title: Thirty percent of ductal carcinoma in situ of the breast in Japan is extremely low-grade ER(+)/HER2(-) type without comedo necrosis.
abstract: Background Overdiagnosis in mammography (MMG) is a problem. Combination of MMG and ultrasonography for breast cancer screening may increase overdiagnosis. Most cases of overdiagnosis are low-grade ductal carcinoma in situ (LGD), but no reports have focused on them. Materials and methods We immunostained 169 ductal carcinoma in situ (DCIS) cases for ER, PgR, HER2 and Ki67 and classified them into 4 subtypes: ER(+)/HER2(-), ER(+)/HER2(+), ER(-)/HER2(-) and ER(-)/HER2(+). The Ki67 index was used to evaluate the grade of malignancy and examined for correlations with each ER/HER2 subtype and the nuclear grade (NG), with/without comedo necrosis. Results The Ki67 index correlated significantly with NG, both with/without comedo necrosis, and reliably evaluated the grade of malignancy. The index for ER(+)/HER2(-) (n=117, 69.2%) was 7.45±7.10, which was significantly lower than for each of the other types. The index was 5.71±6.94 for ER(+)/HER2(-) without comedo necrosis (n=52, 30.8%), which was significantly lower than with comedo necrosis. This was considered LGD, characterized by absence of microcalcification in MMG and either presence of a solid mass or cystic lesion or absence of hypoechoic areas in ultrasound. Conclusion In Japan, ER(+)/HER2(-) without comedo necrosis accounts for about 30% of DCIS and is LGD. This may be being overdiagnosed. J. Med. Invest. 63: 192-198, August, 2016.
authors.affiliation: Department of Surgery, Shikoku Medical Center for Children and Adults.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Kanematsu
authors.forename: Masami
authors.initials: M
authors.lastname: Morimoto
authors.forename: Masako
authors.initials: M
authors.lastname: Takahashi
authors.forename: Junko
authors.initials: J
authors.lastname: Honda
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Bando
authors.forename: Takuya
authors.initials: T
authors.lastname: Moriya
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Tadokoro
authors.forename: Misako
authors.initials: M
authors.lastname: Nakagawa
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Takechi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yoshida
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Toba
authors.forename: Mitsuteru
authors.initials: M
authors.lastname: Yoshida
authors.forename: Aiichiro
authors.initials: A
authors.lastname: Kajikawa
authors.forename: Akira
authors.initials: A
authors.lastname: Tangoku
authors.forename: Issei
authors.initials: I
authors.lastname: Imoto
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Sasa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000737:chemistry / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000737:chemistry / Q000473:pathology*; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D008875:Middle Aged; D009336:Necrosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D011960:Receptors, Estrogen / Q000032:analysis*
chemical_list: D019394:Ki-67 Antigen; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; C508053:ERBB2 protein, human