Urachal cancer is a rare form of cancer that originates from the urachus, a structure present during fetal development. This tube connects the developing bladder to the belly button, or umbilicus. Before birth, the urachus typically shrinks and becomes a solid cord, but occasionally, small remnants of this tissue persist into adulthood. Cancer can rarely form within these remnants, usually near the top of the bladder. It is a rare malignancy, affecting about one in a million people each year. This cancer is distinct from typical bladder cancer, though it often involves the bladder wall due to its anatomical location.
Signs and Symptoms
The presence of blood in the urine, known as hematuria, is the most frequently reported initial symptom of urachal cancer. This blood may be visible to the naked eye, appearing pink, red, or cola-colored, or it might only be detected through microscopic examination. Another common indication is discomfort in the lower abdomen or pelvic region. Individuals might also notice a palpable lump or mass just below the navel.
Some people experience mucus-like or bloody discharge from their belly button. Changes in urination patterns can also occur, such as a painful or burning sensation during urination, increased frequency, or a strong, sudden urge to urinate. Recurring urinary tract infections that are recurrent or persistent can also suggest the presence of urachal remnants that have become cancerous. These symptoms warrant medical evaluation to determine their underlying cause.
Diagnosis and Staging
The diagnostic process for urachal cancer begins after symptoms appear, often involving imaging tests to visualize the tumor. Doctors use computed tomography (CT) scans and magnetic resonance imaging (MRI) of the abdomen and pelvis to assess the tumor’s size, exact location, and whether it has extended into surrounding tissues. These scans help determine if the cancer has spread to nearby lymph nodes or distant organs. Following initial imaging, a cystoscopy is performed.
During a cystoscopy, a thin tube with a camera is inserted through the urethra into the bladder, allowing direct examination of the bladder lining and identification of any abnormal growths, particularly at the dome of the bladder where the urachus connects. The definitive diagnosis of urachal cancer is established through a biopsy. A small tissue sample from the suspicious area is removed during the cystoscopy or another procedure and then examined under a microscope by a pathologist to confirm cancer cells and determine the type, which is most often adenocarcinoma.
Once cancer is confirmed, it is “staged” to describe the extent of the disease, guiding treatment decisions and prognosis. Staging systems classify the cancer based on how deeply the tumor has grown, whether it has spread to nearby lymph nodes, or if it has metastasized to distant parts of the body. Early stages indicate the cancer is confined to the urachus or superficial bladder layers, while later stages signify deeper invasion into the bladder wall, spread to regional lymph nodes, or distant metastasis to organs like the lungs or bones. This assessment helps tailor the treatment plan for each patient.
Treatment Protocols
Surgical removal is the primary treatment approach for localized urachal cancer, aiming to completely excise the tumor and associated structures. The standard procedure involves an “en bloc” resection, removing the tumor along with a section of the bladder (partial cystectomy), the entire urachal ligament, and the belly button (umbilectomy) in one piece. This extensive removal ensures all cancerous tissue and urachal remnants are eliminated, reducing the risk of recurrence. This surgical strategy is associated with favorable long-term outcomes for patients with localized disease.
Chemotherapy plays a different role in managing urachal cancer. It is not typically the first-line treatment for cancer confined to its original site. However, for cases where the cancer has spread beyond the urachus and bladder (metastatic disease) or has a high risk of recurrence, chemotherapy may be considered. Commonly used chemotherapy regimens might include agents like 5-fluorouracil, cisplatin, or gemcitabine, sometimes in combination protocols. These treatments aim to control disease progression and improve survival in more advanced stages.
Radiation therapy is less commonly used as a standalone treatment for urachal cancer due to the tumor’s limited sensitivity to radiation. It may be used in specific circumstances, such as to manage localized pain caused by the tumor or in cases where surgical margins are not clear after an operation. Radiation therapy can also be considered for inoperable localized disease, although strong evidence for its effectiveness in improving cure rates alone is not consistently demonstrated. The treatment strategy is tailored based on the individual’s cancer stage and characteristics.
Prognosis and Follow-Up Care
The long-term outlook for individuals with urachal cancer is influenced by several factors, particularly the stage at which the cancer is diagnosed and the completeness of surgical removal. Tumors detected at an early stage that can be fully resected tend to have a more favorable prognosis. Conversely, cancer that has spread to lymph nodes or distant organs before diagnosis generally carries a less favorable outlook. Five-year overall survival rates can vary, often around 50% across all stages, but are considerably higher for early-stage disease.
Following initial treatment, long-term follow-up care is a standard and important part of managing urachal cancer. This surveillance involves regular monitoring to detect any signs of cancer recurrence as early as possible. Periodic imaging tests are routinely performed to check for new tumor growth or spread. Cystoscopies may also be part of the follow-up schedule to visually inspect the bladder for any suspicious changes. This ongoing vigilance helps ensure that any recurrence can be addressed promptly.