What Is Stage 0 Cancer?
Stage 0 means abnormal cells have been found in the body, but they haven’t yet become invasive cancer. These cells haven’t spread beyond their point of origin or into surrounding tissues.
These abnormal cells, typically too small to form tumors, won’t often show up on imaging like MRIs or ultrasounds. It’s commonly found in external tissues, especially breast tissue, through routine mammograms.
In medical terminology, ‘stage 0’ is often called carcinoma in situ (Latin for “in place”), and a prefix like (in) lungs, cervix, or GI tract may indicate the site of the abnormal cells, such as adenocarcinoma in situ.
“If detected at this stage, cancer can potentially be completely cured, requiring minimal treatment at a significantly lower cost,” says noted oncologist Dr Narayanankutty Warrier, Medical Director, at MVR Cancer Centre and Research Institute, Kozhikode.
In Breast Cancer
In the breast, stage 0 is known as ductal carcinoma in situ (DCIS), referring to abnormal cells in the milk ducts. DCIS only progresses to higher cancer stages if the cells break through the ducts and spread.
Comparison with Later Stages
Stage I: Cancer begins invading nearby tissue.
Stage II: Tumor grows larger; cancer may be in nearby lymph nodes.
Stage III: Greater lymph node involvement and further spread.
Stage IV: Metastatic cancer, spread to other organs—harder to treat and more dangerous.
