Metaplastic Breast Carcinoma in U.S. Population: Racial Disparities, Survival Benefit of Adjuvant Chemoradiation and Future Personalized Treatment with Genomic Landscape

Abstract

Purpose: In this population-based study, we aim to identify factors that are influential on the survival outcome in MBC and investigate novel molecular approaches in personalized disease management. Methods: The data of this study were collected from the SEER database from 2000–2018. A total of 5315 cases were extracted from the database. The data were evaluated for demographics, tumor characteristics, metastasis, and treatment. Survival analysis was completed by using SAS software for multivariate analysis, univariate analysis, and non-parametric survival analysis. The molecular data with the most common mutations in MBC were extracted from the Catalogue of Somatic Mutations in Cancer (COSMIC) database. Results: The mean age at the time of presentation was 63.1 with a standard deviation (SD) of 14.2 years. Most patients were White (77.3%) with 15.7% Black patients, 6.1% Asian or Pacific Islander, and 0.5% American Indian. Histologically, most of the reported tumors were grade III (74.4%); 37% of the cases were triple negative (ER-, PR- and HER2-), whereas the hormone status was unknown in 46% of the cases. Spread was localized in 67.3% of patients while 26.3% had regional spread and 6.3% had distant metastases. Most tumors were unilateral (99.9%) and between 20–50 mm in size (50.6%). The lungs were the most common site for distant metastasis at diagnosis (3.42%) followed by bone (1.94%), liver (0.98%), and brain (0.56%). A combination of surgery, chemotherapy, and radiation therapy was the most common treatment with a cause-specific survival rate of 78.1% (95% CI = 75.4–80.4). The overall survival rate at 5 years was 63.6% (95% confidence interval (CI) = 62.0–65.1) with a cause-specific survival of 71.1% (95% CI = 69.5–72.6). Cause-specific survival was found to be 63.2% (95% CI = 58.9–67.1) in Black patients as compared to 72.4% (95% CI = 70.1–74.1) in White patients. Black patients also presented with higher rates of grade III disease, distant metastasis, and larger tumor size. On multivariate analysis, age > 60, grade III+, metastasis, and tumor size > 50 mm were associated with worse survival. The most common mutations in MBC identified in COSMIC data were TP53, PIK3CA, LRP1B, PTEN, and KMT2C. Conclusion: Though rare, MBC is aggressive, with poor prognosis associated with high-grade tumors, metastasis, tumor size over 50 mm, and advanced age at the time of presentation. Overall, Black women had worse clinical outcomes. MBC is difficult to treat and carries a poor prognosis that affects various races disproportionately. Continued enhancement of treatment strategies to foster more individualized care as well as continued enrollment in clinical trials are needed to improve outcomes among patients with MBC.

Case report: Successful treatment of a rare HER2-positive advanced breast squamous cell carcinoma

“…The etiology of MpBC remains uncertain, predominantly affecting women aged over 50 years, with sporadic occurrences and minimal familial clustering ( Chaudhary et al, 2023 ). Limited data exists regarding the demographics, clinical manifestations, tumor attributes, and therapeutic approaches for MpBC, including SCC ( Ullah et al, 2023 ; Wu et al, 2023 ). The lymph node metastasis rate of MpBC was relatively low, as evidenced by a large-scale study indicating that the incidence of MpBC involving axillary lymph nodes was 21.9%, which is lower than that of invasive ductal carcinoma (IDC) at 34.3% ( Pezzi et al, 2007 ; Lee et al, 2023 ).…”

Presentation and treatment of a rare case of metaplastic breast cancer: A case report

“…So, it can be concluded that there are different points of view about the effect of using NAC or adjuvant chemotherapy on patients’ survival rates. In one of the most extensive studies conducted recently by Ullah et al 13 the results show that the simultaneous use of surgery, radiotherapy, and chemotherapy, compared to the use of each of them alone or the combination of two methods, can increase patients’ survival rate.…”

“…10,12 According to the study by Ullah et al age of more than 60 years, grade IV tumors, tumor size more than 50 mm, and brain metastasis could affect patients' survival rate and increase patients' mortality rate. 13 Breast carcinosarcoma usually shaped solid, well-defined, nodular, and firm tumors. 14 It is a malignant tumor, especially a large tumor, which could lead to skin and/or chest wall fixation, nipple retraction, skin redness, erythema, and ulceration.…”

“… 10 , 12 According to the study by Ullah et al age of more than 60 years, grade IV tumors, tumor size more than 50 mm, and brain metastasis could affect patients’ survival rate and increase patients’ mortality rate. 13 …”