Cervical cancer is a type of cancer that begins in the cells of the cervix, which is the lower, narrow part of the uterus connecting to the vagina. This cancer forms when cells grow abnormally and uncontrollably. Like many other cancers, cervical cancer has the capacity to extend beyond its original location. Understanding how and where this spread occurs is important for comprehending the disease’s progression.
How Cervical Cancer Spreads
Cervical cancer can spread through the body via several primary mechanisms. One way is through direct extension, where cancer cells grow directly into nearby tissues and organs, invading adjacent structures as the tumor expands. Cancer cells can also travel through the lymphatic system, a network of vessels and nodes that are part of the body’s immune defense. Cells can break away from the primary tumor, enter these lymphatic vessels, and then be carried to regional lymph nodes. A third route of spread is through the bloodstream, known as hematogenous spread. Cancer cells enter blood vessels and are transported through the circulatory system to distant parts of the body, where they can settle and form secondary tumors.
Regional Spread Near the Cervix
Cervical cancer commonly spreads to structures located close to the cervix through direct invasion. This can include the vagina, where cancer cells extend into its tissues. The bladder and the rectum are also susceptible to direct invasion. The cancer can also grow into the uterus itself, as well as the parametria, which are the tissues and ligaments surrounding the cervix and uterus.
Lymph nodes within the pelvic region are frequently involved in the early stages of cervical cancer spread. These regional lymph nodes include:
Obturator nodes
Internal iliac nodes
External iliac nodes
Common iliac nodes
Presacral nodes
Hypogastric nodes
Involvement of these pelvic lymph nodes is often an initial indication that the cancer has begun to extend beyond the cervix itself.
Distant Spread to Other Organs
Cervical cancer can spread far beyond the pelvic region, often through the bloodstream or extensive lymphatic involvement. The lungs are a frequent site for distant metastasis, reported in approximately 4.16% to 7.7% of patients, and the liver is another common organ for distant spread. Bones are also susceptible to distant spread, often affecting the axial skeleton, particularly the spine, ribs, and pelvis. Brain metastasis is less common but can occur. Distant lymph nodes outside the pelvis, such as the para-aortic and supraclavicular nodes, can also be affected in advanced stages.
Understanding the Stages of Spread
Knowing where cervical cancer has spread is fundamental for its classification. Medical professionals use staging systems, such as the International Federation of Gynecology and Obstetrics (FIGO) staging system, to define the extent of the cancer based on its spread. This system helps categorize the disease into different stages, with higher stages indicating more extensive spread. The stage of the cancer is a primary factor in determining a patient’s prognosis, or outlook. Understanding the spread helps medical teams classify the disease and plan management strategies.