ABSTRACT
BACKGROUND: Breast cancer mortality has increased in women 25 years and over, and since 2006 it has surpassed cervical cancer. Breast cancer is a heterogeneous disease, with several clinical and histological presentations that require a thorough study of all clinical and pathological parameters, including immunohistochemistry to classify it into subtypes, have a better prognosis, provide individualised treatment, increase survival, and reduce mortality. OBJECTIVE: To evaluate the prevalence of sub-types of breast cancer and the association with the clinical and histopathological features of the tumour. MATERIAL AND METHODS: An observational, retrospective, cross-sectional and analytical study conducted on 1380 patients with a diagnosis of breast cancer have been classified by immunohistochemistry into four subtypes: luminal A, triple negative, luminal B and HER2. An analysis was performed on the association with age, risk factors, and the clinical and histopathological features of the tumour. RESULTS: The mean age of the patients was 53.3 ± 11.4. The frequency was luminal A (65%), triple negative (14%), luminal B (12%), and HER2 (9%). The most frequent characteristics were the 50 to 59 age range, late menopause, the right side, upper external quadrant, stage II, metastatic lymph nodes, and mastectomy. CONCLUSION: The most frequent sub-type was luminal A, and together with the luminal B are those which have better prognosis compared with the triple negative and HER2.
Subject(s)
Breast Neoplasms/classification , Breast Neoplasms/pathology , Adult , Aged , Aged, 80 and over , Breast Neoplasms/epidemiology , Cross-Sectional Studies , Female , Hospitals, General , Humans , Immunohistochemistry , Mexico , Middle Aged , Prevalence , Retrospective StudiesABSTRACT
AIM OF THE STUDY: In breast cancer, oestrogen receptor (ER), progesterone receptor (PgR), and HER2 (HER2/Neu) expression status are used to classify neoplasms into subtypes: Luminal A, Luminal B, HER2/Neu type, and Basallike. The aim of the present study was to establish the molecular subtypes of breast cancers and their association with tumour characteristics and reproductive factors in Mexican women. MATERIAL AND METHODS: A total of 1326 biopsies of breast tumour tissues were analysed for ER, PR, and HER2/Neu by immunohistochemistry (IHC). Information regarding age, tumour characteristics, and node involvement profiles were collected. RESULTS: IHC established that the most common subtype of breast cancer was Luminal A (64.93%), followed by Basal-Like (13.88%), Luminal B (12.52%), and HER2/Neu (8.67%). T2-size tumours (> 2 cm but < 5 cm) were present in 47.59% of all patients. Univariate analysis showed that lymph node positivity (p = 0.009), stage (p = 0.013), and placement of the tumour (p = 0.001) were factors associated with breast cancer subtype. CONCLUSIONS: Our data show that IHC is useful for distinguishing different subtypes of breast cancer and that Luminal A is the most common breast cancer subtype in the Mexican population. All subtypes were associated with unfavourable clinicopathological features, suggesting that late diagnosis is an important contributor to high mortality rates in the Mexican population.
