New treatments are better at slowing chronic lymphocytic leukemia (CLL), but this cancer still isn't curable. Genetic changes in the cancer cells can help doctors predict how the disease will progress and when it may no longer respond to treatment. Doctors call this a relapse or recurrence. It’s when your cancer responded to treatment for 6 months or more, then stopped responding after 6 months or more of treatment. If your cancer comes back, it may be time to restart or change your treatment.

CLL causes large numbers of abnormal white blood cells called lymphocytes to collect in places like your lymph nodes, spleen, and liver. It’s a slow-growing cancer that often takes many years to come back or progress. But when CLL does progress and more abnormal cells build up, the affected organs can't work normally. When it comes back or progresses after you’ve been on treatment, a few symptoms can provide clues that it's time to check back in with your doctor.

Quickly dropping at least 10% of your body weight is a sign your cancer has progressed. If you weigh 160 pounds, for example, that would be a rapid loss of 16 pounds. This happens for a few reasons. First, cancer cells burn more energy than healthy ones. Chemicals your immune system makes to fight cancer can also suppress your appetite. Finally, an enlarged spleen can press on your stomach and make you feel full more quickly after you eat.

Lymph nodes are pea-sized glands on the sides of your neck, under your arms, and in your groin, among other places. They're filled with disease-fighting white blood cells that multiply when you have an infection or your cancer grows. Swollen lymph nodes from an infection are usually tender and disappear within a couple of weeks. Cancer-related swelling is hard and painless, and it lasts longer than 2 weeks.

Cancer fatigue isn't ordinary tiredness. It makes you feel exhausted, even if you sleep well at night. Chemicals that your white blood cells release in response to your cancer can make you tired. Cancer-related stress and pain also contribute to fatigue. So can having too few red blood cells, a condition called anemia. You need these cells to carry oxygen to your brain and other organs. With lower oxygen levels, you’ll feel more tired.

A fever higher than 100.4 F that lasts for more than 2 weeks could be a sign that your cancer has progressed. A fever can also be a sign of infection, which is a bigger risk for people with CLL because the disease weakens your immune system. With an infection, though, you'll usually have other symptoms like a cough, sore throat, or stuffy nose.

Sweating at night could simply mean that your bedroom is too hot or your covers are too heavy. But waking up drenched in sweat with your sheets soaked through could be night sweats from CLL, especially if this symptom lasts longer than a month. Night sweats can be a sign of infection or your body fighting cancer. Chemotherapy can also cause a rise in body temperature that could lead to night sweats.

Your spleen is an organ in your immune system that sits on the left side of your belly, just behind your ribs. It's filled with infection-fighting white blood cells. When leukemia cells multiply inside the spleen, it swells up. You might not be able to see the swelling, but you will likely  feel a fullness in your belly.

CLL can change from a slow-growing or low-grade cancer to an aggressive and fast-growing or high-grade cancer. Bone pain is a sign that your cancer is growing more quickly. The pain happens when leukemia cells multiply in your bone marrow – the spongy material inside your bones – and put pressure on nerves.

As cancer cells multiply in your bone marrow, they crowd out healthy red blood cells and platelets. An abnormal blood test would show that your lymphocytes increased by more than 50% in 2 months or doubled in less than 6 months. Shortness of breath and tiredness are signs of low red blood cells, also called anemia. Unusual bruising and bleeding are signs of low platelets, called thrombocytopenia.

Your doctor will choose the right treatment for you based on many things, including what treatment you were on before, how well and how long it worked, and specifics about you and your cancer. Your medical team will monitor you often during and after treatment. If you have symptoms between visits, let your doctor know. An exam and blood tests can confirm whether your cancer has come back or progressed. Treatment could include the same medicines you took before or a different kind of cancer drug.