Metastatic cancer is a cancer that has spread from its primary site to other parts of the body. This spread of cancer cells is called metastasis or metastatic growth. The fatality rate is high with metastatic cancer. The most common metastasis from solid tumours occurs in the lungs, liver, brain and bones.
There are several routes by which the cancer cells from the primary site travel throughout the body.
- Transcoelomic spread: When the cancer cells spread into the body cavities such as peritoneal (lining of abdomen), pleural (lining of lung), pericardial (lining of heart), or subarachnoid space (around the brain), it is called transcoelomic spread.
- Lymphatic spread: The cancer cells break from the primary tumour and travels through lymph vessels to reaches other parts of the body. It is the most common route for metastatic cancer.
- Blood spread: The cancer cells get into the blood stream and reach to the arteries and veins.
- Transplatation or implantation: When the regional lymph nodes from the primary tumour are affected with cancer cells, it is known as nodal involvement.
Spread of cancer from primary organ
Bones is the commonest metastatic cancer from breast cancer. It does spread to lungs, liver, skin of the chest and brain.
Cancer of cervix first spreads to the vagina, uterus and then to pelvis, rectum and bladder. In most advanced stage it can grow into bones, nerves, liver, and lungs.
This type of blood cancer can spread outside the blood too. It affects the subarachoid space in the brain, spinal cord, spleen, and liver.
There are high chances that lung cancer can spread to any organ in the body.
Cancer of ovary/ovaries most often spread to the peritoneal cavity, peritoneum, and pleural cavity. Later it may involve liver, lungs, and brain.
Most often it spread to adrenal gland (organ situated above the kidney), boned, brain, liver and lung.
Metastasis of pancreas occurs in liver, lung and peritoneum.
Signs and Symptoms of Metastatic Cancer
Onset of symptoms depends on the size and location of metastasis. Fatigue, tired feeling, unintentional weight loss are the general signs and symptoms of metastatic cancer.
Organ specific symptoms
Bones: Pain is the common symptom when metastasis occurs in bone. It is worse at night and relieved by motion. In advanced stage it becomes progressive.
Lymph nodes: Swollen firm lymph nodes which may compress the structures near to them, causing complications.
Lungs: Cough, shortness of breath, coughing up blood (hemoptysis)
Brain: Headaches, dizziness, convulsions.
Tests and Diagnosis of Metastatic Cancer
When the tissue from the metastatic cancer is examined under microscope they look the same as cells of the original cancer.
High level of calcium indicates metastasis has occurred in bones.
Tumour markers: PSA (prostate-specific antigen) for prostate cancer and CEA (carcinoembryonic antigen) for colon cancer.
- CT (computed tomography) scan
- MRI (magnetic resonance imaging)
- PET (positron emission tomography) scan
- Bone scan
Biopsy: an examination of tissue removed from the tumour to detect the metastasis.
Bone marrow aspiration and biopsy.
Lumbar puncture: It detects cancer which has spread to the fluid or tissues (the meninges) that surround the brain and spinal cord.
Paracentesis: To detect cancer cells in the fluid in the abdominal cavity.
Thoracentesis: To examine the fluid that has built up in the space around the lung for cancer cells.
Treatment of Metastatic Cancer
It depends on various factors such as:
- Type of primary cancer
- The size, location of metastatic tumors
- patient’s age and general health
Accordingly treatment plan includes surgery, chemotherapy, radiotherapy or combination of these therapies.
Prevention of Metastatic Cancer
Early detection of cancer can prevent it to grow and metastasize by appropriate treatment.