As reported in a nationwide epidemiological survey conducted in Japan, patients with chronic pancreatitis exhibited a risk of pancreatic cancer that is approximately 11.8 times higher than the general population [11]. Notably, the patient presented in this case had a history of side-to-side pancreaticojejunostomy, a procedure commonly recognized as the Partington procedure, performed 40 years previously. The purpose of such interventions is multifaceted and primarily aimed at alleviating pain and mitigating the risk of further complications, including pancreatic cancer [8, 12]. Ueda et al. reported that the incidence of pancreatic cancer was significantly lower in patients who had undergone surgery for chronic pancreatitis than in those who had not (hazard ratio 0.11; 95% confidence interval, 0.0014–0.80; p = 0.03).

Although no pathological signs of acute pancreatitis were observed in this case, recent studies highlight the importance of considering acute pancreatitis as a risk factor for pancreatic adenocarcinoma. Munigala have highlighted that the long-term risk of pancreatic ductal adenocarcinoma is elevated following episodes of acute pancreatitis, irrespective of the cause, underscoring the need for careful monitoring in patients with any form of pancreatitis.

The surgical approach of pancreaticojejunostomy has been proven to prevent the progression of chronic pancreatitis by modulating pancreatic duct drainage, thereby addressing the root cause of inflammation [9]. Zheng et al. emphasized the potential preventative effect of early surgical intervention on the onset of pancreatic cancer and found that the interval between the diagnosis of chronic pancreatitis and surgical intervention was an independent risk factor for developing pancreatic cancer [9]. These findings underscore the possible protective effect of surgical interventions such as the Partington procedure against carcinogenesis, particularly when performed early in the disease course. In this case, the Partington procedure appears to have effectively moderated the chronic inflammation, as evidenced by the diminished pancreatic calcifications observed in the computed tomography conducted prior to the pancreaticoduodenectomy.

The prior pancreaticojejunostomy posed considerable surgical intricacies due to altered anatomy. If the tumor had been distant from the prior pancreaticojejunostomy, surgery to preserve this lateral anastomosis might have been possible. In that case, a new pancreaticojejunostomy could have been avoided by preserving the elevated jejunum. In this case, the previous pancreaticojejunostomy did not extend to the tail of the pancreas, and a portion of the pancreatic tail could be retained. Although the remaining pancreas was small, the patient's glucose tolerance was maintained after surgery, and there were no significant digestive or absorptive disturbances; therefore, we believe there was considerable benefit in preserving the small pancreas.

Regarding pancreatic cancer that develops after surgery for chronic pancreatitis, Zhen reported that patients who underwent surgery for CP showed a higher cumulative incidence of PC with rates of 1.48% at 3 years, 2.63% at 6 years, and 3.71% at 9 years after surgery [9]. However, we could not find any detailed reports on PC post-pancreatitis surgery in the English literature, and there were only two case reports in Japanese. Nagahisa et al. reported a case of intraductal papillary mucinous carcinoma of the pancreatic body that developed 25 years after Partington’s procedure and was treated with distal pancreatectomy [13], and Tamura et al. reported a case of pancreatic invasive ductal carcinoma that developed 30 years after surgery for chronic pancreatitis and was treated with distal pancreatectomy 15 (Table 2). Including the present case, in all three instances, PC was detected after more than 25 years following surgery for CP, with tumor sizes exceeding 2.5 cm. It should be noted that pancreatic cancer after surgery for chronic pancreatitis can occur even after a long time after surgery, and physicians need to follow-up with patients with CP over a long period of time, even after surgery for CP.

In conclusion, while surgical interventions for chronic pancreatitis reduce the risk of pancreatic cancer, it should be noted that pancreatic cancer can occur even after a long time after the surgery. Further studies and case series would be invaluable in elaborating best practices for such complex cases.