Cancer staging

The stage generally takes into account the size of a tumor, whether it has invaded adjacent organs, how many regional (nearby) lymph nodes it has spread to (if any), and whether it has appeared in more distant locations (metastasized).

Pathologic staging is usually considered to be more accurate because it allows direct examination of the tumor in its entirety, contrasted with clinical staging which is limited by the fact that the information is obtained by making indirect observations of a tumor which is still in the body.

[2] Some of the problems associated with overtesting include patients receiving invasive procedures, overutilizing medical services, getting unnecessary radiation exposure, and experiencing misdiagnosis.

Oversight of one cell can mean misstaging and lead to serious, unexpected spread of cancer.

For example, the mRNA for GCC (guanylyl cyclase c), present only in the luminal aspect of intestinal epithelium, can be identified using molecular screening (RT-PCR) with a high degree of sensitivity and exactitude.

Because of its high sensitivity, RT-PCR screening for GCC greatly reduces underestimation of disease stage.

Within the TNM system, a cancer may also be designated as recurrent, meaning that it has appeared again after being in remission or after all visible tumor has been eliminated.