Diffuse Malignant Mesothelioma - Mesothelioma Attorney
Differential Diagnosis
Benign asbestos pleurisy occurs in about 3 to 5% of asbestos workers. 49,95 Its latency period from first exposure is usually < 20 years, monectomy (EPP). In patients with stage II or III mesothelioma, Boutin recommends surgery and postoperative radiation therapy. In the United States, a cohort of specialized cancer centers have evolved that have maintained an interest in the surgical management of the disease. In general, innovative, multi-modality protocols which incorporate surgery as part of the package are being explored in larger numbers of patients.
Staging for Pleural Mesothelioma. As described by Rusch,229a the staging systems prior to the International Mesothelioma Interest Group (IMIG) Staging System have '(been) to some extent imprecise and incompletely validated." The Butchart classification (Table 89.2) suffers from an absence of TNM descriptors, vague statements regarding lymph node involvement, and degrees of chest wall invasion. Chahinian54,64a was the first to devise a TNM-based mesothelioma staging system, with an attempt to qualify the influence of such parameters as loco-regional lymph node involvement and specific sites as well as the extent of invasion (Table 89.3).
The Union Internationale Contre le Cancer (UICC) proposed a TNM staging system that evolved into the presently described IMIG Staging system described by Rusch (Table 89.4). The IMIG staging system has only recently been available, but it has been validated in two large surgical series of mesothelioma.195b,299 Sugarbaker has proposed the alternative but complementary Brigham Staging System based on tumor, resectability, and nodal status.257a In any evaluation for the patient with mesothelioma, careful attention must be paid to the diaphragmatic extent of the tumor with suspicious scans confirmed by laparoscopic evaluation for transdiaphragmatic extension.71a
There are now data that suggest that the most important preoperative prognostic indicator may be the T status of the patients. Tumor volumes associated with DMM patients who are found to have no spread to lymph nodes are significantly smaller than in those patients with positive nodes. Moreover, progressively higher IMIG stage is associated with higher median preoperative solid volume of tumor in DMM patients.195b Further studies verifying that preresection tumor volume is representative of T status in DMM and can predict overall and progression-free survival as well as postoperative IMIG stage are needed to complement metabolic imaging studies.
Indications for Surgical Management. Eiselberg90a is credited with the earliest resection of mesothelioma in a 46-year-old man, in whom he removed chest wall and a portion of lung, and much of the original interest in en bloc resection for diffuse malignant mesothelioma originated in Germany between 1920 and 1960. With advances both in surgery and anesthetic management, a more extensive resection that included the lung, pleura, and diaphragm became technically feasible.
Surgery is involved in the management of pleural mesothelioma either for diagnosis, palliative therapy, or as part of a multi-modal therapeutic plan. The operations involved in this management include thoracoscopy, pleurectomy/decortication or EPP. The indications for each of these operations will depend on the extent of disease, performance and functional status of the patient, and the philosophy of the treating institution. Basically, operative intervention in mesothelioma is for primary effusion control, for cytoreduction prior to multi-modal therapy, or to deliver and monitor innovative intrapleural therapies.
In general, the indications for palliative surgery include the control or prevention of effusion that results in disabling dyspnea. The most efficacious, and least invasive of the surgical procedures to accomplish effusion control is thoracoscopy with talc pleurodesis. Success rates in effusion control with talc, used either via thoracoscopy or via slurry, approach 90%. Failure of these techniques are usually associated with mesothelioma with entrapped lung, a large solid tumor mass, a long history of effusion with multiple thoracenteses leading to loculations, or age > 70 years. This technique is widely used, once the diagnosis of mesothelioma is made. Primary-care physicians, however, should carefully deliberate prior to the use of sclerosants and consider the extent of visceral and parietal pleural disease.
The use of talc or other sclerosants could impact on the suitability for patients to enter innovative trials that incorporate either pleurectomy or EPP and could jeopardize the ability of the surgeon to spare a lung that may not have visceral pleural implants. The results of videothoracoscopic talc pleurodesis specifically for mesothelioma have shown success rates of 80 to 100% with median survivals ranging from 7 to 9 months, success being defined as no further need for tapping after 1 month.43a,64b,279a Patients who were able to have a successful pleurodesis had a significantly longer survival than those who did not, and success depended on the presence of trapped lung or degree of invasion of the pleura.
Effusion control via palliative surgery is occasionally attempted after lesser procedures (including sclerotherapy) have failed due to the inability of the lung to expand. Generally, the procedure of choice for such palliation is a pleurectomy, with or without decortication of the underlying lung. The use of EPP for palliative intent is only rarely described in the literature, and due to its morbidity and mortality, some surgeons state that EPP should never be used for palliative purposes.
The majority of patients seeking treatment for mesothelioma are middle to older aged individuals with a long latency period between asbestos exposure and tumor development. If surgical intervention is to be considered, a detailed physiologic-functional work-up, directed chiefly at the cardiopulmonary axis, must be performed. Poor underlying pulmonary function in patients with malignant mesothelioma usually reflects the burden of asbestos exposure, concomitant smoking history (up to 70% of the patients have had a heavy tobacco intake), and degree of lung trapped by tumor or fluid, and patient age. Cardiac evaluation is important as well. Operations for DMM are
Mesothelioma Info
There are three distinct types of malignant mesothelioma: pleural, peritoneal and malignant mesothelioma. The only known cause of malignant mesothelioma is asbestos exposure.
If you or a loved one has been diagnosed with mesothelioma, contact a mesothelioma attorney or asbestos attorney to get information about your right to compensation.