The Role of Positron Emission Tomography/Computed Tomography (PET/CT) for Staging and Disease Response Assessment in Localized and Locally Advanced Pancreatic Cancer

Surgery for Locally Advanced Pancreatic Cancer Following Induction Chemotherapy: A Single-Center Experience

BACKGROUND

The use of surgery in patients with locally advanced pancreatic cancer (LAPC) following induction chemotherapy is increasing. However, most series do not report on the total cohort of patients undergoing surgical exploration; therefore, this single-center study investigates outcomes among all consecutive patients with LAPC who underwent surgical exploration.

METHODS

We conducted a retrospective, single-center analysis including all consecutive patients with LAPC (Dutch Pancreatic Cancer Group criteria) who underwent surgical exploration with curative intent (January 2014-June 2023) after induction therapy. Primary outcomes were resection rate and overall survival (OS) from the time of diagnosis.

RESULTS

Overall, 127 patients underwent surgical exploration for LAPC, whereby 100 patients (78.7%) underwent resection and 27 patients (21.3%) underwent a non-therapeutic laparotomy due to the extent of vascular involvement (n = 11, 8.7%) or occult metastases (n = 16, 12.6%). The overall in-hospital/30-day mortality rate was 0.8% and major morbidity was 31.3% (in patients after resection: 1.0% and 33.3%, respectively). The overall 90-day mortality rate was 5.5%, which included 3.1% mortality due to disease progression. Resection was associated with longer median OS {29 months (95% confidence interval [CI] 26-43) vs. 17 months (95% CI 11-26); p < 0.001} compared with patients undergoing non-therapeutic laparotomy, with corresponding 5-year OS rates of 28.4% and 7.7%. In Cox proportional hazard regression analysis, only pancreatic body/tail tumors independently predicted OS (hazard ratio 1.788 [95% CI 1.042-3.068]).

CONCLUSION

This single-center series found a resection rate of 78.7% in patients with LAPC selected for surgical exploration, with a low risk of mortality and morbidity in all explored patients and a 5-year OS rate after resection of 28.4%.

Radiomics analysis in predicting vascular invasion in gastric cancer based on enhanced CT: a preliminary study

BACKGROUND

Vascular invasion (VI) is closely related to the metastasis, recurrence, prognosis, and treatment of gastric cancer. Currently, predicting VI preoperatively using traditional clinical examinations alone remains challenging. This study aims to explore the value of radiomics analysis based on preoperative enhanced CT images in predicting VI in gastric cancer.

METHODS

We retrospectively analyzed 194 patients with gastric adenocarcinoma who underwent enhanced CT examination. Based on pathology analysis, patients were divided into the VI group (n = 43) and the non-VI group (n = 151). Radiomics features were extracted from arterial phase (AP) and portal venous phase (PP) CT images. The radiomics score (Rad-score) was then calculated. Prediction models based on image features, clinical factors, and a combination of both were constructed. The diagnostic efficiency and clinical usefulness of the models were evaluated using receiver operating characteristic (ROC) curves and decision curve analysis (DCA).

RESULTS

The combined prediction model included the Rad-score of AP, the Rad-score of PP, Ki-67, and Lauren classification. In the training group, the area under the curve (AUC) of the combined prediction model was 0.83 (95% CI 0.76-0.89), with a sensitivity of 64.52% and a specificity of 92.45%. In the validation group, the AUC was 0.80 (95% CI 0.67-0.89), with a sensitivity of 66.67% and a specificity of 88.89%. DCA indicated that the combined prediction model might have a greater net clinical benefit than the clinical model alone.

CONCLUSION

The integrated models, incorporating enhanced CT radiomics features, Ki-67, and clinical factors, demonstrate significant predictive capability for VI. Moreover, the radiomics model has the potential to optimize personalized clinical treatment selection and patient prognosis assessment.

Preoperative CA19‑9 level and dual time point FDG‑PET/CT as strong biological indicators of borderline resectability in pancreatic cancer: A retrospective study

Tumor resectability, which is increasingly determined based on preoperative chemotherapy, is critical in determining the best treatment for pancreatic cancers. The present study evaluated the usefulness of serum carbohydrate antigen 19-9 (CA19-9) and the preoperative 8F-fluorodeoxyglucose positron emission tomography/computed tomography standardized uptake value (SUV) percentage change (SUVmax%=[(SUVmax2-SUVmax1)/SUVmax1] ×100, where SUVmax1 and SUVmax2 represent the initial and delayed phases, respectively) as biological factors indicative of tumor resectability. The present study included patients with resectable pancreatic cancer who underwent complete surgical resection, for whom both CA19-9 and SUVmax% were documented using cut-off values of 500 U/ml and 24.25%, respectively. Patients were classified as follows: i) High CA19-9 and SUVmax%: both CA19-9 and SUVmax% were elevated; ii) high CA19-9 or SUVmax%: either CA19-9 or SUVmax% were elevated; or iii) low CA19-9 and SUVmax%: neither value met the cut-off. Relapse-free survival (RFS) and overall survival (OS) were calculated, for which univariate and multivariate analyses were performed. Of the 86 patients included, 39 were classified as high CA19-9 or SUVmax% and 12 as high CA19-9 and SUVmax%, with the former group having a significantly worse RFS (vs. low CA19-9 and SUVmax%; P<0.001; vs. high CA19-9 or SUVmax%; P=0.011) and OS (vs. low CA19-9 and SUVmax%, P=0.002; vs. high CA19-9 or SUVmax%, P<0.001). Therefore, high CA19-9 and SUVmax% was an independent predictor of worse RFS (P<0.001) and OS (P=0.003). In conclusion, CA19-9 and SUVmax% can be utilized as biological indicators of resectability.

Impact of a non-therapeutic laparotomy in patients with locally advanced pancreatic cancer treated with induction (m)FOLFIRINOX: Trans-Atlantic Pancreatic Surgery (TAPS) Consortium study

BACKGROUND

Surgery in selected patients with locally advanced pancreatic cancer after induction chemotherapy may have drawbacks related to surgical risks and breaks or delays in oncological treatment, in particular when curative intent resection is not possible (that is non-therapeutic laparotomy). The aim of this study was to assess the incidence and oncological impact of a non-therapeutic laparotomy in patients with locally advanced pancreatic cancer treated with induction (m)FOLFIRINOX chemotherapy.

METHODS

This was a retrospective international multicentre study including patients diagnosed with pathology-proven locally advanced pancreatic cancer treated with at least one cycle of (m)FOLFIRINOX (2012-2019). Patients undergoing a non-therapeutic laparotomy (group A) were compared with those not undergoing surgery (group B) and those undergoing resection (group C).

RESULTS

Overall, 663 patients with locally advanced pancreatic cancer were included (67 patients (10.1%) in group A, 425 patients (64.1%) in group B, and 171 patients (25.8%) in group C). A non-therapeutic laparotomy occurred in 28.2% of all explorations (67 of 238), with occult metastases in 30 patients (30 of 67, 44.8%) and a 90-day mortality rate of 3.0% (2 of 67). Administration of palliative therapy (65.9% versus 73.1%; P = 0.307) and median overall survival (20.4 [95% c.i. 15.9 to 27.3] versus 20.2 [95% c.i. 19.1 to 22.7] months; P = 0.752) did not differ between group A and group B respectively. The median overall survival in group C was 36.1 (95% c.i. 30.5 to 41.2) months. The 5-year overall survival rates were 11.4%, 8.7%, and 24.7% in group A, group B, and group C, respectively. Compared with group B, non-therapeutic laparotomy (group A) was not associated with reduced overall survival (HR = 0.88 [95% c.i. 0.61 to 1.27]).

CONCLUSION

More than a quarter of surgically explored patients with locally advanced pancreatic cancer after induction (m)FOLFIRINOX did not undergo a resection. Such non-therapeutic laparotomy does not appear to substantially impact oncological outcomes.

Serum CEA as a Prognostic Marker for Overall Survival in Patients with Localized Pancreatic Adenocarcinoma and Non-Elevated CA19-9 Levels Treated with FOLFIRINOX as Initial Treatment: A TAPS Consortium Study

INTRODUCTION

About 25% of patients with localized pancreatic adenocarcinoma have non-elevated serum carbohydrate antigen (CA) 19-9 levels at baseline, hampering evaluation of response to preoperative treatment. Serum carcinoembryonic antigen (CEA) is a potential alternative.

METHODS

This retrospective cohort study from five referral centers included consecutive patients with localized pancreatic adenocarcinoma (2012-2019), treated with one or more cycles of (m)FOLFIRINOX, and non-elevated CA19-9 levels (i.e., < 37 U/mL) at baseline. Cox regression analyses were performed to assess prognostic factors for overall survival (OS), including CEA level at baseline, restaging, and dynamics.

RESULTS

Overall, 277 patients were included in this study. CEA at baseline was elevated (≥5 ng/mL) in 53 patients (33%) and normalized following preoperative therapy in 14 patients (26%). In patients with elevated CEA at baseline, median OS in patients with CEA normalization following preoperative therapy was 33 months versus 19 months in patients without CEA normalization (p = 0.088). At time of baseline, only elevated CEA was independently associated with (worse) OS (hazard ratio [HR] 1.44, 95% confidence interval [CI] 1.04-1.98). At time of restaging, elevated CEA at baseline was still the only independent predictor for (worse) OS (HR 1.44, 95% CI 1.04-1.98), whereas elevated CEA at restaging (HR 1.16, 95% CI 0.77-1.77) was not.

CONCLUSIONS

Serum CEA was elevated in one-third of patients with localized pancreatic adenocarcinoma having non-elevated CA19-9 at baseline. At both time of baseline and time of restaging, elevated serum CEA measured at baseline was the only predictor for (worse) OS. Therefore, serum CEA may be a useful tool for decision making at both initial staging and time of restaging in patients with non-elevated CA19-9.

Preoperative chemotherapy, radiotherapy and surgical decision-making in patients with borderline resectable and locally advanced pancreatic cancer

Surgical resection combined with systemic chemotherapy is the cornerstone of treatment for patients with localized pancreatic cancer. Upfront surgery is considered suboptimal in cases with extensive vascular involvement, which can be classified as either borderline resectable pancreatic cancer or locally advanced pancreatic cancer. In these patients, FOLFIRINOX or gemcitabine plus nab-paclitaxel chemotherapy is currently used as preoperative chemotherapy and is eventually combined with radiotherapy. Thus, more patients might reach 5-year overall survival. Patient selection for chemotherapy, radiotherapy and subsequent surgery is based on anatomical, biological and conditional parameters. Current guidelines and clinical practices vary considerably regarding preoperative chemotherapy and radiotherapy, response evaluation, and indications for surgery. In this Review, we provide an overview of the clinical evidence regarding disease staging, preoperative therapy, response evaluation and surgery in patients with borderline resectable pancreatic cancer or locally advanced pancreatic cancer. In addition, a clinical work-up is proposed based on the available evidence and guidelines. We identify knowledge gaps and outline a proposed research agenda.

Complete Primary Pathological Response Following Neoadjuvant Treatment and Radical Resection for Pancreatic Ductal Adenocarcinoma

INTRODUCTION

Neoadjuvant treatment (NAT) for borderline (BD) or locally advanced (LA) primary pancreatic cancer (PDAC) is now a widely adopted approach. We present a case series of patients who have achieved a complete pathological response of the primary tumour on final histology following neoadjuvant chemotherapy +/- chemoradiation and radical surgery.

METHODS

Patients who underwent radical pancreatic resection following neoadjuvant treatment between March 2006 and March 2023 at a single institution were identified by retrospective case note review of a prospectively maintained database.

RESULTS

Ten patients were identified to have a complete primary pathological response (ypT0) on postoperative histology. Before treatment, five patients were considered BD and five were LA according to National Comprehensive Cancer Network guidelines. All patients underwent staging Computed Tomography (CT) and nine underwent 18Fluorodeoxyglucose Positron Emission Tomography (18FDG-PET/CT) imaging, with a mean maximum standardized uptake value (SUVmax) of the primary lesion at 6.14 ± 1.98 units. All patients received neoadjuvant chemotherapy, and eight received further chemoradiotherapy prior to resection. Mean pre- and post-neoadjuvant treatment serum Ca19-9 was 148.0 ± 146.3 IU/L and 18.0 ± 18.7 IU/L, respectively (p = 0.01). The mean duration of NAT was 5.6 ± 1.7 months. The mean time from completion of NAT to surgery was 13.1 ± 8.3 weeks. The mean lymph node yield was 21.1 ± 10.4 nodes, with one patient found to have 1 lymph node involved. All resections were reported to be R0. The mean length of stay was 11.8 ± 6.2 days. At the time of analysis, one death was reported at 35 months postoperatively. Two cases of recurrence were reported at 16 months (surgical bed) and 33 months (pulmonary). All other patients remain alive and under active surveillance. The current overall survival is 26.6 ± 20.7 months and counting.

CONCLUSIONS

Complete primary pathological response is uncommon but possible following neoadjuvant treatment in patients with PDAC. Further work to identify the common denominator within this unique cohort may lead to advances in the therapeutic approach and offer hope for patients diagnosed with borderline or locally advanced pancreatic ductal adenocarcinoma.

A cancer-associated fibroblast gene signature predicts prognosis and therapy response in patients with pancreatic cancer

Pancreatic cancer is a lethal malignancy with a 5-year survival rate of about 10% in the United States, and it is becoming an increasingly prominent cause of cancer death. Among pancreatic cancer patients, pancreatic ductal adenocarcinoma (PDAC) accounts for more than 90% of all cases and has a very poor prognosis with an average survival of only 1 year in about 18% of all tumor stages. In the past years, there has been an increasing interest in cancer-associated fibroblasts (CAFs) and their roles in PDAC. Recent data reveals that CAFs in PDAC are heterogeneous and various CAF subtypes have been demonstrated to promote tumor development while others hinder cancer proliferation. Furthermore, CAFs and other stromal populations can be potentially used as novel prognostic markers in cancer. In the present study, in order to evaluate the prognostic value of CAFs in PDAC, CAF infiltration rate was evaluated in 4 PDAC datasets of TCGA, GEO, and ArrayExpress databases and differentially expressed genes (DEGs) between CAF-high and CAF-low patients were identified. Subsequently, a CAF-based gene expression signature was developed and studied for its association with overall survival (OS). Additionally, functional enrichment analysis, somatic alteration analysis, and prognostic risk model construction was conducted on the identified DEGs. Finally, oncoPredict algorithm was implemented to assess drug sensitivity prediction between high- and low-risk cohorts. Our results revealed that CAF risk-high patients have a worse survival rate and increased CAF infiltration is a poor prognostic indicator in pancreatic cancer. Functional enrichment analysis also revealed that "extracellular matrix organization" and "vasculature development" were the top enriched pathways among the identified DEGs. We also developed a panel of 12 genes, which in additional to its prognostic value, could predict higher chemotherapy resistance rate. This CAF-based panel can be potentially utilized alone or in conjunction with other clinical parameters to make early predictions and prognosticate responsiveness to treatment in PDAC patients. Indeed, it is necessary to conduct extensive prospective investigations to confirm the clinical utility of these findings.