Additional Study Information: The purpose of this study is to compare the effects, both good and bad, of the study drugs temozolomide and capecitabine to the usual chemotherapy treatment for this disease of cisplatin or carboplatin (referred to as platinum therapy) and etoposide. Usually the first treatment given for this cancer is platinum therapy and etoposide. The chemotherapy drugs temozolomide and capecitabine are also used to treat this disease but usually not until the first treatment, platinum therapy and etoposide, stops working. It is not known if this is the best approach or if the temozolomide and capecitabine should be given first instead. The use of temozolomide and capecitabine could shrink your cancer but it could also cause side effects. For patients who receive the usual treatment for this cancer, it is usually about 6 months before the usual treatment stops working and a different treatment is needed. To be better, the study drugs should increase how long you are able to live with your cancer before you need to switch to different treatment, by 4 months or more compared to the usual approach. There will be about 126 people taking part in this study.