title: Long-term complete remission of metastatic breast cancer, induced by a steroidal aromatase inhibitor after failure of a non-steroidal aromatase inhibitor.
abstract: METHODS
  Female, 56 FINAL DIAGNOSIS: Breast cancer Symptoms: Solid mass in the right breast Medication: Exemestane Clinical Procedure: - Specialty: Oncology.
  
  
  OBJECTIVE
  Unusual clinical course.
  
  
  BACKGROUND
  The efficacy of third-generation aromatase inhibitors for hormone receptor-positive postmenopausal metastatic breast cancer is well established. Although several clinical trials have reported incomplete cross-resistance between different aromatase inhibitors, few cases of complete responses of recurrent metastatic breast cancer occurring after substituting a second aromatase inhibitor have been reported. We here present a rare case of non-steroidal aromatase inhibitor-tolerant metastatic breast cancer with long-term complete remission following substitution of a steroidal aromatase inhibitor.
  
  
  METHODS
  We present the case of a 56-year-old Japanese woman who underwent right breast-conserving surgery for breast cancer, TNM staging T1, N0, M0, Stage I. She received adjuvant chemotherapy with 6 cycles of FEC100 and radiation therapy, and then began hormonal therapy with anastrozole. Twelve months postoperatively, computed tomography (CT) revealed multiple lung metastases. Exemestane was substituted for anastrozole. After 3 months of exemestane, CT showed that all lung metastases had completely resolved. Her complete response was maintained for 5 years: she died during a tsunami 6 years after the initial surgery.
  
  
  CONCLUSIONS
  Substitution of a steroidal for a non-steroidal aromatase inhibitor produced a sustained complete remission in a patient with hormonal receptor-positive postmenopausal recurrent breast cancer. Achieving complete response after switching from a non-steroidal to a steroidal aromatase inhibitor in a hormonal receptor-positive postmenopausal recurrent breast cancer contributed to a higher quality of life for the patient. Further investigation is needed to identify the predictors of long-term remission following such a switch.
authors.affiliation: Department of Surgery, Iwate Medical University, Morioka, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Shioi
authors.affiliation: Department of Surgery, Iwate Medical University, Morioka, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kashiwaba
authors.affiliation: Department of Surgery, Iwate Medical University, Morioka, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Inaba
authors.affiliation: Department of Surgery, Iwate Medical University, Morioka, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Komatsu
authors.affiliation: Department of Pathology, Iwate Medical University, Morioka, Japan.
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Sugai
authors.affiliation: Department of Surgery, Iwate Medical University, Morioka, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Wakabayashi
keywords: Aromatase Inhibitors; Breast Neoplasms – therapy; Neoplasm Metastasis