Pancreatic cancer is still relatively challenging to treat as it is often diagnosed at an advanced stage. In approximately 20% of resectable tumors, the recurrence rate of pancreatic cancer remains as high as 80% even after curative pancreaticoduodenectomy, with a 5-year survival rate of approximately 10–40% [4].
The liver and local regional sites are the most common site of metastasis after curative resection, followed by the lung and peritoneum [5]. However, small-bowel metastasis is quite rare. To the best of our knowledge, only one case report, which was performed by Miyasaka et al. in 2018, documented small-bowel metastasis after pancreaticoduodenectomy [6]. In this case, the patient presented with fever and bowel obstruction at 2 years after the primary surgery, leading to the diagnosis of metastases in the transverse colon and jejunum. Due to this life-threatening condition, partial resection of these two sites was performed. The patient successfully recovered postoperatively and survived for 7 months but, ultimately, died due to metastasis in the mesenteric lymph nodes at 13 months after the index surgery.
Further, other case reports have documented about colon metastasis after primary resection of pancreatic cancer [7, 8, 9]. Most of these cases involved patients under regular surveillance, with an interval of 2–7 years from the initial surgery to recurrence. In all cases, the presenting symptom was abdominal pain, and CT scan revealed strictures or obstructions in various parts of the colon, including the cecum, ascending colon, and sigmoid colon. These findings suggest that bowel obstruction or narrowing causing symptoms can be an indication for surgical resection.
In addition, Kim et al. emphasized the importance of utilizing tumor markers in the diagnosis of colon metastasis [7]. In their case, the patient exhibited slight elevations in tumor marker levels before any CT scan findings were apparent. After approximately 1 year, following the onset of symptoms, the patient’s cancer antigen 19 − 9 (CA19-9) and carcinoembryonic antigen (CEA) levels increased from 334.8 to 5133 U/mL and from 18.2 to 54.4 ng/mL, respectively. In the case of Inada et al., the patient had normal CEA levels. However, the patient’s CA19-9 levels increased from normal levels to 1886.6. U/mL [8]. Moreover, according to a retrospective study on late recurrent pancreatic cancer in patients with long-term survival after pancreaticoduodenectomy, most patients with late recurrence were asymptomatic. Therefore, CT scans and CA19-9 surveillance should be continuously performed on all patients undergoing pancreaticoduodenectomy [4].
In most cases, pancreatic cancer recurrence is treated with chemotherapy. However, recent reports on successful re-surgeries indicate that surgical intervention can be possibly beneficial for these patients. Moletta et al. performed a literature review. Results showed that the overall survival rate of patients with recurrent pancreatic cancer who underwent surgical treatment was 26% after a median follow-up of 64.5 months [4]. The disease-free interval after resection of recurrent lesions was 14.2 months. Patients with recurrent pancreatic cancer who underwent surgery had a significantly higher median 26-month overall survival (range: 6–11 months after recurrence diagnosis) than those who did not undergo resection. The postoperative mortality and morbidity rates were 1.8% and 28.1%, both of which are considered acceptable. Serafini et al. conducted a more recent meta-analysis that supported these findings [10]. They compared six large retrospective studies. Results showed that the median overall survival benefit was 28.7 months and that the median survival benefit was 15.2 months after re-resection. These results indicate that surgery should be considered as a possible treatment option for recurrent pancreatic cancer.
Patients with disseminated distant metastasis are not eligible for surgery. However, surgical resection should be considered in cases of limited (oligometastatic) recurrence if complete tumor excision is feasible. Nienhüser et al. conducted a literature review to identify which patients can benefit from surgery [11]. Several prognostic benefits were found in patients who survived after re-resection for local recurrence or isolated metastatic recurrence. The most important factors included successful complete resection, an interval of > 9–10 months from the initial resection to the development of recurrence, and effective chemotherapy prior to the second surgery. The other factors were age under 65 years, tumor measuring < 2 cm, positive lymph node status, and a body mass index of > 20 kg/m2. These results are consistent with those of the previous literature. Based on a 2020 multicenter database study, multivariate analysis revealed that a time to recurrence from resection of < 1 year and peritoneal recurrence were significant independent predictors of poor overall survival in patients with recurrent pancreatic cancer [12]. In addition, lymph vessel invasion was an independent risk factor of long-term survival [4].
Nevertheless, only the current National Comprehensive Cancer Network guidelines recommend the use of alternative treatment strategies for patients with recurrent pancreatic cancer who have undergone surgery [13]. In particular, there are other options for re-surgery, with particular emphasis on the potential benefits of pulmonary metastasectomy in cases of lung metastasis. However, further data should be collected to support this approach.
To the best of our knowledge, only a few isolated case studies have reported about pancreatic cancer recurrence in the small intestine after primary resection for pancreatic cancer. In addition to imaging techniques, tumor markers such as CEA and CA19-9 can be useful predictors of recurrence. Surgery is commonly used for the emergency management of symptomatic bowel obstructions. However, with consideration of its potential benefits in overall survival and acceptable postoperative mortality and morbidity rates, it may also be a viable elective option for specific patients, such as those with limited recurrence. Younger patients who have undergone a successful resection of recurrent pancreatic cancer have a longer interval before recurrence, and patients who have received chemotherapy before re-resection are more likely to have better prognoses.
Herein, we present a 56-year-old female patient who was relatively young and diagnosed with IPMN-associated pancreatic cancer without lymph node metastasis. She underwent pancreaticoduodenectomy in 2019. After approximately 5 years, in 2024, recurrence was detected, indicating a relatively long interval from the initial resection to the development of recurrence. The patient had regular follow-ups postoperatively, without recurrence findings on CT scans and with normal CEA and CA19-9 levels. Recurrence was incidentally identified on positron emission tomography-CT scan. After a successful re-surgery, to date, the patient has remained complication-free under regular outpatient department follow-ups. This case represents a successful re-resection of recurrent pancreatic cancer in the small intestine after pancreaticoduodenectomy. Therefore, in selected cases, surgical intervention is a feasible option and may provide substantial benefits.