The worldwide incidence for obesity is increasing. Apart from being associated with increased risks of developing diabetes mellitus, ischaemic heart disease, back problems and joint diseases, obesity is also a risk factor for the development of cancer.

A study from the University of Texas M D Anderson Cancer Center compared 841 patients with pancreatic adenocarcinoma with 754 healthy individuals to see if there is an association between obesity and increased risk of pancreatic cancer (JAMA 2009; 301: 2553 – 2562). Overweight individuals (BMI 25 – 29.9), aged 14 to 39 years, and obese individuals (BMI ≥ 30), aged 20 to 49 years, respectively had a 67% and 158% increased risk of pancreatic cancer. The association was stronger in men than in women. Those who were overweight or obese from the ages of 20 to 49 years had an earlier onset of pancreatic cancer by 2 – 6 years. When non-obese individuals with pancreatic cancer were compared to obese individuals with pancreatic cancer, aged 30 to 79 years, the non-obese individuals had longer overall survival irrespective of the cancer disease stage and tumour resection status.

Once you have become overweight or obese, would losing weight reverse the increased risk of cancer? The Swedish Obese Subjects (SOS) study recently published its study involving 2010 obese patients (BMI ≥ 34 in men and ≥ 38 in women) who underwent weight reduction surgery (bariatric surgery) and 2037 contemporaneously matched obese controls (Lancet Oncol 2009; 10: 653 – 662). The median follow-up time was 10.9 years. Over 10 years, bariatric surgery led to a sustained weight reduction of 19.9 kg while in controls there was a weight gain of 1.3 kg. The risk of developing cancer was reduced by 33% in those who underwent bariatric surgery. However, the risk reduction by bariatric surgery was only seen in women but not in men.

These two studies demonstrate that being overweight or obese will increase your risk of developing cancer. While surgery to help you lose weight can reduce your risk of developing cancer, the goal in life surely is not to become overweight or obese in the first place.

Watch your weight. Keep fit and keep trim.

Recently, a lady from Malaysia consulted me for a second opinion as she had been diagnosed with stage IV pancreatic cancer. Apart from a history of epigastric discomfort, early satiety and slight loss of weight, she felt fine. The CT scan showed a locally advanced pancreatic cancer with metastases to the liver. The family wanted to know why she developed the cancer. Was it something she had eaten, drunk or something she had come into contact with?

Researchers from the National Cancer Institute, USA, studied the link between 5 lifestyle factors and the risk of pancreatic cancer in 450,416 participants in the National Institutes of Health-AARP Diet and Health Study (Arch Intern Med 2009; 169: 764 – 770). During 1995 – 1996, these participants completed a baseline frequency questionnaire eliciting diet and lifestyle information and were followed up through 31^st December 2003. The participants were scored on 5 modifiable lifestyle factors as unhealthy (0 points) or healthy (1 point), receiving 1 point each for non-smoking, limited alcohol use, adherence to the Mediterranean dietary pattern, body mass index (BMI, ≥ 18 and < 25) and regular physical activity. A combined score of 5 meant most healthy and a score of 0 meant least healthy.

The distribution of lifestyle scores was 1.5%, 10.7%, 27.8%, 31.3%, 21.1% and 7.6% for scores of 0, 1, 2, 3, 4 and 5, respectively. Those with higher scores tended to be older, were less likely to be African-American and had a higher educational level. Having a combined lifestyle score of 5 was associated with a 58% risk reduction for pancreatic cancer. Non-smoking and normal BMI were associated with a statistically significant reduction of pancreatic cancer risk. Among the 5 risk factors, non-smoking had the higher population-attributable risk of 14%; that is 14% of cases would have been prevented if all participants were non-smokers.

Among cancers, pancreatic cancer incidence among men and women is 9^th and 10^th respectively. However, the mortality rate is worse compared to other more common cancers and it ranks 4^th among men and women. It carries a much poorer prognosis because the pancreas lies deep at the back of the abdominal cavity. It tends to grow to a more advanced stage before giving symptoms. In order to reduce the burden of this disease we should think more in terms of prevention. The simplest preventative measures should start with what we do and what we eat / drink. We need to modify our lifestyle habits in order to reduce our risk for pancreatic cancer.

As the saying goes - you reap what you sow!

Pancreatic cancers have the poorest overall survival of any major cancer. Part of the reason for this dismal outlook is the lack of symptoms until the tumour is quite advanced. Consequently, initial presentation to the doctor is delayed or late. However, after the initial contact with a doctor, other factors can also lead to delays in diagnosis and subsequent treatment.   

At the recent 2009 Gastrointestinal Cancers Symposium (GICS) held in San Francisco, researchers from Virginia Mason Medical Centre presented the findings of their study on the magnitude of delay in diagnosis and treatment of patients with pancreatic cancer. They reviewed their tumour registry from 2004 and 2005 and identified 134 pancreatic cancer patients – 40 had resectable pancreatic cancer, 40 had locally advanced disease and 48 had metastatic disease (2009 GICS Abstract 137, presented 16/01/2009). They found that the median time from first patient symptom to first provider (ie the doctor) contact was 30 days (range 1 – 1460 days). The median time from first provider contact to date of tissue diagnosis was 35 days (range 1 – 365 days) and time from diagnosis to treatment was 21 days (range 0 – 120 days). The median delay was nearly 4 months (112 days) and 25 of 134 patients (19%) experienced a delay of 6 months or longer.

The typical median survival for patients with resectable pancreatic cancer is 16 – 22 months. For locally advanced disease, it is 9 – 14 months. The best treatment option for patients with pancreatic cancer is surgical removal. However, due to the late presentation, potentially curative surgery is feasible only in a small proportion of patients. Therefore, prolonged delays from the time of presentation to definitive treatment will likely affect patients’ outcome adversely. Anything that could shorten the wait / delay during this period is likely to help, especially with those who have operable / resectable disease.

The one area where the wait / delay can be shortened is the time from first provider contact to date of tissue diagnosis. There are 2 schools of thought on this aspect of the management process for patients with resectable disease. One group of doctors will insist on a tissue diagnosis before proceeding to surgery while the other group of doctors will operate based on clinical and radiological evidence. The former is more conventional in USA and the later is more the British approach.

Either approach is acceptable and widely practiced worldwide. Achieving a tissue diagnosis prior to surgery means there is no chance of operating on a non-malignant problem. However, there is a small chance that, despite biopsy, one is still unable to establish a tissue diagnosis. In such circumstance, the surgeon will still have to consider performing the operation ‘blind’ to the diagnosis. For those who operate based on clinical and radiological evidence, there is always a small chance that a major operation is performed on someone without a malignant condition, thus, subjecting an individual to the risks of an operation. In reality, the risk of performing an unnecessary operation if you have good clinical and radiological evidence is small.

In an ideal environment, we should be able to get a tissue diagnosis within 2 days of contact with the first provider. Subsequently, definitive treatment would be delivered within a week. Unfortunately such is not the case in real life. Even at the famous Memorial Sloane Kettering in New York, a few months ago a patient of mine was told the wait for a liver biopsy appointment for suspected liver metastases was 3 – 4 weeks. Establishing tissue diagnosis prior to surgery can be very important in some circumstances. In this situation, the patient will have to contend with the unavoidable delay. In situations where tissue diagnosis prior to surgery is unlikely to alter the management approach, the step for tissue diagnosis may be omitted and the doctor moves directly to definitive surgery. This will save the patient from an avoidable delay.

The patient should be given the facts and allowed to choose. If the patient wants a definitive diagnosis before surgery then there will be a delay. Ultimately, it is the patient’s choice.