Scholarlink

<p>Panitumumab, an anti-epidermal growth factor receptor (EGFR) antibody, is a standard drug used in patients with <i>RAS</i> wild-type (WT) metastatic colorectal cancer (mCRC). Studies have reported that the <i>KRAS</i> mutation is a negative predictive biomarker; however, <i>EGFR</i> gene amplification may be a predictive biomarker for the response to anti-EGFR antibodies. We encountered two patients with <i>EGFR</i> gene amplification (one with <i>KRAS</i> mutation) who responded to panitumumab monotherapy after failure of standard chemotherapy. Case 1 was an 85-year-old woman with <i>RAS</i> WT transverse colon cancer with liver metastases. After receiving capecitabine monotherapy as first-line therapy, S-1 plus irinotecan plus bevacizumab therapy as second-line, trifluridine/tipiracil (FTD/TPI) monotherapy as third-line, and regorafenib monotherapy as fourth-line therapy, the patient received panitumumab monotherapy as fifth-line therapy. After that, comprehensive gene panel testing showed <i>EGFR</i> gene amplification. This therapy continued for 6.9&#xa0;months without progressive disease (PD), and liver metastases shrank by up to 72%. Case 2 was a 65-year-old man with <i>RAS</i> WT (initially) sigmoid colon cancer and multiple liver metastases. After receiving mFOLFOX6 plus panitumumab therapy as first-line therapy, FOLFIRI plus bevacizumab as second-line, he underwent conversion surgery. After 3&#xa0;months, multiple liver metastases were detected on CT scan, then, comprehensive gene panel testing was done, and it showed high tumor mutational burden (TMB) and <i>EGFR</i> amplification. As third-line therapy, he received pembrolizumab monotherapy. After PD for pembrolizumab, OncoBEAM™ was done and it showed neo-<i>RAS</i> mutation. Regardless of that result, panitumumab was resumed as a fourth-line treatment and administered for 5.2&#xa0;months without PD; liver metastases shrank by up to 50%. We encountered two patients with mCRC and <i>EGFR</i> gene amplification who responded to panitumumab monotherapy. <i>EGFR</i> gene amplification may be a potential biomarker for anti-EGFR antibodies, regardless of <i>RAS</i> status.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Two cases of metastatic colorectal cancer in which epidermal growth factor receptor gene amplification benefited from panitumumab monotherapy

  • 期刊论文

  • 发表日期：

    2025年11月21日

查看全文
  • Taro Sato,
  • Fumio Nagashima,
  • Naohiro Okano,
  • Mariko Nishioka,
  • Masato Hayashi,
  • Yuji Saito,
  • Tadakazu Hisamatsu,
  • Shuichi Hironaka

摘要

Panitumumab, an anti-epidermal growth factor receptor (EGFR) antibody, is a standard drug used in patients with RAS wild-type (WT) metastatic colorectal cancer (mCRC). Studies have reported that the KRAS mutation is a negative predictive biomarker; however, EGFR gene amplification may be a predictive biomarker for the response to anti-EGFR antibodies. We encountered two patients with EGFR gene amplification (one with KRAS mutation) who responded to panitumumab monotherapy after failure of standard chemotherapy. Case 1 was an 85-year-old woman with RAS WT transverse colon cancer with liver metastases. After receiving capecitabine monotherapy as first-line therapy, S-1 plus irinotecan plus bevacizumab therapy as second-line, trifluridine/tipiracil (FTD/TPI) monotherapy as third-line, and regorafenib monotherapy as fourth-line therapy, the patient received panitumumab monotherapy as fifth-line therapy. After that, comprehensive gene panel testing showed EGFR gene amplification. This therapy continued for 6.9 months without progressive disease (PD), and liver metastases shrank by up to 72%. Case 2 was a 65-year-old man with RAS WT (initially) sigmoid colon cancer and multiple liver metastases. After receiving mFOLFOX6 plus panitumumab therapy as first-line therapy, FOLFIRI plus bevacizumab as second-line, he underwent conversion surgery. After 3 months, multiple liver metastases were detected on CT scan, then, comprehensive gene panel testing was done, and it showed high tumor mutational burden (TMB) and EGFR amplification. As third-line therapy, he received pembrolizumab monotherapy. After PD for pembrolizumab, OncoBEAM™ was done and it showed neo-RAS mutation. Regardless of that result, panitumumab was resumed as a fourth-line treatment and administered for 5.2 months without PD; liver metastases shrank by up to 50%. We encountered two patients with mCRC and EGFR gene amplification who responded to panitumumab monotherapy. EGFR gene amplification may be a potential biomarker for anti-EGFR antibodies, regardless of RAS status.