Not infrequently, I have had patients who asked “Can I have this operation later?” after being told that they have a tumour in their liver or colon. My usual first response is “Sooner rather than later. A delay of a few weeks may be alright but not a few months.” As any operation has its attendant mortality risk, it is reasonable for a patient to want some time in order to think things over or to sort out a few things at work and / or at home before undergoing the procedure. So how much delay is acceptable? Is there a critical cut off time for treating cancer?

Researchers from the Aarhus University Hospital in Denmark studied 740 patients diagnosed with colorectal cancer (Br J Surg 2009; 96: 1183 – 1189). There were 458 patients with colonic cancer and 282 rectal cancer patients. The researchers were examining the association between therapeutic delay and survival. Three types of delay were studied: total therapeutic delay – the interval from symptom onset to treatment initiation; provider delay – the interval from first physician contact until treatment initiation and hospital delay – the interval from referral to a hospital until treatment initiation. In colonic cancer patients, the median total therapeutic delay (116 days), provider delay (52 days) and hospital delay (28 days) had no impact on survival in the 458 patients. However, in the rectal cancer group, the study found that a total therapeutic delay of 60 days or more was associated with a 69% increased risk of mortality. In this group, the median total therapeutic delay was 134 days, 49 days for provider delay and the hospital delay was 28 days. The study also found that provider and hospital delay had no impact on the survival of rectal cancer patients. The study showed that early diagnosis of rectal cancer has a significant impact on survival. The longest delay was patient delay – due to non-recognition of symptoms and presenting to the general practitioner late.

The above study highlights the importance of receiving prompt treatment after the onset of symptoms in order to reduce the risk of dying. One cannot find a “Time-table of acceptable delays in initiating treatment” for the different type of cancers. I believe most doctors will adhere to the principle of “Sooner rather than later” when it comes to treating an illness. I strongly urge all patients to subscribe to the same principle too.

Recently the wife of a patient of mine asked “Can he eat beef?”  It transpires that the daughter and son-in-law have told the patient that he is not allowed to eat beef as it will make his cancer worst and beef causes cancer. I have been asked the same question by quite a number of patients. Is cancer caused by eating beef?

A recent study from the National Cancer Institute examined the associations between meat consumption (type of meat, cooking methods and related mutagens), heme iron, nitrite / nitrate and prostate cancer in 175,343 US men aged between 50 and 71 years of age (Am J Epidemiol 2009; 170: 1165 – 1177). These men were followed up for 9 years. The study showed that men who ate the most versus those who ate the least amount of red meat had a 12% higher risk of developing prostate cancer. For processed meat, the risk was 7%. The study also found that heme iron, barbequed/ grilled meat and benzo[a]pyrene were all associated with increased risk of prostate cancer. Nitrite and nitrate intakes were associated with increased risk of advanced prostate cancer.

In certain parts of China, the incidence of cancers of the oesophagus and stomach are much higher than the national average. Detailed studies finally showed that this was related to the pickled vegetables in their diet. The pickled vegetables contained significant amounts of nitrite and nitrate which are known to be carcinogenic. Recent studies have also shown that individuals who drink very hot tea have a higher incidence of cancer of the oesophagus. The likely mechanism here is related to the heat rather than the tea itself.

Cooking certain meats at high temperatures creates chemicals that are not present in uncooked meats. Heterocyclic amines (HCAs) are a group of chemical compounds formed from the cooking of muscle meats such as beef, pork, fowl and fish. HCAs form when amino acids (the building blocks of proteins) and creatine (a chemical in muscles) react at high temperatures during cooking. HCAs are potent compounds that can cause cells to mutate and in experimental animal models HCAs have been shown to induce tumours. Temperature is the most important factor in the formation of HCAs. Frying, barbecuing and broiling involve cooking at very high temperatures and thus produce the largest amounts of HCAs. Baking and oven roasting lead to lower levels of HCAs as the cooking temperature is lower. Poaching, stewing and boiling produce negligible amounts of HCAs. When meat is microwaved for 2 minutes before cooking, the HCA content is reduced by 90%.

From the examples given above, would it be correct to stop drinking tea because drinking hot tea has been shown to be associated with an increased risk of developing oesophageal cancer? Similarly, should one stop eating vegetables because pickled vegetables have been associated with increased risk of developing oesophageal and stomach cancers?

Association is not causation. Furthermore, the reasons behind an association may be due to factors other than the starting ingredient, such as beef. The reason for the association may be because of what you have done to the ingredient.

Two weeks ago I saw a patient who is known to be a carrier of hepatitis C virus (HCV). He was diagnosed in 2005 but for the last few years had not had regular surveillance of his liver. He had felt bloated for a few months and saw his doctor recently. Subsequent investigations showed he had bilobe liver cancer (hepatocellular carcinoma, HCC) in a cirrhotic liver. Curative surgical resection was not an option as he had lesions in both the right and left lobes of the liver. [The best scenario for any patient with HCC is the presence of a small (< 2cm in diameter) tumour confined to one lobe of the liver (i.e. stage I / II cancer).] Would the situation be different if he had had regular surveillance?

Researchers from Hiroshima Prefectural Hospital reported the results of a study evaluating the usefulness of regular check-ups by ultrasonography and contrast-enhanced imaging for early detection of HCC in patients infected with HCV (J Gastroenterol 2009, Oct 29; epub). From April 2001 to March 2007, 240 consecutive HCV patients with HCC were studied. These patients could be classified into 3 groups:- Group A patients had their HCC diagnosed by regular, imaging surveillance; Group B patients had their HCC detected during scheduled doctor visits for liver disease or other diseases such as diabetes and Group C patients had their HCC detected when they felt a need to visit a doctor. The study found that the prevalence of single tumour at the time of diagnosis was 66% in group A patients. Group B patients had a prevalence of 48% while it was only 24% in group C patients. The percentage of stage I and II patients were 83% for group A, 53% for group B and 24% for group C. The number of patients who underwent curative procedure (surgical resection / ablation) was 99/124 (80%) in group A, 42/79 (53%) in group B and 10/37 (27%) in group C.

At the present moment, we cannot, with one blood or x-ray test, predict the risk of developing HCC in anyone who is a carrier of the hepatitis B (HBV) or C virus. The only way we can help these carriers is to perform regular blood and x-ray screening at 6 monthly intervals. The surveillance / screening is to afford us a chance to detect the liver cancer at an earlier stage. It does not stop the development of the cancer. If the liver cancer can be detected at an earlier stage, the chance of having a curative treatment is much higher.     

To all HBV & HCV carriers and people with liver cirrhosis, please remember to go for regular screening. Please do not wait until you have symptoms. It could be a bit late by then.