Abstract

Abstract 5172

Background

Iron deficiency anemia (IDA) is a common initial manifestation of gastrointestinal malignancies, but the relationship between chronic IDA and further cancer development is not established.

Aims

We would like to investigate the cancer risk of chronic IDA over a 10-year period in Taiwan.

Methods

We enrolled patients with iron deficiency anemia from a nationwide health registry in Taiwan during the period 2000–2009. All patients received at least 2 related examinations and were treated with iron supplement. Since IDA is an initial manifestation of many underlying malignancies, we excluded patients whose cancer developed within 1 year after IDA diagnosis. Standardized incidence ratios (SIRs) of cancers were calculated to compare the cancer incidence of chronic IDA patients to general population. The specific types of cancer were addressed.

Results

A total of 4, 373 patient with IDA were identified, and 132 (3. 02%) IDA patients developed cancer 1 year after enrollment (SIR 1. 52; 95% confidence interval [CI] 1. 27 – 1. 80, p < 0. 001). The risks of kidney (SIR 5. 47, 95% CI 2. 73 – 9. 78), bladder (SIR 3. 6, 95% CI 1. 64 – 6. 83), liver (SIR 2. 80, 95% CI 1. 82 – 4. 13), and colorectal malignancies (SIR 1. 93, 95% CI 1. 22 – 2. 90) elevated. The risk of hematological malignancies were not increased in current study (SIR 1. 13, 95% CI 0. 31 – 2. 89, p = 0. 758).

Conclusions

After exclusion of cancer development within the first year, IDA patients still had increased risk of cancer, especially kidney, bladder, liver, and colorectal malignancies.

Table 1.

Characteristics of patients with iron deficiency anemia

TotalMaleFemale
No. of patients 4373 746 3627 
Person-years at risk 21856.6 3320.82 18535.8 
Median follow-up, years (interquartile range) 4.87 (2.66 – 7.18) 4.10 (2.27 – 6.30) 5.06 (2.77 – 7.31) 
Median age, years (interquartile range) 46.35 (38.37 – 58.40) 65.95 (48.70 – 76.83) 45.09 (37.23 – 51.32) 
Age at diagnosis, years    
0 – 19 67 61 
20 – 39 1170 97 1073 
40 – 59 2090 206 1884 
60 – 79 774 316 458 
≥ 80 272 121 151 
TotalMaleFemale
No. of patients 4373 746 3627 
Person-years at risk 21856.6 3320.82 18535.8 
Median follow-up, years (interquartile range) 4.87 (2.66 – 7.18) 4.10 (2.27 – 6.30) 5.06 (2.77 – 7.31) 
Median age, years (interquartile range) 46.35 (38.37 – 58.40) 65.95 (48.70 – 76.83) 45.09 (37.23 – 51.32) 
Age at diagnosis, years    
0 – 19 67 61 
20 – 39 1170 97 1073 
40 – 59 2090 206 1884 
60 – 79 774 316 458 
≥ 80 272 121 151 
Table 2.

Standardized incidence ratios (SIRs) according to age at diagnosis, gender and duration of iron deficiency anemia

TotalMaleFemale
CharacteristicsObservedExpectedSIR (95% CI)ObservedExpectedSIR (95% CI)ObservedExpectedSIR (95% CI)
All cancers 132 86.75 1.52 (1.27 – 1.80) 43 28.11 1.53 (1.11 – 2.06) 89 58.64 1.52 (1.22 – 1.87) 
Age at diagnosis, years          
0 – 19 0.00 0.00 (0.00 – 900.53) 0.00 0.00 (0.00 – 11307.26) 0.00 0.00 (0.00 – 978.45) 
20 – 39 11 3.96 2.78 (1.39 – 4.97) 0.23 0.00 (0.00 – 16.27) 11 3.73 2.95 (1.47 – 5.27) 
40 – 59 51 36.72 1.39 (1.03 – 1.83) 3.46 2.31 (1.00 – 4.56) 43 33.26 1.29 (0.94 – 1.74) 
60 – 79 50 29.71 1.68 (1.25 – 2.22) 25 14.99 1.67 (1.08 – 2.46) 25 14.72 1.70 (1.10 – 2.51) 
≥ 80 20 16.35 1.22 (0.75 – 1.89) 10 9.43 1.06 (0.51 – 1.95) 10 6.91 1.45 (0.69 – 2.66) 
Duration of iron deficiency anemia          
≥ 1 132 86.75 1.52 (1.27 – 1.80) 43 28.11 1.53 (1.11 – 2.06) 89 58.64 1.52 (1.22 – 1.87) 
1 – 5 106 61.65 1.72 (1.41 – 2.08) 38 21.20 1.79 (1.27 – 2.46) 68 40.45 1.68 (1.31 – 2.13) 
≥ 5 26 25.10 1.04 (0.68 – 1.52) 6.91 0.72 (0.23 – 1.69) 21 18.18 1.15 (0.71 – 1.77) 
TotalMaleFemale
CharacteristicsObservedExpectedSIR (95% CI)ObservedExpectedSIR (95% CI)ObservedExpectedSIR (95% CI)
All cancers 132 86.75 1.52 (1.27 – 1.80) 43 28.11 1.53 (1.11 – 2.06) 89 58.64 1.52 (1.22 – 1.87) 
Age at diagnosis, years          
0 – 19 0.00 0.00 (0.00 – 900.53) 0.00 0.00 (0.00 – 11307.26) 0.00 0.00 (0.00 – 978.45) 
20 – 39 11 3.96 2.78 (1.39 – 4.97) 0.23 0.00 (0.00 – 16.27) 11 3.73 2.95 (1.47 – 5.27) 
40 – 59 51 36.72 1.39 (1.03 – 1.83) 3.46 2.31 (1.00 – 4.56) 43 33.26 1.29 (0.94 – 1.74) 
60 – 79 50 29.71 1.68 (1.25 – 2.22) 25 14.99 1.67 (1.08 – 2.46) 25 14.72 1.70 (1.10 – 2.51) 
≥ 80 20 16.35 1.22 (0.75 – 1.89) 10 9.43 1.06 (0.51 – 1.95) 10 6.91 1.45 (0.69 – 2.66) 
Duration of iron deficiency anemia          
≥ 1 132 86.75 1.52 (1.27 – 1.80) 43 28.11 1.53 (1.11 – 2.06) 89 58.64 1.52 (1.22 – 1.87) 
1 – 5 106 61.65 1.72 (1.41 – 2.08) 38 21.20 1.79 (1.27 – 2.46) 68 40.45 1.68 (1.31 – 2.13) 
≥ 5 26 25.10 1.04 (0.68 – 1.52) 6.91 0.72 (0.23 – 1.69) 21 18.18 1.15 (0.71 – 1.77) 

SIR Standardized incidence ratio; CI confidence interval

Table 3.

Standardized incidence ratios (SIRs) for specific cancer types among patients with iron deficiency anemia

Total
Site of cancersObservedExpectedSIR (95% CI)
All cancers 132 86.75 1.52 (1.27 – 1.80) 
Head and neck 4.32 2.08 (0.95 – 3.96) 
Digestive 57 27.93 2.04 (1.55 – 2.64) 
Esophagus 0.98 2.05 (0.25 – 7.41) 
Stomach 4.26 1.64 (0.66 – 3.39) 
Colon and rectum 23 11.91 1.93 (1.22 – 2.90) 
Anus 0.10 0.00 (0.00 – 38.50) 
Liver and biliary tract 25 9.29 2.69 (1.74 – 3.97) 
Pancreas 1.40 0.00 (0.00 – 2.63) 
Lung and mediastinum 9.90 0.50 (0.16 – 1.18) 
Bone and Soft tissue 0.66 0.00 (0.00 – 5.58) 
Skin 1.72 0.58 (0.01 – 3.24) 
Breast 13 16.44 0.79 (0.42 – 1.35) 
Genitourinary 37 16.39 2.26 (1.59 – 3.11) 
Cervix 4.05 0.74 (0.15 – 2.16) 
Uterus 2.35 2.55 (0.94 – 5.56) 
Ovary 2.04 2.45 (0.80 – 5.73) 
Prostate 3.44 0.87 (0.18 – 2.55) 
Bladder 2.50 3.60 (1.64 – 6.83) 
Kidney 11 2.01 5.47 (2.73 – 9.78) 
Thyroid 2.74 1.09 (0.23 – 3.20) 
Hematologic malignancies 3.55 1.13 (0.31 – 2.89) 
All Others 3.09 0.97 (0.20 – 2.84) 
Total
Site of cancersObservedExpectedSIR (95% CI)
All cancers 132 86.75 1.52 (1.27 – 1.80) 
Head and neck 4.32 2.08 (0.95 – 3.96) 
Digestive 57 27.93 2.04 (1.55 – 2.64) 
Esophagus 0.98 2.05 (0.25 – 7.41) 
Stomach 4.26 1.64 (0.66 – 3.39) 
Colon and rectum 23 11.91 1.93 (1.22 – 2.90) 
Anus 0.10 0.00 (0.00 – 38.50) 
Liver and biliary tract 25 9.29 2.69 (1.74 – 3.97) 
Pancreas 1.40 0.00 (0.00 – 2.63) 
Lung and mediastinum 9.90 0.50 (0.16 – 1.18) 
Bone and Soft tissue 0.66 0.00 (0.00 – 5.58) 
Skin 1.72 0.58 (0.01 – 3.24) 
Breast 13 16.44 0.79 (0.42 – 1.35) 
Genitourinary 37 16.39 2.26 (1.59 – 3.11) 
Cervix 4.05 0.74 (0.15 – 2.16) 
Uterus 2.35 2.55 (0.94 – 5.56) 
Ovary 2.04 2.45 (0.80 – 5.73) 
Prostate 3.44 0.87 (0.18 – 2.55) 
Bladder 2.50 3.60 (1.64 – 6.83) 
Kidney 11 2.01 5.47 (2.73 – 9.78) 
Thyroid 2.74 1.09 (0.23 – 3.20) 
Hematologic malignancies 3.55 1.13 (0.31 – 2.89) 
All Others 3.09 0.97 (0.20 – 2.84) 

SIR Standardized incidence ratio; CI confidence interval

Disclosures:

No relevant conflicts of interest to declare.

Author notes

*

Asterisk with author names denotes non-ASH members.