A Survey of Non-Small Cell Lung Cancer Patients with Meningeal Carcinomatosis in Japan: Incidence and Medical Resource Consumption
Advances in Pharmacoepidemiology & Drug Safety
Lung cancer was the second most common cancer in Japanese men males and the fourth most common in Japanese women females in 2005, and the leading cause of cancer-related deaths in men and women in 2009. Lung cancer is generally classified into two types based on histology: non-small cell lung cancer (NSCLC) and small cell lung cancer. The majority (85%) of new cases of lung cancer are NSCLC [1,2]. Meningeal carcinomatosis (MC) is a rare neurologic complication that occurs in approximately 5% of
... patients with cancer  and 1.4% of patients with NSCLC . MC causes severe symptoms such as vomiting, headache, and neurological sequela, and often requires hospitalization and medication. The prognosis of patients with NSCLC and MC remains poor, with a median survival time (MST) without treatment of about 4-6 weeks . The treatment options include radiotherapy, systemic chemotherapy, and intrathecal chemotherapy with methotrexate, thiotepa, and cytarabine . However, the effectiveness of these treatments is limited and MST is only extended to about 2-3 months . Gefitinib and erlotinib are small molecule epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI). Several recent case reports have demonstrated the effectiveness of EGFR-TKI for NSCLC patients with MC [8-10], but there are no data on the health economics of treatment for MC. Therefore, the purpose of this study was to estimate the incidence of MC in NSCLC patients and the costs associated with treatment of these patients. Patients and Methods Study population and clinical data collection A retrospective analysis of medical record data identified a total of 376 consecutive patients with cytologically or histologically proven NSCLC at Kyoto University Hospital between January 1, 2005 and December 31, 2008. Clinical data were collected for gender, age at diagnosis of NSCLC and MC, smoking status, EGFR mutation, Eastern Cooperative Oncology Group (ECOG) performance status at the time of diagnosis of NSCLC and MC, histology of lung cancer, metastatic sites at the time of diagnosis of MC, number of chemotherapy regimens received before diagnosis of MC, history of whole brain radiotherapy before diagnosis of MC, interval between diagnosis of lung cancer and MC, lengths of hospitalization after diagnosis of MC, types and numbers of cycles of radiotherapy, and detailed information on drug treatment and other therapy. The research protocol was approved by the Ethics Committee, Abstract Background: Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) may be effective for patients for non-small cell lung cancer (NSCLC) with meningeal carcinomatosis (MC), but evidence is limited particularly for the economics aspects. This study aimed to estimate the incidence of MC and resource consumption for NSCLC patients with MC as an exploratory study for further pharmacoeconomic evaluation of EGFR-TKI treatment in these patients. Methods: Patients diagnosed with NSCLC in Kyoto University Hospital between January 1, 2005 and December 31, 2008 was identified using medical record data in the hospital. The cumulative incidence of MC was calculated taking into account the competing risk of death. The economic analysis adopted the payer perspective and included direct medical costs (2010 costs) from the date of diagnosis of MC until the time of death. The resource utilization data are expressed as costs per patient per month. Results: Of 376 patients diagnosed with NSCLC in the study period, 28 were diagnosed with MC up to December 31, 2009 and the cumulative incidences at 1 and 2 years after NSCLC diagnosis were 2.4% and 6.0% respectively. The drug costs per patient per month in MC patients treated with an EGFR-TKI were more than twice that in the non-EGFR-TKI group, but the total costs per patient per month were lower in the EGFR-TKI group. A comparison of sub-categories of costs showed that hospitalization accounted for the highest percentage of medical resource consumption. Conclusions: These estimates constitute a basis for cost-effectiveness analysis of EGFR-TKI treatment for NSCLC patients.