Natural history of early gastric cancer: a non-concurrent, long term, follow up study

Background-Controversy has arisen on the natural history of early gastric c ancer (EGC). While some emphasise the effectiveness of early detection in r educing mortality from gastric cancer, others insist that EGC is a pseudo-c ancer. Aims/patients/methods-To elucidate the natural history of EGG, a non-concur rent, long term, follow up study was conducted in 71 patients who were diag nosed endoscopically as having EGG, which was confirmed as cancer on biopsy , but in whom surgical resection was not conducted or delayed by more than six months. Results-The natural course of EGC was observed in 56 cases. Over a period o f 6-137 months, 20 remained in the early stage while 36 progressed to the a dvanced stage. The proportion remaining in the early stage consistently dec reased with time. Median duration of those who remained in the early stage was estimated as 44 months. The cumulative five year risk for progressing t o the advanced stage was 63.0%. In 38 cases there was no evidence for under going surgical resection for gastric cancer. The cumulative five year corre cted survival was estimated as 62.8% among those unresected. Hazard rate ra tio for gastric cancer mortality was 0.65 (p=0.34) for screening detected v ersus non-screening detected. Hazard rate ratio for gastric cancer mortalit y was 0.51, significantly lower for patients whose operations were delayed compared with those unresected. Conclusions-Although EGC showed a relatively long natural history in genera l, it progressed to the advanced stage with time and led to death from gast ric cancer for the most part if left untreated.