The stage of the oncological disease is established according to the results of the examination. There are two classification systems of stages. The first one is clinical, according to it the stages of the disease are marked by numbers I, II, III, IV. The second is TNM Classification of Malignant Tumours. It is used for a more detailed characterization of the growth and spread of the tumor.
In this article, we will look at both systems, the difference between them, and how the disease is treated at different stages.
Clinical classification of thyroid cancer
Stage I - tumor develops inside the gland. The organ is not deformed. No symptoms.
Stage II - the tumor expands and deforms the gland. Malignant cells spread to the adjacent lymph nodes. There may be swelling on the neck, hoarseness.
Stage III - tumor grows through the thyroid gland and beyond. Spreads to lymph nodes. At this stage hoarseness, pain in the neck and the lymph nodes area appears.
Stage IV - metastasis can be found in neighboring (neck, blood vessels) or distant (spine, liver, brain) organs. Symptoms depend on which organ is affected by malignant cells.
TNM classification
This system is used to clarify the diagnosis. It takes into account the diameter of the tumor, the type, and location of metastases. Each component of TNM has its meaning.
T: tumor size
- T1 - less than 1 cm, is inside the gland;
- T2 - 1-4 cm, does not go beyond the thyroid;
- T3 - more than 4 cm;
- T4 - grows beyond the gland;
- T4a - there are regional metastases;
- T4b - the tumor grows into the spine or nearby large blood vessels.
N: Metastasis to the lymph nodes
- N0 - there are no cancer cells in the lymph nodes;
- N1 - cancer grows into regional lymph nodes;
- N1a - the spread of cancer cells into the central neck lymph nodes;
- N1b - neck or thoracic lymph nodes are affected.
M: metastasis to distant organs
- M0 - absence of secondary tumors;
- M1 - the presence of secondary tumors.
How to determine the stage?
Clinical stage | TNM-definition of the stage |
|---|---|
1 | T1 M0 N0 |
2 | T2 M0 N0 |
3 |
|
4 |
|
To determine the stage of the disease doctors uses:
- Examination;
- Ultrasound. Allows to determine the exact location and size of the lesion;
- Biopsy;
- Scintigraphy (radioisotope study). Helps to reveal the properties of pathological cells and check the functioning of the gland;
- CT / MRI. These methods help to examine in detail the thyroid gland and surrounding tissues. MRI shows the size and location of metastases.
Survival at different stages of thyroid cancer
The 5-year survival rate is a prognosis of a life expectancy for patients with different stages of the tumor. This rate shows how many people live 5 years or more after the diagnosis was established.
Stages of thyroid cancer | Five-year survival rate depending on the type of tumor | ||
|---|---|---|---|
Papillary | Follicular | Medullary | |
1 | 100 % | 100 % | 100 % |
2 | 100 % | 100 % | 98 % |
3 | 93 % | 71 % | 81 % |
4 | 51 % | 50 % | 28 % |
Treatment of different stages of thyroid cancer
The plan of therapy is developed individually. Specialists consider the type of tumor, the degree of malignancy of cells, the age of the patient.
Treatment of thyroid cancer at the early stages (1-2)
The main method is surgical removal of the tumor. Depending on the location of the tumor, total thyroidectomy (full) or subtotal thyroidectomy (partial) removal of the gland is carried out. If necessary, lymph nodes are removed as well.
After removal of the thyroid gland, patients develop hypothyroidism (gland hormone deficiency). Hormonal drugs are usually prescribed to compensate for it.
Treatment at advanced stages (3-4)
With growth and metastasis, combined therapy is used. Before removing the formation, gamma irradiation is performed to reduce it.
If there are metastases to other organs, treatment with radioactive iodine is indicated. It is carried out after removal of the thyroid gland. Cancer cells accumulate iodine preparations and, due to this, die or cease to grow.
If metastases affected vital organs, palliative therapy is performed. It consists of irradiation or chemotherapy. These methods help to slow the development of cancer and improve the quality of life of the patient.
Follow-up of patients with thyroid cancer
The purpose of follow-up monitoring is to ensure that the disease is cured completely and to prevent relapse. It includes:
- regular ultrasound (every 3, 6, 12 months);
- a blood test for hormones;
- consultation with the endocrinologist.
The correct definition of the stage allows the appointment of optimal therapy. Therefore, it is so important to undergo comprehensive diagnosis and determine the peculiarities of the disease.