In a cohort of breast cancer screened patients the proportion of HER2 positive cases is lower than that earlier reported and pathological characteristics differ between HER2 3+ and HER2 2+/Her2 amplified cases.
Human epithelial growth factor receptor 2 (HER2) overexpression and/or amplification is of predictive and prognostic value in infiltrating breast carcinoma (IBC). We evaluated the proportion of HER2-positive cases (score 3 overexpression/score 2 plus fluorescence in situ hybridization (FISH) amplification) in a consecutive series of 2163 patients. According to immunohistochemical analysis of HER2 expression, using Herceptest and FDA criteria, 839 cases had score 0, 476 score 1+, 699 score 2+, and 149 score 3+. Of the 699 scoring 2+ cases, 160 (22.88 %) showed Her2 gene amplification by FISH analysis, making a total of 309 (14.28 %) HER2-positive cases. Grade 1 ductal and special type IBC were never HER2 positive, while only three infiltrating lobular carcinomas but a relevant percentage of small IBC were HER2 positive. Of HER2-positive cases, 52.1 % was pT1 and of these, 38.5 % was pT1b or smaller. Logistic regression analysis revealed that estrogen receptor (ER), progesterone receptor (PgR), grade, and pT were significantly associated with HER2 positivity and that HER2 3+ cases were more frequently of higher grade and pT than HER2 2+/Her2 amplified cases. In addition, HER2 3+ cases were more frequently in ER and PgR negative than HER2 2+/Her2 amplified cases. We conclude that the proportion of HER2 positive cases is lower than that reported in older literature and that pathological characteristics differ between HER2 3+ and HER2 2+/Her2 amplified cases.
Unit of Surgical Pathology, Santa Chiara Hospital, Largo Medaglie Oro 9, 38122, Trento, Italy.
Silvia
S
Giuliani
Unit of Medical Statistics, Biometry and Bioinformatics, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
Chiara Maura
CM
Ciniselli
Unit of Surgical Pathology, Santa Chiara Hospital, Largo Medaglie Oro 9, 38122, Trento, Italy.
Elena
E
Leonardi
Unit of Surgical Pathology, Santa Chiara Hospital, Largo Medaglie Oro 9, 38122, Trento, Italy.
Enzo
E
Polla
Unit of Surgical Pathology, Santa Chiara Hospital, Largo Medaglie Oro 9, 38122, Trento, Italy.
Nicola
N
Decarli
Unit of Surgical Pathology, Santa Chiara Hospital, Largo Medaglie Oro 9, 38122, Trento, Italy.
Claudio
C
Luchini
Unit of Surgical Pathology, Santa Chiara Hospital, Largo Medaglie Oro 9, 38122, Trento, Italy.
Chiara
C
Cantaloni
1st Unit of Surgery, Santa Chiara Hospital, Trento, Italy.
Fabio
F
Gasperetti
1st Unit of Surgery, Santa Chiara Hospital, Trento, Italy.
Daniela
D
Cazzolli
2nd Unit of Surgery, Santa Chiara Hospital, Trento, Italy.
Gabriella
G
Berlanda
Unit of Senology, Azienda Provinciale Servizi Sanitari, Trento, Italy.
Daniela
D
Bernardi
Unit of Senology, Azienda Provinciale Servizi Sanitari, Trento, Italy.
Marco
M
Pellegrini
Unit of Medical Oncology, Santa Chiara Hospital, Trento, Italy.
Renza
R
Triolo
Unit of Medical Oncology, Santa Chiara Hospital, Trento, Italy.
Antonella
A
Ferro
Unit of Medical Statistics, Biometry and Bioinformatics, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
Paolo
P
Verderio
Unit of Surgical Pathology, Santa Chiara Hospital, Largo Medaglie Oro 9, 38122, Trento, Italy. mattia.barbareschi@apss.tn.it.|Trentino Biobank, Unit of Surgical Pathology, Santa Chiara Hospital, Trento, Italy. mattia.barbareschi@apss.tn.it.
Mattia
M
Barbareschi
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D018275:Carcinoma, Lobular / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D005784:Gene Amplification / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism
D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human
Breast carcinoma; FISH; HER2; Immunohistochemistry