Malignant pleural mesothelioma is a dreadful tumor. Despite of availability of three modalities of treatment, namely surgery, chemotherapy, and radiotherapy; the prognosis is not good. Transarterial chemoperfusion is a new treatment modality and had shown promising results.
MALIGNANT PLEURAL MESOTHELIOMA- A DREADFUL TUMOR
Malignant pleural mesothelioma is malignant tumor involving pleura. It is a very uncommon tumor affecting approximately 1 person per 100000 persons. However, the tumor is extremely dreadful. The average survival rate is 4-8 months if no treatment is taken. With trimodality treatment (surgery, chemotherapy, radiotherapy):
- Survival rates for Stage I and II are 9.2-16 months,
- For Stage III are 7.9 months and,
- For Stage IV are 2.6 months.
So even with treatment, the prognosis in Stage III & IV is poor.
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CAUSES, DIAGNOSIS AND STAGING OF MALIGNANT PLEURAL MESOTHELIOMA
Malignant pleural mesothelioma is usually caused by exposure to asbestos. It usually occurs 35-45 years after the exposure. Men are more commonly affected than women (3:1). Patient usually presents with cough, dyspnea, chest pain, weight loss, fever, and sweating. A CT scan will show the lesion and associated pleural effusion. It also helps in staging. Pleural fluid cytology or lesion biopsy will help to establish the diagnosis.
There are four Stages-
- Stage1– Mesothelioma is completely resectable, located unilaterally within the capsule of the parietal pleura with or without spreading to the lung, diaphragm, pericardium, mediastinal fat, or Endothoracic fascia of chest wall). There is no adenopathy.
- Stage 2– Mesothelioma is in the pleura lining the unilateral chest wall, and it may have grown into the diaphragm or the lung itself. The cancer has spread to nearby ipsilateral lymph nodes.
- Stage 3– Mesothelioma is involving unilateral pleura with involvement of pericardium or mediastinal fat or endothoracic fascia of chest wall with ipsilateral nearby nodes. Involvement of contralateral and supraclavicular lymph nodes suggest Stage 3 disease. When tumor has grown locally and involves chest wall muscles/rib, opposite pleura, peritoneum trough diaphragm, mediastinal organs, spine and/or heart through pericardium it is considered Stage 3.
- Stage 4– There is presence of metastasis to distant organs like contralateral lung or pleura; peritoneum; liver or bones.
PRESENTLY AVAILABLE TREATMENT OPTIONS FOR MALIGNANT PLEURAL MESOTHELIOMA
Presently there are three modalities of treatment, namely surgery, chemotherapy and radiotherapy.
Most of Stage 1 and some of Stage 2 and 3 diseases are resectable and surgery is the treatment of choice. It is usually combined with chemotherapy and/or radiotherapy.
Many of Stage 2 and 3 and all Stage 4 are unresectable and systemic chemotherapy and palliative radiotherapy are main stay of treatment. However, in spite of available chemotherapy and radiotherapy, the prognosis of the tumor in Stage III and Stage IV is poor.
NEW TREATMENT MODALITY FOR ADVANCED MALIGNANT PLEURAL MESOTHELIOMA
There is a new treatment being proposed for Stage III & IV patients who has no response to chemotherapy and radiotherapy or those who have recurrence after previous treatment. This new treatment is called transarterial chemoperfusion. Patients who have good performance status and are compliant can be given this treatment.
In transarterial chemoperfusion, as the name suggests, they are given in arteries supplying mesothelioma instead of being given chemotherapeutic agents systemically. The procedure is done in a Cath Lab. A 5 French sheath in placed in Common Femoral Artery. For tumors situated anteriorly, ipsilateral internal mammary artery is catheterised and chemotherapeutic drugs are given.
For tumors situated posteriorly, descending aorta angiogram is done with 5 French Pigtail catheter. Intercostal arteries supplying tumor are defined. The infusion catheter is then placed proximal to the most cephalic artery supplying tumor and then chemotherapy is given.
Results of transarterial chemoperfusion are encouraging. In one retrospective study  of 39 patients, transarterial chemoperfusion was done with cisplatin, mitomycin and gemcitabine. As palliative treatment, 14 (36%) patients had a partial response and 19 (49%) patients had a stable disease. The mean survival time starting from the first treatment session was 14.2 months.
Based on these results a prospective trial is going on to determine the disease control rate of transarterial chemoperfusion treatment with cisplatin, methotrexate and gemcitabine in patients with unresectable malignant pleural mesotheliomas .
Till now 27 patients have been enrolled and results are promising. The disease control rate has reached 70%, with a median overall survival rate of 8.5 months and median progression free survival rate of 4.6 months. The median overall survival from disease diagnosis is 28.3 months. Also, the treatment is feasible, safe and with minimal side effects.
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Thus, patients with malignant pleural mesothelioma who fail to respond to conventional trimodality treatment may benefit from transarterial chemoperfusion. It is also safe and is associated with minimal side effects. Hence, transarterial chemoperfusion can serve as a second-line treatment in advanced cases of malignant pleural mesothelioma.
- Kis B, Pereira M, Logeman J, et al. Transarterial chemoperfusion treatment of unresectable pleural mesothelioma – interim results of a phase 2 prospective study. 2020 SIR abstract poster #533. Available at http://www.sirmeeting.org. Accessed on 2020 July 7.
- Vogl TJ, Lindemayr S, Naguib NNN, et al. Nonselective transarterial chemoperfusion: a palliative treatment for malignant pleural mesothelioma. Radiology. 2013;266:649-656.