Transitional cell carcinoma

Signs and symptoms of transitional cell carcinomas depend on the location and extent of the cancer. Symptoms of bladder cancer is blood in the urine. ==Causes==

Urothelial carcinoma is a prototypical example of a malignancy arising from environmental carcinogenic influences. By far the most important cause is cigarette smoking, which contributes to approximately one-half of the disease burden. Chemical exposure, such as those sustained by workers in the petroleum industry, the manufacture of paints and pigments (e.g., aniline dyes), • Radiation exposure • Somatic mutation, such as deletion of chromosome 9q, 9p, 11p, 17p, 13q, 14q and overexpression of RAS (oncogene) and epidermal growth factor receptor (EGFR). • Presence of an abnormal extra chromosome, classified as a small supernumerary marker chromosome (sSMC), in this malignancy's tumor cells. The sSMC has an isochromosome-like structure consisting of two copies of the short (i.e. p) arm of chromosome 5. In consequence, the malignant cells bearing it have four copies of this p arm's genetic material, two from each of the normal chromosome 5's and two from the sSMC. "sSMC i(5)(p10)" is the single most common recurrent structural chromosomal abnormality in transitional cell carcinoma, being present in its malignant cells in most cases of the disease. Transitional cell bladder carcinomas associated with this sSMS are more aggressive and invasive than those not associated with it. ==Growth and spread==

Transitional cell carcinomas are often multifocal, with 30–40% of patients having more than one tumor at diagnosis. The pattern of growth of transitional cell carcinomas can be papillary, sessile, or carcinoma in situ. The most common site of transitional cell carcinoma metastasis outside the pelvis is bone (35%); of these, 40 percent are in the spine. ==Diagnosis==

, version 2.0, ranging from negative to positive for high grade urothelial carcinoma (HGUC). Transitional refers to the histological subtype of the cancerous cells as seen under a microscope. for p53 can help distinguish a PUNLMP from a low grade urothelial carcinoma. Overexpression is seen in 75% of low-grade urothelial carcinomas and only 10% of PUNLMP. Classification Transitional cell carcinomas are mostly papillary (70%, grading for papillary types (papillary neoplasm of low malignant potential [PNLMP], low grade, and high grade papillary carcinoma). High-grade carcinoma typically displays more pleomorphism, multiple mitoses, euchromatin and relatively prominent nucleoli, and uneven distribution of nuclei. File:Low- and high-grade urothelial carcinoma.jpg|Transitional cell carcinoma, being low-grade to the left, and high-grade to the right. H&E stain File:Papillary urothelial carcinoma (low-grade), intermed. mag.1.jpg|Papillary transitional cell carcinoma, low grade Image:Bladder urothelial carcinoma histopathology (1) at trigone.jpg|Histopathology of urothelial carcinoma of the urinary bladder, showing a nested pattern of invasion. Transurethral biopsy. H&E stain Image:Bladder urothelial carcinoma histopathology (2) at trigone.jpg|Histopathology of urothelial carcinoma of the urinary bladder. Image:Bladder urothelial carcinoma histopathology (3) at trigone.jpg|Histopathology of urothelial carcinoma of the urinary bladder. Image:urethral_urothelial_cell_carcinoma.jpg|Micrograph of urethral urothelial cell carcinoma. H&E stain ==Treatment==

Localized/early transitional cell carcinomas of bladder Transitional cell carcinomas can be very difficult to treat. Treatment for localized stage transitional cell carcinomas is surgical resection of the tumor, but recurrence is common. Some patients are given mitomycin into the bladder either as a one-off dose in the immediate post-operative period (within 24 hrs) or a few weeks after the surgery as a six dose regimen. Localized/early transitional cell carcinomas can also be treated with infusions of Bacille Calmette–Guérin into the bladder. These are given weekly for either 6 weeks (induction course) or 3 weeks (maintenance/booster dose). Side effects include a small chance of developing systemic tuberculosis or the patient becoming sensitized to BCG, causing severe intolerance and a possible reduction in bladder volume due to scarring. In patients with evidence of early muscular invasion, radical curative surgery in the form of a cysto-prostatectomy usually with lymph node sampling can also be performed. In such patients, a bowel loop is often used to create either a "neo-bladder" or an "ileal conduit" which act as a place for the storage of urine before it is evacuated from the body either via the urethra or a urostomy respectively. Advanced or metastatic transitional cell carcinomas First-line chemotherapy regimens for advanced or metastatic transitional cell carcinomas consists of gemcitabine and cisplatin) or a combination of methotrexate, vinblastine, adriamycin, and cisplatin (MVAC polychemotherapy). The side effects associated with some of these polychemotherapy treatment options are considered serious and mortality from MVAC treatment has been estimated at approximately 4%. Immunotherapy such as pembrolizumab is often used as second-line therapy for metastatic urothelial carcinoma that has progressed despite treatment with GC or MVAC, however this is based on low certainty evidence. In May 2016, the FDA granted accelerated approval to atezolizumab for locally advanced or metastatic urothelial carcinoma treatment after failure of cisplatin-based chemotherapy. The confirmatory trial (to convert the accelerated approval into a full approval) failed to achieve its primary endpoint of overall survival. In April 2021, the FDA granted accelerated approval to sacituzumab govitecan for people with locally advanced or metastatic urothelial cancer (mUC) who previously received a platinum-containing chemotherapy and either a programmed death receptor-1 (PD-1) or a programmed death-ligand 1 (PD-L1) inhibitor. ==Prostate==

Transitional cell carcinomas can also be associated with the prostate. == See also ==