The purpose of this study was to evaluate the complete response rate (CR) of trastuzumab biosimilars and pertuzumab biosimilars combined with oxaliplatin and capecitabine in neoadjuvant treatment of patients with locally advanced (cT3/T4, N+, distance from the lower edge of the tumor to the anal verge ≤12 cm) HER2-positive rectal adenocarcinoma.
Age ≥ 18 years old;
Patients with rectal cancer confirmed by histology or cytology; locally advanced (cT3/T4, N+, distance from the lower edge of the tumor to the anal verge ≤ 12 cm) rectal adenocarcinoma (using the 8th edition of the AJCC TNM staging);
HER2 positive after detection: HER2 positive is defined as IHC test result 3+, or IHC test result 2+ and FISH method confirms positive HER2 gene amplification;
Tumor tissue gene test RAS/BRAF is wild type (previous test results are acceptable);
Patients who have received anti-HER2 drug treatment in the past;
Patients with known clinical symptoms of central nervous system metastasis or meningeal metastasis, or other evidence that individual central nervous system metastasis or meningeal metastasis has not been controlled, and are judged by the investigator to be unsuitable for inclusion;
Patients who are receiving long-term immunosuppressive therapy (such as cyclosporine) or require daily systemic steroid therapy (such as >20 mg prednisone or equivalent drugs), except those who use local glucocorticoids by nasal spray, inhalation or other routes;
The adverse reactions of previous anti-tumor treatment have not recovered to CTCAE 5.0 grade evaluation ≤1 (except for toxicities such as alopecia that the investigator judges to have no safety risks);