotherapy.

RESULTS

41 patients from eight international IBC referral centers were included (61 % with primary, de novo mTN-IBC, 61 % with visceral disease). All received ICIs plus first line chemotherapy and 24 % underwent breast surgery and/or locoregional radiotherapy. After a median follow-up of 19.3 months, the 6-months rwPFS rate was 30 % (95 % Confidence Interval [CI], 17-45 %), the median rwPFS was 3.3 months (95 % CI: 2.2-5.4), the median overall survival was 15.7 months (95 % CI: 6.8-16.3).

CONCLUSIONS

This one-sample analysis showed a poor outcome of patients with mTN-IBC, despite the treatment with ICI, in contrast with the expected benefit based on preclinical evidence of immune-vulnerability of IBC. These results suggest the need to further investigate the role of immunotherapy in this aggressive and rare type of breast cancer presentation.

Navigating Breast Cancer Oligometastasis and Oligoprogression: Current Landscape and Future Directions

PURPOSE

We examine the potential for curative approaches among metastatic breast cancer (MBC) patients by exploring the recent literature on local ablative therapies like surgery and stereotactic body radiation therapy (SBRT) in patients with oligometastatic (OM) breast cancer. We also cover therapies for MBC patients with oligoprogressive (OP) disease.

KEY FINDINGS

Surgery and SBRT have been studied for OM and OP breast cancer, mainly in retrospective or non-randomized trials. While many studies demonstrated favorable results, a cooperative study and single-institution trial found no support for surgery/SBRT in OM and OP cases, respectively.

CONCLUSION

While there is interest in applying local therapies to OM and OP breast cancer, the current randomized data does not back the routine use of surgery or SBRT, particularly when considering the potential for treatment-related toxicities. Future research should refine patient selection through advanced imaging and possibly explore these therapies specifically in patients with hormone receptor-positive or HER2-positive disease.

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.

Improved Rate of Negative Margins for Inflammatory Breast Cancer Using Intraoperative Frozen Section Analysis

BACKGROUND

Inflammatory breast cancer (IBC) is a rare and aggressive form of breast cancer with a poor survival rate. Modified radical mastectomy (MRM) with negative pathologic margins is critical for improved survival. We aim to study the potential benefit of intraoperative frozen section analysis (FSA) to improve disease-free margins.

METHODS

This prospective, monocentric study included 19 patients who underwent MRM for IBC. For each patient, a 2 mm continuous skin edge was sent for FSA to guide further resection. The rate of tumor-free margins and the concurrence between the FSA and permanent pathological results were analyzed.

RESULTS

Overall, 15 of the 19 patients achieved negative margins, including four patients who would have had positive margins without FSA. The odds ratio of achieving a negative final margin with FSA was infinity (p = 0.031), and there was a strong agreement between the FSA and permanent pathological results (Kappa-0.83; p < 0.0001).

CONCLUSIONS

The FSA technique decreased the number of positive margins in IBC patients undergoing MRM, thereby potentially reducing the need for re-operation, allowing immediate wound closure, and preventing delays in the administration of adjuvant radiation therapy. More extensive trials are warranted to establish the use of intraoperative FSA in IBC treatment.

Conservative Surgery in cT4 Breast Cancer: Single-Center Experience in the Neoadjuvant Setting

BACKGROUND

The diffusion of screening programs has resulted in a decrease of cT4 breast cancer diagnosis. The standard care for cT4 was neoadjuvant chemotherapy (NA), surgery, and locoregional or adjuvant systemic therapies. NA allows two outcomes: 1. improve survival rates, and 2. de-escalation of surgery. This de-escalation has allowed the introduction of conservative breast surgery (CBS). We evaluate the possibility of submitting cT4 patients to CBS instead of radical breast surgery (RBS) by assessing the risk of locoregional disease-free survival, (LR-DFS) distant disease-free survival (DDFS), and overall survival (OS).

METHODS

This monocentric, retrospective study evaluated cT4 patients submitted to NA and surgery between January 2014 and July 2021. The study population included patients undergoing CBS or RBS without immediate reconstruction. Survival curves were obtained using the Kaplan-Meyer method and compared using a Log Rank test.

RESULTS

At a follow-up of 43.7 months, LR-DFS was 70% and 75.9%, respectively, in CBS and RBS (p = 0.420). DDFS was 67.8% and 29.7%, respectively, (p = 0.122). OS was 69.8% and 59.8%, respectively, (p = 0.311).

CONCLUSIONS

In patients with major or complete response to NA, CBS can be considered a safe alternative to RBS in the treatment of cT4a-d stage. In patients with poor response to NA, RBS remained the best surgical choice.

Modified Radical Mastectomy in De Novo Stage IV Inflammatory Breast Cancer

BACKGROUND

There are few studies on surgical management in patients with de novo metastatic inflammatory breast cancer (IBC). The objective of this study is to examine the association between modified radical mastectomy (MRM) and disease-specific survival (DSS) in patients with de novo stage IV IBC.

PATIENTS AND METHODS

The Surveillance, Epidemiology, and End Result Program was queried for patients ≥18 years old with cT4d/pT4d pathology, histology type 8530 and 8533 with distant disease between 2010 and 2016. The sample was divided into two groups: (1) the MRM group, defined as MRM or mastectomy with at least ten lymph nodes removed, and (2) the no-surgery group. Sociodemographic and clinical variables were compared between the groups on bivariable analysis. After propensity score matching, Kaplan-Meier curves and a Cox proportional-hazards model examined DSS.

RESULTS

1293 patients were included in the study, of whom 240 underwent MRM. A higher percentage in the MRM group had only one metastatic site (69.8% versus 52.2%), received chemotherapy (88.3% versus 66.1%) and radiation (58.8% versus 26.0%) compared with the no-MRM group. MRM was associated with an increase in DSS compared with no MRM [HR 0.63 (95% CI 0.50-0.80), p < 0.001]. Patients with MRM had a 5-year DSS rate of 31.4% compared with 17.7% for patients not undergoing surgery (p = 0.001). Survival time was 38 months (range 27-45 months) for the MRM group versus 27 months (22-29 months) for the no-MRM group.

CONCLUSION

MRM in patients with de novo metastatic IBC may improve DSS in a subset of patients.

Refusal of cancer-directed surgery in male breast cancer

It has been reported that some male breast cancer patients may refuse the recommended surgery, but the incidence rate in the United States is not clear. The purpose of this study was to identify the incidence, trends, risk factors, and eventual survival outcomes associated with the rejection of such cancer-directed surgery.We collected data on 5860 patients with male breast cancer (MBC) from the Surveillance, Epidemiology, and End Results database, including 50 patients refusing surgery as recommended. Kaplan-Meier survival analysis and Cox proportional hazard regression were used to identify the effects of refusing surgery on cancer-specific survival (CSS) and overall survival (OS). The association between acceptance or rejection of surgery and mortality were estimated by nested Cox proportional hazards regression models with adjustment for age, race, clinical characteristics, and radiation.Of the 5860 patients identified, 50 (0.9%) refused surgery. Old age (≥65: hazard ratio [HR]: 3.056, 95% confidence interval [CI]: 1.738-5.374, P < .0001), higher AJCC stage (III: HR: 3.283, 95% CI: 2.134-5.050, P < .0001, IV: HR: 14.237, 95% CI: 8.367-24.226, P < .0001), progesterone receptor status (negative: HR: 1.633, 95% CI: 1.007-2.648, P = .047) were considered risk factors. Compared with the surgery group, the refusal group was associated with a poorer prognosis in both OS and CSS (χ2 = 94.81, P < .001, χ2 = 140.4, P < .001). Moreover, significant differences were also observed in OS and CSS among 1:3 matched groups (P = .0002, P < .001).Compared with the patients undergoing surgery, the patients who refused the cancer-directed surgery had poor prognosis in the total survival period, particularly in stage II and III. The survival benefit for undergoing surgery remained even after adjustment, which indicates the importance of surgical treatment before an advanced stage for male breast cancer patients.

The Role of Mastectomy in De Novo Stage IV Inflammatory Breast Cancer

INTRODUCTION

The role of modified radical mastectomy (MRM) in patients with de novo stage IV inflammatory breast cancer (IBC) remains controversial. We evaluated the impact of MRM on outcomes in this population.

METHODS

Ninety-seven women presenting with stage IV IBC were identified in an institutional database (2007-2016) and were stratified by receipt of MRM or no surgery (non-MRM). Demographic, clinicopathologic, and treatment factors were compared. Local-regional recurrence patterns were described and survival analyses were conducted.

RESULTS

All patients initially received chemotherapy. Fifty-two patients (53.6%) underwent MRM; 47 received post-mastectomy radiation. Differences between the non-MRM and MRM groups included tumor receptor subtypes (hormone receptor-positive [HR+]/human epidermal growth factor receptor 2-positive [HER2+]: 4.4% vs. 19.2%; HR+/HER2-negative [HER2-]: 31.1% vs. 44.2%; HR-negative [HR-]/HER2+: 24.4% vs. 15.4%; and HR-/HER2-: 40.0% vs. 21.2%; p = 0.03), number of metastatic sites (3 vs. 2; p = 0.01), and clinical partial/complete response to chemotherapy (13.3% vs. 75.0%; p < 0.001). Of the 47 patients who completed trimodality therapy, 6 (12.8%) had a local-regional recurrence. Median overall survival (OS) was 19 months in the non-MRM group and 58 months in the MRM group (p < 0.001). On multivariable analysis, clinical N3 disease (hazard ratio 2.16, 95% confidence interval [CI] 1.07-4.37; p = 0.03) as well as tumor subtypes HR+/HER2- (hazard ratio 4.98, 95% CI 1.15-21.47; p = 0.03) and HR-/HER2- (hazard ratio 7.18, 95% CI 1.66-31.07; p = 0.008) were associated with decreased OS. Partial/complete response of distant disease to chemotherapy (hazard ratio 0.43, 95% CI 0.24-0.77; p = 0.005) and receipt of MRM (hazard ratio 0.52, 95% CI 0.29-0.93; p = 0.03) were independently associated with improved OS.

CONCLUSIONS

In our retrospective study, MRM in de novo stage IV IBC patients is an independent factor associated with improved OS. Our findings strongly support the need for prospective randomized trials evaluating possible survival benefits of MRM in de novo stage IV IBC patients.

Locoregional therapy of the primary tumour in de novo stage IV breast cancer in 216 066 patients: A meta-analysis

Patients presenting with de novo stage IV metastatic breast cancer have a complex disease which is normally treated with palliative intent and systemic therapy. However, there is mounting evidence that resection of the primary tumour and/or localised radiotherapy (locoregional therapy; LRT) could be associated with overall survival improvements. We aimed to conduct a meta-analysis to inform decision making. Using the PubMed, Cochrane and Ovid SP databases, a literature review and meta-analysis were conducted to assess the effect of LRT on overall survival. Studies were analysed for the impact of LRT on survival. All forms of LRT resulted in a significant 31.8% reduction in mortality (N = 42; HR = 0.6823 (95% CI 0.6365; 0.7314)). Surgical resection resulted in a significant 36.2% reduction in mortality (N = 37; HR = 0.6379 (95% CI 0.5974; 0.6811)). The prospective trials reported a 19.23% reduction in mortality which was not statistically significant (N = 3, HR = 0.8077 (95% CI 0.5704; 1.1438). 216 066 patients were included. This is the largest meta-analysis regarding this question to date. Our meta-analysis shows that LRT of the primary tumour seems to improve overall survival in de novo stage IV disease. Therefore, this therapeutic option should be considered in selected patients after a careful multidisciplinary discussion.

Better survival after surgery of the primary tumor in stage IV inflammatory breast cancer

INTRODUCTION

Information regarding the effects of resection of the primary tumor in stage IV inflammatory breast cancer (IBC) is scarce. We analyzed the impact of resection of the primary tumor on overall survival (OS) in a large stage IV IBC population.

MATERIALS AND METHODS

Patients diagnosed with stage IV IBC between 2005 and 2016 were selected from the Netherlands Cancer Registry, excluding patients without any treatment. To correct for immortal time bias, we performed a landmark analysis including patients alive at least six months after diagnosis. With propensity score matching, patients undergoing surgery of the primary tumor were matched to patients not receiving surgery. Multivariable Cox proportional hazard analyses were performed to determine the association between treatment strategy and OS in the non-matched and matched cohort.

RESULTS

Of the 580 included patients after landmark analysis, 441 patients (76%) received only non-surgical treatments and 139 (24%) underwent surgery (96% mastectomy). Median follow-up was 28.8 and 20.0 months in the surgery and no surgery group, respectively. Surgery in the non-matched cohort was independently associated with better survival (HR0.56[95%CI:0.42-0.75]). In the matched cohort (n = 202), surgically treated patients had improved survival over nonsurgically treated patients (p < 0.005). Multivariable analysis of the matched cohort revealed that surgery was still associated with better survival (HR0.62[95%CI:0.44-0.87]).

CONCLUSION

Although residual confounding and confounding by severity cannot be ruled out, this study suggests that surgery of the primary tumor is associated with improved OS and should be considered as part of the treatment strategy in stage IV IBC.

Poor Response to Neoadjuvant Chemotherapy Correlates with Mast Cell Infiltration in Inflammatory Breast Cancer

Our understanding is limited concerning the tumor immune microenvironment of inflammatory breast cancer (IBC), an aggressive form of primary cancer with low rates of pathologic complete response to current neoadjuvant chemotherapy (NAC) regimens. We retrospectively identified pretreatment (N = 86) and matched posttreatment tissue (N = 27) from patients with stage III or de novo stage IV IBC who received NAC followed by a mastectomy. Immune profiling was performed including quantification of lymphoid and myeloid infiltrates by IHC and T-cell repertoire analysis. Thirty-four of 86 cases in this cohort (39.5%) achieved a pathologic complete response. Characterization of the tumor microenvironment revealed that having a lower pretreatment mast cell density was significantly associated with achieving a pathologic complete response to NAC (P = 0.004), with responders also having more stromal tumor-infiltrating lymphocytes (P = 0.035), CD8⁺ T cells (P = 0.047), and CD20⁺ B cells (P = 0.054). Spatial analysis showed close proximity of mast cells to CD8⁺ T cells, CD163⁺ monocytes/macrophages, and tumor cells when pathologic complete response was not achieved. PD-L1 positivity on tumor cells was found in fewer than 2% of cases and on immune cells in 27% of cases, but with no correlation to response. Our results highlight the strong association of mast cell infiltration with poor response to NAC, suggesting a mechanism of treatment resistance and a potential therapeutic target in IBC. Proximity of mast cells to immune and tumor cells may suggest immunosuppressive or tumor-promoting interactions of these mast cells.

Homeoprotein DLX4 expression is increased in inflammatory breast cancer cases from an urban African-American population

Protein expression of Distal-less homeobox 4 (DLX4) was analyzed in inflammatory breast cancer (IBC) cases from an African-American (AA) population to determine if a) DLX4 gene over expression exists in this cohort and b) if the overexpression is associated with breast cancer clinicopathological characteristics (ER, PR, HER2, triple-negative). Twenty-nine blocks of formalin-fixed paraffin-embedded (FFPE) tissue from well-characterized human IBC cases were used for immunohistochemical staining (IHC). IHC results were assigned an intensity and percentage score. Percentage scores were assigned as 0, 1, 2, 3, or 4 and intensity scores were assigned 0, 1+, 2+ or 3+. For the analysis of the IHC, a percentage score of 3 or 4 and an intensity score of 2+ or 3+ were categorized as high. Chi-square or Fisher's exact tests were used to compare the high and low groups. In this cohort, 89.7% (26 out of 29) of IBC cases showed high percentages of positive cells staining for the DLX4 protein, while 40.0% (12 out of 30) of normal breast tissue from reduction mammoplasty cases demonstrated DLX4 expression (p < 0.01). In IBC patients, 65.5% of cases showed a high level of staining intensity, compared to 20.0% of normal breast tissues (test, p = 0.001). Intensity to DLX4 was higher in the HER2 negative status (78.3%) than the HER2 positive status (16.7%) (test, p = 0.011). DLX4 expression is higher in the IBC cases in this study of an urban AA population than in normal breast tissue cases. HER2 negative status is positively associated with high intensity of DLX4.