Clinical Manifestation and Etiology

INTRODUCTION Colorectal cancer (CRC) ranks among the 10 most common cancers in the world,1 including Indonesia.2 It is the most environmentally-related cancer and in this country sporadic CRC affects 35.2% of people below 40 years old,2 as compared to only 3% in developed countries,3 making it an increasingly important health issue as the disease deprives the country of resources and productivity. Surgery is the main treatment modality, but more than 30% of CRC present already with metastasis – whereas another 30% will eventually delevop the condition – so chemotherapy will eventually have to be considered at one point.4,5 In the last few years, the development of chemotherapy of CRC has seen more new drugs than other types of cancers. The drug 5-fluorouracil (5-FU) has been and is still the backbone of the cytostatic regimen, further enhanced with folinic acid (leucovorin) and in recent years with the addition of irinotecan6 and oxaliplatin.7-9 Several regimens were used in various institutions, i.e., the AIO, Roswell Park, and the de Gramont regimen, all of them involving the intravenous administration of the drugs. In 2004 an oral 5-FU analog, capecitabine, was introduced,8,10-12 and found to be at least equivalent to the standard 5-FU/FA regimen13 with a high level of stabilization and favourable toxicity profile in the metastatic setting.14 More recently, capecitabine has been approved as treatment for CRC in the adjuvant setting,15 initially in patients refractory to the 5-FU/FA regimen,14 subsequently as first-line treatment.16 It is also used in breast cancer, both as a single agent or combination with other cytostatics.17 It is used as replacement of 5-FU/ FA in combination with oxaliplatin.18