Download Metaplastic and Medullary Mammary Carcinomas Do Not Express

Anatomic Pathology / Metaplastic and Medullary Mammary Carcinoma
Metaplastic and Medullary Mammary Carcinomas Do Not
Express Mammaglobin
Carolina Reyes, MD, Carmen Gomez-Fernández, MD, and Mehrdad Nadji, MD
Key Words: Mammaglobin; Metaplastic mammary carcinoma; Medullary mammary carcinoma; Neoplasm metastasis; Micrometastasis;
Minimal residual disease detection
DOI: 10.1309/AJCP5W5SEZSEHUHE
Abstract
Mammaglobin A (MG-A) is purportedly useful
for detecting metastatic carcinomas suspected to be
of breast origin and has been advocated as a useful
marker of micrometastasis in sentinel lymph nodes and
minimal residual tumor in bone marrow. Little is known
about its expression frequency in histologic subtypes of
breast cancer.
Excisional biopsy specimens from 1,079 untreated
invasive mammary carcinomas were evaluated for
immunohistochemical expression of MG-A. In addition
to estrogen (ER) and progesterone receptors (PR)
and HER2, staining for p63 and HLA-DR was used to
further characterize histologic subtypes.
Of the carcinomas, 36 were classified as
metaplastic (based on morphologic features, ER–/PR–/
HER2–, p63+), 38 as medullary (ER–/PR–/HER2–,
HLA-DR+), and 1,005 as ductal, no special type
(NST). All metaplastic and medullary carcinomas were
negative for MG-A. Of 1,005 ductal carcinomas, NST,
492 (49.0%) were MG-A+, 62.0% with a reaction in
fewer than 25% of the cells.
MG-A immunohistochemical studies failed to
detect all medullary and metaplastic cancers and more
than 50% of ductal carcinomas, NST. In two thirds
of MG-A+ ductal carcinomas, the reaction was only
focal and usually in a minority of cells. These findings
suggest that MG-A has limited value in identifying the
mammary origin of carcinomas, particularly in small
biopsy specimens used to detect metastasis or minimal
residual disease.
Detection of breast cancer in metastatic sites, including
micrometastases in lymph nodes or minimal residual tumor in
bone marrow, has gained major importance as a guide to early
therapeutic intervention. Various biomolecular markers have
been proposed for the detection of breast cancer cells in metastatic sites and in peripheral blood.1 However, the expression
of most of these markers is not limited to breast tissue,2 and,
thus, the search for truly specific mammary epithelial cell
markers has been ongoing. Recent findings point to a number
of genes that are preferentially expressed in breast tissue.
These include mammaglobin A (MG-A), mammaglobin B
(MG-B), and lipophilin B.3-6 Of these potential mammary cell
markers, MG-A has been the most extensively studied.
In 1996, Watson and Fleming3 used reverse transcription–polymerase chain reaction and Northern blot analysis to
identify a gene that seemed to be expressed only in breast epithelial cells and overexpressed in breast cancer. This gene was
named mammaglobin. Subsequently, Becker et al4 identified a
gene highly homologous to mammaglobin and named it mammaglobin B; the original mammaglobin was named mammaglobin A. MG-A and MG-B are members of the secretoglobin
superfamily, a group of small secretory dimeric proteins that
are mainly expressed in mucosal tissues.7 Although MG-B
was similarly proposed to be a marker for detection of breast
cancer micrometastases, it was later shown to be expressed by
a number of other cancers and, hence, lacked specificity for
mammary tumors.8,9
The MG-A gene encodes a 93-amino acid protein with
a molecular mass of 10.5 kDa.3 In breast tissue, it exists in 2
forms with molecular masses of 18 and 25 kDa.7 Although
MG-A was originally thought to be confined to normal and
neoplastic mammary epithelium, it was later shown that it
© American Society for Clinical Pathology
Am J Clin Pathol 2012;137:747-752
747
DOI: 10.1309/AJCP5W5SEZSEHUHE
747
747
Reyes et al / Metaplastic and Medullary Mammary Carcinoma
is also expressed by a number of cells and tissues other than
breast.3,10-13
Expression of MG-A at the RNA and protein levels has
been reported in 70% to 80% of primary and metastatic breast
cancers.14-16 These studies, however, have assessed MG-A
expression mainly in ductal and lobular subtypes of breast
carcinomas. To our knowledge, there are no studies that have
analyzed the immunohistochemical expression of MG-A in
histologic subtypes of mammary carcinomas, including metaplastic and medullary types. The purpose of this study was to
investigate the immunohistochemical expression of MG-A in
ductal and in immunophenotypically proven medullary and
metaplastic mammary carcinomas.
Materials and Methods
Excisional biopsy specimens from 1,079 consecutive
cases of untreated invasive breast carcinomas from the files
of the Department of Pathology, University of Miami/Jackson
Memorial Medical Center and University of Miami/Sylvester
Cancer Center, Miami, FL, were evaluated for the immunohistochemical expression of MG-A. All specimens were
previously analyzed for estrogen receptor (ER), progesterone
receptor (PR), and HER2. We specifically enriched the cohort
with mammary carcinomas that, based on morphologic assessment and/or immunohistochemical studies, were suspected or
proven to be of metaplastic and medullary phenotypes.
The diagnosis of invasive mammary carcinoma was
confirmed in all cases. In the cases in which a metaplastic
or medullary phenotype was morphologically suspected, the
following immunohistochemical markers were used for confirmation: p63 for metaplastic carcinoma and HLA-DR for
medullary carcinoma.
We used 4-μm-thick, formalin-fixed, paraffin-embedded
sections for MG-A, p63, and HLA-DR immunohistochemical studies following heat-induced antigen retrieval. ❚Table 1❚
shows the clones and sources of reagents. Normal breast tissue
was used as a positive control sample for MG-A and p63. Normal tonsil served as the positive control sample for HLA-DR.
Three pathologists (C.R., C.G.F., and M.N.) independently evaluated the staining results for MG-A and semiquantitatively scored them in the following manner: 1+, 1% to 10%
of positive cells; 2+, 11% to 25% of positive cells; and 3+,
more than 25% of positive cells.
For metaplastic carcinomas, p63 immunoreaction was
seen as dense nuclear staining. In medullary carcinomas,
HLA-DR positivity was observed as a cytoplasmic membrane
reaction.
Results
Based on histomorphologic features and immunophenotype, 1,005 tumors were classified as invasive ductal carcinoma, no special type (NST). Of the cases, 36 were classified
as metaplastic carcinomas and 38 were true medullary carcinomas with pushing borders. All metaplastic and medullary
carcinomas were triple-negative for ER, PR, and HER2.
❚Table 2❚ summarizes the results of MG-A staining in the
histologic types of breast cancer. Briefly, of the 1,005 invasive ductal carcinomas, NST, 492 (49.0%) were positive for
MG-A. Among the 492 MG-A+ ductal carcinomas, staining
was 3+ in 187 (38.0%) and 2+ in 103 (20.9%) of the cases
❚Image 1❚. The remaining 202 cases (41.1%) exhibited only a
scattered 1+ reaction in a few cells ❚Image 2❚. Most of the ductal carcinomas that showed a positive reaction for MG-A (425
[86.4%]) were grade 1 and 2 ❚Table 3❚. The remaining tumors
were grade 3 (67 [13.6%]). All metaplastic and medullary
carcinomas were negative for MG-A ❚Image 3❚ and ❚Image 4❚.
❚Table 1❚
Commercial Sources, Clones, and Working Dilutions of
Antibodies Used in the Study
Antibody
Dilution Clone
HLA-DR
1:400
p63
1:50
Mammaglobin A 1:50
LN3
BC4A4
304-1A5
Discussion
Vendor
Biogenex, San Ramon, CA
Biocare Medical, Concord, CA
DAKO, Carpinteria, CA
❚Table 2❚
Frequency of Mammaglobin Expression in Histologic
Subtypes of Breast Cancer
Histologic Type
No. of
Cases
No. (%) Positive for
Mammaglobin A
Ductal, no special type
Metaplastic
Medullary
1,005
36
38
492 (49.0)
0 (0)
0 (0)
748
748
Am J Clin Pathol 2012;137:747-752
DOI: 10.1309/AJCP5W5SEZSEHUHE
Although MG-A was originally considered a specific
marker for benign and malignant breast epithelial cells,17
subsequent studies showed its expression in various nonmammary tissues, including normal cervix, ovary, uterus, skin,
sweat glands, kidney, testis, and salivary glands, as well as in
tumors of lung, ovaries, and sweat glands.13,14,18 In addition to
its lack of specificity, the sensitivity of detection of MG-A in
mammary carcinomas was also reported from less than 50%
up to 84%. The overall rate of expression of MG-A in our
study was 45.6% (492/1,079). Specifically, in ductal carcinomas, NST, the rate was 49.0% (492/1,005). This is lower than
the 82% rate reported by Watson et al12 and 84% by Han et
al.17 Our results however, agree with the findings of a study
© American Society for Clinical Pathology
Anatomic Pathology / Original Article
A
B
❚Image 1❚ Infiltrating ductal carcinoma of no special type (A, H&E, ×50). Positive immunohistochemical reaction for
mammaglobin is seen in about 25% of tumor cells (B, ×50).
A
B
❚Image 2❚ Infiltrating ductal carcinoma of no special type (A, H&E, ×50). Positive immunohistochemical reaction for
mammaglobin is seen in fewer than 5% of tumor cells (B, ×50).
by Eiichi et al,19 who found positive MG-A in 49% of 214
ductal carcinomas.
There has been no previous study that specifically focused
on the immunohistochemical reaction of MG-A in subtypes of
mammary carcinoma. Eiichi et al19 reviewed metastatic mammary carcinomas to the brain for the presence of MG-A. Their
cohort included 1 case of medullary and 2 cases of metaplastic
mammary carcinomas; all 3 were negative for MG-A. One
case of metaplastic carcinoma in the series reported by Bhargava et al20 also did not stain for MG-A.
Metaplastic and medullary types of breast cancer are
typically negative for ER, PR, and HER2 and, hence, fall into
the category of triple-negative mammary carcinomas. As a
❚Table 3❚
Frequency of Mammaglobin Expression in Ductal
Carcinomas* in Relation to Tumor Grade
Tumor Grade
No. (%) Positive for Mammaglobin A
1 and 2
3
425 (86.4)
67 (13.6)
*
There were 492 positive cases, designated no special type.
group, the triple-negative cancers have a poor prognosis but
comprise a heterogeneous histomorphologic spectrum. On the
basis of gene expression profiles, the majority of triple-negative breast cancers show a basal-like genotype.21,22 Traditionally, basal/myoepithelial cytokeratins have been advocated
© American Society for Clinical Pathology
Am J Clin Pathol 2012;137:747-752
749
DOI: 10.1309/AJCP5W5SEZSEHUHE
749
749
Reyes et al / Metaplastic and Medullary Mammary Carcinoma
B
A
❚Image 3❚ Infiltrating mammary carcinoma with a metaplastic
(squamous) phenotype (A, H&E, ×50). Tumor cells show
positive nuclear staining for p63 (B, ×50). There is no reaction
for mammaglobin (C, ×50).
C
as surrogate immunohistochemical markers for the basal-like
phenotypes.23-25 Other studies, however, have questioned the
use of molecular profiling as a “gold standard” in general
(reviewed by Gusterson26) and the use of basal cytokeratin
immunohistochemical studies for identification of basal-like
phenotypes in particular.27,28 In this study, we therefore chose
not to use the controversial term “basal-like” and instead
concentrated on the 2 morphologically distinct types of triplenegative breast cancers, metaplastic and medullary, as they
could to some extent, be objectively characterized by histologic and immunohistochemical studies.
Metaplastic mammary carcinomas are a morphologically
heterogeneous group of breast cancers characterized by lack of
expression of ER, PR, and HER2 and expression of purported
basal/myoepithelial markers. They show a wide spectrum of
histomorphologic types, from the classic squamous cell carcinomas to matrix-forming carcinomas, spindle cell carcinomas,
750
750
Am J Clin Pathol 2012;137:747-752
DOI: 10.1309/AJCP5W5SEZSEHUHE
and carcinosarcomas.29-31 Most, particularly the squamous and
spindle cell types, express p63.32,33 None of the p63+ metaplastic carcinomas in our study expressed MG-A. Conversely, none
of the ductal carcinomas were positive for p63.
True medullary carcinomas are characterized by syncytial growth patterns composed of large cells with pleomorphic
nuclei and large nucleoli. These tumors are, by definition,
fairly well circumscribed with a prominent lymphocytic infiltrate.34 Nevertheless, because objective histologic distinction
between true medullary and atypical medullary carcinomas
of the breast are not universally agreed on, we chose only
the tumors that had pushing borders and HLA-DR positivity.
It has been shown that most classic medullary carcinomas
express HLA-DR, a component of the MHC class II antigenic
system.34-36 The expression of this marker has also been demonstrated in undifferentiated nasopharyngeal carcinomas and
in lymphoepithelioma-like carcinomas of other organs such
© American Society for Clinical Pathology
Anatomic Pathology / Original Article
A
C
as skin, gastrointestinal tract, and urinary bladder. Parenthetically, it is not unreasonable, therefore, to consider true medullary carcinomas as lymphoepithelioma-like carcinomas of
the breast. None of the 38 true medullary carcinomas showed
reactivity for MG-A by immunohistochemical analysis.
Our study also shows that the expression of MG-A in the
group of ductal carcinomas, NST, is focal and only present in
fewer than 25% of the cells in approximately two thirds of the
cases. This will limit the use of MG-A for detecting the breast
origin of metastatic tumors in small biopsy specimens.
The correlation of MG-A positivity with a lower histologic grade of breast cancer has been reported before. Span
et al37 demonstrated that MG-A expression is associated with
low grade and steroid receptor–positive breast tumors. Our
study supports that finding. Of the 49.0% ductal carcinomas
that showed a positive reaction for mammaglobin, 86.4%
were grades 1 and 2.
B
❚Image 4❚ Infiltrating mammary carcinoma with a medullary
phenotype (A, H&E, ×50). Tumor cells are positive for HLA-DR,
as are the host lymphocytes (B, ×50). There is no reaction for
mammaglobin (C, ×50).
We conclude that MG-A is not expressed by metaplastic
and medullary cancers of the breast. Furthermore, because this
marker is neither completely specific nor sensitive for ductal
carcinomas and, when present, is expressed only focally, it
should be used only in conjunction with other putative breast
markers for the determination of breast origin of metastatic
carcinomas. This is especially important when detection of
micrometastasis or minimal residual disease in patients with
history of mammary cancer is intended.
From the Department of Pathology, University of Miami Miller
School of Medicine, Jackson Memorial Hospital, and Sylvester
Cancer Center, Miami, FL.
Address reprint requests to Dr Nadji: Dept of Pathology,
University of Miami Miller School of Medicine and Jackson
Health System, 1611 NW 12th Ave, Holtz-2147, Miami, FL 33136;
[email protected].
© American Society for Clinical Pathology
Am J Clin Pathol 2012;137:747-752
751
DOI: 10.1309/AJCP5W5SEZSEHUHE
751
751
Reyes et al / Metaplastic and Medullary Mammary Carcinoma
References
1. Noguchi S, Aihara T, Motomura K, et al. Detection of breast
cancer micrometastases in axillary lymph nodes by means of
reverse transcription–polymerase chain reaction: comparison
between Muc-1 mRNA and keratin-19 mRNA amplification.
Am J Pathol. 1996;148:649-656.
2. Dingemans AM, Brakenhoff RH, Postmus PE, et al.
Detection of cytokeratin-19 transcripts by reverse
transcription–polymerase chain reaction in lung cancer
cell lines and blood lung cancer patients. Lab Invest.
1997;77:213-220.
3. Watson MA, Fleming TP. Mammaglobin, a mammaryspecific member of the uteroglobin gene family, is
overexpressed in human breast cancer. Cancer Res.
1996;56:860-865.
4. Becker RM, Darrow C, Zimonjic DB, et al. Identification of
mammaglobin B, a novel member of the uteroglobin gene
family. Genomics. 1998;54:70-78.
5. Colpitts TL, Billing-Medel P, Friedman P, et al.
Mammaglobin is found in breast tissue as a complex with
BU101. Biochemistry. 2001;40:11048-11059.
6. Ni J, Kalff-Suske M, Gentz R, et al. All human genes of the
uteroglobin family are localized on chromosome 11q12.2 and
form a dense cluster. Ann N Y Acad Sci. 2000;923:25-42.
7. Watson MA, Darrow C, Zimonjic DB, et al. Structure and
transcriptional regulation of the human mammaglobin
gene, a breast cancer associated member of the uteroglobin
gene family localized to chromosome 11q13. Oncogene.
1998;16:817-824.
8. Aihara T, Fijiwara Y, Miyake Y, et al. Mammaglobin B gene
as a novel marker for lymph node micrometastasis in patients
with abdominal cancers. Cancer Lett. 2000;150:79-84.
9. Aihara T, Fijiwara Y, Ooka M, et al. Mammaglobin B as a
novel marker for detection of breast cancer micrometastases
in axillary lymph nodes by reverse transcription–polymerase
chain reaction. Breast Cancer Res Treat. 1999;58:137-140.
10. Leygue E, Snell L, Dotzlaw H, et al. Mammaglobin, a
potential marker of breast cancer nodal metastasis. J Pathol.
1999;189:28-33.
11. Min CJ, Tafra L, Verbanac KM. Identification of superior
markers for polymerase chain reaction detection of breast
cancer metastasis in sentinel lymph nodes. Cancer Res.
1998;58:4581-4584.
12. Watson MA, Dintzis S, Darrow CM, et al. Mammaglobin
expression in primary, metastatic, and occult breast cancer.
Cancer Res. 1999;59:3028-3031.
13. Sjodin A, Guo D, Hofer PA, et al. Mammaglobin in normal
human sweat glands and human sweat gland tumors. J Invest
Dermatol. 2003;121:428-429.
14. Grunewald K, Haun M, Fiegl M, et al. Mammaglobin
expression in gynecologic malignancies and malignant
effusions detected by nested reverse transcriptase–polymerase
chain reaction. Lab Invest. 2002;82:1147-1153.
15. Sjodin A, Guo D, Sorhaug S, et al. Dysregulated
secretoglobin expression in human lung cancers. Lung
Cancer. 2003;41:49-56.
16. Zehentner BK, Carter D. Mammaglobin: a candidate
diagnostic marker for breast cancer. Clin Biochem.
2004;37:249-257.
17. Han JH, Kang Y, Shin HC, et al. Mammaglobin expression
in lymph nodes is an important marker of metastatic breast
carcinoma. Arch Pathol Lab Med. 2003;127:1330-1334.
18. Lehrer RI, Nguyen T, Zhao C, et al. Secretory lipophilins:
a tale of two species. Ann N Y Acad Sci. 2000;923:59-67.
752
752
Am J Clin Pathol 2012;137:747-752
DOI: 10.1309/AJCP5W5SEZSEHUHE
19. Eiichi S, Noboyuki T, Yukata H, et al. Breast-specific expression
of MGB1/mammaglobin: an examination of 480 tumors from
various organs and clinicopathological analysis of MGB1positive breast cancers. Mod Pathol. 2007;20:208-214.
20. Bhargava R, Beriwal S, Dabbs DJ. Mammaglobin vs GCDFP15: an immunohistologic validation survey for sensitivity and
specificity. Am J Clin Pathol. 2007;127:103-113.
21. Perou CM, Sorlie T, Eisen MD, et al. Molecular portraits of
human breast tumors. Nature. 2000;406:747-752.
22. Sotirin C, Neo SY, McShane LM, et al. Breast cancer
classification and prognosis based on gene expression profiles
from a population based study. Proc Natl Acad Sci U S A.
2003;100:10393-10398.
23. Nielsen TO, Hsu FD, Jensen K, et al. Immunohistochemical
and clinical characterization of the basal-like subtype of
invasive breast carcinoma. Clin. Cancer Res. 2004;10:53675374.
24. Rakha EA, Putti TC, Abd El-Rehim DM, et al.
Morphological and immunophenotypic analysis of breast
carcinomas with basal and myoepithelial differentiation.
J Pathol. 2006;208:495-506.
25. Badve S, Dabbs DJ, Schnitt SJ, et al. Basal-like and triplenegative breast cancers: a critical review with an emphasis on
the implications for pathologists and oncologists. Mod Pathol.
2011;24:157-167.
26. Gusterson B. Do “basal-like” breast cancers really exist? Nat
Rev Cancer. 2009;9:128-134.
27. Moinfar F. Is “basal-like” carcinoma of the breast a distinct
entity? a critical review with cautionary notes. Pathobiology.
2008;75:119-131.
28. Gusterson BA, Ross DT, Heath VJ, et al. Basal cytokeratins
and their relationship to the cellular origin and functional
classification of breast cancer. Breast Cancer Res. 2005;7:143148.
28. Wargotz ES, Norris HJ. Metaplastic carcinoma of the breast,
I: matrix-producing carcinoma. Hum Pathol. 1989;20:628635.
30. Wargotz ES, Deos PH, Norris HJ. Metaplastic carcinoma
of the breast; II: spindle cell carcinoma. Hum Pathol.
1989;20:732-740.
31. Brenner RJ, Turner RR, Schiller V, et al. Metaplastic
carcinoma of the breast: report of three cases. Cancer.
1998;82:1082-1087.
32. Tse GM, Tan PH, Chaiwun B, et al. p63 is useful in the
diagnosis of mammary metaplastic carcinomas. Pathology.
2006;38:16-20.
33. Koker MM, Kleer CG. p63 expression in breast cancer: a
highly sensitive and specific marker of metaplastic carcinoma.
Am J Surg Pathol. 2004;11:1506-1512.
34. Ridolfi RL, Rosen PP, Port A, et al. Medullary carcinoma of
the breast: a clinicopathologic study with 10 year follow-up.
Cancer. 1977;40:1365-1385.
35. Yazawa T, Kamma H, Ogata T. Frequent expression of
HLA-DR antigen in medullary carcinoma of the breast. Appl
Immunohistochem. 1993;1:289-296.
36. Lazzaro B, Anderson AE, Kajdacsy-Balla A, et al. Antigenic
characterization of medullary carcinoma of the breast:
HLA-DR expression in lymph node positive cases. App
Immunohistochem Mol Morphol. 2001;9:234-241.
37. Span PN, Waanders E, Manders P, et al. Mammaglobin is
associated with low-grade steroid receptor–positive breast
tumors from postmenopausal patients, and has independent
prognostic value for relapse-free survival time. J Clin Oncol.
2004;22:691-698.
© American Society for Clinical Pathology