Successful treatment of a locally advanced unresectable pancreatic cancer patient with interstitial pneumonitis by conversion surgery following gemcitabine plus nab-paclitaxel chemotherapy: A case report.

Conversion surgery is an attractive strategy to improve the outcomes for locally advanced unresectable (UR-LA) pancreatic ductal adenocarcinoma (PDAC). The present case report, presents a case of successful conversion surgery following the treatment of a patient with UR-LA PDAC, suffering from interstitial pneumonitis (IP), using a combination of gemcitabine and nab-paclitaxel (GnP). A 67-year-old woman presented at the hospital with a high level of carbohydrate antigen 19-9 (CA19-9; 1,713 U/ml). Radiological examination revealed a pancreatic tumor in contact with the superior mesenteric artery, with invasion extending to the most proximal draining jejunal branch into the superior mesenteric vein. The patient was diagnosed with UR-LA PDAC. Following 6 courses of GnP therapy, the tumor size markedly decreased from 50 to 18 mm, and the level of CA19-9 also decreased from 1,713 to 60.1 U/ml. Due to the progression of IP, the patient was administered steroid medication along with a restart of tacrolimus for the treatment of dermatomyositis and IP. After recovery from her lung condition, an additional 3 courses of GnP therapy were administered, and then pancreatoduodenectomy was performed. The patient was still alive 14 months post-surgery with no recurrence. Between July 2009 and September 2017, conversion surgery was performed for 18 cases of UR-LA PDAC treated with gemcitabine plus S-1 (GS) therapy, and 11 cases with GnP therapy. The percentage of median CA19-9 and median tumor volume reductions were 73.7 and 51.6%, respectively, following GS therapy, and 86.7 and 68.8%, respectively, following GnP therapy. Tumor reduction following GnP therapy was significantly higher than that after GS therapy (P=0.02). GnP therapy is a suitable regimen to shrink the tumor mass in patients with UR-LA PDAC. Careful management of systemic conditions is required to treat patients with PDAC and IP when using GnP therapy. Conversion surgery should be considered for recognizing radiological responses (tumor shrinkage adjacent to major arteries) and reductions in CA19-9 levels.