Multicentric/multifocal breast cancer with a single histotype: is the biological characterization of all individual foci justified?
BACKGROUND
Invasive multiple breast cancers with a single histological feature (MBCSH) are routinely assessed for biological parameters to indicate adjuvant treatments only in the largest invasive carcinomas. However, the heterogeneity of individual foci in multiple carcinomas has not been widely studied. We analyzed whether such biological features are differently expressed in different MBCSH foci.


METHODS
One hundred and thirteen invasive MBCSH were tested over a 5-year period. The expression of estrogen (ER) and progesterone (PgR) receptors, Ki-67 proliferative index, expression of HER2 and tumor grading were prospectively determined in each tumor focus, and mismatches among foci were recorded.


RESULTS
Mismatches in ER status were present in 5 (4.4%) cases and PgR in 18 (15.9%) cases. Mismatches in tumor grading were present in 21 cases (18.6%), proliferative index (Ki-67) in 17 (15%) cases and HER2 status in 11 (9.7%) cases.


CONCLUSIONS
In our experience, invasive MBCSH showed heterogeneity among foci. In our clinical practice, such assessment led to 14 (12.4%) patients receiving different adjuvant treatments compared with what would have been indicated if we had only taken into account the biologic status of the primary tumor.
Breast Unit.
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F
Buggi
Breast Unit. Electronic address: s.folli@ausl.fo.it.
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S
Folli
Breast Unit.
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A
Curcio
Oncology Unit, Morgagni-Pierantoni Hospital, Forlì.
D
D
Casadei-Giunchi
Medical Oncology Unit, Romagna Cancer Institute (IRST), Meldola.
A
A
Rocca
Medical Oncology Unit, Romagna Cancer Institute (IRST), Meldola.
E
E
Pietri
Surgical Pathology Unit, Morgagni-Pierantoni Hospital, Forlì, Italy.
L
L
Medri
Surgical Pathology Unit, Morgagni-Pierantoni Hospital, Forlì, Italy.
L
L
Serra
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000628:therapy*; D044584:Carcinoma, Ductal / Q000378:metabolism / Q000473:pathology; D018275:Carcinoma, Lobular / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000096:biosynthesis; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis; D011960:Receptors, Estrogen / Q000096:biosynthesis; D011980:Receptors, Progesterone / Q000096:biosynthesis
D019394:Ki-67 Antigen; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone