Volume 198 - Issue 10
Investigating iron deficiency anaemia
Authors: William Sievert, Finlay A Macrae and Barbara A Leggett, for the Gastroenterological Society of Australia
Med J Aust 2013; 198 (10): 563. || doi: 10.5694/mja12.11506
Published online: 3 June 2013
Published online: 3 June 2013
Persistent unexplained iron deficiency should always be investigated, but iron deficiency is common and colorectal cancer rare in young women - the risks of investigation must be balanced against the risks of serious pathologyWe would like to express our sympathy to the family and to acknowledge the tragedy of the circumstances in regard to the death of their
29-year-old family member from metastatic colon cancer.
To ...
Persistent unexplained iron deficiency should always be investigated, but iron deficiency is common and colorectal cancer rare in young women — the risks of investigation must be balanced against the risks of serious pathology
We would like to express our sympathy to the family and to acknowledge the tragedy of the circumstances in regard to the death of their 29-year-old family member from metastatic colon cancer.
To summarise, the woman presented at the age of 22 years with severe iron deficiency anaemia (IDA) and fatigue but no history of excessive menstrual blood loss. She underwent gastroscopy to test for coeliac disease; colonoscopy was not performed. She was treated with iron supplementation over 6 months, although her father notes that her iron reserves remained depleted. Tragically, she later presented with metastatic colon cancer.
The patient’s father notes that current guidelines for the management of patients with IDA indicate that, in premenopausal women, gastrointestinal (GI) investigation should be reserved for those with colonic symptoms, a strong family history or persistent IDA after iron supplementation and correction of potential causes. From our understanding, the young woman had persisting IDA despite iron supplementation and would have come within Gastroenterological Society of Australia recommendations for further diagnostic investigation (http://www.gesa.org.au/files/editor_upload/File/Professional/Iron_def.pdf).
The patient’s father also comments on the risks of placing too much emphasis on family history. While we agree that patients may not always be aware of this information, when it is available it becomes important for those with an increased risk of colorectal cancer (CRC) because of such a history. Family history of CRC has a prominent position in international guidelines regarding screening.
Iron deficiency is common among premenopausal women. A recent Australian study showed a prevalence of 10.6% among females under 50 years of age, 2.8% among females over 50 years of age, and 0.3% among males.1 The high prevalence in young women relates to menstrual losses and lower dietary iron intake rather than to a higher prevalence of GI disease, and it is in this context that the Gastroenterological Society of Australia recommendations were written. While it is important to make an accurate and early diagnosis of CRC, it is also important to avoid overinvestigating young women with iron deficiency who have a more likely cause such as menstrual loss and/or inadequate diet and who respond appropriately to iron replacement and gynaecological treatment. Colonoscopy is generally safe but has potentially life-threatening complications in 1 in 1000 to 1 in 5000 cases. It has been suggested that faecal occult blood testing (FOBT) could be used to eliminate the likelihood of CRC or to provide justification for colonoscopy. Unfortunately, FOBT is falsely negative in 20% of people who have CRC and would provide false reassurance.2 FOBT reduces CRC mortality when used to screen asymptomatic people, but it is not a good diagnostic test. An experienced GI physician or surgeon must judge the clinical significance of IDA and then make a recommendation for further endoscopic investigation that considers the benefit of the procedure in relation to the risk for that individual patient.
In contrast to iron deficiency, CRC is not common in young women. While two United States studies showed an increased incidence in 20–29-year-olds between 1992 and 2005, CRC remains uncommon in this age group.3,4 In 2006, the incidence in 20–24-year-olds was 1.5 per 100 000, which means there is only a 1 in 66 000 chance that a person in this age group will develop the disease over the next year.4 To put this in context, the incidence among 65–69-year-olds was 160.9 per 100 000. The Australian Institute of Health and Welfare projected that the CRC incidence among men aged 20–24 years would rise from 1.1 to 2.6 per 100 000 in 2011, and among women aged 20–24 years, from 1.1 per 100 000 in 2001 to 1.3 per 100 000 in 2011. In comparison, the projected incidence per 100 000 for 2011 in the 65–69-year age group was 304.3 for men and 203.6 for women.5 Overall, while there is an increase in CRC incidence among individuals aged in their 20s, the absolute number with CRC remains very low.
Competing interests
No relevant disclosures.
References
- Ahmed F, Coyne T, Dobson A, McClintock C. Iron status among Australian adults: findings of a population based study in Queensland, Australia. Asia Pac J Clin Nutr 2008; 17: 40-47. 0_CHDCEAIH
- Morikawa T, Kato J, Yamaji Y, et al. A comparison of the immunochemical fecal occult blood test and total colonoscopy in the asymptomatic population. Gastroenterology 2005; 129: 422-428. 0_i1115610
- Siegel RL, Jemal A, Ward EM. Increase in incidence of colorectal cancer among young men and women in the United States. Cancer Epidemiol Biomarkers Prev 2009; 18: 1695-1698. 0_i1115612
- Davis DM, Marcer JE, Frattini JC, et al. Is it time to lower the recommended screening age for colorectal cancer? J Am Coll Surg 2011; 213: 352-362. 0_i1115616
- Australian Institute of Health and Welfare, Australasian Association of Cancer Registries, National Cancer Strategies Group; McDermid I. Cancer incidence projections, Australia 2002 to 2011. Canberra: AIHW, AACR, NCSG, 2005. (AIHW Cat. No. CAN 25.) http://www.aihw.gov.au/WorkAreaDownloadAsset. aspx?id=6442454503 (accessed May 2013).
Provenance: Commissioned; not externally peer reviewed.