Indication for resection and possibility of observation for intraductal papillary mucinous neoplasm with high-risk stigmata

BACKGROUND/OBJECTIVES

According to the revised international intraductal papillary mucinous neoplasm (IPMN) guidelines (2017), the indication for surgery is based on risk classification. However, some IPMNs with high-risk stigmata (HRS) can be observed for long periods without resection. Hence, we need to reconsider the risk stratification, and this study aimed to propose a novel risk stratification for HRS-IPMNs.

METHODS

We enrolled 328 patients diagnosed with IPMN using endoscopic ultrasound between 2012 and 2019. We compared clinicopathological features between HRS and worrisome features (WF) and evaluated outcomes of HRS-IPMN.

RESULTS

Fifty-three patients (HRS 38, WF 15) underwent resection at initial diagnosis and 275 patients were observed. Following observation for 30 months, 22 patients (17 HRS, 5 WF) underwent resection. Analysis of resected IPMNs (n = 75) revealed that HRS had dominantly pancreatobiliary mucin subtype. Pancreatobiliary-type IPMN had larger nodule sizes and lymphatic invasion and high recurrence with poor prognosis. Seventy-four patients were diagnosed with HRS, 55 underwent resection, and 19 continue to be observed. The resected group had larger nodule sizes (median 8 mm vs. 5 mm; P = 0.060), whereas the observed group had more main pancreatic duct (MPD) dilation (median 10 mm vs. 5 mm; P = 0.005). In the resected HRS group, only patients with MPD dilation ≥10 mm (n = 10) had no recurrence but had a favorable prognosis compared with those nodule size ≥5 mm (n = 45).

CONCLUSIONS

Large nodule size may be associated with pancreatobiliary subtype and poor prognosis; however, patients with MPD dilation ≥10 mm with nodule size <5 mm did not require resection.

Adjuvant therapy is associated with improved overall survival in patients with pancreatobiliary or mixed subtype ampullary cancer after pancreatoduodenectomy - A multicenter cohort study

BACKGROUND/OBJECTIVE

The benefit of adjuvant therapy in ampullary cancer (AMPAC) patients following pancreatoduodenectomy (PD) is debated. The aim of this study was to determine the role of adjuvant therapy after pancreatoduodenectomy (PD) in histological subtypes of AMPAC.

METHODS

Patients undergoing PD for AMPAC at 5 high-volume European surgical centers from 1996 to 2017 were identified. Patient baseline characteristics, surgical and histopathological parameters, and long-term overall survival (OS) after resection were evaluated.

RESULTS

214 patients undergoing PD for AMPAC were included. ASA score (ASA1-2 149 vs. ASA 3-4 82 months median OS, p = 0.002), preoperative serum CEA (CEA <0.5 ng/ml 128 vs. CEA >0.5 ng/ml 62 months, p = 0.013), preoperative serum CA19-9 (CA19-9 < 40 IU/ml 147 vs. CA19-9 > 40IU/ml 111 months, p = 0.042), T stage (T1-2 163 vs. T3-4 98 months, p < 0.001), N stage (N0 159 vs. N+ 110 months, p < 0.001), grading (G1-2 145 vs. G3-4 113 months, p = 0.026), R status (R0 136 vs. R+ 38 months, p = 0.031), and histological subtype (intestinal subtype 156 vs. PB/M subtype 118 months, p = 0.003) qualified as prognostic parameters. In multivariable analysis, ASA score (HR 1.784, 95%CI 0.997-3.193, p = 0.050) and N stage (HR 1.831, 95%CI 0.904-3.707, p = 0.033) remained independent prognostic factors. In PB/M subtype AMPAC, patients undergoing adjuvant therapy showed an improved median overall survival (adjuvant therapy 85 months vs. no adjuvant therapy 65 months, p = 0.005), and adjuvant therapy remained an independent prognostic parameter in multivariate analysis (HR 0.351, 95%CI 0.151-0.851, p = 0.015). There was no significant benefit of adjuvant therapy in intestinal subtype AMPAC patients.

CONCLUSION

Adjuvant treatment seems indicated in pancreatobiliary or mixed type AMPAC.

Ampullary cancer of intestinal origin and duodenal cancer - A logical clinical and therapeutic subgroup in periampullary cancer

Periampullary cancers include pancreatic, ampullary, biliary and duodenal cancers. At presentation, the majority of periampullary tumours have grown to involve the pancreas, bile duct, ampulla and duodenum. This can result in difficulty in defining the primary site of origin in all but the smallest tumors due to anatomical proximity and architectural distortion. This has led to variation in the reported proportions of resected periampullary cancers. Pancreatic cancer is the most common cancer resected with a pancreaticoduodenectomy followed by ampullary (16%-50%), bile duct (5%-39%), and duodenal cancer (3%-17%). Patients with resected duodenal and ampullary cancers have a better reported median survival (29-47 mo and 22-54 mo) compared to pancreatic cancer (13-19 mo). The poorer survival with pancreatic cancer relates to differences in tumour characteristics such as a higher incidence of nodal, neural and vascular invasion. While small ampullary cancers can present early with biliary obstruction, pancreatic cancers need to reach a certain size before biliary obstruction ensues. This larger size at presentation contributes to a higher incidence of resection margin involvement in pancreatic cancer. Ampullary cancers can be subdivided into intestinal or pancreatobiliary subtype cancers with histomolecular staining. This avoids relying on histomorphology alone, as even some poorly differentiated cancers preserve the histomolecular profile of their mucosa of origin. Histomolecular profiling is superior to anatomic location in prognosticating survival. Ampullary cancers of intestinal subtype and duodenal cancers are similar in their intestinal origin and form a logical clinical and therapeutic subgroup of periampullary cancers. They respond to 5-FU based chemotherapeutic regimens such as capecitabine-oxaliplatin. Unlike pancreatic cancers, KRAS mutation occurs in only approximately a third of ampullary and duodenal cancers. Future clinical trials should group ampullary cancers of intestinal origin and duodenal cancers together given their similarities and their response to fluoropyrimidine therapy in combination with oxaliplatin. The addition of anti-epidermal growth factor receptor therapy in this group warrants study.