With Alex Trebek’s recent announcement that his pancreatic cancer is in remission, many people have wondered if this difficult cancer is now easier to treat. Pancreatic cancer remains a major cancer killer, but advances are happening.
As a medical oncologist who specializes in treating and studying pancreatic cancer, I’ll try to provide insights, including some from the American Society of Clinical Oncology (ASCO) meeting now underway.
Pancreatic cancer and its toll
We oncologists, or cancer specialists, call the disease “pancreatic ductal adenocarcinoma,” or PDAC. It is a leading cause of cancer-related death, currently ranking as the seventh leading cause of cancer deaths globally and the third in the U.S.
Often diagnosed at an advanced stage, pancreatic cancer has a low survival rate of 9% or less.
Although cancers are usually classified as stages from I to IV, in PDAC we have found that a different system which corresponds to how we actually treat these tumors is more useful. The earliest stage is when the cancer is determined to be surgically resectable, that is, removable through surgery. About 15% of patients’ tumors are found at this stage.
About 40% of patients’ tumors have further progressed to where they attach themselves to or encompass local structures. This is further broken down into borderline tumors that, although technically removable, require chemotherapy and radiation therapy prior to surgery to ensure their complete removal.
Locally advanced tumors cannot be surgically removed in most cases as they completely surround critical blood vessels or infiltrate into adjoining critical organs.
The remainder of pancreatic cancers are already metastatic – they have already spread to distant areas. Nearly all long-term pancreatic cancer survivors are diagnosed when their cancer is, or can be made, surgically removable. Contrarily, because of the limited number of treatment options, and inherent resistance to treatment, exceedingly few five-year survivors present with Stage IV disease.
Lack of screening an impediment
Bruce Blaus/Wikimedia Commons, CC BY-SA
A key challenge in treating pancreatic cancer is the lack of good screening techniques to identify such cancers in their earliest stages, as the pancreas lies in an anatomically unfavorable position for early diagnosis, toward the back of the abdomen.
By the time the diagnosis of pancreatic adenocarcinoma is suspected, typically by symptoms such as jaundice, pain and weight loss, the tumor has already grown to a point where surgical removal is difficult. Critical vascular and other structures hamper surgical excision. Or, it has grown to a point where it has spread to distant sites.
Additionally, well before a physician diagnoses a patient’s pancreatic cancer, there is often what we call microscopic metastatic disease. This means that cancer cells are already hiding in other parts of the body. Preoperative and postoperative chemotherapy and radiation are used to try to kill such stealth tumor cells. However, despite these treatments, most patients whose tumors are surgically removed will die of recurrence resulting from these remaining tumor cells.
Chemo, and more chemo
Once spread to other organs either at presentation or in relapse, PDAC is not curable except in rare circumstances. However, treatment of patients with metastatic disease can yield benefits in terms of overall survival and a quality of life.
Historically, standard chemotherapy for these patients has included one or two drugs, but newer chemotherapy combinations are being used in patients who can tolerate more aggressive systemic therapy. Some of these may be used in combination.