CNS and Cutaneous Involvement in Patients With Chronic Myeloid Leukemia Treated With Imatinib in Hematologic Complete Remission: Two Case Reports
Authors: E. Abruzzese, M. Cantonetti, L. Morino, G. Orlandi, A. Tendas, M.I. Del Principe, M. Masi, S. Amadori, A. Orlandi, L. Anemona, Elena Campione
Journal: Journal of Clinical Oncology (2003)

To the Editor: Gill et al 1 examined 2,043 cases of gastric cancer treated at a Canadian institution, and reported that Asian subjects, largely of Chinese descent, exhibited a hazard ratio lower than that of non-Asian subjects (0.89), but that this difference was not statistically significant.They also detected a greater benefit from curative surgery in Asians as compared with non-Asians.They concluded that, while their study may have been underpowered, ". . .even if we assume the lower limit of [the calculated 95%] CI to be the true effect, a 26% proportional reduction in mortality would only improve a 5-year survival estimate of 12% to 20%. . .," which is ". . .insufficient to account for the great disparity with Asian survival rates, which remain three-fold higher than North American rates."Our prior study of 3,770 Southern Californian gastric cancer subjects had sufficient power to detect a 34% increased risk of dying among non-Asian subjects compared with Asian subjects of primarily of Japanese, Korean, and Vietnamese descent.This result is likewise insufficient to explain the great disparity between Japanese and US gastric cancer survival. 2Given the complexity of comparisons of Eastern and Western gastric cancer survival, however, it should come as little surprise that one explanation is insufficient to resolve the current conundrum.It is clear that other issues bias in favor of improved Asian gastric cancer survival.For example, Japanese patients are more likely to be diagnosed with node-negative gastric cancer that can be cured with surgical resection. 3Furthermore, studies comparing survival rates in gastric cancer subjects in the East and West are compromised by variability in diagnostic criteria for malignancy, because in Japan, gastric cancer is diagnosed on nuclear and structural criteria even when invasion is absent according to the Western viewpoint. 4 The tendency of Japanese pathologists to diagnose malignancy without evidence of invasion will increase Japanese gastric cancer cure rates.Also, studies comparing survival rates in patients from the East and West also are compromised by variability in surgical treatment, 3 with US patients being much less likely to undergo a D2-level dissection.The tendency of US subjects to have limited lymph nodes examined for malignancy produces stage migration (the Will Rogers effect) and may affect cure rates, both of which will decrease stage-stratified gastric cancer survival in the United States.Thus, while we agree with Gill et al that results from their study are insufficient to explain the entire disparity between Eastern and Western gastric cancer survival, it is important to realize that this conclusion should not be misinterpreted to imply that differences in tumor biology do not contribute to the disparate gastric cancer outcomes between the two regions.