Carcinogénèse mammaire et chimiothérapie néo-adjuvante chez des patientes de l’ouest algérien.

Résumé (Français et/ou Anglais) : Despite all therapeutic advances over the past twenty years, operable breast cancer prognosis remains redoubtable. Neoadjuvant chemotherapy (NCT) is used in combination with surgical local treatment, recently expanded, in order to increase the rate of breast conserving surgery. Receptor status has led to classification of molecular subtypes of different prognosis. The aim of this study is to identify the main factors associated with overall survival (OS) and disease-free survival (DFS) in response to the NCT, used as a guide to clinicians. Firstly we analyzed the predictive and prognostic factors of survival. Secondly, we evaluated the response to the NCT as function of phenotypes tumour, for which there would be a differential benefit. A retrospective cross-sectional study was conducted between January 2008 and June 2014 in 84 women with operable breast cancer, admitted to the oncology department of the University Hospital of Sidi Bel Abbes for cures NCT followed by surgery and adjuvant treatments. The statistical analysis of our database was performed using SPSS for windows, release 22.0, 2013 software. Patients had a median age of 47 years (28-75), whose 56% was clinically diagnosed stageIII. After a median follow up of 30.5 months, the univariate analysis showed a significant relationship between DFS and SBR grade (p = 0.026). Prognostic factors ie, hormonal receptor (HR) and node involvement were associated with survival (p <0.007, p <0.013 respectively). A significant relationship was observed between HER2 status and OS (p = 0.032. In multivariate analysis, prognostic factor in OS was node involvement with a relative risk (RR) equal to 3.3 (p = 0.019). The positive HR significantly improved DFS with a RR equal to 0.33 (p = 0.009). Patients in stage III are significantly associated with the risk of relapse and death compared to those with stage II (45% vs 16%, p = 0.006) and (38% vs 14%, p = 0.011). Twelve patients (14.3%) had a rate of tumour grade SBRI, which was associated with subtypes luminal A (30%) and luminal B (28%), however weak and non-existent in the respective phenotypes HER2 + and triple negative (10 % and 0%, p = 0.005). After a NCT, the mastectomy was avoided in 14.3% of patients, phenotype of luminal B is the most likely to benefit from breast conserving treatment (BCT), compared with triple negative (28% vs 8%). Univariate analysis of OS at 5 years in luminal B and luminal A tumours was significantly associated with a better prognosis with respective survival rates of 100% and 85% compared with HER2 + tumours (60%) and triple negative (55% , p = 0.001). In response to the NTC, the statutes of lymph node involvement and HR are the main prognostic factors for survival. It should be considered for patients with breast cancer stage II and, especially in Luminal A and Luminal B phenotypes, for which it would be possible to increase the chance to BCT, reducing the need to lumpectomy and thus improve the survival of the Algerian women population. Keywords: Breast Cancer, Chemotherapy, neoadjuvant, phenotypes, prognosis, survival.
Doctorat en Sciences