Author: Beth Sissous
Kidney cancer can cause persistent lower back pain on one side, but this is usually when a tumor has grown very large. Early-stage kidney cancer often has no symptoms.
Back pain is a very common medical problem in the United States. It is most often due to injury or overuse but can sometimes be due to an underlying condition such as kidney cancer.
When kidney cancer causes back pain, a person may feel it on one side of the back or below the ribcage.
This article examines the link between kidney cancer and back pain, other signs and symptoms, diagnosis, and outlook.
Kidney cancer can cause pain on one side of the lower back. A person is more likely to experience back pain if their tumor is larger than 3 centimeters.
Although it is possible for people to feel a lump at their side or back due to a tumor, this is unlikely.
The kidneys are deep in the upper abdomen against muscle, so a tumor would have to be very large for a person to feel it.
If a person has back pain caused by kidney cancer, they will usually feel it in the lower back, on one side, between the ribs and hips.
A person will feel persistent pain that does not go away and is not due to an injury.
The kidneys are two small organs, roughly the size of a fist. The kidneys sit on either side of the spine, just under the rib cage.
A person is unlikely to have symptoms if they have early-stage kidney cancer.
As kidney cancer progresses, a person is more likely to have symptoms. According to the Centers for Disease Control and Prevention (CDC), the most common symptoms of kidney cancer are:
- blood in urine
- lump or swelling in the lower back or abdomen
- persistent pain in the back or side
- frequent tiredness or fatigue
- persistent fever
- loss of appetite
- unexplained weight loss
- a feeling of something blocking the bowels
- a general feeling of discomfort or being unwell
Other conditions, such as bladder infections, urinary tract infections, or kidney stones, may also cause some of these symptoms.
It is important to consult a doctor if a person experiences any of these symptoms to determine the underlying cause.
According to the American Urological Association, doctors discover more than half of abnormal growths in the kidneys by chance. When a person attends a routine screening or health check, a doctor may discover kidney problems.
There are no specific tests to find kidney tumors, but doctors may carry out a range of tests to check kidney health and diagnose a kidney condition:
- medical history and physical examination
- basic or complete metabolic panel (CMP), which shows how well organs are functioning
- complete blood count (CBC), a blood test to check for any markers of disease
- urine test, to check for any infections, and test for blood or protein in the urine
- kidney function tests, such as serum creatinine levels, to show how well the kidneys are eliminating waste
- ultrasound, to show images of the kidneys
If a kidney mass is present, doctors may use the following tests to determine whether it is cancerous:
- CT or MRI scans to diagnose the type and stage of a kidney mass
- biopsy of the kidney mass to check the type of tumor
- X-ray of the chest and bone scan to check whether cancer has spread
When to contact a doctor
People should consult a doctor if they have persistent, unexplained back pain.
If a person has symptoms of kidney cancer, such as blood in the urine, continuous fatigue, or unexplained weight loss, they should also contact a doctor.
A doctor might refer a person to a urologist, who specializes in the urinary system.
The American Cancer Society recommends that people with a higher risk of kidney cancer attend regular scans to check for kidney tumors.
People at high risk include those with inherited conditions, such as von Hippel-Lindau disease, or people with a family history of kidney cancer.
People may need to attend regular screening for kidney cancer, which may include CT and MRI scans or ultrasounds.
The outlook for kidney cancer can depend on the cancer stage at diagnosis and whether it has spread beyond the kidneys, alongside a person’s age and overall health.
According to the National Cancer Institute almost 7 out of 10 people receive a kidney cancer diagnosis before it has spread.
If doctors diagnose and begin treating kidney cancer in the early stages, the survival rates are very high.
A 5-year survival rate is the likelihood that a person will still be alive 5 years after diagnosis. The American Cancer Society provides the following 5-year survival rates for people with a kidney cancer diagnosis between 2010–2016:
- Localized — cancer only present in the kidney: 93% 5-year survival rate.
- Regional — cancer has spread to nearby areas or lymph nodes: 70% 5-year survival rate.
- Distant — cancer has spread to the lungs, bones, brain, or other distant areas: 13% 5-year survival rate.
These survival rates use older data. As treatments are constantly improving, the current outlook may be better.
Although early-stage kidney cancer may not cause symptoms, more developed kidney tumors might.
People may experience lower back pain on one side, between the ribs and the hips. In rare cases, people may feel a lump. Other symptoms can include blood in the urine, loss of appetite, fatigue, and persistent fever.
If people have persistent, unexplained back pain or any other symptoms of kidney cancer, they should consult a doctor.
Symptoms of kidney cancer can overlap with several benign conditions. Back pain is a common medical problem, but it is always important to check whether there is an underlying cause for persistent lower back pain.
Prompt treatment can usually cure early-stage kidney cancer.