Efficacy and side effects of modern radiotherapy in prophylactic extended field irradiation for locally advanced cervical cancer: A systematic review and meta-analysis (307)

Abstract

Objectives: For locally advanced cervical cancer (LACC) patients without para-aortic lymph node metastasis, the standard treatment is pelvic radiotherapy plus concurrent chemotherapy. After standard treatment, 7-15% of patients had a recurrence in para-aortic lymph nodes. The present study aimed to evaluate the efficacy and side effects of modern radiotherapy in prophylactic extended field irradiation (EFI) for locally advanced cervical cancer (LACC). The present meta-analysis has been registered in PROSPERO (no. CRD42020167302). Methods: A systemic review and meta-analysis of recent studies retrieved from PubMed, EMBASE, and Cochrane databases from the establishment of the database to March 2021 was performed. All LACC patients with negative para-aortic lymph nodes received concurrent chemoradiotherapy. The experimental group consisted of patients undergoing pelvic irradiation plus prophylactic EFI, but the control group was undergoing pelvic irradiation. The primary outcomes were overall survival (OS) and para-aortic control. The secondary outcomes were: disease-free survival (DFS)/progression-free survival (PFS), distant metastasis, pelvic control, and toxicities. The quality of RCT was evaluated by the Cochrane bias risk tool. The quality of the retrospective study was evaluated by the Newcastle Ottawa scale (NOS). Revman5.3 software was used for statistical analysis. Results: A total of 180 studies were evaluated and six literatures met the inclusion criteria. Prophylactic EFI significantly improved 5-year OS (HR: 0.36 [0.22-0.59], p <0.0001) and DFS (3-year: HR: 0.53 [0.32-0.87], p=0.01; 5-year: HR: 0.45 [0.27-0.77], p=0.004). Prophylactic EFI reduced the rate of para-aortic failure (3-year: OR: 0.09 [0.01-0.70], p=0.02; 5-year: OR: 0.09 [0.03-0.30], p<0.0001) and distant metastasis (3-year: OR: 0.22 [0.11-0.45], p <0.0001; 5-year: OR: 0.53 [0.33-0.87], p=0.01). EFI did not increase the gastrointestinal toxicities (acute: OR: 1.94 [0.59-6.35], p=0.27; chronic: OR: 1.24 [0.65-2.40], p=0.51) and acute hematotoxicities (leukopenia: OR: 1.59 [0.98-2.59], p=0.06; thrombocytopenia: OR: 2.81 [0.87-9.03], p=0.08). Conclusions: The results of the present study suggested that prophylactic EFI using modern radiation techniques is beneficial for patients with LACC. Because five out of six pieces of literature included in our study are retrospective studies, prospective, large sample, and multicenter clinical trials are needed to further verify the impact of prophylactic EFI. Objectives: For locally advanced cervical cancer (LACC) patients without para-aortic lymph node metastasis, the standard treatment is pelvic radiotherapy plus concurrent chemotherapy. After standard treatment, 7-15% of patients had a recurrence in para-aortic lymph nodes. The present study aimed to evaluate the efficacy and side effects of modern radiotherapy in prophylactic extended field irradiation (EFI) for locally advanced cervical cancer (LACC). The present meta-analysis has been registered in PROSPERO (no. CRD42020167302). Methods: A systemic review and meta-analysis of recent studies retrieved from PubMed, EMBASE, and Cochrane databases from the establishment of the database to March 2021 was performed. All LACC patients with negative para-aortic lymph nodes received concurrent chemoradiotherapy. The experimental group consisted of patients undergoing pelvic irradiation plus prophylactic EFI, but the control group was undergoing pelvic irradiation. The primary outcomes were overall survival (OS) and para-aortic control. The secondary outcomes were: disease-free survival (DFS)/progression-free survival (PFS), distant metastasis, pelvic control, and toxicities. The quality of RCT was evaluated by the Cochrane bias risk tool. The quality of the retrospective study was evaluated by the Newcastle Ottawa scale (NOS). Revman5.3 software was used for statistical analysis. Results: A total of 180 studies were evaluated and six literatures met the inclusion criteria. Prophylactic EFI significantly improved 5-year OS (HR: 0.36 [0.22-0.59], p <0.0001) and DFS (3-year: HR: 0.53 [0.32-0.87], p=0.01; 5-year: HR: 0.45 [0.27-0.77], p=0.004). Prophylactic EFI reduced the rate of para-aortic failure (3-year: OR: 0.09 [0.01-0.70], p=0.02; 5-year: OR: 0.09 [0.03-0.30], p<0.0001) and distant metastasis (3-year: OR: 0.22 [0.11-0.45], p <0.0001; 5-year: OR: 0.53 [0.33-0.87], p=0.01). EFI did not increase the gastrointestinal toxicities (acute: OR: 1.94 [0.59-6.35], p=0.27; chronic: OR: 1.24 [0.65-2.40], p=0.51) and acute hematotoxicities (leukopenia: OR: 1.59 [0.98-2.59], p=0.06; thrombocytopenia: OR: 2.81 [0.87-9.03], p=0.08). Conclusions: The results of the present study suggested that prophylactic EFI using modern radiation techniques is beneficial for patients with LACC. Because five out of six pieces of literature included in our study are retrospective studies, prospective, large sample, and multicenter clinical trials are needed to further verify the impact of prophylactic EFI.