A malignant tumor (cancer); a disease in which cells grow uncontrollably. Usually written in kana as がん.
母は先月、がんと診断されました。
My mother was diagnosed with cancer last month.
早期発見すれば、がんは治療できる場合もある。
If detected early, cancer can sometimes be treated.
喫煙は肺がんのリスクを高める。
Smoking increases the risk of lung cancer.
がんの治療には手術や化学療法が含まれることが多い。
Cancer treatment often includes surgery and chemotherapy.