Localised cancer
Localised cancer is confined to the place where it began, with no evidence of spread beyond that area on the assessment performed.
That does not necessarily mean the tumour is small or that treatment will be simple. Its location, type and relationship to nearby structures still matter. Tests also have limits: a finding of no visible spread cannot rule out every microscopic cancer cell.
Locally advanced cancer
Locally advanced generally means that cancer has extended into nearby tissues or structures. Nearby lymph nodes may also be involved, depending on the disease and terminology used.
It is different from distant spread. It does not have one universal stage number, and it does not automatically mean that no treatment with a curative aim is possible.
For some cancers, local involvement can make surgery difficult or unsuitable. The pancreatic-cancer operability article explains a specific example. That example should not be applied unchanged to every other cancer.
Metastatic cancer
Metastatic cancer has spread to a distant part of the body. The new site usually retains the identity of the original cancer. Bowel cancer that has spread to the liver, for example, is treated as bowel cancer with liver metastases, not as a new primary liver cancer.
A nearby lymph node and a distant organ are not interchangeable findings. Ask which sites are involved rather than relying on the word spread alone.
Does extent decide the treatment aim?
Extent is important, but cancer biology, available treatments, previous treatment, general health and personal preferences also influence the plan.
Metastatic disease is often treated with a non-curative aim. There are exceptions in selected situations, so neither a promise of cure nor a blanket statement that cure is impossible follows from the label alone.
Stage and grade and palliative anti-cancer treatment explain related terms.
Questions that make the description clearer
Ask where the cancer started, where it has been found, which findings are confirmed and what the proposed treatment is intended to achieve. If someone says advanced, ask whether they mean local involvement, distant spread or something else.
