TNM for breast cancer
The TNM classification is divided into three areas, where the “T” stands for the size of the tumour, the “N” for the number of affected lymph nodes and “M” for distant metastases. The exact specification in each category allows a good prognosis and at the same time determines the treatment options. For example, a small tumour that has not yet spread is primarily operated on, thus achieving good chances of recovery.
A large tumour, on the other hand, may have to be irradiated first so that it loses volume before it can be operated on. From a medical point of view, the details of the breast cancer must be much more precise, so that the size of the tumour is divided into T1 (<2cm), T2 (2-5cm), T3 (>5cm) and T4 (any breast cancer that affects the breast wall or skin). The number of affected lymph nodes is also indicated more specifically by additionally naming the exact region (axilla, collarbone, etc.).
The final classification then results in an individual scheme for each patient, which always serves as a reference for the course of treatment. Improvements or deteriorations are thus objectifiable from a medical point of view. However, this classification also offers some patients the opportunity to better understand their disease and to get a rough idea of its extent.
What’s the prognosis?
The prognosis of individual breast cancers results from the interaction of many important factors. Therefore, it cannot be given in a generalized form. In addition to the type of breast cancer, lymph node involvement plays a particularly important role.
Basically, the most important prognosis factor is the lymph node involvement in the armpit. From there, tumours of the breast form metastases in other organs, which worsens survival enormously. An unfavourable prognostic factor is the presence of the Her2 receptor on the surface of the tumour.
Such breast cancers tend to behave aggressively, which is why their prognosis is worse compared to tumours without the Her2 receptor. The worst prognosis factor is a negative hormone receptor status of the breast cancer. This means that there are no receptors for hormones such as oestrogen or progesterone.
This means that there are no therapeutic options with drugs that target these receptors. The prognosis for such tumours is therefore rather poor. The “G” in the classification of breast cancer stands for “grading” and describes nothing else than the cells from a sample of the tumour.
A pathologist uses defined cell characteristics to assess how malignant the cells look and classifies them from well differentiated to poorly differentiated. Differentiation means how similar the cells look to the actual cells of the original tissue or, simply put, whether they still have a similarity to healthy body cells. The more they resemble the body’s own cells, the better the prognosis.
G1 means that the cancer is well differentiated. The prognosis is therefore in principle good from a histological point of view. G2 means that the cancer cells from the sample taken are less similar to the actual endogenous cells.
The degeneration of the tissue is therefore to be considered more severe than in stage G1. In medical terminology, G2 is described as moderately differentiated. A typical characteristic here is, for example, the shape and size of the cell nuclei, which deviates more clearly from the norm than in G1.
G3 is understood to be a poorly differentiated tumour. The cells therefore no longer bear any resemblance to the original cells in the breast tissue. This usually means that this cancer is very aggressive and spreads quickly. The prognosis is accordingly worse than for the other G-stages. For therapy, this means keeping sufficient safety margins during surgery and subsequent chemotherapy or radiation if necessary.
