title: Differences in Ki67 expressions between pre- and post-neoadjuvant chemotherapy specimens might predict early recurrence of breast cancer.
abstract: The prognosis of breast cancer patients not obtaining a pathological complete response (pCR) with neoadjuvant chemotherapy (NAC) is poorer than that of pCR patients. Identifying new prognostic factors for non-pCR patients is important because fractions of this population might benefit from novel adjuvant treatments currently under development. High Ki67 expression in remnant disease after NAC has been described as a poor prognostic factor. Studies have shown that a reduction in Ki67 expression is more often observed in good responders to chemotherapy. We hypothesized that the change in Ki67 expression might be useful for predicting patient outcomes and thus retrospectively examined pairs of biopsy and surgical specimens of breast tissue from individual patients. One hundred sixteen patients with remnant invasive disease in the breast, who received NAC and underwent surgery at our institution, were retrospectively examined. Differences in Ki67 expression between pre- and post-NAC specimens were analyzed in relation to patient outcomes. The mean Ki67 expression value after NAC was higher in patients who developed metastasis than in those without metastasis (P<.01). Tumors showing higher Ki67 expression in the surgical than in the biopsy specimen were more frequent in patients with metastasis (P<.01). This trend was more obvious in patients who developed metastasis within 1 year after surgery. Our results indicate that a difference in Ki67 expressions after versus before NAC might be an important predictor of early metastasis. Evaluating not only absolute Ki67 values, but also any changes in response to NAC, may improve the prediction of patient outcomes.
authors.affiliation: Department of Breast Oncology, Juntendo University School of Medcine, Tokyo 113-0033, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Tokuda
authors.affiliation: Department of Breast Oncology, Juntendo University School of Medcine, Tokyo 113-0033, Japan; Department of Pathology and Oncology, Juntendo University School of Medicine, Tokyo 113-0033, Japan. Electronic address: yoshiyahorimoto@hotmail.com.
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Horimoto
authors.affiliation: Department of Human Pathology, Juntendo University School of Medicine, Tokyo 113-0033, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Arakawa
authors.affiliation: Department of Breast Oncology, Juntendo University School of Medcine, Tokyo 113-0033, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Himuro
authors.affiliation: Department of Breast Oncology, Juntendo University School of Medcine, Tokyo 113-0033, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Senuma
authors.affiliation: Department of Breast Oncology, Juntendo University School of Medcine, Tokyo 113-0033, Japan.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Nakai
authors.affiliation: Department of Breast Oncology, Juntendo University School of Medcine, Tokyo 113-0033, Japan.
authors.forename: Mitsue
authors.initials: M
authors.lastname: Saito
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism*; D008408:Mastectomy; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009362:Neoplasm Metastasis; D018365:Neoplasm, Residual; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014041:Tokyo; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D019394:Ki-67 Antigen
keywords: Breast cancer; Ki67; MIB-1; Neoadjuvant chemotherapy; Residual disease