Thursday, September 14, 2006

Weight loss in CLL

One of the criteria for treatment of CLL is weight loss. The criterion has been lifted straight from the criteria identified for the Ann Arbor staging of Hodgkin's disease that advance the stage from A to B. Weight loss of greater than 10% body weight over 6 months, fever and night sweats were included, while other systemic characteristics like alcohol induced pain, itching and rash were not. The criteria for Hodgkins's disease date from the 1971, at a time when we did not have CT scanning for abdominal glands.

Patients with apparent stage 0 or 1 CLL might have these systemic symptoms yet appear to have low bulk disease. CT scanning usually reveals that they have lymph nodes at the back of the abdomen that cannot be felt with the hand. This is particularly common in younger men who have the 11q deletion.

But it is important to realize that systemic symptoms like this may have causes other than CLL. Weight loss occurs with thyrotoxicosis (an over active thyroid gland), with malabsorption, with anorexia, and of course in many systemic illnesses like TB and other chronic infections. It also occurs with old age. Aging reduces muscle bulk. Muscles need constant exercise to keep their size, and the relative immobility of the old means that they lose weight. Sometimes anabolic steroids (the kind that atheletes use illegaly are given to old people to prevent this.

As I see it, systemic symptoms in low stage CLL should be an indication for investigation. This almost certainly should include a CT scan. They should not be regarded as a sole indication for treatment, unless there are other indications of progression. For one thing it would be foolhardy to give cytotoxic drugs to someone with occult TB.

Cacchexin is the old name for tumor necrosis factor (TNF). It causes, among other things, cacchexia (the wasting condition associated with cancer). TNF is made by CLL cells so it is hardly surprising that weight loss should occur in CLL, but I can't remember a single patient in my experience where this was the sole indication for treatment.

2 comments:

Anonymous said...

I eschew CT scans, as each abdominal CT scan is the equivalent of 400 (!) chest X-rays.

MRIs give equivalent information, and involve no radiation.

Terry Hamblin said...

This is a misleading statistic. There is an MRI expert who has been publicizing this atatistic on Medscape. An abdominal X-ray has as much radiation as 75 chest X-rays. An abdominal CT is equivalent to 6 abdominal X-rays. Although excessive CT scans can be hazardous, orthodox opinion is that the Medscape doctor is over-egging the pudding.