Summary Detection or prognosis of cancer such as cancer such as esophageal squamous cell carcinoma using novel therapeutic agents for cancer such as esophageal squamous cell carcinoma, methods for determining the prognosis of cancer and samples that can be collected minimally invasively A method for making a determination is disclosed. The cancer therapeutic agent contains, as an active ingredient, an antibody or an antigen-binding fragment thereof that undergoes an antigen-antibody reaction with FGFRL1 and suppresses the growth of cancer cells. The method for determining the prognosis of cancer includes examining the expression level of FGFRL1 in cancer tissue separated from a living body, and a high expression level of FGFRL1 indicates that the prognosis will be poor. The method for detecting cancer includes measuring FGFRL1 or a fragment thereof extracted from a living tissue or FGFRL1 or a fragment thereof in blood separated from the living body, wherein the concentration of FGFRL1 or a fragment thereof is present in a healthy human tissue or blood. A higher concentration than FGFRL1 or a fragment thereof indicates the presence of cancer.要約食道扁平上皮癌のような癌の新規な治療剤、癌の予後の判定方法及び低侵襲的に採取可能な試料を用いて食道扁平上皮癌のような癌のような癌の検出又は予後の判定を行う方法が開示されている。癌治療剤は、FGFRL1と抗原抗体反応し、癌細胞の増殖を抑制する抗体又はその抗原結合性断片を有効成分として含有する。癌の予後の判定方法は、生体から分離した癌組織中のFGFRL1の発現量を調べることを含み、FGFRL1の発現量が多いことが、予後が悪いであろうことを示す。癌の検出方法は、生体組織から抽出したFGFRL1若しくはその断片又は生体から分離した血液中のFGFRL1若しくはその断片を測定することを含み、FGFRL1又はその断片の存在濃度が健常人の組織又は血中のFGFRL1又はその断片の濃度よりも高いことが、癌の存在を示す。
