MPM is an aggressive malignancy with poor prognosis. In advanced disease, cisplatin/pemetrexed chemotherapy has been shown to improve overall survival (OS) and improve quality of life. On disease progression there is no standard second-line (2L) treatment.
We performed a retrospective chart review of patients with histologically confirmed MPM seen at two large cancer centres in Sydney, who received palliative chemotherapy from 2000-2012. Patient demographic, clinical, treatment and survival data were collected. The association between several variables (age, gender, histology, response to and PFS from first-line therapy) and response to 2L therapy was determined.
133 patients with a median age of 67 were identified (83% male, 17% female). There was a history of asbestos exposure in 88%, and ECOG performance status was 0 (14.7%), 1 (74.4%) and 2 (10.1%). Tumour histopathology was predominantly epitheliod (61.7%). Median PFS from first-line chemotherapy was 7.4 months and median OS 11.6 months. Patients received carboplatin/pemetrexed (51.1%), cisplatin/pemetrexed (35.3%), carboplatin/gemcitabine (5.3%) and other agents (8.3%) as first-line treatment with an objective response rate (ORR) of 38.5% and disease control rate (DCR) of 77.9%. 55 patients (52.6%) received 2L chemotherapy. Carboplatin/gemcitabine (47.1%), carboplatin/pemetrexed (34.3%) and pemetrexed alone (4.3%) were the most commonly used regimens. The ORR to 2L therapy was 23.8% and DCR 66.7%. The only factor associated with response to 2L therapy on univariate analysis was PFS>6 months from first-line chemotherapy (OR10.1; P0.02). 25 patients received third-line chemotherapy (ORR 19.1%, DCR 47.6%) and 7 patients fourth-line chemotherapy (ORR 0%, DCR 20.0%).
Approximately half of the patients in this cohort received 2L chemotherapy, with response rates higher than reported in previous retrospective series. PFS >6 months from first-line therapy was the only variable associated with response to 2L treatment. Prospective trials are required to formally evaluate the role of chemotherapy in pre-treated MPM.