Worst type of breast cancer
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The Worst Type of Breast Cancer: A Comprehensive Analysis
Metaplastic Breast Carcinoma: An Aggressive Subtype
Metaplastic Breast Carcinoma (MBC) is identified as one of the most aggressive forms of breast cancer. MBC is a rare subtype that generally exhibits poorer overall survival compared to other triple-negative breast cancers (TNBC). Among the histologic subtypes of MBC, the squamous subtype is associated with the worst survival outcomes, with a 5-year breast cancer-specific survival (BCSS) rate of only 56%. This is significantly lower than the heterologous mesenchymal subtype, which has a BCSS rate of 88%. Overall, patients with MBC have worse survival rates compared to those with non-MBC TNBC, highlighting the need for tailored therapeutic approaches.
Triple-Negative Breast Cancer: The Most Challenging Subtype
Triple-Negative Breast Cancer (TNBC) is another subtype known for its poor prognosis. TNBC lacks the expression of estrogen receptors (ER), progesterone receptors (PR), and HER2, making it unresponsive to hormonal or HER2-targeted therapies. Studies have consistently shown that TNBC has the worst breast cancer-specific survival (BCSS) and overall survival (OS) rates among all breast cancer subtypes . For instance, the 5-year BCSS rate for TNBC is approximately 77%, which is significantly lower than other subtypes such as HR+/HER2- (95.5%) and HR+/HER2+ (94.1%) .
Small Tumors and Prognosis: T1a TNBC
Even among small tumors, TNBC shows a particularly poor prognosis. T1a TNBC, which refers to tumors less than 1 cm in size, has been found to have the worst prognosis among small tumors of TNBC and HER2-rich subtypes. This subtype often omits adjuvant chemotherapy, leading to worse outcomes compared to T1a HER2+/HoR- and T1b HER2+/HoR- tumors. This indicates the necessity for more intensive adjuvant treatment even for small TNBC tumors.
Molecular Subtypes and Survival
Breast cancer can be classified into various molecular subtypes based on the expression of ER, PR, and HER2. Among these, the triple-negative subtype (ER-/PR-/HER2-) consistently shows the worst survival outcomes. Studies have shown that the 5-year relative survival for triple-negative breast cancer is around 76%, which is significantly lower than other subtypes such as ER+/PR+/HER2- (96%). This subtype is also more prevalent among younger women, non-Hispanic black or Hispanic populations, and those with lower socioeconomic status.
Conclusion
In summary, both Metaplastic Breast Carcinoma (MBC) and Triple-Negative Breast Cancer (TNBC) are among the worst types of breast cancer in terms of prognosis. MBC, particularly the squamous subtype, and TNBC, especially in its T1a form, exhibit significantly poorer survival rates compared to other breast cancer subtypes. These findings underscore the urgent need for more effective and tailored treatment strategies for these aggressive forms of breast cancer.
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