By Dennis Thompson
MONDAY, June 4, 2018 (HealthDay News) -- Innovative ways of using chemotherapy can significantly extend the lives of patients with pancreatic cancer, one of the most deadly cancers known, two new clinical trials report.
"You take overall survival from just under three years to almost five years," said Dr. Daniel Labow, a cancer surgeon at Mount Sinai Hospital in New York City. "That, for pancreas cancer, is a relative home run because survival in general is so poor."
Meanwhile, a second preliminary study from the Netherlands found that combining chemotherapy and radiation therapy before pancreatic cancer surgery extended overall survival, particularly for those patients whose tumors were successfully removed.
Results from the studies were presented Monday at the American Society of Clinical Oncology's annual meeting, in Chicago.
Both studies offer hope for people with a cancer that typically evades early detection and is incredibly difficult to treat, ASCO President Dr. Bruce Johnson said.
"About 95 percent of patients who get pancreatic cancer will die from it," said Johnson, chief clinical research officer at the Dana-Farber Cancer Institute in Boston. "This is a pretty grim one. It's identified by the United States Congress as one of the two worst cancers to get." The other is small-cell lung cancer.
Removing the pancreatic tumor using surgery is essential for long-term survival, but the patient still faces a tough road, said Labow, who wasn't involved in the studies.
That's because the tumor releases cancer cells that infect other organs even after it's been surgically removed, Labow said.
"We all have patients where you remove the pancreas, everything looks good, and then they recur shortly thereafter," he said.
The French study, led by Dr. Thierry Conroy of the Institut de Cancerologie de Lorraine in Nancy, focused on a powerful four-drug chemotherapy regimen intended to prevent postoperative spread of cancer to other organs.
Between three and 12 weeks after surgery, 493 pancreatic cancer patients in France and Canada randomly received either the chemo drug gemcitabine (Gemzar), the current standard of care, or a combination of the drugs oxaliplatin (Eloxatin), leucovorin (folinic acid), irinotecan (Camptosar), and 5-fluorouracil (Adrucil). The combo is called mFOLFIRINOX.
Average overall survival was a little more than 54 months with the four-drug chemo versus 35 months with the single drug, researchers found.
"Talking about five-year survivors in pancreas cancer is something that is pretty unique and new," Labow said. "We usually talk about survival in months, or one or two years, not multiple years."
In addition, the four-drug regimen nearly doubled the time before pancreatic cancer recurrence (almost 22 months versus nearly 13 months) and the cancer's spread to other organs (around 30 months versus 17 months).
"These are four drugs that have already been around for a long time, but in this combination the four-drug regimen has been definitely a huge benefit for pancreas cancer," Labow said.
The four-drug combo is toxic, however. About three-quarters of patients receiving it experienced severe side effects, compared with roughly half of those who got gemcitabine. However, researchers said the side effects were manageable.
"It is not for patients who can't tolerate the toxicity of an aggressive chemotherapy regimen, but if you can get through it, it's obviously of benefit," Labow said.
The Netherlands trial, led by Dr. Geertjan Van Tienhoven of the Academic Medical Center in Amsterdam, focused on chemotherapy and radiation therapy before pancreatic cancer surgery, to improve the odds of surgery and increase overall survival.
Surgery can be dicey for patients whose tumors are large, Labow said.
"The big issue with pancreas cancer is the vessels that run underneath the pancreas towards the liver are ones you cannot live without," he said. "They are intimately associated with the pancreas, and therefore if the pancreas cancer grows down and involves those vessels, that can make it unresectable."
In the study, 246 patients were assigned to either have their tumors removed immediately or to undergo a combination of chemo and radiation therapy for 10 weeks followed by surgery. Both groups received the same chemotherapy regimen after surgery.
Average overall survival was roughly 17 months for people who received preoperative chemo and radiation therapy, compared to less than 14 months for those who underwent immediate surgery, researchers reported.
The preop treatment allowed doctors to completely remove the tumor in 63 percent of patients, versus 31 percent of patients who just received surgery, trial results showed.
"It doubled the rate you could take the tumor out," Johnson said.
Survival was more than doubled in patients whose tumors were successfully removed -- more than 42 months with preop therapy versus nearly 17 months with immediate surgery.
Patients who got the preop treatment had a 42 percent two-year survival rate, compared with 30 percent of those who went straight to the operating room.
The two trials show that both preoperative and postoperative chemotherapy are essential for extending the lives of pancreatic cancer patients, Labow said.
"If you combine these two trials, theoretically you may be getting the benefit of both," he said. That's what researchers will be looking at now, he added.
Research presented at meetings is usually considered preliminary until published in a peer-reviewed medical journal.