From the Guidelines
Bladder cancer is graded based on how abnormal the cancer cells appear under a microscope, which helps predict how aggressive the cancer is, with the most recent and highest quality study 1 providing a classification system that includes low-grade and high-grade classifications. The grading system for bladder cancer includes:
- Low-grade bladder cancer cells, which look more like normal cells and tend to grow slowly, with less likelihood of invading the muscular wall of the bladder or spreading to other parts of the body.
- High-grade bladder cancer cells, which look very abnormal and are more likely to grow aggressively, invade the bladder wall, and spread to other organs. Additionally, bladder cancer is staged using the TNM system (Tumor, Node, Metastasis), ranging from:
- Ta (non-invasive papillary carcinoma)
- T1 (invasion into the lamina propria)
- T2 (invasion into the muscle)
- T3 (invasion into perivesical tissue)
- T4 (invasion into nearby organs) The grade and stage together help determine the appropriate treatment approach, which may include:
- Surgery
- Intravesical therapy
- Chemotherapy
- Immunotherapy
- Radiation therapy depending on the specific characteristics of the cancer, as outlined in the European Association of Urology classification system 1. Some key points to consider in the management of bladder cancer include:
- The use of a scoring system and risk assessment table to predict disease recurrence and progression in patients with Ta-T1 disease 1.
- The importance of complete history and physical examination, blood counts, creatinine, chest X-ray (or CT), CT scan of the abdomen and pelvis, and urine cytology in the diagnosis and staging of bladder cancer 1.
- The role of radical cystectomy as the standard treatment for patients with muscle-invasive bladder cancer, with bladder-preserving approaches as reasonable alternatives for patients who are medically unfit for surgery or seek an alternative 1.
From the Research
Grades of Bladder Cancer
- Bladder cancer can be classified into different grades, including low-grade and high-grade tumors 2.
- Low-grade tumors are typically non-invasive and have a low risk of progression, while high-grade tumors are more aggressive and have a higher risk of invasion and metastasis 3, 2.
- The grade of the tumor is determined by the pathological evaluation of the tumor tissue, and it is an important factor in determining the treatment and prognosis of the patient 2.
Low-Grade Bladder Cancer
- Low-grade bladder cancer accounts for approximately 70% of all bladder cancer cases and is characterized by recurrence and rare progression to high-grade tumors 4.
- Low-grade Ta tumors pose minimal risk to patients in terms of progression and disease-specific survival, and can be managed conservatively with office cystoscopy and fulguration or active surveillance 5.
- The International Bladder Cancer Group recommends that low-grade non-muscle-invasive bladder cancer be managed with a risk-adapted approach, taking into account the patient's individual risk factors and tumor characteristics 5.
High-Grade Bladder Cancer
- High-grade bladder cancer is more aggressive and has a higher risk of invasion and metastasis than low-grade tumors 3, 2.
- High-grade tumors are typically treated with more aggressive therapies, such as radical cystectomy and urinary diversion or trimodal therapy with maximal endoscopic resection, radiosensitizing chemotherapy, and radiation 3.
- The treatment of high-grade bladder cancer is undergoing rapid changes, with the introduction of new therapies such as immunotherapy with checkpoint inhibitors, targeted therapies, and antibody-drug conjugates 3.
Mixed Grade Tumors
- Mixed grade tumors are tumors that contain both low-grade and high-grade components, and account for approximately 5% of non-muscle-invasive bladder tumors 6.
- The clinical course of patients with mixed grade tumors is similar to that of patients with low-grade tumors, with a low risk of progression and disease-specific mortality 6.
- However, the management of mixed grade tumors can be challenging, and requires careful consideration of the patient's individual risk factors and tumor characteristics 6.