Cancer treatment requires a multidisciplinary team of specialists who work together to arrive at the best cancer treatment modality. For doing so, it becomes essential to know the exact stage at which cancer is presently. Staging of cancer is a universal language identified and recognized by healthcare providers.
Stages of cancer
Generally, cancer can be divided into 5 stages—starting at stage 0 and going up to stage IV. Cancer staging is needed to help identify the extent of spread of cancer in the body. Each stage of cancer is briefly described below:
• Stage 0: This is the starting stage of cancer, in which abnormal cells have not spread elsewhere in the body.
• Stage I: This stage is marked by the appearance of a small tumor, localized in a particular area.
• Stage II: By this stage, the tumor grows larger in size, with possible infiltration to nearby lymph nodes.
• Stage III: The tumor grows deeper into the surrounding tissue and even spreads to the lymph nodes.
• Stage IV: This is considered as the last stage of cancer. By now, cancer metastasizes to other tissues and distant areas of the body.
How is cancer staging done?
Cancer staging requires knowledge about the size of the tumor, its location, and whether it has metastasized (spread) to other parts of the body. For this, the TNM system is commonly employed. TNM stands for:
• T (Tumor): Measures the size of the tumor.
• N (Nodes): Determines whether cancer has spread to nearby lymph nodes.
• M (Metastasis): Evaluates how far the cancer has spread and whether it has affected distant organs, such as lungs, liver, or bones.
Decoding A, B, C, and D in cancer staging
At times, healthcare providers divide the 5 stages of cancer further into categories A, B, C, or D. Sometimes your healthcare provider may use terms such as stage IIA (2A) or IIIB (3B) of cancer. These alphabets offer more insight into your diagnosis.
Generally, “A” denotes less aggressive and slower growing cancers while “D” describes, faster growing and more aggressive cancers within each numeric stage of cancer. This means that stage IIA is less aggressive than stage IIB whereas stage IIIA cancer is more aggressive than stage IIB cancer.
Diagnostic techniques to assess cancer staging
The following diagnostic techniques are usually employed to determine cancer stage:
• Computed Tomograpy (CT) Scan: CT scan helps healthcare providers to identify early-stage cancers, along with the location of the tumor.
• Positron Emission Tomography (PET) Scan: Using PET scan, healthcare providers can determine how far the tumor has spread to distant areas of the body.
• Endoscopy: In this technique, a thin endoscopic tube is inserted into hollow organs to check for signs of cancer.
• Biopsy: Tissue samples are taken to analyse for more information about cancer.
• Blood tests: Tumor markers are substances present in the blood or serum which helps determine tumor size or the amount of cancer in the body.
Importance of staging of cancer
1. Treatment Planning: Staging of cancer helps in determining if the tumor in question requires a localized treatment (e.g. surgery, radiation) or systemic therapy (e.g. chemotherapy, immunotherapy).
2. Universal language of care: To provide a uniform and streamlined method of cancer care, staging of cancer helps in maintaining uniformity.
3. Supporting Research: Staging of cancer is essential for enabling clinical trials and research to improve cancer treatment.
4. Patient Expectations: Often, patients diagnosed with cancer want to know about their prognosis and expected outcome. Cancer staging helps healthcare providers deliver the right prognosis.
Cancer symptoms are often not observed until the time it is too late. Early identification of the cancer stage helps in deciding appropriate treatment plans to treat and curb its spread. Although this alpha-numeric method of staging cancer can be confusing for the patients, it is helpful for the healthcare provider to create treatment plans, collaborate with fellow oncology specialists, and develop a prognosis for the patient.