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Toronto,
ON— With pancreatic cancer having such a poor prognosis,
only 20 per cent presenting with potentially resectable disease,
and most patients who do have surgery not being cured, new approaches
are needed. A large clinical trial conducted by the European Society
of Pancreatic Cancer (ESPAC-3) and the National Cancer Institute
of Canada (NCIC) has set out to ascertain whether chemotherapy given
shortly after surgery will improve the rate of cure for these patients.
“The general theory is that local treatment alone is very unlikely
to impact on the survival of pancreatic cancer. At best you need
a combination approach, and this has shown benefit in other tumours
like breast and colon cancer,” Malcolm Moore, MD, Chair of
the NCIC GI Tumour Committee, said. “We have finally started
to do some decent randomized trials, so we will get some answers.”
In ESPAC-3/NCIC.PA.2, a third of patients are receiving gemcitabine,
a third are getting bolus 5-FU/leukovorin, and a third are getting
no treatment.
Meanwhile, in the United States, where 5-FU plus radiation is considered
standard adjuvant therapy following pancreatic resection, a trial
has been launched to compare the benefits of 5-FU versus gemcitabine.
While adjuvant therapy is not standard therapy in Canada, researchers
here acknowledge that there are inferential data showing that systemic
gemcitabine may be helpful, said Dr. Moore, a medical oncologist
and clinical pharmacologist.
“At Princess Margaret, for patients who are reasonably fit
and who want an aggressive approach after surgery, we do consider
giving them systemic gemcitabine for four to six months,” he
said.
What is known
Everyone who has had surgery for pancreatic cancer is at high risk
of recurrence—greater than 80 per cent will recur, Dr. Moore
said. Various trials have shown that the median survival after resection
is just 12 to 18 months, and the five-year survival is five per
cent to 20 per cent.
“In our Toronto patients, we have seen some patients fail after
five years. The patterns of failure are both local and distant.”
ESPAC-1, which enrolled 580 patients, provided a large source of
useful data about the disease, he said. Patients were randomized
to receive 5-FU/leukovorin or nothing. Twenty per cent had positive
margins. At two years, however, less than half of the patients were
alive. This trial showed that chemoradiation has no role as adjuvant,
whereas chemotherapy may provide a benefit.
As well, “We know that there’s a 30 per cent mortality
reduction in treating node-positive colon cancer with 5-FU, despite
the low response rate in metastatic disease,” he said.
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