The first multicenter study analyzing recurrence patterns following post-surgery treatments for pancreatic cancer has shown that adjuvant chemotherapy is a good way to go, as it thwarts both local and distant recurrence. By comparison, adjuvent chemoradiation beats back local recurrence but not metastasis, which translates to less impact on overall survival.
The study was published online Feb. 16 in the Journal of the American College of Surgeons.
Led by Alexander Parikh, MD, MPH, Vanderbilt University, researchers retrospectively reviewed the cases of 1,130 patients who underwent resection of pancreatic ductal adenocarcinoma, the most common type of pancreatic cancer, at eight medical centers over a 10-year period.
The team split the cases into three groups: 392 patients who had surgery alone, 291 who had adjuvant chemo and 447 who had adjuvant chemoradiation. Median follow-up was 18 months.
They found that the overall local-recurrence rate for the entire sample was 22 percent and did not differ significantly among the groups (20 percent for surgery alone, 21 percent for adjuvant chemo, 23 percent for adjuvant chemoradioation).
Meanwhile, rates of local recurrence were notably cut by both chemotherapy (41 percent) and chemoradiation (49 percent).
However, the incidence of distant recurrence (i.e., metastasis) was significantly lower only after the chemo.
Plus, after controlling for various factors, the team found the chemo produced a 29 percent improvement in overall survival vs. surgery alone, while chemoradiation did not significantly improve survival.
In their discussion, Parikh et al. urge further studies to consider longer treatment periods of systemic chemotherapy, adding that detailed stratification models will be needed to account for important confounding factors such as lymph node and margin status.
Data on recurrence patterns “will be helpful in elucidating mechanisms associated with survival outcomes,” they write, “and ultimately allow us to develop a more tailored and directed approach in the multimodality treatment of pancreas cancer.”
In remarks published in a press release sent by the American College of Surgeons, Parikh says all these patients should get at least six months of chemotherapy.
“If there is a role for chemoradiotherapy,” he stresses, “it should not be given at the expense of giving less chemotherapy.”
The college cites CDC statistics showing that pancreatic cancer is the fourth most common cause of cancer death in the U.S., with nearly 50,000 new cases per year and with most patients not getting diagnosed until their disease is locally advanced, metastatic or both.