Autoimmune pancreatitis and pancreatic cancer: Epidemiological aspects and immunological considerations

Table 1 Schematic overview of the clinical studies investigating the association between autoimmune pancreatitis and pancreatic cancer.

Ref.	Study population (disease)	Total patients (n)	AIP type 1 (n)	Cancer (overall) (n)	Pancreatic cancer (n)	Median follow-up (yr)	Additional specifications
Yamamoto et al[17] (Japan, 2012)	IgG4-RD	106	10	2	0	NA	-
Shiokawa et al[18] (Japan, 2013)	AIP	108	104	18	0	3.3	These 18 malignancies were diagnosed in 15 patients.
Hart et al[15] (International, 2013)	AIP	1064	978	57	5	NA	No patients with AIP type 2 developed any malignancies.
Gupta et al[25] (United States, 2013)	CP	58	11	NA	7 (PanIN)	N/A	Retrospective analysis of patients with CP. There was no statistically significant difference in the frequency of PanIN between ordinary CP and AIP: in the latter group, no difference between type 1 and type 2. In general, the only case of PanIN3 was detected in one AIP type 1 specimen.
Gupta et al[25] (United States, 2013)	AIP	84	NA	NA	2	4.1	These 2 cases of pancreatic cancer were diagnosed in type 1 AIP patients.
Hart et al[19] (United States, 2014)	AIP	116	116	23	1	3.6	-
Hirano et al[20] (Japan, 2014)	IgG4-RD	113	95	14	2	6	2 IgG4-RD patients diagnosed with malignancy (out of 14) were not affected with AIP.
Huggett et al[16] (United Kingdom, 2014)	IgG4-RD	115	106	13	3	2.7	Of these 3 cases of pancreatic malignancies, 2 were cholangiocarcinoma cases and 1 was a pancreatic adenocarcinoma.
Ikeura et al[26] (Japan, 2014)	AIP	63	63	NA	3	5.2	-
Shimizu et al[21] (Japan, 2015)	AIP	84	84	9	1	4.5	-
Buijs et al[22] (The Netherlands, 2015)	AIP	107	96	8	0	6.25	-
Ngwa et al[27] (United States, 2015)	AIP	99	99	NA	0	NA	The aim of this study was to evaluate the clinical significance of elevated sgG4 levels in patients with AIP and pancreatic cancer and potential prognostic implications of those in patients with pancreatic cancer.
Xiang et al[28] (China, 2019)	AIP	74	74	NA	4	NA	3 patients were diagnosed with pancreatic ductal adenocarcinoma and 1 with cholangiocarcinoma. There was also 1 case of solitary extramedullary plasmacytoma.
Tang et al[31] (China, 2020)	IgG4-RD	587	NA	17	0	5.1	-
Ishikawa et al[32] (Japan, 2020)	AIP	123	123	NA	2	4.6	-

AIP: Autoimmune pancreatitis; CP: Chronic pancreatitis; IgG4-RD: Immunoglobulin G 4-related disease; N/A: Not applicable; NA: Not available; PanIN: Pancreatic intra-epithelial neoplasia.