We read the paper by Ostenfeld et al. with interest. The authors reported that use of systemic glucocorticoids does not correlate with risk of colorectal cancer. To clarify this issue in a Taiwanese population, we conducted a cohort study to explore whether there is an association between glucocorticoids use and risk of colorectal cancer by analysing the database from the Taiwan National Health Insurance programme.
The details of the insurance programme can be found in a previous study. In this cohort study, oral use, injection use and topical use of glucocorticoids were included. In total, 131 794 subjects aged 20 years or older with ever use of glucocorticoids were selected as the case group from 2000 to 2002 (57 525 men and 72 177 women, mean age [standard deviation] = 42.44 [15.23] years) and 131 794 subjects without glucocorticoids use were matched with gender and age as the control group.
Both groups were followed up to determine the incidence of colorectal cancer (ICD-9 codes 153 and 154) until the end of 2007. If any cancer was diagnosed before the date at which cases and controls were identified, these subjects were excluded from this study. To reduce biased results, those who had ever used glucocorticoids only within 1 year before the date of diagnosing colorectal cancer or who had ever used glucocorticoids before the date of cases identified were also excluded from this study.
The case group had higher incidence of colorectal cancer than the control group, with statistical significance (1.16 vs. 0.81 per 1000 person-years, 95% CI = 1.30, 1.58).
Similarly, there was also a significant difference of incidence between the case group and the control group in both gender or in three age groups (Table 1).
|Variable||Never use N = 131 794||Ever use N = 131 794||Incidence rate ratio (95% CI)a|
|All||692||0.81||996||1.16||1.43 (1.30, 1.58)|
|Men||373||0.98||538||1.42||1.45 (1.27, 1.65)|
|Women||319||0.67||458||0.96||1.43 (1.24, 1.65)|
|20–39||97||0.23||162||0.39||1.68 (1.31, 2.16)|
|40–64||339||0.47||492||1.44||3.05 (2.66, 3.51)|
|65–84||256||2.68||342||3.60||1.34 (1.14, 1.58)|
Sidler et al. reported that colorectal cancer cells produce immunoregulatory glucocorticoids in vitro, which further suppress activation of the immune system. Therefore, cancer can escape from the immune surveillance of the host. In this present study, subjects with ever use of glucocorticoids have a 1.4-fold increased risk of developing colorectal cancer.
This means that glucocorticoids use may also suppress activation of the host's immune system. Hence, the colorectal cancer cells can escape from immune surveillance clinically. As there is a conflicting result between Ostenfeld et al. and our studies, further exploration is needed to confirm the role of glucocorticoids use on risk of colorectal cancer.