Comparison of survival in non-metastatic inflammatory and other T4 breast cancers: a SEER population-based analysis

Treatment Response, Tumor Infiltrating Lymphocytes and Clinical Outcomes in Inflammatory Breast Cancer-Treated with Neoadjuvant Systemic Therapy

Inflammatory breast cancer (IBC) is a rare (1%-5%), aggressive form of breast cancer, accounting for approximately 10% of breast cancer mortality. In the localized setting, standard of care is neoadjuvant chemotherapy (NACT) ± anti-HER2 therapy, followed by surgery. Here we investigated associations between clinicopathologic variables, stromal tumor-infiltrating lymphocytes (sTIL), and pathologic complete response (pCR), and the prognostic value of pCR. We included 494 localized patients with IBC treated with NACT from October 1996 to October 2021 in eight European hospitals. Standard clinicopathologic variables were collected and central pathologic review was performed, including sTIL. Associations were assessed using Firth logistic regression models. Cox regressions were used to evaluate the role of pCR and residual cancer burden (RCB) on disease-free survival (DFS), distant recurrence-free survival (DRFS), and overall survival (OS). Distribution according to receptor status was as follows: 26.4% estrogen receptor negative (ER-)/HER2-; 22.0% ER-/HER2+; 37.4% ER+/HER2-, and 14.1% ER+/HER2+. Overall pCR rate was 26.3%, being highest in the HER2+ groups (45.9% for ER-/HER2+ and 42.9% for ER+/HER2+). sTILs were low (median: 5.3%), being highest in the ER-/HER2- group (median: 10%). High tumor grade, ER negativity, HER2 positivity, higher sTILs, and taxane-based NACT were significantly associated with pCR. pCR was associated with improved DFS, DRFS, and OS in multivariable analyses. RCB score in patients not achieving pCR was independently associated with survival. In conclusion, sTILs were low in IBC, but were predictive of pCR. Both pCR and RCB have an independent prognostic role in IBC treated with NACT.

SIGNIFICANCE

IBC is a rare, but very aggressive type of breast cancer. The prognostic role of pCR after systemic therapy and the predictive value of sTILs for pCR are well established in the general breast cancer population; however, only limited information is available in IBC. We assembled the largest retrospective IBC series so far and demonstrated that sTIL is predictive of pCR. We emphasize that reaching pCR remains of utmost importance in IBC.

ER+/PR- phenotype exhibits more aggressive biological features and worse outcome compared with ER+/PR+ phenotype in HER2-negative inflammatory breast cancer

The loss of progesterone receptor (PR) often predicts worse biological behavior and prognosis in estrogen receptor-positive (ER +) breast cancer. However, the impact of PR status on inflammatory breast cancer (IBC) has not been studied. Therefore, the purpose of our study was to investigate the influence of PR on IBC. Patients with ER+ and HER2-negative IBC were selected from the Surveillance, Epidemiology and End Results database. Pearson's χ2 test was used to compare the clinicopathological characteristics between patients with estrogen receptor-positive/progesterone receptor-positive (ER+/PR +) and patients with estrogen receptor-positive/progesterone receptor-negative (ER+/PR-). Univariate and multivariate analyses were performed to investigate the effects of PR status on the breast cancer-specific survival (BCSS) and overall survival (OS) in IBC. Overall, 1553 patients including 1157 (74.5%) patients with ER+/PR+ and 396 (25.5%) patients with ER+/PR- were analyzed in our study. The patients with ER+/PR- were more likely to be high histological grade (p < 0.001) and liver metastasis (p = 0.045) compared to patients with ER+/PR+. Despite higher chance of receiving chemotherapy (83.6% vs 77.3%, P = 0.008), patients with ER+/PR- showed worse BCSS (5-year BCSS rate, 34.3% vs 51.3%, P < 0.001) and OS (5-year OS rate, 31.3% vs 46.1%, P < 0.001) compared with ER+/PR+ phenotype. Multivariate survival analysis showed that patients with ER+/PR- still had worse BCSS (hazard ratios [HR]: 1.764, 95% confidence intervals [CI] 1.476-2.109, P < 0.001) and OS (HR: 1.675, 95% CI 1.411-1.975, P < 0.001) than ER+/PR+ phenotype. Furthermore, patients with ER+/PR- showed worse outcomes than ER+/PR+ phenotype in most subgroups, especially in patients with younger age (≤ 60 years), lower histological grade, lymph node involved and distant metastasis. Patients with ER+/PR- had more aggressive biological behaviors and worse outcomes than patients with ER+/PR+ in IBC. Stronger treatments maybe needed for IBC patients with ER+/PR-.

Racial disparities in treatment and outcomes between non-Hispanic Black and non-Hispanic White women with nonmetastatic inflammatory breast cancer

PURPOSE

The incidence rate of inflammatory breast cancer (IBC) is higher among non-Hispanic Black (NHB) than non-Hispanic White (NHW) women. We examined the differences in treatment and outcomes between NHB and NHW women with IBC, accounting for demographic, clinicopathological, and socioeconomic factors.

METHODS

We collected data from the Surveillance, Epidemiology, and End Results database for NHB and NHW women with IBC diagnosed between 2010-2016. We analyzed the odds of receiving chemotherapy, radiation, and surgery between NHB and NHW women. We evaluated overall survival (OS) with Kaplan-Meier methods and Cox proportional hazards methods. Competing risk analysis was used to compare the risk of breast cancer death between NHB and NHW women. We also evaluated the magnitude of survival disparities within the strata of demographic, socioeconomic, and treatment factors.

RESULTS

Among 1,652 NHW and 371 NHB women with IBC, the odds of receiving chemotherapy, surgery, and radiation were similar for NHB and NHW. After 39-month follow-up, the median OS was 40 and 81 months for NHB and NHW, respectively (p < 0.0001). The risk of breast cancer death was higher for NHB than NHW women (5-year risk of breast cancer death, 51% vs. 35%, p < 0.0001).

CONCLUSION

After adjustment for demographic, clinicopathological, and socioeconomic factors; NHB women with IBC had similar odds of receiving surgery, chemotherapy, and radiation therapy, but were more likely to die of the disease compared to their NHW counterparts. Our findings suggest the presence of masked tumor biology, treatment, or socioeconomic factors associated with race that can lead to worse IBC outcomes.

Comparison of the genomic alterations present in tumor samples from patients with metastatic inflammatory versus non-inflammatory breast cancer reveals AURKA as a potential treatment target

Inflammatory breast cancer (IBC) is a rare but aggressive subtype of breast cancer, mainly characterized using primary tumor samples. Here, using public datasets, we compared the genomic alterations in primary and metastatic samples from patients with metastatic IBC versus patients with metastatic non-IBC. We observed a higher frequency of AURKA amplification in IBC. We further showed that AURKA amplification was associated with increased AURKA mRNA expression, which we demonstrated was higher in IBC. Finally, higher protein expression of AURKA was associated with worse prognosis in patients with IBC. These findings deserve further investigation given the existence of AURKA-inhibitors.

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.