内容紹介
Standard Chemotherapy with Bevacizumab as First-Line Therapy for Metastatic Colorectal Cancer with RAS Mutation
Summary
Aim: We examined the outcome of treatment with first-line chemotherapy with bevacizumab(Bmab)for metastatic colorectal cancer in our hospital to clarify the outcome for RAS mutant patients. Subjects and methods: From January 2013 to April 2016, 28 patients who initiated standard chemotherapy(2 chemotherapeutic agents)with Bmab as the first-line regimen for metastatic colorectal cancer were enrolled in this retrospective study. Time to treatment failure(TTF)and overall survival(OS)were analyzed. Results: The median age was 66.5(46-81)years old, including 16 men and 12 women, 11 cases with RAS wild type, and 17 cases with mutant type. The response rate was 30.8% in 2 cases of CR, 6 cases of PR, 14 cases of SD, 4 cases of PD, and 4 cases with conversion surgery after chemotherapy. TTF was 6.5 months and OS was 32.1 months. Among those with RAS mutations, 3 cases received conversion surgery. TTF of the mutant and wild type were 6.3 and 5.6 months, respectively, and OS was 35.8 and 32.1 months, respectively, without any significant difference. In addition, excluding conversion cases, the OS of mutant and wild type patients was 22.7 and 29.5 months, respectively. Conclusion: The outcome of treatment using first-line chemotherapy with Bmab for metastatic colorectal cancer with RAS mutations was retrospectively analyzed. There was no difference in therapeutic effect between RAS mutated and not, and it seems that an OS of more than 20 months can be expected for those with RAS mutations with this choice of treatment.
要旨
目的: 今回,当院でbevacizumab(Bmab)併用一次治療を施行した進行再発大腸癌症例の治療成績について,RAS変異型の治療成績を明らかにすることを目的に後方視的に検討した。方法: 2013年1月～2016年4月までに当院で進行再発大腸癌に対し,一次治療として標準治療(化学療法剤2剤)にBmabを併用した28人を対象に一次治療と治療成功期間(TTF),全生存期間(OS)を中心に解析した。結果: 年齢中央値66.5(46～81)歳で男性16例,女性12例,RAS遺伝子は野生型11例,変異型17例であった。抗腫瘍効果はCR 2例,PR 6例,SD 14例,PD 4例で奏効率30.8%,化学療法後に再発巣切除を4例に認めた。TTF 6.5か月,OSは32.1か月であった。RAS遺伝子別には変異型で3例に再発巣切除があり,TTFは変異型/野生型で各6.3,5.6か月,OSは各35.8,32.1か月で差はなかった。また,再発巣切除した症例を除くとOSは各22.7,29.5か月であった。結語: Bmab併用一次治療を施行した進行再発大腸癌症例の治療成績について,RAS変異別に後方視的に検討した。RAS変異別に治療効果に差はなく,治療選択の少ないRAS変異型でも20か月以上のOSが期待できると考えられた。
目次
Summary
Aim: We examined the outcome of treatment with first-line chemotherapy with bevacizumab(Bmab)for metastatic colorectal cancer in our hospital to clarify the outcome for RAS mutant patients. Subjects and methods: From January 2013 to April 2016, 28 patients who initiated standard chemotherapy(2 chemotherapeutic agents)with Bmab as the first-line regimen for metastatic colorectal cancer were enrolled in this retrospective study. Time to treatment failure(TTF)and overall survival(OS)were analyzed. Results: The median age was 66.5(46-81)years old, including 16 men and 12 women, 11 cases with RAS wild type, and 17 cases with mutant type. The response rate was 30.8% in 2 cases of CR, 6 cases of PR, 14 cases of SD, 4 cases of PD, and 4 cases with conversion surgery after chemotherapy. TTF was 6.5 months and OS was 32.1 months. Among those with RAS mutations, 3 cases received conversion surgery. TTF of the mutant and wild type were 6.3 and 5.6 months, respectively, and OS was 35.8 and 32.1 months, respectively, without any significant difference. In addition, excluding conversion cases, the OS of mutant and wild type patients was 22.7 and 29.5 months, respectively. Conclusion: The outcome of treatment using first-line chemotherapy with Bmab for metastatic colorectal cancer with RAS mutations was retrospectively analyzed. There was no difference in therapeutic effect between RAS mutated and not, and it seems that an OS of more than 20 months can be expected for those with RAS mutations with this choice of treatment.
要旨
目的: 今回,当院でbevacizumab(Bmab)併用一次治療を施行した進行再発大腸癌症例の治療成績について,RAS変異型の治療成績を明らかにすることを目的に後方視的に検討した。方法: 2013年1月～2016年4月までに当院で進行再発大腸癌に対し,一次治療として標準治療(化学療法剤2剤)にBmabを併用した28人を対象に一次治療と治療成功期間(TTF),全生存期間(OS)を中心に解析した。結果: 年齢中央値66.5(46～81)歳で男性16例,女性12例,RAS遺伝子は野生型11例,変異型17例であった。抗腫瘍効果はCR 2例,PR 6例,SD 14例,PD 4例で奏効率30.8%,化学療法後に再発巣切除を4例に認めた。TTF 6.5か月,OSは32.1か月であった。RAS遺伝子別には変異型で3例に再発巣切除があり,TTFは変異型/野生型で各6.3,5.6か月,OSは各35.8,32.1か月で差はなかった。また,再発巣切除した症例を除くとOSは各22.7,29.5か月であった。結語: Bmab併用一次治療を施行した進行再発大腸癌症例の治療成績について,RAS変異別に後方視的に検討した。RAS変異別に治療効果に差はなく,治療選択の少ないRAS変異型でも20か月以上のOSが期待できると考えられた。