The following article, written by Barry Peterson, Director of Oncology Pharmacy at Oncology Analytics, is the second of a four-part series on key trends and findings from the American Society of Clinical Oncology (ASCO) Annual Meeting, held in Chicago May 31-June 4, 2019.
Pancreatic cancer begins when abnormal cells in the pancreas grow uncontrollably, forming a tumor. As the tumor continues to grow and spread, it causes a myriad of symptoms such as pain in the abdomen radiating to the back, weight loss, yellowing of the skin and eyes, nausea, pancreatitis, and diabetes. Since the symptoms are non-specific, most pancreatic cancers are identified when they are in an advanced stage. Accordingly, cure is uncommon, and most patients with advanced pancreatic cancer succumb to their disease.
Only about 5-10% of pancreatic cancers are associated with a family history; the rest do not have a specific cause. Some characteristics such as age, diabetes, chronic pancreatitis, obesity, smoking, and BRCA2 gene mutation may be risk factors for the development of pancreatic cancer.
About 56,000 people will be diagnosed with pancreatic cancer each year, and about 46,000 people will die from the disease. This represents about 3% of all cancer diagnoses. The 1-year survival rate for all stages of pancreatic cancer combined is 20%, with a five-year survival rate of 7%. When surgery is an option, the five-year survival rate increases to 10% and as high as 35% if the tumor is completely removed. New treatment options are needed in this difficult to treat cancer.
Research is ongoing to identify factors that can detect pancreatic cancer in earlier stages. There are currently no effective screening tools to identify pancreatic cancer. Since the pancreas is located deep inside the body, it is difficult for doctors to detect when the cancer has started. For now, efforts are focused on treatment. Surgery is one of the best options to treat early pancreatic cancer. For pancreatic cancers that have progressed, surgery can no longer help, and chemotherapy with or without radiation is the best option.
New research has identified that medications belonging to the PARP inhibitor class are more specific for treating pancreatic cancers that have a BRCA2 or BRCA1 mutation. A promising study that used a PARP inhibitor called olaparib as maintenance therapy after initial chemotherapy was presented at #ASCO2019
PARPs are proteins that play an important role in the life cycle of each cell. They help to repair damaged or broken DNA, and once fixed, it allows the cell to live normally. For normal cells, this is a good result. However, for cancer cells that may have a lot of DNA damage, by not fixing the damage, it can actually cause the cancer cells to die. PARP inhibitors are drugs that have been shown to work in pancreatic cancers that have a BRCA2 or BRCA1 mutation.
A phase 3 study was conducted in 154 patients with BRCA1/2 mutations who received either olaparib or placebo as maintenance therapy after initial chemotherapy. Patients who were randomized to olaparib received 300 mg tablets twice a day until disease progression or intolerable side effects. Patients who took olaparib had stable disease for 7.4 months compared to only 3.8 months for those who took a placebo. Only 5.5% of patients who took olaparib discontinued therapy due to side effects. This represents an important development for the treatment of pancreatic cancer.
One of the most prominent current-day celebrities to have pancreatic cancer is Alex Trebek, the long-time host of Jeopardy!. Like many pancreatic cancer patients, Alex was diagnosed with pancreatic cancer when it had already spread throughout his body. Having stage 4 pancreatic cancer meant he could only receive chemotherapy for his cancer. Originally diagnosed in March of 2019, Trebek has stated that his treatment is “kind of mind-boggling, as the doctors say they hadn’t seen this kind of positive result in their memory…some of the tumors have already shrunk by more than 50%”. He also states that he is doing well, even if he doesn’t always feel well, as the chemotherapy can leave him feeling weak. On the bright side, Alex plans to return to film the 36th season as the host of Jeopardy! this September.