In our study, TTS had no impact on DFS and OS in patients with upfront resected PA. Similar rates of hemorrhage, fistula, or severe post-operative complications were observed regardless of TTS. This is the first study to evaluate the impact of TTS on the 90-day morbidity.
Shortening time to treatment has been a promising approach to improve survival. TTS has been set as a quality care index in other malignancies(6, 7, 21, 22). As an example, HCC radiofrequency ablations warrant an under five-week management delay to avoid any impact on prognosis(6).
In PA, TTS impact remains unclear. Our results are consistent with most of the previous cohorts that showed no significant influence of TTS on survival rate for patients undergoing a curative intent resection for PA(15, 17, 23). Eshuis et al. concluded that biliary drainage and prolonged TTS do not impair survival rates in a randomized controlled trial(24). On the contrary, Swords et al. showed a modestly improved OS (1.8 months) and a higher 30 and 90-day post-operative mortality in shorter TTS, but at the cost of including a large number of patients(25). Subgroup analysis suggested that shorter TTS could improve resecability rate and prognosis in small tumors(15, 25, 26). Finally, none of these studies analyzed the consequences of shorter TTS on postoperative complications such as hemorrhage, fistulas or Dindo-Clavien classification.
Published studies, including ours, have failed to demonstrate a significant survival benefit with shorter delays before upfront surgery in PA. However, PA arises from pancreatic parenchyma decades before being symptomatic and diagnosed, suggesting slow growth at early stages(27). There is also evidence to support the rapid growth of PA, in later natural history once diagnosed, with an estimated time to progression from a T1 to a T4 stage of approximately 14 months(28). Tumor volume growth could thereby be considered as a factor distinct from the disease stage. Marchegiani et al. showed a TTS effect on survival for smaller tumors (T1 and T2)(26). Shorter TTS could impact resecability and disease-free survival in this specific patient subgroup. In our study, only 28 patients (16.7%) had a T1 or T2 disease stage, making subgroup analyses futile.
Nevertheless, median TTS seems to be increasing year after year due to the incremental PA incidence and the frequent referral to expert centers(21). As TTS has no or little impact on prognosis, management strategy could be modified to allow sufficient time to confirm diagnosis in ambivalent cases and integrate preoperative chemotherapy and prehabilitation strategy. A 28-day minimum delay between last liver imaging and surgery remains well established to avoid any curative surgery performed on patients with liver metastases(3).
No link was observed for fistula, hemorrhage, or severe post-operative complications when TTS was shortened. Post pancreatectomy hemorrhage is mainly due to anastomotic leaks causing pseudoaneurysms(29). Also, when performed early, these interventions are less likely to be the subject of technical debate in multidisciplinary surgical meetings and patients may be less well prepared (uncorrected coagulation, nutritional status, or jaundice). Moreover, significantly higher median bilirubin in the shorter delay group can lead to troubled hemostasis, facilitating post-operative hemorrhage(30).
Our study has several limitations. First, patients with macroscopically incomplete resection (R2) or those who finally did not undergo a curative surgery, despite an initially resectable primary tumor, were not included. These patients could potentially have longer delays explaining tumor progression. Unfortunately, they were not considered in our analysis avoiding performing an intention-to-treat analysis. Furthermore, patients who waited longer without any treatment but finally underwent a curative surgical procedure may have had slower-progressive disease with a better prognosis. Preselecting candidates for curative surgery on their time to progression in the setting of such an aggressive disease seems unethical. Also, 116 patients (69%) were diagnosed upon jaundice presentation, while only 64 (38.1%) experienced a radiological or endoscopic biliary drainage. Patients treated before 2010 were more frequently resected with higher bilirubin levels. Moreover, the power of the study could be insufficient due to the limited number of inclusion centers and retrospectively included patients. Finally, three of the four inclusion centers, including 92.9% of the patients, were tertiary hospitals. We cannot exclude a selection bias and a confusion effect due to highly skilled techniques developed in these centers with low complication rates.
Surgery remains the only existing treatment to cure PA(3). Recent progress with polychemotherapy regimens and better patient selection for surgery has modestly improved overall survival(31, 32). Moreover, new management strategies including neoadjuvant and induction chemotherapies are to be interpreted differently from passive delay where no therapeutic interventions occur. New perspectives must be found to increase the survival and quality of life of these patients. PA may not be the most suitable malignancy to study TTS as a quality metric(33). However, the COVID-19 pandemic has called for urgent case hierarchization and has thereby raised new questions about carcinologic surgical priorities. Ongoing multicentric CAPANCOVID-19 (https://clinicaltrials.gov/ct2/show/NCT04406571) tries to measure the impact of the COVID-19 pandemic causing prolonged management delay, from surgery to palliative situations.
We showed that TTS seems to have no impact on OS, DFS and 90-day postoperative morbidity. Other trials need to be carried out to understand the role of TTS in smaller tumor sizes.