Redaniel et al. BMC Cancer 2010, 10:100 http://www.biomedcentral.com/1471-2407/10/100 Page 4 of 9 computed for each data set, which were then combined. The PROC MI and MIANALYSIS commands in the SAS Statistical Analysis Software were used to perform these analyses. All analyses were done with the SAS Sta- tistical Analysis Software version 9.2 [34]. Special macros were used for standard and modelled period sur- vival analysis as previously described [31,35]. Results The distribution of cases for each population group by specific cancer site, sex, age group, stage, histology, sur- gery and radiotherapy are shown in Table 1. Colon and rectum cancer were about equally common for the Phi- lippine residents, whereas the proportion of colon can- cers was much larger for both SEER populations. The sex distribution was almost equal in all groups. Cauca- sians on average were older than the other patient groups, with more than half aged 70 or above, while Filipinos residing in the Philippines were youngest with almost 50 percent below 60 years of age. Both US SEER populations were diagnosed at earlier stages than Filipi- nos in the Philippines, with larger proportions of patients presenting with localized tumors. In all three population groups, adenocarcinomas are the predomi- nant histological type, between 80 and 90% of patients underwent surgery and less than 15% received radio- therapy. The random sample of Philippine resident patients was representative of all registered eligible CRC cases with respect to socio-demographic characteristics (data not shown). Age adjusted overall, site- and sex-specific estimates, as well as age specific estimates of absolute and relative 5-year cancer survival are shown in Table 2. Generally, much lower survival was seen in Filipinos living in the Table 1 Tumor and socio-demographic characteristics of colorectal cancer patients among the Philippine resident population and Filipino-Americans and Non-Hispanic Whites from US SEER, 1993-2002 Philippine resident population (N = 1635) Filipino-Americans (N = 2671) Non-Hispanic Whites (N = 133551) Variable Site Sex Colon Rectum Male Female Age group <50 50-59 60-69 70-79 80+ Stage Localized Regional Distant Unknown Morphology Adenocarcinoma Others NOS1 Surgery With surgery Without surgery Unknown Radiotherapy With radiotherapy Without radiotherapy Unknown 1includes: Neoplasms; Carcinoma, NOS Freq 829 806 851 784 424 359 416 331 105 332 507 272 524 1205 202 228 1121 262 252 168 1008 459 % 50.7 49.3 52.1 48.0 25.9 22.0 25.4 20.2 6.4 29.9 45.6 24.5 85.6 14.4 81.1 18.9 14.3 85.7 Freq 1663 1008 1514 1157 357 483 674 692 465 1009 1019 504 139 1820 791 60 2350 320 1 382 2263 26 % 62.3 37.7 56.7 43.3 13.4 18.1 25.2 25.9 17.4 39.9 40.2 19.9 69.7 30.3 88.0 12.0 14.4 85.6 Freq 97150 36401 66908 66643 8648 15703 28436 43704 37060 53532 49179 24139 6701 87048 42351 4152 118460 14936 155 14188 118309 1054 % 72.7 27.3 50.1 49.9 6.5 11.8 21.3 32.7 27.8 42.2 38.8 19.0 67.3 32.7 88.8 11.2 10.7 89.3 p-value <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001