The normal haemoglobin range for males and females is 13 – 18 gm / dL and 12 – 16 gm / dL respectively. When your haemoglobin level falls below the lower limit of the normal range, you are said to be anaemic. Lack of haemoglobin can be due to inadequate production or excessive loss of red blood cells (RBC). Inadequate production of RBCs can be due to a lack of iron in the body (leading to microcytic anaemia), a lack of folate in the body (leading to macrocytic anaemia) or a bone marrow that is not working normally. In women, the most common cause of anaemia is a combination of inadequate intake of iron and / or folate coupled with blood loss from the period. Men do not have a regular, monthly blood loss event to give them anaemia. At present, one of the main concerns for physicians when dealing with unexplained iron deficiency anaemia in a patient is the possibility of an underlying colon cancer.

Ferritin is a protein that stores iron in the body. The serum ferritin level tells you the amount of ferritin in your body and is directly proportional to the amount of iron stored in your body. It is proven that serum ferritin is the most accurate non-invasive test for diagnosing iron deficiency anaemia. It is often used to select patients for colonoscopy. It has been shown that patients with a serum ferritin level of < 50 ng / mL have a high prevalence of an underlying colon cancer and should undergo prompt colonoscopy. However, the prevalence of colonic cancer in anaemic patients with a serum ferritin level of > 50 ng / mL is not known. (Iron deficiency anaemia is unlikely if the serum ferritin level is > 100 ng / mL.) Do anaemic individuals with serum ferritin levels of 51 – 100 ng / mL have a higher risk of harbouring an underlying colon cancer?

A recent study from University of Minnesota looked at 747 individuals (mostly men) who were undergoing colonoscopy for investigation of anaemia or as a screening test for possible colonic neoplasia (Am J Gastroenterol 2007; 102: 82 – 88). The anaemic group of patients was stratified into 3 groups: serum ferritin ≤ 50 ng / mL, serum ferritin 51 – 100 ng / mL and serum ferritin > 100 ng / mL. The fourth group consisted of asymptomatic, non-anaemic individuals undergoing colonoscopy as part of a cancer screening programme. The incidence of advanced colonic neoplasia in those with serum ferritin > 100 ng / mL was 1.7%. This was similar to the 1.2% seen in the asymptomatic non-anaemic group. In anaemic patients with serum ferritin ≤ 50 ng / mL, the incidence of advanced colonic neoplasia was 7.9%. In those with a serum ferritin level of 51 – 100 ng / mL, the incidence was 7.2%. Compared to the non-anaemic individuals and those with a serum ferritin level of > 100 ng / mL, all patients with a serum ferritin level of < 50 ng / mL and 51 – 100 ng / mL were found to be nearly 5 times more likely to be harboring an underlying advanced colonic neoplasia.

Colon cancer is the second most common cause of cancer-related death in the developed countries. Any non-invasive test that helps to improve the public and the medical profession alertness to a potential underlying colon cancer is welcome. However this interesting finding will need further study to confirm its utility. In the meantime we should be aware that colonoscopy is an important tool for diagnosing colon polyps and colon cancer in an individual. In good hands, it is a very safe procedure that is performed on an outpatient / day case basis. Anyone who is 50 years old or above and with no family history of colon cancer is recommended to undergo a screening colonoscopy. If this first examination is normal, then the next one is 10 years later unless you develop new bowel symptoms before then. If you have unexplained iron deficiency anaemia, irrespective of your age, you must consult your doctor immediately.

Recently a 72 year old patient of mine returned to consult me about treatment options for her recurrent colorectal liver metastases. After hearing that chemotherapy, as a treatment option recommended by her medical oncologist, is only for palliation and is indefinite, her daughter asked if there was a potential curative option. Having heard that a liver operation is potentially curative, the patient said she was reluctant to consider surgery because she feels that her body is not ‘as strong as’ it was 2 years ago.

Both among the lay public and in the medical fraternity, getting old (or aging) is often taken to be synonymous with frailty. Consequently, cancer treatment, be it chemotherapy or surgery, has not been offered as readily to the aged population as to younger individuals. As one gets older, the chances of being affected by cancer of some sort increase. Since the aged population is increasing worldwide, the incidence of cancer among older individuals will rise.

The suitability assessment of an aged individual for cancer treatment is complex. It is certainly not one based on the chronological age of the individual. The aged population is highly diverse and the idea that frailty goes hand in hand with being old should be dispelled. Physiological age and not chronological age is much more important in our assessment. Aging involves a progressive decline in the functional reserve of the various organs and systems in the body. With a loss of functional reserve, we then observe the onset of functional impairment. This then progresses to disability, handicaps, functional dependence and eventually death. Loss of functional reserve not only increases one’s susceptibility to acute diseases but also makes the disease more drawn out, more disabling and more serious. It will also increase the chance of complications related to any medical interventions offered. This, however, must not preclude an aged individual from the chance of receiving the appropriate medical treatment or interventions. The key is to be able to assess which aged individual will tolerate and benefit from the treatment.

Animal experiments support the concept that human lifespan is predetermined and cannot be prolonged. If the onset of disease and disability can be delayed, then we can prolong the ‘active life expectancy’ of an individual. If the disease is established and has caused an individual’s functional reserve to become depleted, any interventions at that stage will thus be unable to restore normal function. While it is not possible to define this ‘point of no return’ in an aged individual, there are assessment methods to help guide medical and surgical oncologists in choosing the right aged patient for cancer treatment. The various tests essentially help the oncologists to answer the question: Is the patient able to tolerate the treatment of cancer? Some of these tests are: comprehensive geriatric assessment (CGA), the timed ‘get up and go’ test, and measurement of the levels of IL-6, D-dimer and C-reactive protein. As CGA is cumbersome and time-consuming to use and laboratory measurements are still considered research tools, oncologists (both medical and surgical) in practice use more practical ways to gauge individual suitability.

Simplistically, aging reduces our ability to tolerate stress. In other words, aging reduces our functional reserve. The presence of a cancer stresses the body. Chemotherapy and surgery stress the body. My patient was right in fearing that surgery may stress her body too much, but she failed to appreciate that prolonged chemotherapy is likely to do the same. The task of the medical and surgical oncologist is to assess which treatment or combination of treatments would deplete the functional reserve least and preserve the ‘active life expectancy’ of the patient most at the same time. While the medical and surgical oncologists can advise on the most appropriate treatment, the patient may have a different view.

Do I hear you saying “How do you increase one’s functional reserve?” Well, that would require another article another time.