Oncologic Emergencies – 9 – SVC Syndrome
Oncologic Emergencies PART – 9
(All the articles published in past are available at www.shyamhemoncclinic.com/blog/)
Question: Last time we discussed Back Pain as an emergency. 1. We discussed impact of cord compression on quality of life, i.e. living with paraplegia. 2. How stage 4 patients live very long now with good quality of life, in many cases including cure. Such as lymphoma, myeloma, lung, breast, prostate cancer. It is important to individualize, rather than consider all stage 4 patients as same. 3. Cost of the interventions to prevent paraplegia are low. Also, many options exist even for poor patients. What is the next oncologic emergency?
Ans: SVC Syndrome – Superior Vena Cava syndrome. Resulting from external compression of SVC or Thrombosis. This is a fairly common oncologic issue, either in newly diagnosed cancer patients or those under treatment. Traditionally considered an emergency. HOWEVER, for last about couple of decades, oncology experts have come to an understanding that this is not a true emergency in most cases. Earlier empiric Steroids and/or Radiotherapy were started right away, considering this a real emergency. Over time, with better documentation and research, we have however learned that most cases have some collateral circulation by the time they present to us. Only those with respiratory issues like Stridor (due to laryngeal edema) or associated airway compression by tumor represent true emergency.
Que: How do these patients present? And what are common cancers associated with SVC syndrome?
Ans: Most of the time, presentation is dramatic enough to be diagnostic. Obvious swelling of face and neck, with symptoms of headache, fullness in head, difficulty breathing. Plus symptoms exacerbated by lying down or bending forward. In addition, there may be dilated chest veins, and various symptoms from underlying malignancy itself. As mentioned earlier, a TRUE EMERGENCY is uncommon, with stridor, or drowsiness/coma from cerebral edema.
LUNG cancer, and LYMPHOMA are the most common cancers. Rarely, germ cell tumor, thymoma, others. Few non malignant conditions can also cause SVC syndrome.
Que: How do you treat them? And why did you mention TRUE Emergency again?
Ans: I would like readers to know that most cases are not true emergency. This is important to avoid empiric steroids, as a large number of cases are due to lymphoma. Empiric steroids can cause marked changes in lymphoma tissue. Biopsy interpretation may become impossible in several cases. Also, steroids have little role in non lymphoma cases. HENCE, MOST IMPORTANT POINT IS TO RECOGNIZE this condition, and refer patient to an oncologist or appropriate specialist right away. These patients do need rapid diagnosis and then treatment. Rapid diagnosis of underlying condition and its treatment is the mainstay. Lung cancer and lymphoma are treated very differently. Also, patients with central venous catheters is also a significant subset of SVC syndrome these days. Catheter related thrombosis is a common condition now, due to rising use of these catheters, in many specialties. CT scan of chest is usually diagnostic. CT guided biopsy, or bronchoscopy are most common ways to obtain biopsy nowadays. Post biopsy, if lymphoma is suspected, steroids can be initiated. For other patients, chemotherapy or other appropriate treatment is given. For patients with lung cancer, SVC syndrome correlated with poor prognosis, median survival less than six months. In such cases, for quality of life, SVC stent may be considered. More so if patient has developed SVC syndrome after failure of first line treatment. SVC stent has good success rate, and low rate of recurrent thrombosis, if an expert is available. Also, symptom resolution is faster compared to other therapies, except in lymphoma. Role of anticoagulation is not very clear in SVC syndrome. It is not recommended if there is no thrombus. However even with thrombus, one has to be very careful, as many patients with advance cancer may have contraindications to anticoagulation. Post SVC stent, only antiplatelet agents may be sufficient, or short term anticoagulation for few months if no contraindications. For catheter related thrombosis, removal of catheter followed by anticoagulation for few months. Thorombolytic therapy is also a consideration in cases with severe symptoms. However it is used less and less due to risk of serious bleeding in cancer patients (such as with brain metastases, or GI bleed). SVC stent is preferable for serious symptoms, in case of tumors that are not very chemotherapy sensitive.
Prognosis in non lymphoma cases is poor, less than six months. Hence overall treatment planning, and expenses should be done with prognosis in mind. Referral to a palliative care center or Hospice center is also an important option. Such centers are increasing in number in Gujarat nowadays.
August 18th 2020. Dr Chirag A. Shah; M.D. Oncology/Hematology (USA), 079 26754001. Diplomate American Board of Oncology and Hematology. Ahmedabad. drchiragashah@gmail.com