内容紹介
A Case of Stage Ⅳ Metaplastic Breast Cancer in Which Primary Tumor Was Removed after Treatment with Anti-HER2 Systemic Therapy
Summary
The patient was a 58-year-old postmenopausal woman. Vacuum assisted biopsy of the left breast tumor revealed invasive ductal carcinoma. Immunohistochemical examination was negative for estrogen receptor(ER), negative for progesterone receptor(PgR), and showed an HER2 score of 3+. FDG-PET/CT revealed multiple metastases to the left supracravicular and axillary lymph nodes and lungs. She was diagnosed with HER2-positive T3N3M1, Stage Ⅳ breast cancer. A 2-year regimen of chemotherapy with trastuzumab and vinorelbine achieved a complete response with regard to the metastatic sites; however, the size of the primary tumor increased despite the chemotherapy, and surgical resection of the left breast with axillary lymph node dissection was performed for local control. Pathological examination of the surgical specimen revealed metaplastic carcinoma with sarcoma component surrounded by non-invasive ductal carcinoma. No component of invasive ductal carcinoma was found. Immunohistochemically, metaplastic carcinoma was negative for ER, negative for PgR, and revealed an HER2 score of 0. There was discordance of HER2 status between pre- and post-chemotherapy. The patient received no further chemotherapy following surgery and has been without disease progression for 6 years. We suggest there is heterogeneity, that is, the metastatic sites and the partial primary tumor were HER2-positive invasive ductal carcinoma and the remainder of the primary tumor was triple negative metaplastic carcinoma. As a result, the patient was able to discontinue chemotherapy with higher quality of life.
要旨
症例は58歳,閉経後女性。2009年2月初診,左乳房腫瘤を認め,針生検により浸潤性乳管癌,ER(-),PgR(-),HER2 score(3+)と診断した。FDG-PET/CTにて肺,左鎖骨上窩,腋窩リンパ節転移を認め,T3N3M1,Stage Ⅳであった。trastuzumabとvinorelbineにより転移部位はCRとなるも原発巣はPDとなり,2011年3月に局所制御目的で乳房切除術+腋窩リンパ節郭清術を施行した。病理診断結果にて組織型は肉腫様の形態を主成分とするmetaplastic carcinomaであり,その周辺に非浸潤性乳管癌(DCIS)が広がっていた。浸潤性乳管癌の成分は認められなかった。ER(-),PgR(-),HER2 score(0)であり,HER2は陰転化していた。術後6年間,全身薬物療法を行わず,無再発生存中である。本症例は腫瘍のheterogeneityがあり,原発巣の一部と転移巣はHER2陽性の浸潤性乳管癌,原発巣の一部はトリプルネガティブのmetaplastic carcinomaであった可能性が示唆される。結果として,原発巣切除により抗HER2療法を中止することができ,QOLの改善,長期生存につながったと考えられる。
目次
Summary
The patient was a 58-year-old postmenopausal woman. Vacuum assisted biopsy of the left breast tumor revealed invasive ductal carcinoma. Immunohistochemical examination was negative for estrogen receptor(ER), negative for progesterone receptor(PgR), and showed an HER2 score of 3+. FDG-PET/CT revealed multiple metastases to the left supracravicular and axillary lymph nodes and lungs. She was diagnosed with HER2-positive T3N3M1, Stage Ⅳ breast cancer. A 2-year regimen of chemotherapy with trastuzumab and vinorelbine achieved a complete response with regard to the metastatic sites; however, the size of the primary tumor increased despite the chemotherapy, and surgical resection of the left breast with axillary lymph node dissection was performed for local control. Pathological examination of the surgical specimen revealed metaplastic carcinoma with sarcoma component surrounded by non-invasive ductal carcinoma. No component of invasive ductal carcinoma was found. Immunohistochemically, metaplastic carcinoma was negative for ER, negative for PgR, and revealed an HER2 score of 0. There was discordance of HER2 status between pre- and post-chemotherapy. The patient received no further chemotherapy following surgery and has been without disease progression for 6 years. We suggest there is heterogeneity, that is, the metastatic sites and the partial primary tumor were HER2-positive invasive ductal carcinoma and the remainder of the primary tumor was triple negative metaplastic carcinoma. As a result, the patient was able to discontinue chemotherapy with higher quality of life.
要旨
症例は58歳,閉経後女性。2009年2月初診,左乳房腫瘤を認め,針生検により浸潤性乳管癌,ER(-),PgR(-),HER2 score(3+)と診断した。FDG-PET/CTにて肺,左鎖骨上窩,腋窩リンパ節転移を認め,T3N3M1,Stage Ⅳであった。trastuzumabとvinorelbineにより転移部位はCRとなるも原発巣はPDとなり,2011年3月に局所制御目的で乳房切除術+腋窩リンパ節郭清術を施行した。病理診断結果にて組織型は肉腫様の形態を主成分とするmetaplastic carcinomaであり,その周辺に非浸潤性乳管癌(DCIS)が広がっていた。浸潤性乳管癌の成分は認められなかった。ER(-),PgR(-),HER2 score(0)であり,HER2は陰転化していた。術後6年間,全身薬物療法を行わず,無再発生存中である。本症例は腫瘍のheterogeneityがあり,原発巣の一部と転移巣はHER2陽性の浸潤性乳管癌,原発巣の一部はトリプルネガティブのmetaplastic carcinomaであった可能性が示唆される。結果として,原発巣切除により抗HER2療法を中止することができ,QOLの改善,長期生存につながったと考えられる。