title: Long-term survival after a favorable response to anti-EGFR antibody plus chemotherapy to treat bone marrow metastasis: a case report ofKRAS-wildtype rectal cancer.
abstract: Bone marrow metastasis is a rare consequence of colorectal cancer that results in a poor prognosis; few reports describe a favorable response to doublet chemotherapy combined with targeted therapy, which is currently the standard treatment. We experienced a case where anti-epidermal growth factor receptor (EGFR) antibody produced a marked anti-tumor response to bone marrow metastasis that led to long-term survival. A 51-year-old man was diagnosed with a primaryKRAS-wildtype rectal cancer with multiple metastases, including the bone marrow. Disease control was achieved for 10.8 months following chemotherapy with a modified FOLFOX6 regimen combined with an anti-EGFR antibody. He died of cancer 22.7 and 16.6 months after disease onset and first-line chemotherapy, respectively. This case shows that early tumor shrinkage and deepness of response to the anti-EGFR antibody were observed even in a patient with bone marrow metastasis. Anti-EGFR antibody therapy should therefore be considered even when a patient's medical condition appears to be poor owing to bone marrow metastasis. Moreover, tumors that are likely to be sensitive to chemotherapy, such asRAS-wildtype colorectal cancers, can be considered for anti-EGFR antibody therapy even if the patient is considered unfit for chemotherapy.
authors.affiliation: Department of Clinical Oncology, Yamagata University Faculty of Medicine, Yamagata, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: Department of Clinical Oncology, Yamagata University Faculty of Medicine, Yamagata, Japan.
authors.forename: Tadahisa
authors.initials: T
authors.lastname: Fukui
authors.affiliation: Department of Clinical Oncology, Yamagata University Faculty of Medicine, Yamagata, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: Department of Clinical Oncology, Yamagata University Faculty of Medicine, Yamagata, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takeda
authors.affiliation: Department of Clinical Oncology, Yamagata University Faculty of Medicine, Yamagata, Japan.
authors.forename: Kaname
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Department of Clinical Oncology, Yamagata University Faculty of Medicine, Yamagata, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshioka
keywords: anti-epidermal growth factor receptor antibody; colorectal cancer; disseminated intravascular coagulation; molecular targeted therapies; standard of care