title: Imatinib could be a new strategy for pulmonary hypertension caused by pulmonary tumor thrombotic microangiopathy in metastatic breast cancer.
abstract: BACKGROUND
  Pulmonary tumor thrombotic microangiopathy (PTTM) is rare, cancer-related pulmonary complication leading to hypoxia, pulmonary hypertension, and heart failure. The standard treatment for PTTM is not established. However, imatinib, a tyrosine kinase inhibitor of the PDGF receptor, may cause regression of pulmonary hypertension and pulmonary artery remodeling in PTTM.
  
  
  METHODS
  We report two cases of PTTM who received an anti-PDGF agent of imatinib for PTTM developed during chemotherapy for metastatic breast cancer. Case 1: 61-year-old woman who underwent resection of the left breast and axillary lymph node dissection and received adjuvant chemotherapy (CAF followed by docetaxel), then endocrine therapy for 5 years. Twelve years after surgery, multiple bone and mediastinal lymph node metastases occurred. She was under treatment with eribulin for one year but admitted because of rapid progressing dyspnea. Case 2: 45-year-old woman with metastatic breast cancer in multiple bones was under treatment for 5 years. Receiving capecitabine, she suffered from dyspnea for 2 months, she was admitted to our hospital with diagnosis of severe hypoxia. In both cases, the wedged pulmonary arterial blood cell sampling revealed cytologically malignant cells which confirmed the diagnosis of PTTM. They were treated with imatinib, which alleviated pulmonary hypertension. However, they died due to progression of metastatic breast cancer.
  
  
  RESULTS
  Single use of imatinib did not showed sufficient efficacy. It is necessary to conduct a well-designed clinical trial using chemotherapies combined with imatinib for PTTM.
  
  
  CONCLUSIONS
  Imatinib, which alleviated pulmonary hypertension, could be a new strategy for pulmonary tumor thrombotic microangiopathy in patient with metastatic breast cancer.
authors.affiliation: Breast Medical Oncology, Breast Oncology Center, The Cancer Institute Hospital of the Japanese Foundation for Cancer Research, 3-8-31, Ariake, Koto-ku, Tokyo, 135-8550 Japan.
authors.forename: Ippei
authors.initials: I
authors.lastname: Fukada
authors.affiliation: Breast Medical Oncology, Breast Oncology Center, The Cancer Institute Hospital of the Japanese Foundation for Cancer Research, 3-8-31, Ariake, Koto-ku, Tokyo, 135-8550 Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Araki
authors.affiliation: Breast Medical Oncology, Breast Oncology Center, The Cancer Institute Hospital of the Japanese Foundation for Cancer Research, 3-8-31, Ariake, Koto-ku, Tokyo, 135-8550 Japan.
authors.forename: Kokoro
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Breast Medical Oncology, Breast Oncology Center, The Cancer Institute Hospital of the Japanese Foundation for Cancer Research, 3-8-31, Ariake, Koto-ku, Tokyo, 135-8550 Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Shibayama
authors.affiliation: Cardiovascular Medicine, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Hatano
authors.affiliation: Medical Oncology, The Cancer Institute Hospital of the Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Breast Surgical Oncology, Breast Oncology Center, The Cancer Institute Hospital of the Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Takuji
authors.initials: T
authors.lastname: Iwase
authors.affiliation: Breast Oncology Center, The Cancer Institute Hospital of the Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Ohno
authors.affiliation: Breast Medical Oncology, Breast Oncology Center, The Cancer Institute Hospital of the Japanese Foundation for Cancer Research, 3-8-31, Ariake, Koto-ku, Tokyo, 135-8550 Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ito
keywords: Imatinib; Metastatic breast cancer; Pulmonary hypertension; Pulmonary tumor thrombotic microangiopathy