Pancreatic cancer has been ranked as the fourth-leading cause of cancer-related mortality in the West with 20 percent, 40 percent and 40 percent of the cases presented with a resectable lesion, unresectable locally advanced and metastatic disease, respectively.
Pancreatic ductal adenocarcinoma (PDAC) has been reported to be one of the most aggressive types of pancreatic cancers, as well as having the highest occurrence among pancreatic cancers with poor chemoradiation results. It has an aggressive tumor biology, a delayed diagnosis, and a five-year survival rate of only 5 percent that could not be increased to more than 30 percent even with a combination of resection and adjuvant therapy.
A number of advances in surgical techniques have been applied in the treatment strategy for this cancer. Likewise, there have been new molecular and imaging diagnostic approaches as well as improvements in the endoscopies and adjuvant therapy in the treatment of this cancer.
However, none of these improvements was able to make a noticeable difference in the five-year survival rate, which makes it a pressing priority to come up with a novel effective strategy that can have a bigger impact on the survival rate of pancreatic cancer.
One of the adjunctive treatments highly studied for PDAC (unresectable locally advanced) has been radiofrequency ablation (RFA), which happens to be the most common thermal ablation technique used in order to reduce tumor burden in the treatment of solid abdominal organ tumors. It appears to be an attractive option in all aspects, including: indications, contraindications, feasibility, success rate, safety, complications and survival impactability, as long as there is no metastasis in the picture and the correct temperature used at an appropriate distance from vital structures.
Although still evolving, the application of RFA has been promising and has been recommended as a complementary step to the current standard therapy in the multimodal management of the disease with an expanding indication and patient selection criteria.
The rate of morbidity and mortality from RFA-related complications has been reported to be 10-37 percent (10-15 percent in most) and 0-19 percent (0-5 percent in most), respectively. These complications included: pancreatic fistulae, portal vein thrombosis, gastrointestinal bleeding and acute pancreatitis. Some of the RFA-related complications that led to patients' death were reported to be sepsis and gastrointestinal bleeding.
On the other hand, the overall complication rate of 10-43 percent has been reported for RFA, including: peritoneal cavity abscess, acute renal failure, pneumonia, hepatic insufficiency, transient ascites, pseudomembrane colitis, haemoeritoneum, abdominal fluid retention, gastric bypass fistula, gastrointestinal ulcer and choledocholithiasis.
In terms of survival rate following RFA, studies have not uniformly reported this information, but based on the ones with the reported survival rate, it was in the range of 20-36 months in patients with stage III locally advanced PDAC.
It has been collectively agreed that in order to minimize the RFA complications, some patient-selection criteria should be used, as well as three other factors that need to be considered.
First, the RFA performance temperature should not exceed 90 degrees C. Secondly, the distance between the RFA probe and structures surrounding it should not be less than 5 mm and 10 mm with reference to portomesenteric vessels and duodenum, respectively. Thirdly, preventive intraluminal duodenal cooling could be used to minimize any potential thermal duodenome damage.
In summary, RFA looks promising in the treatment strategy for unresectable locally advanced PDAC. However, further systematic approach needs to be taken toward studying the prospective of this technology by designing large multicenter trials controlling the variability of devices, RFA settings used (temperature, ablation duration, power) along with defined patient-selection criteria.
