Introduction: Invasive breast cancer is the most common malignancy affecting women worldwide and also an important cause of cancer death. Apocrine carcinoma is a rare subtype of invasive ductal carcinoma of the breast, accounting for 0.3-1% of all breast cancers. This type of breast cancer is commonly ER (estrogen receptor), PR (progesterone receptor) and HER2 (receptor type 2) negative (triple negative), while expressing AR (androgen receptor). Our study sought to explore the characteristics (e.g. receptor status, treatment patterns, demographics and clinical characteristics) of this rare subset of breast cancer and compare outcomes with that of the more common triple negative invasive ductal carcinoma (TNBC).
Methods: The National Cancer Database (NCDB) Participant User File (PUF) for breast cancer from 2004- 2013 was queried, with two cohorts - apocrine carcinoma versus triple negative invasive ductal carcinoma identified. Descriptive and univariate statistics were calculated for all variables. A multivariable Cox proportional hazard model was used to compare overall survival (OS) between the two cohorts. Univariate and multivariate stratified analyses were also performed to investigate possible interactions between covariates and cohorts. Propensity score matching was performed to further reduce selection bias.
Results: There were 2,807,541 patients in the NCDB Breast PUF 2012 database, 38,514 patients (2537 (6.6%) apocrine carcinoma and 35,977 (93.4%) TNBC) met study criteria. 72.1% of the total study population was at least 50 years old. In terms of race, 73.4% were white and 21.9% were black. In multivariable analysis, patients with TNBC were at a higher risk of death compared to apocrine carcinoma (HR=1.40, p <0.001) and a HR=1.34, (p <0.001) based on propensity score matching approach. Stratified analyses showed a better outcome in apocrine carcinoma cohort for younger group (<50), the receipt of chemotherapy, LN positive, LVI present and HER2 when compared with the TNBC cohort.
Conclusion: This retrospective analysis of a national cancer database suggests that apocrine carcinoma of the breast has a better outcome, in terms of survival, than TNBC.
Table of Contents
2.1 Study Design and Patient
2.2 Variables and Measurement
2.3 Statistical Analyses
3.1. Descriptive Statistics
3.2. Univariate Association with Study Cohorts
3.3. Univariate/Multivariate Association with Overall Survival
3.4. Univariate Stratified Analyses (Kaplan Meier Curve)
3.5. Multivariate Stratified Analyses
3.6. Propensity Score Matching
3.7. Overall Survival in Matched Sample
About this Master's Thesis
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|Apocrine Carcinoma of the Breast: Treatment Patterns and Outcomes ()||2018-08-28||