title: Morphologic features do not influence response to trastuzumab-containing neoadjuvant chemotherapy in HER2-positive breast cancer.
abstract: Trastuzumab-containing neoadjuvant chemotherapy in patients with HER2-positive breast cancer is highly effective in reducing tumor volume and enables more patients to have breast-conserving surgery. The tumor hormone receptor level has been shown to significantly influence response to trastuzumab-containing neoadjuvant chemotherapy. In this study, we comprehensively evaluated various morphologic features and proliferative activity in 50 HER2-positive invasive breast carcinomas treated with trastuzumab-containing neoadjuvant chemotherapy to determine whether any of these features have the same predictive value as tumor hormone receptor content. The tumor proliferation activity as measured by Ki-67 and various morphologic parameters were compared between tumors that achieved >50% tumor volume reduction including pathologic complete response (pCR) and tumors that showed ≤50% tumor volume reduction. Thirty-seven cases (74%) showed >50% tumor volume reduction including 18 cases with pCR. Thirteen cases (26%) showed ≤50% tumor volume reduction. Neither morphologic variables nor Ki-67 labeling index were predictive of >50% tumor volume reduction. In contrast, hormone receptor status and semiquantitative H scores for hormone receptors were predictive of>50% tumor volume reduction. The mean estrogen and progesterone receptor H scores for tumors that showed >50% tumor volume reduction (including pCR) were 77 (median 10) and 31 (median 0), respectively, compared with 168 (median 200) and 79 (median 75) for cases that showed ≤50% tumor volume reduction. Semiquantitative scoring for hormone receptors provides useful information in terms of therapeutic response in HER2-positive tumors.
authors.affiliation: Department of Pathology, Magee-Womens Hospital of UPMC, Pittsburgh, PA.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Amal
authors.initials: A
authors.lastname: Kanbour-Shakir
authors.forename: David J
authors.initials: DJ
authors.lastname: Dabbs
authors.forename: Rohit
authors.initials: R
authors.lastname: Bhargava
mesh_terms: D000328:Adult; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage* / Q000009:adverse effects; D054316:Biomarkers, Pharmacological / Q000378:metabolism; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000188:drug therapy* / Q000473:pathology; D002277:Carcinoma / Q000175:diagnosis* / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005260:Female; D006801:Humans; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011237:Predictive Value of Tests; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology / Q000378:metabolism; D000068878:Trastuzumab; D016896:Treatment Outcome; D047368:Tumor Burden / Q000187:drug effects
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D054316:Biomarkers, Pharmacological; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab