Abstract
PurposeWe investigated potential factors, including clinicopathological features, treatment modalities, neutrophil-to-lymphocyte ratio (NLR), carbohydrate antigen (CA) 19-9 level, tumor responses correlating with overall survival (OS), local progression (LP), and distant metastases (DMs), in patients with locally advanced pancreatic cancer (LAPC) who received definitive radiotherapy (RT).MethodsWe retrospectively analyzed demographic characteristics; biologically effective doses (BED10, calculated with an α/β of 10) of RT; and clinical outcomes of 57 unresectable LAPC (all pancreatic adenocarcinoma) patients receiving definitive RT using modern techniques with and without systemic therapy between January 2009 and March 2019 at our institution. We used Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 to evaluate the radiographic tumor response after RT. The association between prognostic factors and OS was assessed using the Kaplan–Meier analysis and a Cox regression model, whereas baseline characteristics and treatment details were collected for competing-risk regression of the association with LP and DM using the Fine–Gray model.ResultsA median BED10 of 67.1 Gy resulted in a disease control rate of 87.7%, and the median OS was 11.8 months after a median follow-up of 32.1 months. The 1-year OS rate, cumulative incidences of LP, and DM were 49.2%, 38.5%, and 62.9%, respectively. Multivariate analyses showed that pre-RT NLR ≥3.5 (adjusted hazard ratio [HR] = 8.245, p < 0.001), CA19-9 reduction rate ≥50% (adjusted HR = 0.261, p = 0.005), RT without concurrent chemoradiotherapy (adjusted HR = 5.903, p = 0.004), and administration of chemotherapy after RT (adjusted HR = 0.207, p = 0.03) were independent prognostic factors for OS. Positive lymph nodal metastases (adjusted subdistribution HR [sHR] = 3.712, p = 0.003) and higher tumor reduction after RT (adjusted sHR = 0.922, p < 0.001) were significant prognostic factors for LP, whereas BED10 ≥ 67.1 Gy (adjusted sHR = 0.297, p = 0.002), CA19-9 reduction rate ≥50% (adjusted sHR = 0.334, p = 0.023), and RT alone (adjusted sHR = 2.633, p = 0.047) were significant prognostic factors for DM.ConclusionOur results indicate that pre-RT NLR and post-RT monitoring of CA19-9 and tumor size reduction can help identify whether patients belong to the good or poor prognostic group of LAPC. The incorporation of new systemic treatments during and after a higher BED10 RT dose for LAPC patients is warranted.
Highlights
Pancreatic cancer is one of the most devastating gastrointestinal malignancies in Taiwan and is the seventh leading cause of cancerrelated deaths in both men and women [1]
We demonstrated that RT with concurrent systemic therapy provided the optimal median overall survival (OS) of 14.0 months, which is in accordance with the median OS ranging from 8 to 16 months obtained from the concurrent chemoradiotherapy (CCRT) arm of randomized phase III trials for locally advanced pancreatic cancer (LAPC) patients [6, 7, 24]
We demonstrated that positive regional lymph node metastases and reduced tumor size reduction are two factors that significantly correlate with local progression (LP), and BED10 < 67.1 Gy, reduction of carbohydrate antigen 19-9 (CA19-9)
Summary
Pancreatic cancer is one of the most devastating gastrointestinal malignancies in Taiwan and is the seventh leading cause of cancerrelated deaths in both men and women [1]. According to Abbreviations: RT, radiotherapy; OS, overall survival; DMs, distant metastases; LAPC, locally advanced pancreas cancer; ECOG, Eastern Cooperative Oncology Group; CCRT, concurrent chemoradiotherapy; LP, local progression; PFS, progression-free survival; CA19-9, carbohydrate antigen 19-9; NLR, neutrophilto-lymphocyte ratio; PLR, platelet-to-lymphocyte ratio; NMR, neutrophil-tomonocyte ratio; BED, biologically effective doses; PTV, planning target volume; IMRT, intensity-modulated radiation therapy; VMAT, volumetric modulated arc therapy; KPS, Karnofsky Performance Status; GTV, gross target volume; CTV, clinical target volume; 5-FU, fluorouracil; RECIST, Response Evaluation Criteria in Solid Tumors; CR, complete remission; PR, partial remission; HR, hazard ratio; sHR, subdistribution hazard ratio; SBRT, stereotactic body radiation therapy; SD, stable disease; DCR, disease control rate; RTOG, Radiation Therapy Oncology Group; WBCs, white blood cells
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
