The Importance of Reading the Skin: Cutaneous Metastases of Pancreatic Cancer, a Systematic Review

Background: Pancreatic cancer is notorious for its aggressive nature and low survival rate, with less than 10% of patients surviving beyond five years. Early detection is difficult, but skin metastases can be a rare but significant indicator. This systematic review focuses on the epidemiology, clinical features, and histology of skin metastases from pancreatic cancer to determine their importance in early diagnosis and overall management of the disease. Materials and methods: Following PRISMA guidelines, we conducted an exhaustive search of MEDLINE/PubMed, EMBASE, and SCOPUS databases up to June 2023, using specific keywords. Four independent investigators screened the studies using predefined criteria, and two investigators checked the accuracy and consistency of the data extraction. We assessed the quality of the trials using adapted criteria from the Joanna Briggs Institute. A narrative synthesis rather than a meta-analysis was chosen because of the different study designs. Results: The final analysis included 57 patients with skin metastases from pancreatic cancer. Cutaneous metastases, although rare, presented with approximately equal gender distribution and a mean age of 63.4 years. Predominantly non-umbilical (77%), these metastases showed clinical diversity, ranging from asymptomatic nodules to painful or ulcerated lesions. Notably, skin metastases often preceded the diagnosis of primary pancreatic cancer (58%). Primary tumor characteristics revealed different localizations, with adenocarcinoma being the most prevalent histological type (77%). A significant association (p = 0.008) was observed between pancreatic tumor location and the timing of presentation of skin metastases. Tumors located in the body and tail of the pancreas were more likely to manifest skin metastases as an initial clinical manifestation (62.2%) than those in the head of the pancreas (20.8%). Conclusions: In conclusion, although skin metastases are rare, they are important indicators of pancreatic cancer, highlighting the need for multidisciplinary healthcare collaboration and thorough skin examination. Recognizing them could lead to earlier diagnosis, which is crucial in a cancer with limited treatment options.