Active Symptom Control With or Without Chemotherapy in the Treatment of Malignant Pleural Mesothelioma

Chemotherapy is widely used in the treatment of malignant mesothelioma, but it has never been compared in a randomized trial with active symptom control (ASC) alone.

At this year’s American Society of Clinical Oncology meeting in Chicago, Martin F. Muers, MD, Leeds General Infirmary at Leeds Teaching Hospital NHS Trust, Leeds, United Kingdom, discussed initial results of the Medical Research Council/British Thoracic Society MS01 trial—a randomized, Phase III trial evaluating ASC with or without chemotherapy in the treatment of malignant pleural mesothelioma.

Patients enrolled in the trial were randomized to either ASC or one of two chemotherapy regimens. ASC was defined as regular follow-up in a specialist clinic; treatment could include corticosteroids, analgesics, bronchodilators, and palliative radiotherapy. The two chemotherapy arms were MVP (4 thrice-weekly cycles of mitomycin 6 g/m², vinblastine 6 mg/m², and cisplatin 50 mg/m²) and N (12 weekly injections of vinorelbine 30 mg/m²).

For this interim report, data on 409 of a planned 420 patients (136 in the ASC group, 137 in the ASC MVP group, and 136 in the ASC N group) were analyzed. Median age of study enrollees were 65 years; 81% had Stage III or IV disease.

The proportion of patients whose symptoms improved at 6 months (compared with baseline) are shown in the table. None of the differences was statistically significant.

Symptom

ASC

ASC MVP

ASC N

Dyspnea

23%

12%

26%

Lethargy

48%

30%

45%

Chest pain

52%

47%

50%

Sweating

47%

76%

67%

Anorexia

75%

54%

75%

In the ASC MVP group, 61% of patients received all four cycles; in the ASC N group, 49% received at least 10 weekly cycles. Good symptom palliation (defined as prevention, control, or improvement) was achieved in all three groups, and no between-group differences were observed in four pre-defined quality-of-life(QOL) subscales (physical functioning, dyspnea, pain, and global QOL).

A small, nonsignificant survival benefit was seen in the ASC CT group relative to the ASC group (8.5 vs. 7.6 months). Exploratory analyses suggested a survival advantage for the ASC N group relative to the SC group (9.4 vs. 7.6 months).

Dr. Muers states that this was the second-largest— ever randomized trial in malignant mesothelioma, and the first to compare ASC alone with ASC plus chemotherapy. “Although the addition of chemotherapy to ASC did not result in a conventionally significant survival benefit, there was an indication that vinorelbine should be investigated further, and that MVP probably has no role in this disease.”