Pancreatic carcinoma is known to have a poor prognosis and frequently develops recurrence even after curative resection [
14]. The major recurrence pattern of PDAC is local spread in the remnant pancreas, multiple liver metastases and peritoneal dissemination within 1–2 years after resection [
15,
16]. In the present patients, surgical resection of the remnant pancreas was performed because the recurrence of PDAC after PpPD was limited to the remnant pancreas without distant metastasis, nodal involvement and peritoneal dissemination. There have been anecdotal reports of repeated pancreatectomy for recurrent PDAC in the remnant pancreas [
4,
5,
6,
7,
8,
9,
10,
11,
12,
13]. Some of the previous reports demonstrated long survival after surgical resection for the second PDAC [
5,
6,
8,
10,
12]. These patients and our patients show the same clinical feature, that is, curative resection with negative surgical margins at both the first and second operations. The effectiveness of repeated pancreatectomy for PDAC in the remnant pancreas is obscure because of the lack of a sufficient number of patients, but the safety of repeated pancreatectomy has been reported recently [
9]. We believe that repeated pancreatectomy may provide good results in selected patients in whom complete removal of PDAC in the remnant pancreas can be achieved.
It is difficult to clarify whether PDAC developing in the remnant pancreas is a local recurrence or a second primary carcinoma. According to Schnelldorfer et al. [
3], 5-year survival after PpPD or pancreatoduodenectomy for PDAC was no guarantee of cure, because 16% of this subset died of PDAC up to 7.8 years after the operation. On the other hand, Launois et al. [
17] observed the incidence of 32% of multifocal carcinomas in the pancreas in a series of 47 total pancreatectomies for patients with PDAC. Progression of atypical ductal hyperplasia or carcinoma in situ to an invasive PDAC has been documented [
18]. A minute cancerous lesion may coexist in the remnant pancreas at the initial operation. In our patients, the second carcinoma seems to be a recurrent lesion because both the first and second cancers showed similar histological characteristics, even with the long interval period between the first and second operations. Although it is obscure whether PDAC in the remnant pancreas is a local recurrence or not, periodic examinations including measurement of tumor markers and imaging studies such as CT scan might have an important role for early detection of PDAC developing in the remnant pancreas after pancreatectomy for PDAC.
Recent advancement of adjuvant and neoadjuvant therapy including chemotherapy and radiotherapy improves the survival benefit in patients undergoing curative resection of PDAC [
19,
20,
21]. Adjuvant therapy may inhibit the growth of carcinoma in the remnant pancreas after pancreatectomy for PDAC. Some PDAC is chemosensitive and preoperative chemotherapy provides a histopathological response and a high R0 resection rate [
22]. In our second patient administration of S-1 made the recurrent tumor shrink, and curative resection was performed. Effects of chemotherapy may increase the chance of curative resection of a secondary primary or recurrent pancreatic carcinoma in the remnant pancreas.
In conclusion, curative resection for PDAC developing in the remnant pancreas after PpPD for PDAC may be possible as in our patients. Repeated pancreatectomy may provide a chance of long-term survival if the recurrence of PDAC is limited to the remnant pancreas.
