Research has shown that smoking is associated with an increased risk of developing myeloproliferative neoplasms (MPNs), as well as further risks if you already have MPNs.

MPNs are a group of blood cancers that are caused by a genetic mutation in the stem cells of the bone marrow. The mutated stem cells start making too much of one or more types of blood cells: white blood cells, red blood cells, or platelets. The four major types of MPNs are based on which types of cells are affected:

• Polycythemia vera (PV) — Too many red blood cells
• Essential thrombocythemia (ET) — Too many platelets
• Primary myelofibrosis (PMF) — Impaired production of granulocytes (a type of white blood cell) and red blood cells
• Chronic myelogenous leukemia (CML) — Too many white blood cells

Researchers aren’t exactly sure what causes MPNs, but studies have pointed to environmental and genetic risk factors as contributors. One environmental risk factor is smoking. Tobacco contains many carcinogens (substances that can cause cancer), among them benzene.

Here’s what to know about the connection between smoking and MPNs, as well as the benefits of quitting smoking if you have an MPN — including fewer or less severe symptoms, more effective MPN treatments, and more.

How Is Smoking Connected to MPNs?

Cigarette smoke contains more than 4,000 chemicals and 60 carcinogens. When cigarette smoke is inhaled, the body launches an inflammatory response to minimize damage from the chemicals. If the inflammatory response lasts too long or the body can’t shut it down properly, it leads to chronic inflammation. If the source of the chronic inflammation is not removed, cells can begin to mutate and multiply rapidly, increasing the risk of cancer. Additionally, benzene — one of the carcinogens found in cigarette smoke — has been shown to cause acute leukemia.

Several studies have documented the connection between smoking and MPNs. In a 2018 study, researchers used data from the Danish Health Examination Survey to uncover a significant association between smoking and the development of MPNs.

Another meta-analysis of several studies concluded that smoking increased several inflammatory markers in the blood. These markers were linked to increased risk of MPNs in people who currently or formerly smoked compared to people who never smoked.

Benefits of Quitting Smoking

Quitting smoking has several important benefits if you’re living with an MPN.

Reduce Symptoms of MPNs

Data from the Mayo Clinic and the Myeloproliferative Neoplasm Quality of Life Group show that people who smoke or formerly smoked self-report worse symptoms than people who don’t use tobacco. People who smoke or formerly smoked reported more feelings of fatigue, early satiety (feeling full when eating), and problems concentrating compared to those who didn’t smoke. Researchers went on to say that quitting smoking can help lessen the intensity of symptoms over time.

Increase the Effectiveness of Treatments

Smoking has been shown to interfere with cancer treatments, causing delays, dose reductions, or early treatment cessation. With PV and ET, treatment may include aspirin to reduce the risk of thrombosis (blood clots). Smoking reduces the effectiveness of the anti-clotting mechanism of aspirin, resulting in aspirin treatment that is ineffective or that requires a higher dosage than usual.

Toxins in tobacco can change the outcomes of cancer treatments, too. Depending on the individual, smoking can increase the toxicity of chemotherapy drugs or make them less effective.

Quitting smoking can help cancer treatments do their job and allow your body to heal more quickly.

Help Reduce the Side Effects of Treatments

Cancer treatments like chemotherapy, surgery, or radiation can have side effects such as nausea, fatigue, weight loss, and pain. Smoking while in treatment can intensify side effects and cause them to linger.

One study tracked people undergoing radiation or chemotherapy treatment for cancer. Six months after treatment ended, people who smoked reported more sleep problems, depression, concentration problems, and weight loss than people who didn’t smoke. In comparison, people who didn’t smoke reported fewer side effects that lasted for less time. Moreover, people who quit smoking before treatment showed side-effect results similar to people who didn’t smoke.

Reduce the Chances of Secondary Cancers

Quitting smoking reduces the chance that cancer will occur elsewhere in the body. Cancer can occur anywhere. Smoking increases the risk of almost all cancers, as the toxins in cigarette smoke affect nearly all the body’s major organs.

Cutting Back Vs. Quitting

Because cigarette smoke contains known carcinogens, there is no safe limit to smoke. However, reducing the amount you smoke can be a step in the right direction to stop smoking completely.

What About E-Cigarettes?

E-cigarettes (also known as vaping) are often perceived as a safer alternative to smoking tobacco products. However, research has shown that using e-cigarettes causes an inflammatory reaction and contributes to cell DNA damage. Further research is needed to fully understand how e-cigarettes impact health.

Talking With Your Doctor About Quitting Smoking

People who smoke and who have been diagnosed with MPNs may be reluctant to talk with their health care providers about their smoking. You may feel that quitting smoking after receiving a diagnosis is useless, or you may worry that your health care team will judge you if you’re honest about your smoking habits. However, your health care team is there to support you, and these hard conversations are often well worth it.

For example, people who quit even after a diagnosis can improve their overall health and obtain a better quality of life. A 2012 study of people who quit smoking documented an improvement in quality of life that persisted three years after quitting.

Your doctor can help you stop smoking by giving you suggestions to reduce cravings and increase healthy habits. If you are concerned about your smoking and how it may impact your health, talk with your health care provider.

Talk With Others Who Understand

Quitting smoking is tough for many people, but you don’t have to go through it alone. On myMPNteam, the social network for people with myeloproliferative neoplasms, more than 2,000 members come together to ask questions, give advice, and share their stories with others who understand life with myeloproliferative neoplasms.

Have you quit smoking since being diagnosed with an MPN? Share your experience in the comments below, or start a conversation by posting on myMPNteam.