Pancreatic cancer
Pancreatic cancer has usually a dismal prognosis. Unlike some tumor types like breast, lung, liver and colon cancers, little progress has been made in its management for decades. Because of the limited benefit of the conventional treatments, new methods like percutaneous ablation have been introduced as a result of technological developments. Percutaneous ablation can kill most of the tumor mass in the pancreas, relieve pain and provide local control for a long time. In our experience, the most promising one of these ablations is cryoablation (freezing) treatment. In this method, we insert special needles from the skin into the tumor and freeze the cancer mass to death. The whole procedure is done with ultrasound and CT guidance under local anesthesia and conscious sedation. In some patients, we additionally do intratumoral immunotherapy to introduce tumor cells to the immune system by injecting immunotherapy medication into the frozen area. At our centers, we do cryoablation with local anesthesia and conscious sedation since 2012. This treatment lasts 1-2 hours and the patient can go home the same evening or the next day. The serious complication (side effect) rate in these treatments is around 2% in our experience.
Pancreatic cancer is encountered with an increasing frequency, especially in developed countries. Although it is more common in alcohol users, smokers and diabetic patients, many patients do not have any obvious risk factors. The frequency of pancreatic cancer also increases with age; It is very rare under the age of 40, approximately half of the cases are over the age of 70. Pancreatic cancer usually presents with complaints such as abdominal pain, nausea, vomiting, weakness, jaundice, and dark urine. However, these symptoms occur in the late stages of the disease, and there are usually no complaints in the early stages. Histologically, there are 2 types of pancreatic cancer: exocrine and endocrine. Exocrine tumors arise from cells in the pancreas that produce digestive enzymes and secrete them into the intestine, and they constitute 98% of all pancreatic cancers. The most common of these is adenocarcinoma, which accounts for 85% of all pancreatic cancers. Endocrine (or neuroendocrine) tumors originate from cells that produce some hormones (insulin, gastrin, glucagon, etc.) released from the pancreas into the blood and constitute 2% of all pancreatic cancers. In general, exocrine tumors, especially adenocarcinoma, have a faster course, and neuroendocrine tumors have a slower course.
Very rarely, metastases originating from another organ may also occur in the pancreas. One of the tumors that most commonly metastasize to the pancreas is kidney cancer (renal cell carcinoma).
How is it diagnosed?
Pancreatic cancers are detected on ultrasound, tomography, MRI or PET-CT examinations either incidentally or done due to symptoms such as pain, jaundice and weight loss. Nowadays, with the frequent use of these imaging methods for other reasons, many pancreatic cancers are diagnosed at a relatively early stage and generally incidentally. When a mass is seen in the pancreas a biopsy is required to make the diagnosis. The patient should never be operated without a biopsy, because although rare, benign tumors can also be seen in the pancreas. This will also create an unnecessary risk of surgery for the patient and will delay the start of treatments such as chemotherapy and radiotherapy. Additionally, the hard layer (desmoplastic reaction) that is formed around pancreatic cancers may mimic the cancer itself and cause the surgeon to get the biopsy from the wrong place.
The ideal biopsy method in the pancreas is core (trucut) needle biopsy performed under ultrasound or tomography guidance. With this procedure, the following critical points can be clarified:
1. The nature of the mass (benign vs malignant).
2. The type of the cancer (primary pancreatic cancer or metastasis from other organs)
3. The type of the pancreatic cancer (adenocarcinoma vs neuroendocrine tumor)
4. The presence or absence of genetic mutations (these tests may show which drugs or methods the tumor is more sensitive to).
In our centres, pancreatic core biopsy is performed painlessly under local anesthesia with the coaxial method. The procedure takes approximately 15 minutes, and the patient can return to normal life after an hour observation.
Staging in pancreatic cancer
Pancreatic cancer is divided into 4 stages according to the extent of the tumor. In stages 1 and 2, the tumor is within the pancreas and these stages may be suitable for surgery. However, stages 1 and 2 constitute only 10-15% of all pancreatic cancer cases. In stage 3, the tumor has spread outside the pancreas, to the stomach, intestines or large vessels. Surgery is not useful in this stage, which constitute 40% of all pancreatic cancers. In stage 4, which constitutes 40% of pancreatic cancers, there are metastases to distant organs and surgery is not an option also in this group. In stage 3 and 4, generally only chemotherapy and supportive treatment are given to the patient.
How is it treated?
In pancreatic cancer, surgery is the first choice of treatment if the general condition of the patient and the stage of the tumor are suitable. However, only 10-15% of patients diagnosed with pancreatic cancer are suitable for surgery. In these patients, the most frequently performed procedure is the "Whipple" operation. In this surgery, the pancreas and duodenum are removed, and then the stomach and liver bile duct are connected to the remaining intestine. Whipple is a technically difficult and complicated surgery; mortality rate (loss of life) is around 5% and complication rate is around 40%. Therefore, it should only be performed in experienced centers that perform this operation frequently. However, even after a well-performed Whipple surgery, the median survival is only 18 months and the 5-year survival rate is only around 10-20%.
The most common treatment for pancreatic cancer is chemotherapy. Chemotherapy can be applied to facilitate the operation (neoadjuvant), after the operation (adjuvant), or as a single treatment in patients who cannot be operated on. In chemotherapy, it has recently been shown that a regimen consisting of 4 drugs gives better results compared to the classical regimen. However, since it has more side effects, it is only recommended for young patients with a good general condition. Another treatment for pancreatic cancer is radiotherapy. Radiotherapy is usually applied together with chemotherapy rather than alone. In some cases, it can be given before or after surgery. However, the benefit of radiotherapy in pancreatic cancer is controversial and is not routinely applied.
New treatment methods in pancreatic cancer
As mentioned above, there is no local treatment option for 85% of pancreatic cancers that are not suitable for surgery. In such patients only systemic chemotherapy is given, but its benefit is limited. For this reason, several percutaneous ablation methods (radiofrequency, Nanoknife, cryoablation) have been tried in some centers. Our Varisson Radiology centers have become one of the most experienced institutions in the world in pancreatic ablation as we have performed all types of percutaneous ablation since 2012.
Interventional oncology in cancer management
Prof Saim Yilmaz, MD