Factors influencing the development of visceral metastasis of breast cancer: A retrospective multi-center study.
OBJECTIVE
Visceral metastasis of breast cancer (BC) is an alarming development and correlates with poor median overall survival. The purpose of this retrospective study is to examine the risk factors for developing visceral metastasis by considering tumor biology and patient characteristics.


METHODS
Using the BRENDA database, the risk factors such as histological and intrinsic subtypes of BC, age at primary diagnosis, grading, nodal status, tumor size and year of primary diagnosis were examined in univariate and multivariate analysis. Categorical variables were compared by using χ2 tests. Furthermore, multivariate Cox proportional hazards regression models, Kaplan-Meier product-limit method and log-rank test were applied. The results of two tree-building algorithms, "exhausted CHAID" (Chi-squared Automatic Interaction Detector) and CART (Classification and Regression Trees) were verified with further multivariate analysis, radial basis function networks (RBF-net), feedforward multilayer perceptron networks (MLP) and logistic regression.


RESULTS
In a patient collective of 886 metastasized patients, 56.9% had developed visceral metastases and 27.1% visceral-only metastases. The different histological and intrinsic subtypes of BC and the grading correlate significantly with the visceral-only metastasis behavior, whereas the age at primary diagnosis, the nodal status, the tumor size and the year of the primary diagnosis had no influence. Patients with ductal/other BC, LuminalB/HER2, TNBC, HER2 overexpressing subtype and grade 3 had an increased risk for the development of visceral-only metastasis.


CONCLUSIONS
Intrinsic and histological subtypes as well as the grading of BC affected significantly the visceral metastasis behavior.
Department for Obstetrics and Gynecology, University Hospital Würzburg, Josef-Schneider-Str. 4, D-97080 Würzburg, Germany. Electronic address: Bartmann_c@ukw.de.
Catharina
C
Bartmann
Department for Obstetrics and Gynecology, University Hospital Würzburg, Josef-Schneider-Str. 4, D-97080 Würzburg, Germany.
Joachim
J
Diessner
Institut für Medizinische Biometrie, Epidemiologie und Informatik (IMBEI), University of Mainz, Obere Zahlbacher Str. 69, 55131 Mainz, Germany.
Maria
M
Blettner
Department for Obstetrics and Gynecology, University Hospital Würzburg, Josef-Schneider-Str. 4, D-97080 Würzburg, Germany.
Sebastian
S
Häusler
Department for Obstetrics and Gynecology, University Hospital Ulm, Prittwitzstr. 43, 89075 Ulm, Germany.
Wolfgang
W
Janni
Department for Obstetrics and Gynecology, University Hospital Ulm, Prittwitzstr. 43, 89075 Ulm, Germany.
Rolf
R
Kreienberg
Department for Obstetrics and Gynecology, University Hospital Würzburg, Josef-Schneider-Str. 4, D-97080 Würzburg, Germany.
Mathias
M
Krockenberger
Department for Obstetrics and Gynecology, University Hospital Ulm, Prittwitzstr. 43, 89075 Ulm, Germany.
Lukas
L
Schwentner
Department for Obstetrics and Gynecology, University Hospital Würzburg, Josef-Schneider-Str. 4, D-97080 Würzburg, Germany.
Roland
R
Stein
Department for Obstetrics and Gynecology, University Hospital Würzburg, Josef-Schneider-Str. 4, D-97080 Würzburg, Germany.
Tanja
T
Stüber
Department for Obstetrics and Gynecology, University Hospital Würzburg, Josef-Schneider-Str. 4, D-97080 Würzburg, Germany.
Achim
A
Wöckel
Faculty of Mathematics and Computer Science, University of Bremen, Universitätsallee, GW1, 28359 Bremen, Germany.
Manfred
M
Wischnewsky
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000737:chemistry / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000556:secondary*; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000556:secondary*; D016015:Logistic Models; D008175:Lung Neoplasms / Q000556:secondary*; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
Breast cancer; Liver metastases; Lung metastases; Subtypes; Visceral metastasis; Visceral-only metastasis