Prostate cancer originates in the prostate gland. While often treatable when confined, a significant concern arises if it spreads beyond its initial location. This process, known as metastasis, means cancer cells have traveled from the primary tumor to establish new growths in other parts of the body.
How Prostate Cancer Spreads
Prostate cancer can spread through several pathways. One method is direct extension, where the cancer grows into nearby tissues, such as the seminal vesicles or the bladder.
Cancer cells can also enter the lymphatic system. Once in the lymphatic vessels, cancer cells can travel to nearby lymph nodes, particularly those in the pelvic area, and then to more distant lymph nodes.
Another pathway is through the bloodstream. Cancer cells can detach from the primary tumor, enter small blood vessels, and circulate to distant organs, forming new tumors.
Most Common Locations of Spread
Bones are the most frequent site for prostate cancer to metastasize. Over 60% of men with advanced prostate cancer may develop bone metastases. Common bone sites include the spine, pelvis, ribs, and hips, which can lead to pain and increased fracture risk.
Lymph nodes are also a common location for prostate cancer spread. Cancer cells often first travel to lymph nodes near the prostate gland, then extend to more distant nodes.
The lungs represent another potential site for distant spread. While less common than bone or lymph node involvement, lung metastases are a recognized pattern of advanced prostate cancer.
The liver is another organ where prostate cancer can spread. Liver metastases typically indicate an advanced stage of the disease, sometimes detected late due to a lack of early symptoms.
Spread to the brain is less common. When it occurs, it is typically seen in advanced cases, but remains a possible outcome of widespread disease.
Recognizing Symptoms of Spread
When cancer metastasizes to the bones, persistent bone pain is common, often felt in the back, hips, or pelvis. Bones may also become weaker and more prone to fractures. If the cancer spreads to the spine, it can compress the spinal cord, potentially causing weakness, numbness, or tingling in the legs, which requires immediate medical attention.
Spread to lymph nodes may not always cause symptoms. If it does, it might lead to swelling and discomfort in the affected area, or swelling in the legs if lymphatic fluid drainage is blocked.
Lung metastasis can present with respiratory symptoms. These may include a persistent cough, shortness of breath, or chest pain.
Liver metastasis can cause abdominal pain or discomfort, often in the upper right side of the abdomen. Other indicators might include jaundice (yellowing of the skin and eyes), fatigue, or unexplained weight loss.
Brain metastasis can manifest with symptoms such as headaches, seizures, changes in vision, or cognitive alterations. Weakness or numbness on one side of the body can also occur.
Identifying Distant Spread
Blood tests are often part of the evaluation, including monitoring prostate-specific antigen (PSA) levels. A rising PSA can indicate advanced disease or recurrence.
Imaging scans are crucial for detecting and locating metastatic sites. Bone scans use a radioactive tracer to highlight areas of increased bone activity, indicating cancer spread.
Computed Tomography (CT) scans provide detailed cross-sectional images that can reveal cancer in lymph nodes or other organs. Magnetic Resonance Imaging (MRI) uses magnetic fields and radio waves to create detailed pictures, useful for assessing spread to lymph nodes or other soft tissues.
PSMA PET scans are also used, involving a radioactive tracer that binds specifically to prostate cancer cells. This allows for sensitive detection of cancer anywhere in the body.
If a suspicious area is identified through imaging, a biopsy may be performed to confirm the presence of cancer cells and determine their type.