Improving the cure for pancreatic cancer remains one of the major remaining challenges in oncology. It is one of the most aggressive and mortality-intensive neoplasms, mainly due to its rapid growth, the absence of early specific symptoms and its often late diagnosis. The last comprehensive data that we have are from 2012, year in which was the reason for 173.827 deaths around the world, which constitutes 3.7% of all cancer deaths.
In Spain there are about 4,000 cases per year, 2,129 of men and 1,750 of women; therefore, we have a slightly more frequent tumor among them than in them. On the other hand, most pancreatic cancers are diagnosed between the ages of 65 and 75, but are not proportionally infrequent among younger individuals, although the most painful fact is that average survival after pancreatic cancer is scarce; in no country in the world is more than 10% at age 5.
The reason is, as has been explained, their speed of spread and the lack of clear symptoms in almost 40% of cases, which makes that when it is detected in advanced stages, in which the tumour surrounding veins or bile ducts, or has gone to other organs (metastasis). In the other 60% of the cases, in which the tumor starts from the head of the pancreas, can produce early symptoms such as jaundice, which can lead to its early detection and treatment, although the survival at 5 years will be very much conditioned by the ability to remove the tumor before it spreads.
The challenge of treating advanced tumors
In cases of advanced detection (phases III and IV), survival may fall to 2-3% at age 5, among other reasons because it is impossible to treat the tumor surgically because it is in contact with, or surrounds, veins and bile ducts, or because it has metastasized to the liver (more likely) or other organs. Chemotherapy and radiation therapy can only be used in these cases, but the average survival rates are one year, so new techniques are sought to allow tumor ablation without affecting adjacent vessels and ducts to prevent injuries that could increase the death rate.
“Tumour ablation is a therapeutic technique that has been established for years in oncology, which consists of eliminating tumors by directly destroying them in situ, without removing them, using needles that are placed inside them,” explains Dr. Eduardo Crespo Vallejo, head of the Vascular and Interventional Radiology Service at the Jiménez Díaz University Hospital, in whose operating rooms a novel ablation technique has been successfully applied that casts hopes for the treatment of advanced cases of pancreatic adenocarcinoma.
In the past, tumor destruction has been experienced with ablation techniques that involved injecting chemicals into the tumor, or with needles that caused very low or very high temperatures. But in all these cases the irrigation of the pancreas can be affected and therefore mortality increases. That is to say that they get freeze or burn the tumor, but also the vessels and ducts that surround him, negating the body.
Irreversible electroporation; successful intervention
This is not the case of the electroporation irreversible, the technique with which it has managed successfully treated a patient of 62 years of the Fundación Jiménez Díaz, who had severe pain refractory to other techniques of treatment of the tumor. “In irreversible electroporation, needles are also used to destroy the tumor, but what they do is generate a high voltage electric current within a predetermined space; this electric current causes the cells to die by destabilizing the lining membrane,” explains Dr. Crespo.
“In the absence of heat injury, the anatomical structures in the treated area, such as vessels or bile ducts, are kept intact but depopulated of cells, which allows to treat tumors, it is not affordable any other way to be affecting vital structures”, stresses the doctor, who nonetheless warns: “we must make clear that it is not a procedure indicated in all patients, and we have to be rigorous in the selection of the same to identify those who may benefit from the technique”.
The ideal patient profile for electroporation is that which has a good general condition and a tumour less than 3 to 4 centimeters limited to the pancreas, but which cannot be removed surgically because it invades the vascular structures of the area. “This characteristic determines that it is considered to be a locally advanced tumor,” Crespo reveals, which ends with a new requirement: “although the tumor is in an advanced state in the place it originated, it is necessary that there be no invasion of other distant organs, that is, that there be no metastases.