Prognosis in malignant mesothelioma is difficult to assess consistently because there is great variability in the time before diagnosis and the rate of disease progression. In large retrospective series of pleural mesothelioma patients, important prognostic factors were found to be:[1,2][Level of evidence: 3iiiA]
In its early stages, lung cancer normally has no symptoms. When symptoms start to appear, they are usually caused by blocked breathing passages or the spread of cancer further into the lung, surrounding structures, other parts of the body.
Lung cancer symptoms may include:
Chronic, hacking, raspy coughing, sometimes with blood-streaked mucus
Recurring respiratory infections, including bronchitis or pneumonia
Increasing shortness of breath, wheezing, persistent chest pain
Two prognostic scoring systems have been developed for advanced unresectable mesothelioma and are used to stratify patients enrolling in clinical trials: the Cancer and Leukemia Group B (CALGB) index and the European Organization for the Research and Treatment of Cancer (EORTC) index.
The CALGB index was developed retrospectively using the clinical characteristics of 337 patients treated on clinical trials of chemotherapy for advanced mesothelioma during a 10-year period.[Level of evidence: 3iiiA] These characteristics were used collectively to define six prognostic groups with median survivals ranging from 13.9 months (Eastern Cooperative Oncology Group [ECOG] performance status [PS] = 0, age <49 years; or PS = 0, age ≥49 years and hemoglobin ≥14.6g/dL) to 1.4 months (PS = 1 or 2 and white blood cell [WBC] count ≥15.6 × 109/L).
The prognostic value of the CALGB index was evaluated retrospectively in a phase II clinical trial of 105 patients.[Level of evidence: 3iii] Median survival in this study for patients in the best CALBG prognostic group was 29.9 months compared with 1.8 months for patients in the worst prognostic group. However, the intermediate groups 2 to 4 overlapped in their survival times.
The EORTC index was also developed retrospectively using the characteristics of 181 patients from five phase II clinical trials of chemotherapy during a 9-year period.[Level of evidence: 3iiiA] In a multivariate analysis, the following characteristics were associated with poorer survival:
WBC count >8.3 × 109/L.
ECOG PS ≥1.
Unconfirmed histology on central review.
Patients were allocated a numerical prognostic score based on each of these variables (+0.55 if WBC >8.3 × 109/L, +0.60 if ECOG PS ≥1, +0.52 if unconfirmed histology, and +0.60 if male gender). Subsequently, patients were classified into two prognostic groups that included low-risk patients with a prognostic score of ≤1.27 (0-2 risk factors) and high-risk patients with a prognostic score of >1.27 (3-5 risk factors). High-risk patients had a relative risk of death of 2.9 compared with low-risk patients, P < .001; the 1-year survival rate was 40% for the low-risk group compared with 12% for the high-risk group.