- Mesothelioma should be reported as epithelial, sarcomatoid or biphasic, because these subtypes have a clear prognostic significance.
- The optimal approach to mesothelioma measurement requires the expertise of a radiologist to identify measurement sites on CT as per modified RECIST for mesothelioma.
- When offering maximal surgical cytoreduction, lung-sparing options (pleurectomy/decortication (P/D), extended P/D) should be the first choice, due to decreased operative and long-term risk. Extrapleural pneumonectomy (EPP) may be offered in highly selected patients when performed in centers of excellence.
- Maximal surgical cytoreduction as a single modality treatment is generally insufficient; additional anti-neoplastic treatment (chemotherapy and/or radiation therapy) should be administered. It is recommended that this treatment decision should be made with multidisciplinary input.
- Chemotherapy should be offered to patients with mesothelioma because it improves survival and quality of life.
- The recommended first-line chemotherapy for patients with mesothelioma is pemetrexed plus platinum. Patients should also be offered the option of enrolling in a clinical trial.
- The addition of bevacizumab to pemetrexed-based chemotherapy improves survival in select patients and therefore may be offered to patients with no contraindications to bevacizumab.
- In patients who may not be able to tolerate cisplatin, carboplatin may be offered as a substitute for cisplatin.
- Radiation therapy should be offered as an effective treatment modality to palliate patients with symptomatic disease.
- Clinicians should perform an initial thoracentesis when patients present with symptomatic pleural effusions and send pleural fluid for cytologic examination for initial assessment for possible mesothelioma. (Strong Recommendation; EB-I)
- In patients for whom antineoplastic treatment is planned, it is strongly recommended that a thoracoscopic biopsy should be performed. (Strong Recommendation; EB-H) This will:
a) enhance the information available for clinical staging
b) allow for histologic confirmation of diagnosis
c) enable more accurate determination of the pathologic subtype of mesothelioma (epithelial, sarcomatoid, biphasic)
d) make material available for additional studies (e.g. molecular profiling).
- When performing a thoracoscopic biopsy, the minimal number of incisions (≤2) is recommended and should ideally be placed in areas that would be used for subsequent definitive resection in order to avoid tumor implantation into the chest wall. (Strong Recommendation; EB-H)
- In patients with suspected mesothelioma in whom treatment is planned, an open pleural biopsy should be performed if the extent of tumor prevents a thoracoscopic approach. The smallest incision possible is encouraged (generally ≤6 cm is recommended). (Moderate Recommendation; EB-I)
- In patients who are not candidates for thoracoscopic biopsy or open pleural biopsy, who also have a non-diagnostic thoracentesis or do not have a pleural effusion, clinicians should perform a core needle biopsy of an accessible lesion. (Strong Recommendation; EB-I)
- Cytologic evaluation of pleural fluid can be an initial screening test for mesothelioma, but it is not a sufficiently sensitive diagnostic test. Whenever definitive histologic diagnosis is needed, biopsies via thoracoscopy or CT guidance offer a better opportunity to reach a definitive diagnosis. (Strong Recommendation; EB-I)
- Histologic examination should be supplemented by immunohistochemistry using selected markers expected to be positive in mesothelioma (e.g., calretinin, keratins 5/6, and nuclear WT1) as well as markers expected to be negative in mesothelioma (e.g., CEA, EPCAM, Claudin 4, TTF-1). These markers should be supplemented with other markers that address the differential diagnosis in that particular situation. (Strong Recommendation; EB-I)
- Mesothelioma should be reported as epithelial, sarcomatoid or biphasic, because these subtypes have a clear prognostic significance. (Strong Recommendation; EB-H)
- In surgical, thoracoscopic, or open pleural biopsies with sufficient tissue, further subtyping and quantification of epithelial vs. sarcomatoid components of mesothelioma may be undertaken. (Moderate Recommendation; IC)
- The non-tissue based biomarkers that are under evaluation at this time do not have the sensitivity or specificity to predict outcome or monitor tumor response and are therefore NOT recommended. (Moderate Recommendation; EB-I)
- While tumor genomic sequencing is currently done on a research basis in mesothelioma and it may become clinically applicable in the near future, it is NOT recommended at this time. (Moderate Recommendation; EB-I)
- A CT scan of the chest and upper abdomen with IV contrast is recommended as the initial staging in patients with mesothelioma. (Strong Recommendation; EB-I)
- An FDG PET/CT should usually be obtained for initial staging of patients with mesothelioma. This may be omitted in patients who are not being considered for definitive surgical resection. (Strong Recommendation; EB-I)
- If abnormalities that suggest metastatic disease in the abdomen are observed on a chest and upper abdomen CT or on a PET/CT then consideration should be given to perform a dedicated abdominal (+/- pelvic) CT scan, preferably with IV and oral contrast. (Strong Recommendation; EB-I)
- An MRI (preferably with IV contrast) may be obtained to further assess invasion of the tumor into the diaphragm, chest wall, mediastinum and other areas. (Moderate Recommendation; EB-I)
- For patients being considered for maximal surgical cytoreduction, a mediastinoscopy and/or endobronchial US should be considered if enlarged and/or PET-avid mediastinal nodes are present. (Strong Recommendation; EB-I)
- In the presence of contralateral pleural abnormalities detected on initial PET/CT or chest CT scan, a contralateral thoracoscopy may be performed to exclude contralateral disease. (Moderate Recommendation; EB-I)
- In patients with suspicious findings for intra-abdominal disease on imaging and no other contraindications to surgery, it is strongly recommended that a laparoscopy be performed. (Strong Recommendation; EB-I)
- The current AJCC/UICC staging classification remains difficult to apply to clinical staging with respect to both T and N components and thus may be imprecise in predicting prognosis. Physicians should recognize that in patients with clinical stage I/II disease, upstaging may occur at surgery. (Strong Recommendation; EB-H)
- The optimal approach to mesothelioma measurement requires the expertise of a radiologist to identify measurement sites on CT as per modified RECIST for mesothelioma. This approach requires calculating the sum of ≤6 measurement sites with ≥1 cm thickness measured perpendicular to the chest wall or mediastinum with ≤2 sites on each of 3 CT sections separated by ≥1 cm axially. (Strong Recommendation; EB-I)
- Assessment of tumor volume by CT scan may enhance clinical staging
and provide prognostic information but remains investigational and thus
is NOT recommended. (Strong Recommendation; EB-I)
- It is recommended that tumor response classification be determined based on RECIST criteria from the comparisons of these sums across serial CT scans. (Strong Recommendation; EB-I)