Évaluation de l’efficacité du trastuzumab en néoadjuvant dans le cancer du sein her2+

Abstract

Introduction: Overexpression of the Her2 receptor is found in 15 to 30% of breast cancers. Trastuzumab, leader of these therapies, is indicated for all stages of the disease in neoadjuvant, adjuvant and metastatic. The NOAH study demonstrated the efficacy and safety of trastuzumab as a neoadjuvant for localized and locally advanced breast cancers with a doubling of the pCR rate compared to a chemotherapy alone, hence the systematic indication of trastuzumab by neoadjuvant. The objective of this work is to determine the rate of pCR in patients receiving trastuzumab in neo adjuvanate and compare the responses between the reference molecule and the two biosimilar. Material and methods: This is a cross-sectional descriptive study on a series of 30 patients registered in the medical oncology department between 2015 and 2018. The study lasted 4 months from (03 December 2018 to 30 March 2019). SPSS 21/23 and Excel were the computer tools used to perform the statistical analysis. Results: all patients are female, and the most affected age group is between [30-40 years old], with an average age of 48 years. The majority of tumors are T3 and N1 with a predominance of stage III , CCI is the most frequent histological type and SBR2 is predominant, as well as a positive hormone status. The ki67% of 0-10% is predominant, as well as pT1c and pT2, pN1a and p N2a. 46.66% of patients are under herceptin and 26.66% for each biosimilar, the 3FEC / FAC + 3TH protocols are the most used protocols, the majority of patients underwent mastectomy with lymph node dissection. 20% of complete pathological and clinical responses were obtained. Most pCRs are obtained most with T3 and N1, stage III, SBR2 and 3, the sequential protocol, regular treatment and surgery time less than 5 weeks. The pCR level is 33.33% in each arm of the three products with a non significant khi2 test. Discussion: In our series, the average age joins the data of the 2016 atlas in half of the cases, the majority of the tumors and PCR are T3 and N1 concordant in part with the data of a French study, having describes a similar prevalence, and a rate of 37.5% of N0s that are absent in our series showing delayed diagnosis. SBR2 is the most common, going in the same direction as two AMAT and IAN studies and discordant with two CALAIS and PIERGA studies noted the predominance of SBR3. pT1c and pT2 are the majority, approaching the results of a RABAT study. The 3FEC / FAC + 3 docetaxel protocols are the most used protocols according to the NCCN guidelines. The majority of patients underwent a mastectomy with lymph node dissection, although some patients are candidates for atumourectomy that was not performed at the NCCN. Because of the unavailability of the clips. The pCR rate is 20% discordant with the data of the 40% NOAH study and coming close to a Moroccan study at 13.8%, this pCR rate is distributed uniformly over the three products without any statistically significant difference. This is consistent with data from several US and Korean studies that showed a similarity between the similar bio and the neoadjuvant reference molecule. Conclusion: Our study has shown that the pCR rate is 20%, with no statistically significant difference between the three arms of biosimilar and the reference molecule. New therapeutic approaches such as the protocols involving pertuzumab and TDM1 are on the horizon to improve the rate of pathological responses strongly correlated with better overall survival.