Background and Aims: HER-2 positive breast cancer, especially the locally advanced HER-2 positive breast cancer in young patients, PCH regimen (paclitaxel + carboplatin + trastuzumab) is recommended for neoadjuvant therapy. However, the commonly used solvent paclitaxel is prepared with polyoxyethylene castor oil, which may cause the side effects such as allergic reactions, myelosuppression and peripheral neurotoxicity. Therefore, this study was designed to investigate the efficacy and safety of neoadjuvant therapy using the modified PCH regimen (albumin-bound paclitaxel + carboplatin + trastuzumab) in the treatment of young patients with initially diagnosed locally advanced HER-2 positive breast cancer.  
Methods: Using a prospective protocol, the treatment-na?ve young females (aged from 18 to 40 years) diagnosed with locally advanced HER-2 positive breast cancer in the Department of Breast Surgery of Affiliated Suqian Hospital of Xuzhou Medical university from June 2016 to December 2018 were enrolled. The patients were assigned to two groups by random number table, and then underwent neoadjuvant therapy with PCH regimen (PCH group) or modified PCH regimen (PCH group). In all patients, the treatment responses and adverse reactions were evaluated after 6 cycles of chemotherapy, and then modified radical mastectomy was performed. Trastuzumab treatment was continued for a full year after operation, and the progression-free survival (PFS) and overall survival (OS) of the two groups of patients were compared.
Results: A total of 62 patients were enrolled, with 30 cases in PCH group and 32 cases in modified PCH group, and the preoperative data between the two groups of patients were comparable. After neoadjuvant therapy, complete clinical response (cCR) was obtained in 6 patients, complete pathological response was achieved in 2 patients, and partial response was found in 22 patients in PCH group, while 14 patients had cCR, 8 patients had pCR and 10 patients had PR in modified PCH group. Both cCR and pCR rates in modified PCH group were significantly higher than those in PCH group (43.8% vs. 20.0%, χ2=3.997, P=0.046; 25.0% vs. 6.7%, χ2=4.098, P=0.043). No treatment-associated death occurred in all patients during chemotherapy. The incidence of neutropenia in modified PCH group was significantly lower than that in PCH group (31.3% vs. 60%, χ2=5.168, P=0.023), while the incidence of peripheral sensory neurotoxicity in modified PCH group was significantly higher than that in PCH group (40.6% vs. 20.0%, χ2=3.997, P=0.046), but all reactions presented as numbness or tingling in hands or feet, and no neurotoxic reaction of 3 to 4 degree occurred in both groups. There were no significant differences between the two groups in other common adverse reactions such as nausea and vomiting, alopecia and rash (all P>0.05). The parameters of cardiac function of the two groups of patients were within the normal range during treatment. The median PFS time and the median OS time were 13.1 months and 35.4 months in modified PCH group, and were 7.8 months and 21.6 months in PCH group, and the difference had statistical significance (χ2=8.302, 8.557, P=0.005, 0.004).
Conclusion: In young patients with treatment-na?ve locally advanced HER-2 positive breast cancer, using the modified PCH regimen not only increases the cCR rate, but also improves the pCR rate to a certain extent compared with PCH regimen. The short-term efficacy in patients is satisfactory, with relatively mild adverse reactions. So, it is recommended to be used in clinical paractice.