Lupus and Cancer

According to PubMed, part of the National Library of Medicine in the US, individuals with systemic lupus erythematosus (a lupus condition) have an increased susceptibility to certain types of cancer, at a rate 3-4x in comparison to the general, unaffected population. While this statistic seems concerning, there are fortunately a few methods that those with the condition can undertake to decrease their risk.

However, first, it is important to understand why those with lupus are at higher risk for certain cancers, and what these cancers are to understand how they may be prevented.

*Disclaimer:

The information provided in this article is for general informational purposes only and is not intended as medical advice. It should not be used as a substitute for professional diagnosis, treatment, or advice from a qualified healthcare provider. Reliance on any information provided in this article is solely at your own risk.

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Firstly, it is important to note that for lupus patients, the total risk across all cancers is only elevated by 15% by having the condition. Whilst this increase is not insignificant, it puts into perspective that the heightened risk is manageable.

In reality, the pattern for cancer risk for lupus is incredibly scattered and varies from patient-to-patient. The statistic listed at the top of the article applies for haematological cancers – most specifically non-hodgkins lymphoma. Then, in order of decreasing risk, lung cancer has increased risk (although the reason for this will be debated later), as well as cervical dysplasia (a precancerous condition in females), breast, uterine and ovarian, as well as prostate (for males) cancers.

The reason why lupus appears to affect multiple organs found only in females is because 90% of lupus patients are women, and women are often already at higher risk for these cancers as they age. However, whilst lupus is often a condition associated with middle aged women, it is important to remark that lupus can affect men and teenagers as well. In fact – most who do develop lupus do so between 14 and 44.

Not necessarily all cancers are caused as a result of the condition itself – but rather, lifestyle choices made therefrom. For example, smoking has increased the rate of lung cancer diagnoses in lupus patients – not as a result of the condition but because smoking has been proven to be the number one risk factor for lung cancer.

Simply, the relationship between lupus and cancer, much like the relationship between the condition and other factors – is multifaceted and complex, but scientists have a few ideas for what causes lupus to increase the prevalence of these few cancers, one of which is immunosuppressive exposures. In simple terms, immunosuppressive exposures mean that via medication or environment, the immune system loses its ‘cancer-control’ ability by becoming immunocompromised – mostly through a process known as resultant dysregulated lymphocyte proliferation. This is when the immune system becomes unable to regulate the lifecycle (division, survival, etc.) of its T-cells – which coordinate the immune system’s attack, and B-cells – which produce antibodies against infections and diseases such as cancer. In the context of cancer, this means the immune system is less able to recognise a tumour and coordinate itself to fight and destroy it, thereby increasing the risk factor of certain cancers for individuals with lupus.

According to Johns Hopkins, other causes of increased cancer risk are certain medications sometimes prescribed to lupus patients – including Imuran and Cellcept*. Those with Sjogren's syndrome as well as lupus equally have an increased risk.

* azathioprine, mycophenolate mofetil

To prevent lung cancer, it is imperative that those with lupus do not smoke, as for those with lupus, lung cancer risk is already 140% the average population. 85% of lung cancer is caused as a result of tobacco. Therefore, lung cancer risk can be reduced by quitting smoking. At the same time, smoking inhibits lupus drugs like Plaquenil from functioning as intended, and increases the risk for secondary lupus conditions such as cardiovascular disease.

Regular screening and vigilance of cancers is equally important. For example, scheduled mammograms can allow healthcare professionals to spot breast cancer before it has the chance to grow and cause serious health issues. For the increased risk in cervical dysplasia, cervical screening may be helpful to those with lupus.

For each higher-risk cancer, the corresponding imaging technique is listed below:

Non-Hodgkins Lymphoma -> CT/PET/MRI

Cervical Dysplasia -> Cervical Screening

Breast Cancers -> Mammogram

Uterine Cancers -> Pelvic ultrasound, endometrial tissue sampling

Ovarian Cancers -> Transvaginal Ultrasound

Prostate Cancers -> DRE, MRI

Please note that the cancers that have been italicised are only screened for if a patient has symptoms – not only on the basis that they have lupus. Mammograms are performed regularly for women above 40, regardless if they have lupus or not. However, those with lupus may indeed benefit from more regular cervical screening than the general public. If you have concerns, please speak to a fully qualified medical professional before you make any decisions regarding screening.

Whilst the topic of cancer often is daunting to everyone, it is especially important that those with lupus are aware of and take active steps to reduce their risk. With methods on how to prevent cancer, and ideas about what causes lupus’ increased risk, the relationship between lupus and cancer becomes navigable for individuals with the condition.

Lupus and cancer | NIH

02 Lupus and cancer | BMJ

Lupus Facts and Statistics | Lupus Foundation of America

Lung Cancer Risk Factors | CDC

Lupus and Cancer | Johns Hopkins Lupus Centre