Is computed tomography a necessary part of a metastatic evaluation for castration-resistant prostate cancer? Results from the Shared Equal Access Regional Cancer Hospital Database.
BACKGROUND
Metastatic lesions in prostate cancer beyond the bone have prognostic importance and affect clinical therapeutic decisions. Few data exist regarding the prevalence of soft-tissue metastases at the initial diagnosis of metastatic castration-resistant prostate cancer (mCRPC).


METHODS
This study analyzed 232 men with nonmetastatic (M0) castration-resistant prostate cancer (CRPC) who developed metastases detected by a bone scan or computed tomography (CT). All bone scans and CT scans within the 30 days before or after the mCRPC diagnosis were reviewed. The rate of soft-tissue metastases among those undergoing CT was determined. Then, predictors of soft-tissue metastases and visceral and lymph node metastases were identified.


RESULTS
Compared with men undergoing CT (n = 118), men undergoing only bone scans (n = 114) were more likely to have received primary treatment (P = .048), were older (P = .013), and less recently developed metastases (P = .018). Among those undergoing CT, 52 (44%) had soft-tissue metastases, including 20 visceral metastases (17%) and 41 lymph node metastases (35%), whereas 30% had no bone involvement. In a univariable analysis, only prostate-specific antigen (PSA) predicted soft-tissue metastases (odds ratio [OR], 1.27; P = .047), and no statistically significant predictors of visceral metastases were found. A higher PSA level was associated with an increased risk of lymph node metastases (OR, 1.38; P = .014), whereas receiving primary treatment was associated with decreased risk (OR, 0.36; P = .015).


CONCLUSIONS
The data suggest that there is a relatively high rate of soft-tissue metastasis (44%) among CRPC patients undergoing CT at the initial diagnosis of metastases, including some men with no bone involvement. Therefore, forgoing CT during a metastatic evaluation may lead to an underdiagnosis of soft-tissue metastases and an underdiagnosis of metastases in general. Cancer 2015. © 2015 American Cancer Society. Cancer 2016;122:222-229. © 2015 American Cancer Society.
Urology Section, Veterans Affairs Medical Center, Durham, North Carolina.
Brian T
BT
Hanyok
Urology Section, Veterans Affairs Medical Center, Durham, North Carolina.|Department of Biostatistics and Bioinformatics, Duke University School of Medicine, Durham, North Carolina.
Lauren E
LE
Howard
Division of Urology, Department of Surgery, Oregon Health and Science University, Portland, Oregon.
Christopher L
CL
Amling
Urology Section, Department of Surgery, Veterans Affairs Medical Center of Greater Los Angeles, Los Angeles, California.|Department of Urology, University of California Los Angeles Medical Center, Los Angeles, California.
William J
WJ
Aronson
Division of Urology, Department of Surgery, University of California San Francisco Medical Center, San Francisco, California.
Matthew R
MR
Cooperberg
Division of Urology, Department of Surgery, University of California San Diego Medical Center, San Diego, California.
Christopher J
CJ
Kane
Urology Section, Division of Surgery, Veterans Affairs Medical Center, Augusta, Georgia.|Division of Urologic Surgery, Department of Surgery, Medical College of Georgia, Augusta, Georgia.
Martha K
MK
Terris
Division of Hematology/Oncology, Cedars-Sinai Medical Center, Los Angeles, California.
Edwin M
EM
Posadas
Urology Section, Veterans Affairs Medical Center, Durham, North Carolina.|Division of Urology, Department of Surgery, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, California.|Center for Integrated Research in Cancer and Lifestyle, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, California.
Stephen J
SJ
Freedland
D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D016208:Databases, Factual; D018572:Disease-Free Survival; D006801:Humans; D016015:Logistic Models; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood*; D064129:Prostatic Neoplasms, Castration-Resistant / Q000097:blood / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology; D012189:Retrospective Studies; D018570:Risk Assessment; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000556:secondary*; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed / Q000379:methods
D017430:Prostate-Specific Antigen
castration-resistant prostatic neoplasms; computed X-ray tomography metastasis; logistic models; prevalence; prostate-specific antigen; soft-tissue neoplasms