RESPONSE TO WEEKLY PACLITAXEL AND CARBOPLATIN REGIMEN IN METASTATIC BREAST CANCER AND ITS RELATION TO P53 EXPRESSION

Summaryp53 mutations characterize 20-40% of breast cancer patients and there is evidence that over expression of p53 is involved in breast cancer progression.p53 mutations were strongly correlated with clinical stage III or IV, Large tumer size, early lymph node (LN) metastasis, and poor response to chemotherapy.Metastatic breast cancer is considered to be a chronic disease. Whilst prolonged disease control can be achieved using endocrinal and/or chemotherapy, most patients ultimately die due to their cancer. Optimal use of the different available treatment modalities should be considered to achieve maximal palliation and to delay disease progression and death with a little toxicity as possible.This study aimed to evaluate efficacy and toxicity of weekly paclitaxel and carboplatin regimen at a dose of 100 mg/m2 and AUC 2 respectively, also to detect correlation between tissue p53 expression by IHC in metastatic breast cancer patients and response to treatment. Forty female patients with metastatic breast cancer were included in this study and all patients were subjected to history and clinical examination, routine laboratory investigations radiological studies and special investigations to assess p53 expression by IHC.All patients were treated with paclitaxel 100 mg/m2 and carboplatin AUC 2 for successive 3 weeks followed with 1 week rest of treatment (one cycle).Patients were evaluated for response after 3 cycles and responding patients continued for 6 cycles then response and toxicity were evaluated.It was noticed that p53 over expression by IHC was (+)ve in 15 patients (37.5%) while it was (-)ve in 25 patients (62.5%).It was observed that reduced expression of p53 (-)ve p53 had a statistically significant association with response to weekly paclitaxel and carboplation.As regard response of weekly paclitaxel and carboplatin, overall response (CR + PR) was 55.9% after the first 3 courses of therapy. The response of this protocol had a statistically significant association with P53 status (better response was achieved with (-)ve p53 expression).Weekly paclitaxel and carboplatin regimen not only active but also tolerable with low toxicity therefore, weekly paclitaxel and carboplatin provide an attractive option for the treatment of metastatic breast cancer patients.CONCLUSIONSWeekly paclitaxel at 100 mg/m2 and carboplatin AUC 2 is active and tolerable in treatment of metastatic breast cancer.p53 status of expression is evolving as predictive factor for response to treatment with paclitaxel and reduced expression was with better response to treatment, over expression of p53 was with bad response.