Complete Pathologic Response of Multiple Liver Metastases and Clinical Complete Response of Rectal Cancer in a Patient with Ataxia-Telangiectasia Mutated Gene Mutations After XELOXIRI Plus Bevacizumab: A Case Report

Abstract

Yu Cheng,1– 4 Gang Wu,5 Simeng Zhang,1– 4 Yunpeng Liu,1– 4 Jinglei Qu,1– 4 Xiujuan Qu1– 4 1Department of Medical Oncology, The First Hospital of China Medical University, Shenyang, People’s Republic of China; 2Key Laboratory of Anticancer Drugs and Biotherapy of Liaoning Province, The First Hospital of China Medical University, Shenyang, People’s Republic of China; 3Liaoning Province Clinical Research Center for Cancer, Shenyang, People’s Republic of China; 4Key Laboratory of Precision Diagnosis and Treatment of Gastrointestinal Tumors, Ministry of Education, The First Hospital of China Medical University, Shenyang, People’s Republic of China; 5Department of Hepatobiliary Surgery, The First Hospital of China Medical University, Shenyang, People’s Republic of ChinaCorrespondence: Xiujuan Qu; Jinglei Qu People’s Republic of ChinaTel [phone]Fax [phone]Email [email protected]; [email protected]: Doublet or triplet chemotherapy plus or minus targeted drugs can achieve a high objective response rate (ORR) and are currently considered to be the backbone of conventional therapy for liver metastatic colorectal cancer (mCRC). However, current biomarkers (such as UGT1A1 and DPYD) are limited to the prediction of toxicity and there are no effective biomarkers to predict chemotherapy response. Therefore, personalized cancer chemotherapy underpinned by genomic alterations in mCRC has received increasing attention.Case Presentation: We present a case of a 28-year-old female rectal cancer patient with multiple liver metastases (clinical risk score, CRS = 5 points). The patient underwent XELOXIRI plus bevacizumab regimen that consisted of irinotecan (150 mg/m2), oxaliplatin (100 mg/m2) on day 1, capecitabine (1700 mg/m2 per day from day 2 to 15), bevacizumab (7.5 mg/kg) on day 1 (on the second cycle), given every three weeks for eight cycles. After multi-disciplinary team (MDT) discussion, the patient underwent right hemihepatectomy, partial liver resection of segment IV and cholecystectomy. Surprisingly, the patient achieved a complete pathologic response (pCR) of the hepatic metastasis and clinical complete response (cCR) of the primary rectal lesion. A paired tumor molecular profile revealed somatic mutations in ataxia-telangiectasia mutated (ATM) genes that may explain why the patient achieved such a dramatic tumor response. Treatment was discontinued after eight cycles of a single oral dose of capecitabine and the patient started a follow-up program of physical and radiological examinations. To monitor the signs of recurrence, we also obtained blood samples to analyze circulating tumor DNA (ctDNA). To date, the patient has remained disease-free.Conclusion: The XELOXIRI-bevacizumab regimen is a feasible and effective regimen for patients with mCRC. Mutations in the ATM genes may characterize a subset of patients with a better prognosis who are more sensitive to chemotherapy plus biological agents.Keywords: XELOXIRI, bevacizumab, ATM, case report, rectal cancer

Keywords

• xeloxiri
• bevacizumab
• atm
• case report
• rectal cancer