Exceptions to this are the functioning PanNETs, where over-production of various active hormones can give rise to symptoms (which depend on the type of hormone).Bearing in mind that the disease is rarely diagnosed before the age of 40, common symptoms of pancreatic adenocarcinoma occurring before diagnosis include:

Pain in the upper abdomen or back, often spreading from around the stomach to the back. The location of the pain can indicate the part of the pancreas where a tumor is located. The pain may be worse at night and may increase over time to become severe and unremitting. It may be slightly relieved by bending forward. In the UK, about half of new cases of pancreatic cancer are diagnosed following a visit to a hospital emergency department for pain or jaundice. In up to two-thirds of people, abdominal pain is the main symptom, for 46% of the total accompanied by jaundice, with 13% having jaundice without pain. Jaundice, a yellow tint to the whites of the eyes or skin, with or without pain, and possibly in combination with darkened urine, results when a cancer in the head of the pancreas obstructs the common bile duct as it runs through the pancreas. Unexplained weight loss, either from loss of appetite, or loss of exocrine function resulting in poor digestion. The tumor may compress neighboring organs, disrupting digestive processes and making it difficult for the stomach to empty, which may cause nausea and a feeling of fullness.
As a result, this causes peripheral nerve endings to report painful stimuli. Immunity
As mentioned previously, PGE2 contributes to the inflammation when bound to EP2 receptors. In terms of immunity, prostaglandins have the ability to regulate lymphocyte function. PGE2 affect T-lymphocyte formation by regulating apoptosis of immature thymocytes. In addition, it can suppress an immune response by inhibiting B lymphocytes from forming into antibody-secreting plasma cells. When this process is suppressed, it causes a decrease in a humoral antibody response because of the decrease in production of antibodies. PGE2 also has roles in inhibition of cytotoxic T-cell function, cell division of T-lymphocytes, and the development of TH1 lymphocytes. Neurological effects
In response to physiologic and psychologic stress, prostaglandin E2 is involved in several inflammation and immunity pathways. As one of the most abundant prostaglandins in the body, Prostaglandin E2 is involved almost all typical inflammation markers such as redness, swelling, and pain. It regulates these responses through binding to G coupled protein prostaglandin E2 (PGE2) receptors (EP1, EP2, EP3, and EP4). The activation of these different EP receptors is dependent on the type of triggering stress stimuli and results in the corresponding stress response. Activation of EP1 via PGE2 results in the suppression of impulse behaviors in response to psychological stress. Prostaglandin E2 is involved in regulating illness induced memory impairment via activation of EP2. Prostaglandin E2 activation of EP3 results in regulation of illness induced fever. EP4 is functionally similar to EP2 and has also been shown in studies to have a role in hypothermia and anorexia.