As I introduced in my last post, the superior vena cava SVC syndrome occurs in about 2-4% of lung cancer cases, and lung cancer is the leading reason for it. One of the most important factors in managing it is to determine, usually with CT imaging, the cause of the SVC syndrome -- generally whether it's caused from tumor or a blood clot, such as around a catheter.

To recap, the appearance of a CT scan may look like this, with the large vein known as the SVC compressed between the tumor (in the lung, which is black) and the mass of lymph nodes toward the middle of the chest:

(Click to enlarge)

If this is an initial presentation and there is no diagnosis yet, it's important to get tissue as one of the first steps. The symptoms usually develop over weeks, and studies have actually shown that it's rare for there to be significant consequences in taking the time to complete the workup and figure out the cause, rather than just frantically start treating without knowing what you're treating. The treatment of choice depends in part on whether this is SCLC, NSCLC, lymphoma, or something else. And just jumping in with something like radiation can make it hard to determine the actual diagnosis later.

Studies have actually compared radiation as the initial treatment to chemo as the initial treatment or a combination of both, and they're all overall about the same. But SCLC and lymphoma, as well as less common causes like germ cell tumors, are often very sensitive to chemotherapy, so there isn't a clear reason to start radiation if you need to provide a more global treatment and chemotherapy will treat the local problem effectively. In some cases, such as limited disease SCLC, the standard treatment approach is a combination of chemo and radiation that is usually going to work quite well. NSCLC, on the other hand, doesn't tend to shrink as reliably or rapidly with chemo, so radiation may be added in the setting of more advanced disease to get some initial control over the SVC syndrome. If it's in a palliative setting, like advanced NSCLC, this is most typically going to be a relatively short course of radiation over 2-3 weeks, often given before starting any chemo. However, if the situation is stage III, unresectable but potentially curable NSCLC, the optimal approach may be a longer course of higher dose radiation given concurrent with chemotherapy. However, it's been reported that SVC syndrome in the setting of NSCLC is associated with a worse prognosis (abstract here); this hasn't been seen for SCLC (abstract here).

Some other treatments that are commonly used to improve symptoms are steroids, diuretics like lasix, and head elevation. These don't have proven benefits in dedicated studies, but there have been improvements described in several case studies. Steroids are often rapidly effective for lymphomas and germ cell tumors.

Other options are placing a stent in the SVC, which can be done without a tissue diagnosis, or rarely surgery. And for patients with a blood clot as a cause, blood thinners are generally given. This is often in the setting of having an indwelling catheter, which is nearly always going to need to be removed.

There are certainly some specific issues that arise for particular cases, such as SVC syndrome developing in patients with recurrence of disease, but at least we've outlined the basics here.