title: Time to Progression of Pancreatic Cancer: Evaluation with Multi-Detector Computed Tomography.
abstract: OBJECTIVE
  The aim of this study is to evaluate the natural history of untreated pancreatic cancer, with a particular emphasis on the growth rate of primary tumor and development of metastatic disease.
  
  
  METHODS
  One hundred patients with histologically proven pancreatic ductal adenocarcinoma examined with at least two CT scans with no intervening treatment were included. Tumor diameters and volumes were measured in CT scans and tumor growth rates and volume doubling times (VDTs) were calculated. The relationship between initial tumor size, growth rate, and distant metastasis development were investigated.
  
  
  RESULTS
  Included tumors were 1.0-6.2 cm (mean, 2.9 ± 1.3 cm) in diameter and 5.5-1225.9 cm3(mean, 120.6 ± 158.9 cm3) in volume at the initial CT. Tumor growth rates were -0.4 to 19.9 cm/year (mean, 4.2 ± 3.8 cm/year) in diameter, and 11.1-13,321.5 cm3/year (mean, 727.8 ± 1609.5 cm3/year) in volume corresponding to VDT of 20.0-976.8 days (mean, 132.3 ± 132.1 days). The growth rate was significantly associated with the initial diameter and volume (p < 0.001). The development of distant metastasis was significantly associated with initial diameter (p < 0.05), volume (p = 0.015), and volume growth rate (p = 0.002).
  
  
  CONCLUSIONS
  The growth rate and VDTs of untreated pancreatic cancers varied widely, from less than a month to more than 4 years, positively associated with tumor size. The small tumors tend to grow slowly and have low risk for developing metastasis.
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul, South Korea.
authors.forename: Su Joa
authors.initials: SJ
authors.lastname: Ahn
authors.affiliation: Department of Radiology, Gachon University Gil Medical Center, 1198, Guwol-dong, Namdong-Gu, Incheon, 405-760, Republic of Korea. sjchoi1118@gmail.com.
authors.forename: Seung Joon
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Department of Radiology, Gachon University Gil Medical Center, 1198, Guwol-dong, Namdong-Gu, Incheon, 405-760, Republic of Korea.
authors.forename: Hyung Sik
authors.initials: HS
authors.lastname: Kim
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary; D018450:Disease Progression; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D010534:Peritoneal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary; D012189:Retrospective Studies; D013997:Time Factors; D047368:Tumor Burden
keywords: Computed tomography; Growth rate; Pancreatic ductal adenocarcinoma