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Symptoms of Cancer

By Bruce A. Chabner, MD, Elizabeth Chabner Thompson, MD, MPH

At first, cancer, as a tiny mass of cells, causes no symptoms whatsoever. As a cancer grows, its physical presence can affect nearby tissues. Also, some cancers secrete certain substances or trigger immune reactions that cause symptoms in other parts of the body that are not near to the cancer (paraneoplastic syndromes—see see Paraneoplastic Syndromes).

Sometimes the initial indication is an abnormal result on a laboratory test done for another reason (for example anemia resulting from colon cancer found on a routine complete blood count).

Cancer affects nearby tissues by growing into or pushing on them, thus irritating or compressing them. Irritation typically causes pain. Compression may keep tissues from performing their normal functions. For example, a bladder cancer or a cancerous lymph node in the abdomen may compress the tube (ureter) connecting a kidney with the bladder, blocking the flow of urine. A lung cancer may block airflow through one segment of a lung, causing partial lung collapse and predisposing to infection. When cancer grows in an area with a lot of space, such as in the wall of the large intestine or the lung cavity, it may not cause any symptoms until it becomes quite large. In contrast, a cancer growing in a more restricted space, such as on a vocal cord, may cause symptoms (such as hoarseness) when it is relatively small. If a cancer spreads (metastasizes) to other parts of the body, the same local effects of irritation and compression eventually occur, but in the new location, so the symptoms may be quite different. Cancers that involve the membrane covering the lungs (pleura) or the baglike structure that surrounds the heart (pericardium) often ooze fluid, which collects around those organs. Large fluid collections can interfere with breathing or the pumping of the heart.

Some Complications of Cancer



Cardiac tamponade

Fluid accumulates in the baglike structure surrounding the heart (pericardium, or pericardial sac). This fluid puts pressure on the heart and interferes with its ability to pump blood. Fluid can accumulate when a cancer invades the pericardium and irritates it.

Pleural effusion

Fluid accumulates in the baglike structure around the lungs (pleural sac), causing shortness of breath.

Superior vena cava syndrome

Cancer partially or completely blocks the vein (superior vena cava) that drains blood from the upper part of the body into the heart. Blockage of the superior vena cava causes the veins in the upper part of the chest and neck to swell, resulting in swelling of the face, neck, and upper part of the chest.

Spinal cord compression

Cancer compresses the spinal cord or the spinal cord nerves, resulting in pain and loss of function (such as urinary or fecal incontinence). The longer the compression of the spinal cord or spinal cord nerves persists, the less likely normal nerve function will return when the compression is relieved.

Brain dysfunction

The brain functions abnormally as a result of a cancer growing within it, either as a primary brain cancer or more commonly as a metastasis from a cancer elsewhere in the body. Many different symptoms can occur, including confusion, drowsiness, agitation, headaches, abnormal vision, abnormal sensations, weakness, nausea, vomiting, and seizures.


Bleeding may result from invasion and death of normal tissues and blood vessels or from the growth of abnormal, fragile blood vessels within a tumor.

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