内容紹介
Summary
Although S-1 is an effective oral anticancer drug in patients with metastatic breast cancer, it is difficult for some patients to continue taking S-1 because of its side effects in the approved regimen of 4 weeks of administration followed by a 2-week rest. When S-1 is administered for 5 days followed by a 2-day rest(5-day on/2-day off), the drug concentration is almost equal to that of the approved regimen, and it can be administered for longer without deterioration of its clinical effect. We retrospectively analyzed the effect and safety in 25 cases in which S-1 was administered using the“5-day on/2-day off” regimen in patients with metastatic breast cancer between November 2006 and August 2014 in our hospital. Patients were all female, and their median age was 68 years(44-87). ER was positive/negative in 15/10 cases, and PS 0/1/2 were found in 8/10/7 cases. They had no prior chemotherapy and had measurable lesions. S-1 was administered at a dose of 80 mg/m2 twice a day on a“5-day on/2-day off”schedule and was reduced when its side effects were appeared. The median treatment duration was 25(3-214)weeks, and CR/PR/long SD/SD/PD as clinical responses were observed in 0/8/5/5/7 cases. The overall response rate was 32% and clinical benefit rate was 52%. There was no difference in response rates whether visceral metastases were present or not. In terms of hematologic toxicity, anemia was seen in one case, and there were no cases of neutropenia. In non-hematologic toxicity, no more than Grade 3 side effects were shown. Discontinuance was observed in only one case because of diarrhea. A“5-day on/2-day off”regimen of S-1 in metastatic breast cancer is well tolerated, and we can continue administering it to elderly patients or those with poor PS without reducing QOL; thus, it can be considered as one of the effective metronomic treatments. In the future, a prospective study is warranted to ascertain these results.
要旨
S-1は転移再発乳癌に対して有効な経口抗癌剤であるが,承認されている4週投薬2週休薬では副作用のために減量やスケジュール変更を余儀なくされる場合がみられる。S-1を5日投薬2日休薬(5投2休)で繰り返し投与した場合,薬剤強度は承認用法の場合とほぼ等しくなり,効果を減弱することなく治療継続性を高める可能性がある。当院で2006年11月～2014年8月までにS-1単剤を5投2休で投与したHER2陰性転移再発乳癌25例を対象として,有効性と安全性について検討した。患者は全員女性,年齢中央値は68(44～87)歳,ER陽性15例,ER陰性10例,PSは0/1/2が8/10/7例であった。全例で再発後の化学療法歴はなく,いずれも評価可能病変を有していた。S-1は80 mg/m2の5投2休とし,副作用が発現した場合は減量した。投与期間は3～214週で中央値25週であった。臨床的効果はCR/PR/long SD/SD/PDが0/8/5/5/7例,奏効率32%,臨床的有用率は52%であった。内臓転移の有無で奏効率に差はなかった。血液毒性はヘモグロビン減少の1例のみで,好中球減少は認められなかった。非血液毒性は下痢,食欲低下,手足症候群,色素沈着障害,流涙などが観察されたが,Grade 3以上はなく中止は下痢の1例のみであった。転移再発乳癌に対してS-1の5投2休は,副作用が少なくQOLを保持しながら高齢者やPSの悪い患者にも治療を継続することが可能であり,有効なメトロノミック治療の一つであると考えられる。今後は前向き臨床試験による検証が必要である。
目次
Although S-1 is an effective oral anticancer drug in patients with metastatic breast cancer, it is difficult for some patients to continue taking S-1 because of its side effects in the approved regimen of 4 weeks of administration followed by a 2-week rest. When S-1 is administered for 5 days followed by a 2-day rest(5-day on/2-day off), the drug concentration is almost equal to that of the approved regimen, and it can be administered for longer without deterioration of its clinical effect. We retrospectively analyzed the effect and safety in 25 cases in which S-1 was administered using the“5-day on/2-day off” regimen in patients with metastatic breast cancer between November 2006 and August 2014 in our hospital. Patients were all female, and their median age was 68 years(44-87). ER was positive/negative in 15/10 cases, and PS 0/1/2 were found in 8/10/7 cases. They had no prior chemotherapy and had measurable lesions. S-1 was administered at a dose of 80 mg/m2 twice a day on a“5-day on/2-day off”schedule and was reduced when its side effects were appeared. The median treatment duration was 25(3-214)weeks, and CR/PR/long SD/SD/PD as clinical responses were observed in 0/8/5/5/7 cases. The overall response rate was 32% and clinical benefit rate was 52%. There was no difference in response rates whether visceral metastases were present or not. In terms of hematologic toxicity, anemia was seen in one case, and there were no cases of neutropenia. In non-hematologic toxicity, no more than Grade 3 side effects were shown. Discontinuance was observed in only one case because of diarrhea. A“5-day on/2-day off”regimen of S-1 in metastatic breast cancer is well tolerated, and we can continue administering it to elderly patients or those with poor PS without reducing QOL; thus, it can be considered as one of the effective metronomic treatments. In the future, a prospective study is warranted to ascertain these results.
要旨
S-1は転移再発乳癌に対して有効な経口抗癌剤であるが,承認されている4週投薬2週休薬では副作用のために減量やスケジュール変更を余儀なくされる場合がみられる。S-1を5日投薬2日休薬(5投2休)で繰り返し投与した場合,薬剤強度は承認用法の場合とほぼ等しくなり,効果を減弱することなく治療継続性を高める可能性がある。当院で2006年11月～2014年8月までにS-1単剤を5投2休で投与したHER2陰性転移再発乳癌25例を対象として,有効性と安全性について検討した。患者は全員女性,年齢中央値は68(44～87)歳,ER陽性15例,ER陰性10例,PSは0/1/2が8/10/7例であった。全例で再発後の化学療法歴はなく,いずれも評価可能病変を有していた。S-1は80 mg/m2の5投2休とし,副作用が発現した場合は減量した。投与期間は3～214週で中央値25週であった。臨床的効果はCR/PR/long SD/SD/PDが0/8/5/5/7例,奏効率32%,臨床的有用率は52%であった。内臓転移の有無で奏効率に差はなかった。血液毒性はヘモグロビン減少の1例のみで,好中球減少は認められなかった。非血液毒性は下痢,食欲低下,手足症候群,色素沈着障害,流涙などが観察されたが,Grade 3以上はなく中止は下痢の1例のみであった。転移再発乳癌に対してS-1の5投2休は,副作用が少なくQOLを保持しながら高齢者やPSの悪い患者にも治療を継続することが可能であり,有効なメトロノミック治療の一つであると考えられる。今後は前向き臨床試験による検証が必要である。