A brief history or diagnosis is required for all tumour marker assays. This is facilitated on the TML requisition by a simple check-off system. Where possible, this information should include:
histological tumour type
clinical status (no evidence of disease, local disease, metastatic disease)
present treatment (surgery, pre-op, post-op, chemotherapy, radiation therapy)
treatment response (regression, stabilization, progression)
smoking history (packs per day/years)
When available, the BC Cancer Agency patient number should be included so that copies of results will automatically go to the BC Cancer Agency chart.
The lab has been instructed not to process samples unless they have a brief history or diagnosis. Incomplete requisitions will be returned with a history request note, late histories may be phoned into the lab at 877-6000 extension 2090 at which time the sample will be processed immediately (all samples are saved for one month).
With the help of a history/diagnosis we are often able to determine that the best potential tumour marker for the patient has not been requested. When we have added a marker based on history (at no charge), the result has proven useful in 30% of cases. Given the difficulty in keeping up with the rapid developments in tumour markers, many physicians complete the requisition and simply order "tumour markers," letting the tumour marker lab staff choose the appropriate markers.
The TML provides an additional service by including an oncologist's interpretation of selected results. This is clearly only possible in terms of historical information. In addition, historical information allows improvement in efficiency by identifying urgent requests and permitting selection of optimal laboratory conditions for each sample.
As with all patient, hospital, and laboratory services we are having increasing difficulty with funding. It will simply be impossible to provide a comprehensive service unless the use of existing assays is rationalized. Sometimes a tumour marker is requested that has no known value based on the patient history or diagnosis (as provided) or would provide redundant information. These requests may be "lab cancelled."