内容紹介
Indoleamine 2,3-Dioxygenase Activity during Fulvestrant Therapy for Aromatase Inhibitor-Resistant Metastatic Breast Cancer
Summary
We evaluated the clinical significance of indoleamine 2,3-dioxygenase(IDO)during fulvestrant therapy for aromatase inhibitor(AI)-resistant metastatic breast cancer. IDO activity can be measured by the tryptophan(Trp)/kynurenine(Kyn)ratio. Trp and Kyn were measured with high performance liquid chromatography(HPLC). Patients with AI resistant metastatic breast cancer had a 28.6% response rate to fulvestrant therapy, and the clinical benefit rate was 76.2%. AI-resistant metastatic breast cancer patients with distant metastases had a lower serum Trp/Kyn level than patients who had local recurrences. During fulvestrant therapy, IDO activity significantly decreased in the fulvestrant responder group compared to that in the fulvestrant non-responder group. During fulvestrant therapy, the IDO activity correlated with the number of metastatic lesions. These results suggest that measuring the Trp/Kyn ratio is useful for evaluating immunological metastatic status during endocrine therapy.
要旨
aromatase inhibitor(AI)剤耐性の転移・再発乳癌症例に対してfulvestrant(500 mg/28 day)を使用した症例についてindoleamine 2,3-dioxygenase(IDO)の発現程度を検討した。乳癌術後に補助療法としてAI剤を投与していたが転移・再発を認めた21症例を対象とした。転移・再発時に採血を施行し,HPLCを用いてtriptophan(Trp)とkynurenine(Kyn)を測定し,Trp/Kyn ratioからIDOのactivityを測定した。fulvestrantの奏効率は28.6%(6/21例),臨床的有用率は76.2%(16/21例)であった。遠隔転移群は局所再発群に比べて再発時のTrp/Kyn ratioが有意に低かった。また,fulvestrant奏効群は非奏効群に比べて治療中のTrp/Kyn ratioが有意に高かった。ホルモン療法施行中に病勢がコントロールできていた症例は,治療効果に応じてTrp/Kyn ratioが変動した。乳癌術後の転移・再発時の内分泌療法中にTrp/Kynを測定することは,病勢の推測に有用である可能性が示唆された。
目次
Summary
We evaluated the clinical significance of indoleamine 2,3-dioxygenase(IDO)during fulvestrant therapy for aromatase inhibitor(AI)-resistant metastatic breast cancer. IDO activity can be measured by the tryptophan(Trp)/kynurenine(Kyn)ratio. Trp and Kyn were measured with high performance liquid chromatography(HPLC). Patients with AI resistant metastatic breast cancer had a 28.6% response rate to fulvestrant therapy, and the clinical benefit rate was 76.2%. AI-resistant metastatic breast cancer patients with distant metastases had a lower serum Trp/Kyn level than patients who had local recurrences. During fulvestrant therapy, IDO activity significantly decreased in the fulvestrant responder group compared to that in the fulvestrant non-responder group. During fulvestrant therapy, the IDO activity correlated with the number of metastatic lesions. These results suggest that measuring the Trp/Kyn ratio is useful for evaluating immunological metastatic status during endocrine therapy.
要旨
aromatase inhibitor(AI)剤耐性の転移・再発乳癌症例に対してfulvestrant(500 mg/28 day)を使用した症例についてindoleamine 2,3-dioxygenase(IDO)の発現程度を検討した。乳癌術後に補助療法としてAI剤を投与していたが転移・再発を認めた21症例を対象とした。転移・再発時に採血を施行し,HPLCを用いてtriptophan(Trp)とkynurenine(Kyn)を測定し,Trp/Kyn ratioからIDOのactivityを測定した。fulvestrantの奏効率は28.6%(6/21例),臨床的有用率は76.2%(16/21例)であった。遠隔転移群は局所再発群に比べて再発時のTrp/Kyn ratioが有意に低かった。また,fulvestrant奏効群は非奏効群に比べて治療中のTrp/Kyn ratioが有意に高かった。ホルモン療法施行中に病勢がコントロールできていた症例は,治療効果に応じてTrp/Kyn ratioが変動した。乳癌術後の転移・再発時の内分泌療法中にTrp/Kynを測定することは,病勢の推測に有用である可能性が示唆された。