Dermatomyositis is an autoimmune disease primarily affecting the muscles and skin. It can cause complications, including an increased risk of small cell lung cancer (SCLC) and other cancers.
Dermatomyositis can lead to muscle weakness and movement difficulties that gradually worsen. In contrast, SCLC is a highly aggressive type of lung cancer that grows quickly and can potentially spread to other body parts.
Interestingly, dermatomyositis and SCLC share a connection. Sometimes individuals with dermatomyositis may also develop SCLC, and vice versa. For some, dermatomyositis can be an early indicator of underlying SCLC. It’s important that anyone with dermatomyositis symptoms undergo a thorough medical assessment. A healthcare professional may also recommend ongoing monitoring.
This article explores the link between dermatomyositis and SCLC, the causes, and a person’s outlook.
The condition can lead to muscle weakness, particularly in the hips, thighs, shoulders, and upper arms. Over time this leads to difficulty in the following activities:
- climbing stairs
- getting up from a seat
- lifting objects
While the exact cause of DM is still unknown, experts believe it may involve an abnormal immune system response that mistakenly attacks healthy tissues in the body.
There is a recognized association between DM and malignancies. Studies show that individuals with DM have a
How often do lung cancer patients develop DM?
In a retrospective
The exact reasons behind the association are not fully understood. More research is needed to establish a definitive relationship.
Experts remain unsure of the exact underlying mechanisms linking DM and SCLC, but it can include:
One possible explanation for the link is the concept of paraneoplastic syndrome. Paraneoplastic syndromes are a group of disorders that occur due to an
Some experts have found specific antibodies that attack healthy tissues may play a role. This includes an antibody that defends against TIF1-gamma called anti-TIF1-gamma antibodies. It targets markers primarily found in the muscles and skin. Around 84% of people with anti-TIF1-gamma antibodies have cancer-associate DM.
Usually, TIF1-gamma acts as a tumor suppressor and helps regulate cell growth. However, mutations in TIF1-gamma can lead to uncontrolled cell division.
Antibodies produced by the immune system directed against mutated TIF1-gamma proteins in cancer cells may mistakenly bind to normal TIF1-gamma receptors in healthy muscles and skin, triggering DM. This theory is called ‘molecular mimicry’ and can explain how SCLC triggers the autoimmune response of DM.
Another theory focuses on shared genetic factors. Certain genetic predispositions may make individuals more susceptible to both DM and SCLC. This could help explain why some individuals with DM go on to develop SCLC, while others do not.
Furthermore, DM and SCLC may share risk factors
Yes, experts link DM with various cancers. These
- blood cancers
- gastrointestinal cancers
DM is a paraneoplastic response to cancer. It does not cause cancer.
DM treatment aims to manage inflammation and symptoms. While treating DM itself may not directly reduce the risk of developing SCLC, early detection and appropriate management of both conditions is beneficial.
For example, in a 2021 case study, doctors reported the individual experienced a significant improvement in DM symptoms after receiving chemotherapy and radiation treatment for SCLC. However, resolving DM symptoms does not mean the cancer is cured.
Therefore, it is crucial for healthcare professionals to carefully monitor DM cases to check for SCLC. Regular screenings and evaluation, using imaging and pulmonary function tests, may help detect SCLC earlier, potentially improving treatment options and a person’s outlook.
Furthermore, a 2020 study conducted in China noted that the 5-year survival rate for those with DM is between 60% and 90%. But this drops to between 10% and 56% when the person also has cancer.
Dermatomyositis (DM) is a rare autoimmune condition primarily affecting the muscles and skin. DM can arise in individuals with a higher risk of developing cancer, including small cell lung cancer (SCLC).
The connection between the two diseases is not fully understood. However, research suggests a dysfunctional immune response to cancer cells is a likely contributor. There may also be shared risk factors such as smoking.
People with DM and SCLC typically have a less optimistic outlook, but working with their healthcare team to create a personalized treatment plan may help improve their outlook.