Unadjusted incidence of gastric and colon cancers stratified by iron deficiency and symptoms in 9783 anaemic women aged 20–49 years
| Sample size (n) | Cancer* (n) | NND one cancer (95% CI) | Incidence/1000 patients (95% CI) | P value | |
| Gastric cancer, age 20–49 years | |||||
| Random | 9783 | 6 | 1631 (748 to 3558) | 0.61 (0.28 to 1.34) | – |
| Iron deficiency | |||||
| (+) | 6627 | 4 | 1657 (645 to 4260) | 0.60 (0.23 to 1.55) | >0.99 |
| (−) | 3156 | 2 | 1578 (434 to 5754) | 0.63 (0.17 to 2.31) | |
| Any symptoms | |||||
| Yes | 5078 | 6 | 847 (389 to 1847) | 1.18 (0.54 to 2.58) | 0.03 |
| No | 4705 | 0 | – | – | |
| UGI symptoms | |||||
| Yes | 3705 | 5 | 741 (317 to 1735) | 1.35 (0.58 to 3.16) | 0.03 |
| No | 6078 | 1 | 6078 (1074 to 34,431) | 0.16 (0.03 to 0.93) | |
| Dysphagia | |||||
| Yes | 286 | 2 | 143 (40 to 521) | 6.99 (1.92 to 25.10) | 0.01 |
| No | 9497 | 4 | 2375 (924 to 6105) | 0.42 (0.16 to 1.08) | |
| Weight loss | |||||
| Yes | 220 | 3 | 74 (26 to 216) | 13.6 (4.65 to 39.3) | <0.001 |
| No | 9563 | 3 | 3188 (1085 to 9373) | 0.31 (0.11 to 0.92) | |
| Any gastric symptoms: UGI and/or dysphagia | |||||
| All women | |||||
| Yes | 3793 | 5 | 759 (325 to 1776) | 1.32 (0.56 to 3.08) | 0.04 |
| No | 5990 | 1 | 5990 (1059 to 33,933) | 0.17 (0.03 to 0.95) | |
| Iron deficient (+) women (n=6627) | |||||
| Yes | 2563 | 4 | 641 (250 to 1648) | 1.56 (0.61 to 4.01) | 0.02 |
| No | 4064 | 0 | – | – | |
| Iron deficient (−) women (n=3156) | |||||
| Yes | 1230 | 1 | 1230 (218 to 6968) | 0.81 (0.14 to 4.59) | >0.99 |
| No | 1926 | 1 | 1926 (341 to 10,910) | 0.52 (0.09 to 2.94) | |
| Colon cancer, age 20–49 years | |||||
| Random | 9783 | 26 | 377 (257 to 552) | 2.66 (1.81 to 3.89) | – |
| Iron deficiency | |||||
| (+) | 6627 | 18 | 369 (234 to 582) | 2.72 (1.72 to 4.29) | >0.99 |
| (−) | 3156 | 8 | 395 (201 to 779) | 2.53 (1.29 to 4.99) | |
| Any symptoms | |||||
| Yes | 5078 | 21 | 242 (159 to 370) | 4.14 (2.71 to 6.31) | 0.003 |
| No | 4705 | 5 | 941 (403 to 2203) | 1.28 (0.45 to 2.49) | |
| LGI symptoms | |||||
| Yes | 2471 | 16 | 155 (96 to 251) | 6.48 (3.99 to 10.50) | <0.001 |
| No | 7312 | 10 | 732 (398 to 1346) | 1.37 (0.74 to 2.52) | |
| Rectal bleed | |||||
| Yes | 577 | 10 | 58 (32 to 106) | 17.30 (9.44 to 31.60) | <0.001 |
| No | 9206 | 16 | 576 (355 to 935) | 1.74 (1.07 to 2.82) | |
| Weight loss | |||||
| Yes | 220 | 1 | 220 (40 to 1246) | 4.55 (0.80 to 25.30) | 0.48 |
| No | 9563 | 25 | 383 (260 to 565) | 2.61 (1.77 to 3.86) | |
| Any colon symptoms: LGI and/or rectal bleed | |||||
| All women | |||||
| Yes | 2793 | 19 | 147 (95 to 230) | 6.80 (4.36 to 10.60) | <0.001 |
| No | 6990 | 7 | 999 (485 to 2062) | 1.00 (0.49 to 2.07) | |
| Iron deficient (+) women (n=6627) | |||||
| Yes | 1849 | 14 | 133 (79 to 222) | 7.57 (4.52 to 12.70) | <0.001 |
| No | 4778 | 4 | 1195 (465 to 3072) | 0.84 (0.33 to 2.15) | |
| Iron deficient (−) women (n=3156) | |||||
| Yes | 944 | 5 | 189 (82 to 442) | 5.30 (2.26 to 12.30) | 0.02 |
| No | 2212 | 3 | 738 (252 to 2168) | 1.36 (0.46 to 3.98) | |
Comparisons were made using Fisher’s exact tests.
*Within 5 years of the iron deficiency test date.
(−), negative; (+), positive; –, not applicable; LGI, lower gastrointestinal; NND, number needed to detect; UGI, upper gastrointestinal.