How to say "cancer" in Japanese

• がんJLPT N1approx.Common
  nounThe word for cancer as a disease — a diagnosis, treatment, or the illness itself. It is a common word, usually written in kana alone, and the one you will want in almost any context.
  クッキーのお母かあさんはガンで死しんだ。↗

  Cookie's mother died of cancer.
• かに座かにざ
  nounThe constellation Cancer, the Crab, in the night sky. This is the usual name for the star group, and it also serves as the familiar name for the zodiac sign.
• キャンサー
  nounA katakana loanword for the disease. It points to the same thing as がん, but since がん is the common word, this rendering is seldom the one you need.
• 巨蟹宮きょかいきゅう
  nounNames Cancer as the fourth sign of the zodiac rather than the constellation, in astronomical and astrological use. A less common, technical term; かに座 is what you will usually see instead.
• 悪性腫瘍あくせいしゅよう
  nounThe medical term for a malignant tumor or malignancy; in clinical use it covers cancers generally. For speaking of the disease in ordinary words, がん is the choice.

Use 「がん」 for the disease in almost any context; 悪性腫瘍 is the medical term for a malignant tumor; 「かに座」 and 巨蟹宮 name the constellation and the zodiacal sign respectively, and 「キャンサー」 is a loanword you will seldom need.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• がんcancer
• かに座かにざCancer (constellation)
• キャンサーcancer
• 巨蟹宮きょかいきゅうCancer (4th zodiacal sign)
• 悪性腫瘍あくせいしゅようmalignant tumor