Superior vena cava (SVC) syndrome is a potential complication of lung cancer. SVC syndrome can develop over days to weeks and may start as edema (swelling) in the face, neck, or arms. As fluid accumulates, it can cause congestion and an uncomfortable feeling of stuffiness. If it’s not treated quickly, SVC can lead to trouble swallowing or breathing.

Learning how to recognize this potentially dangerous complication is essential for people with lung cancer and their loved ones.

What Causes Superior Vena Cava Syndrome?

SVC syndrome develops when blood is unable to flow normally into the heart. SVC syndrome is most common in people with cancer — especially lung cancer and lymphoma. The SVC is a vein that brings blood from the head, neck, shoulder, and arms back into the heart so it can be pumped out again.

SVC syndrome occurs when there is a disruption or blockage in the SVC. The most common causes are a mass, lymph nodes, or blood clots that compress the SVC and block natural blood flow. Blood backs up and becomes congested, causing the veins in the face, neck, and arms to become enlarged and swollen. The swollen veins lead to cyanosis (bluish skin) and swelling.

Common Symptoms of Superior Vena Cava Syndrome

SVC syndrome can be a life-threatening complication for people with lung cancer.

Symptoms of SVC syndrome include:

• Shortness of breath
• Swelling of veins in the chest or neck
• Headaches
• Facial congestion
• Hoarseness or other voice changes
• Cough
• Stuffiness
• Dizziness
• Bluish skin

Although rare, if left untreated, SVC syndrome may make it hard to swallow and breathe.

If you have lung cancer and notice any of these symptoms, seek medical attention right away. SVC syndrome is considered a medical emergency that requires urgent diagnosis and treatment.

SVC Syndrome Diagnosis

In some cases, SVC syndrome may be the first sign that someone has lung cancer, or that it has spread. SVC syndrome is diagnosed through clinical examination by a health care provider and imaging diagnostics. Imaging tests to help diagnose SVC syndrome include:

• Chest X-ray
• Ultrasound of the neck and arms
• CT scan of the chest
• MRI of the chest, neck, and head
• Angiography or venography (blood vessel study)

Because the severity of SVC syndrome is directly tied to the size of the blockage, these imaging tests can also help determine the best treatments. If you are receiving treatment for SVC syndrome, these tests can also be used to determine if they’re working or not.

Treatments for SVC Syndrome

Fortunately, once diagnosed, SVC syndrome is often treatable. Treatment for SVC syndrome focuses on reducing the size of the SVC obstruction and restoring normal blood flow back into the heart. Your doctor will work with a team of other experts to figure out the best treatment plan. It is common to have a team of specialists such as oncologists, pulmonologists, radiation oncologists, and interventional radiologists involved in the treatment of SVC syndrome.

Your doctor may prescribe diuretics (also known as water pills) to help you get rid of extra water and start feeling better, but these don’t treat the blockage itself. If a lung cancer tumor is obstructing the SVC, chemotherapy or radiation therapy may be used to reduce the size of the mass. If you have SVC syndrome caused by a blood clot, medications called anticoagulants (blood thinners) may be used to help restore blood flow and shrink the clot.

In severe cases, more advanced techniques may be needed to quickly resolve SVC syndrome. These treatments can include the placement of stents to open the SVC or targeted thrombolytic (anti-clotting) therapies for clots. Most procedures to treat SVC syndrome use minimally invasive catheters to navigate to the site of the obstruction and treat it at the source. Procedures to treat SVC are generally saved for cases when SVC syndrome needs immediate treatment, and medications aren’t working.

Does SVC Syndrome Affect Lung Cancer Prognosis?

Estimates suggest that as many as 90 percent of all SVC syndrome cases are caused by cancer, particularly lung cancer. According to a study found in the journal SpringerPlus, as many as 2 percent to 4 percent of all people diagnosed with lung cancer and 10 percent of people with small cell lung cancer may experience SVC syndrome at some point.

Tumor type and metastasis (spread) have a bigger impact on lung cancer outcomes than the development of SVC syndrome. If SVC syndrome develops due to an expansion in the tumor or as a result of tumor spread, this may affect your prognosis (outlook). In some cases when cancer has spread, the best treatment options are palliative efforts aimed at managing your symptoms and improving your comfort and quality of life.

If you have been diagnosed with SVC syndrome, plan to work with your oncologist to determine how this might affect your cancer treatment and prognosis. In many cases, treatment for lung cancer can continue. When malignancy is causing the SVC obstruction, treating cancer may help treat SVC syndrome at the same time.

Lifestyle Changes To Reduce SVC Syndrome Risk

Maintaining regular medical checkups and follow-up appointments can help ensure that your health care team can identify any signs of SVC early. Cutting out smoking can also help reduce your risk of SVC syndrome and improve your long-term prognosis with lung cancer.

MyLungCancerTeam Members on SVC Syndrome

Several members of MyLungCancerTeam have described their experiences with SVC syndrome. “My upper body was swollen, and my toes and fingers turned purple,” wrote one member. “The nurse knew it was critical and notified the doctor. A mass surrounded my superior vena cava and was closing it.”

“I ended up having a mass almost completely shut off my superior vena cava,” shared another member. “The doctors decided to save me by using radiation. It worked, or I would not be here.”

Identifying and promptly treating SVC syndrome is important because it can be a sign of cancer growth or spread. Your doctor and health care team will work to identify the cause of your SVC syndrome and treat it accordingly.

Find Your Team

MyLungCancerTeam is an online social support network for people living with lung cancer and their loved ones. More than 13,000 members gather to ask questions, give advice, and share their stories with other people who understand life with lung cancer.

Have you experienced SVC syndrome with lung cancer? What tests did your oncology team use to determine the cause of SVC syndrome, and how did they treat it? Share your thoughts in the comments below, or start a conversation on your Activities page.