Indications to total pancreatectomy for positive neck margin after partial pancreatectomy: a review of a slippery ground

[Relevance of frozen section diagnostics in pancreatic surgery]

Frozen sections are performed in pancreatic surgery for three reasons: histopathological confirmation of previously unclear space-occupying lesions, determination of the extent of surgical resection in an operative exploration and for possible follow-up resections after previously carried out surgical resections. Overall, in the literature there are heterogeneous data with respect to an improvement in the prognosis of a secondary R0 resection by a repeat resection in comparison to a R1 resection. Nowadays, extended pancreatic resections including vascular resections are technically feasible and safe. Nevertheless, with respect to the precise radicality in the surgical procedure, all patient characteristics should be taken into consideration in addition to the histopathological diagnosis of the frozen sections.

Perioperative and oncologic outcomes after total pancreatectomy and pancreatoduodenectomy for pancreatic head adenocarcinoma-A propensity score-matched analysis from the German Cancer Registry Group

BACKGROUND

To compare perioperative morbidity and mortality in patients receiving pancreatoduodenectomy or total pancreatectomy for pancreatic head adenocarcinoma using German Cancer Registry data.

METHODS

Anonymized pooled data were retrieved from regional cancer registries participating in the German Cancer Registry Group of the Association of German Tumor Centers. Included were patients diagnosed with pancreatic head adenocarcinoma since 2016, receiving curative intent pancreatoduodenectomy or total pancreatectomy. Patients were propensity-score matched according to age, sex, and histopathology. Primary endpoints were 30- and 90-day postoperative mortality. Secondary endpoints were administration of adjuvant chemotherapy, long-term survival, and patterns of cancer recurrence. The data were analyzed using R.

RESULTS

In total, 756 patients per treatment group were matched for further analyses. R0-resection rate was comparable between pancreatoduodenectomy and total pancreatectomy (69.6 vs 73.4%, P = .154). The 30-day (9.5 vs 4.8%, P < .001) and 90-day postoperative mortality (18.0 vs 11.0%, P < .001) rates were significantly lower after pancreatoduodenectomy compared with total pancreatectomy. After pancreatoduodenectomy, more patients received adjuvant chemotherapy (43.6 vs 53.3%, P < .001) and time to adjuvant chemotherapy was shorter (60.1 vs 52.7 days, P = .002) compared with total pancreatectomy. Long-term overall survival was worse after total pancreatectomy (P < .001), also in patients receiving adjuvant chemotherapy (P = .019). The sites of recurrence were comparable between both groups (P = .274).

CONCLUSION

The results of this study show greater perioperative morbidity and mortality after total pancreatectomy compared with pancreatoduodenectomy for pancreatic head malignancy. Also, long-term survival was worse after total pancreatectomy. These results emphasize the role of pancreatoduodenectomy as a standard surgical procedure for pancreatic head adenocarcinoma and suggest that total pancreatectomy should only be performed in selected patients.

Impact of resection margin status on recurrence and survival in patients with resectable, borderline resectable, and locally advanced pancreatic cancer

BACKGROUND

To improve outcomes for patients with pancreatic ductal adenocarcinoma, a complete resection is crucial. However, evidence regarding the impact of microscopically positive surgical margins (R1) on recurrence is conflicting due to varying definitions and limited populations of patients with borderline-resectable and locally advanced pancreatic cancer. Therefore, we aimed to determine the impact of the resection margin status on recurrence and survival in patients with pancreatic ductal adenocarcinoma stratified by local tumor stage.

METHODS

We performed a retrospective cohort study on patients with nonmetastatic pancreatic ductal adenocarcinoma undergoing pancreatectomy at a high-volume academic center (2012-2022). R1 was subclassified into microscopic invasion of the margin (R1 direct) or carcinoma present within 1 mm but not directly involving the margin (R1 <1 mm). Overall survival and time to recurrence were assessed by log-rank test and multivariable Cox regression.

RESULTS

Of 472 included patients, 154 (33%) had an R1 resection. Of those 50 (32%) had R1 <1 mm and 104 (68%) R1 direct. The most commonly involved margin was the uncinate (41%) followed by the pancreatic neck (16%) and vascular margins (9%). Overall, a stepwise shortening of time to recurrence and overall survival was observed with an increasing degree of margin involvement (median time to recurrence: R0 39.3 months, R1 <1 mm 16.0 months, and R1 direct 13.4 months, all comparisons P < .05). Multivariable analyses confirmed the independent prognostic value of R1 direct across all surgical stages.

CONCLUSION

The resection margin status portends an independent prognostic value. Moreover, this association persists in patients with borderline-resectable and locally advanced pancreatic cancer. Increasing the R0-resection rate is the most important potentially influenceable prognostic factor for improving surgery-related outcomes.

Pancreatic Ductal Adenocarcinoma: Update of CT-Based Radiomics Applications in the Pre-Surgical Prediction of the Risk of Post-Operative Fistula, Resectability Status and Prognosis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is the seventh leading cause of cancer-related deaths worldwide. Surgical resection is the main driver to improving survival in resectable tumors, while neoadjuvant treatment based on chemotherapy (and radiotherapy) is the best option-treatment for a non-primally resectable disease. CT-based imaging has a central role in detecting, staging, and managing PDAC. As several authors have proposed radiomics for risk stratification in patients undergoing surgery for PADC, in this narrative review, we have explored the actual fields of interest of radiomics tools in PDAC built on pre-surgical imaging and clinical variables, to obtain more objective and reliable predictors.

METHODS

The PubMed database was searched for papers published in the English language no earlier than January 2018.

RESULTS

We found 301 studies, and 11 satisfied our research criteria. Of those included, four were on resectability status prediction, three on preoperative pancreatic fistula (POPF) prediction, and four on survival prediction. Most of the studies were retrospective.

CONCLUSIONS

It is possible to conclude that many performing models have been developed to get predictive information in pre-surgical evaluation. However, all the studies were retrospective, lacking further external validation in prospective and multicentric cohorts. Furthermore, the radiomics models and the expression of results should be standardized and automatized to be applicable in clinical practice.

Prediction of Early Distant Recurrence in Upfront Resectable Pancreatic Adenocarcinoma: A Multidisciplinary, Machine Learning-Based Approach

Simple Summary

If pancreatic adenocarcinoma is assessed to be technically resectable, curative surgery is still suggested as the primary treatment option; however, the recurrence rate can be very high even in this selected population. The aim of our retrospective study was to develop a preoperative model to accurately stratify upfront resectable patients according to the risk of early distant disease relapse after surgery (<12 months from index procedure). Through a machine learning-based approach, we identified one biochemical marker (serum level of CA19.9), one radiological finding (necrosis) and one radiomic feature (SurfAreaToVolumeRatio), all significantly associated with the early resurge of distant recurrence. A model composed of these three variables only allowed identification of those patients at high risk for early distant disease relapse (50% chance of developing metastases within 12 months after surgery), who would benefit from neoadjuvant chemotherapy instead of upfront surgery.

Abstract

Despite careful selection, the recurrence rate after upfront surgery for pancreatic adenocarcinoma can be very high. We aimed to construct and validate a model for the prediction of early distant recurrence (<12 months from index surgery) after upfront pancreaticoduodenectomy. After exclusions, 147 patients were retrospectively enrolled. Preoperative clinical and radiological (CT-based) data were systematically evaluated; moreover, 182 radiomics features (RFs) were extracted. Most significant RFs were selected using minimum redundancy, robustness against delineation uncertainty and an original machine learning bootstrap-based method. Patients were split into training (n = 94) and validation cohort (n = 53). Multivariable Cox regression analysis was first applied on the training cohort; the resulting prognostic index was then tested in the validation cohort. Clinical (serum level of CA19.9), radiological (necrosis), and radiomic (SurfAreaToVolumeRatio) features were significantly associated with the early resurge of distant recurrence. The model combining these three variables performed well in the training cohort (p = 0.0015, HR = 3.58, 95%CI = 1.98–6.71) and was then confirmed in the validation cohort (p = 0.0178, HR = 5.06, 95%CI = 1.75–14.58). The comparison of survival curves between low and high-risk patients showed a p-value <0.0001. Our model may help to better define resectability status, thus providing an actual aid for pancreatic adenocarcinoma patients’ management (upfront surgery vs. neoadjuvant chemotherapy). Independent validations are warranted.