ESTRO 2022

Session Item

Saturday

May 07

10:30 - 11:30

Room D1

Upper GI

Co-Chair: , France;

Chair: , Austria

Session Code: 1230

Session Type: Proffered Papers

Track: Clinical

11:10 - 11:20

Prognostic factors for isolated local recurrence after resection of pancreatic ductal adenocarcinoma

Iris van Goor, The Netherlands

Presentation Number: OC-0111

Abstract

Abstract Title:

Prognostic factors for isolated local recurrence after resection of pancreatic ductal adenocarcinoma

Authors:

Iris van Goor^1,2, Anne Nagelhout², Marc Besselink³, Bert Bonsing⁴, Koop Bosscha⁵, Lodewijk Brosens⁶, Olivier Busch³, Geert Cirkel⁷, Ronald van Dam⁸, Sebastiaan Festen⁹, Bas Groot Koerkamp¹⁰, Erwin van der Harst¹¹, Ignace de Hingh¹², Geert Kazemier¹³, Gert Meijer¹, Vincent de Meijer¹⁴, Vincent Nieuwenhuijs¹⁵, Daphne Roos¹⁶, Jennifer Schreinemakers¹⁷, Martijn Stommel¹⁸, Robert Verdonk¹⁹, Hjalmar van Santvoort², Quintus Molenaar², Lois Daamen²⁰, Martijn Intven¹

¹UMC Utrecht Cancer Center, Radiation Oncology, Utrecht, The Netherlands; ²Regional Academic Cancer Center Utrecht, UMC Utrecht Cancer Center & St. Antonius Hospital Nieuwegein, Surgery, Utrecht, The Netherlands; ³Cancer Center Amsterdam, Amsterdam UMC, University of Amsterdam, Surgery, Amsterdam, The Netherlands; ⁴Leiden UMC, Surgery, Leiden, The Netherlands; ⁵Jeroen Bosch Hospital, Surgery, Den Bosch, The Netherlands; ⁶Regional Academic Cancer Center Utrecht, UMC Utrecht Cancer Center & St. Antonius Hospital Nieuwegein, Pathology, Utrecht, The Netherlands; ⁷Regional Academic Cancer Center Utrecht, UMC Utrecht Cancer Center & Meander Medical Center Amersfoort, Medical Oncology, Utrecht, The Netherlands; ⁸Maastricht UMC+, Surgery, Maastricht, The Netherlands; ⁹OLVG, Surgery, Amsterdam, The Netherlands; ¹⁰Erasmus MC, Surgery, Rotterdam, The Netherlands; ¹¹Maasstad Hospital, Surgery, Rotterdam, The Netherlands; ¹²Catharina Hospital, Surgery, Eindhoven, The Netherlands; ¹³Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, Surgery, Amsterdam, The Netherlands; ¹⁴UMC Groningen, University of Groningen, Surgery, Groningen, The Netherlands; ¹⁵Isala, Surgery, Zwolle, The Netherlands; ¹⁶Reinier de Graaf Gasthuis, Surgery, Delft, The Netherlands; ¹⁷Amphia Hospital, Surgery, Breda, The Netherlands; ¹⁸Radboud UMC, Surgery, Nijmegen, The Netherlands; ¹⁹Regional Academic Cancer Center Utrecht, UMC Utrecht Cancer Center & St. Antonius Hospital Nieuwegein, Gastroenterology, Utrecht, The Netherlands; ²⁰UMC Utrecht, Imaging, Utrecht, The Netherlands

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Purpose or Objective

About 20% of patients develop isolated local recurrence (ILR) within a median interval of 12 months after pancreatic ductal adenocarcinoma (PDAC) resection. Stereotactic body radiation therapy might improve survival and quality of life in these patients. To start treatment as early as possible, patients with a high risk of developing ILR should be identified. However, little is known about the risk factors for ILR. In this study, we aimed to identify predictive factors for ILR.

Material and Methods

This national cohort study was conducted among all patients who underwent PDAC resection in the Netherlands between 2014-2019. Patients were excluded in case of complication-related mortality within 90 days after resection, and macroscopic irradical resection. Furthermore, patients were also excluded in case of recurrence with unknown location. Baseline and perioperative data were collected from the mandatory, prospective Dutch Pancreatic Cancer Audit. Additional data on follow-up and survival was collected from the patients’ records.

Patients were divided into two groups based on their initial recurrence location: ILR or distant metastases (whether or not combined with synchronous local recurrence). Patients with distant metastases were censored at date of recurrence diagnosis. Patients without disease recurrence were censored at date of last follow-up. Missing data was considered missing at random and handled using multiple imputation with the iterative Markov chain Monte Carlo method. Univariable and multivariable Cox proportional hazard analysis was performed to identify prognostic factors for ILR and Akaike’s information criterion was used to select the best model. Survival was estimated and compared using Kaplan-Meier curves and log-rank test.

Results

A total of 1355 patients with a median follow-up of 33 (IQR 21–54) months were analysed. 957 patients (70%) developed disease recurrence. Among these patients, 201 patients (21%) presented themselves with ILR within a median recurrence-free interval of 14 (IQR 10–23) months. Their median overall survival (mOS) was 25 (IQR 15–35) months, compared to a mOS of 16 (IQR 10–26) months in patients who had distant metastases at initial presentation (Figure 1).

The best predictive model included all significant variables and had an area under the curve of 0.65. Factors associated with ILR were vascular resection (HR 1.70 [95%CI 1.26–2.29]; p <0.001), lymph vascular invasion (HR 0.73 [95%CI 0.54–0.98]; p 0.04), perineural invasion (HR 1.68 [95%CI 1.12–2.53]; p 0.01), lymph node status N2 (HR 1.69 [95%CI 1.13–2.52]; p 0.01) compared to N0, resection margin status R1 <1 mm (HR 1.65 [95%CI 1.23–2.22]; p <0.001), and adjuvant chemotherapy (HR 0.69 [95%CI 0.51–0.93]; p 0.02). Results are shown in Table 1.

Conclusion

In this nationwide cohort, predictive factors for ILR are vascular resection, absence of lymph vascular invasion, perineural invasion, N2 lymph node status, R1 resection margin status, and omission of adjuvant chemotherapy.