Impact of Neoadjuvant Therapy on Survival Following Margin-Positive Resection for Pancreatic Cancer

Clinical Outcomes of Neoadjuvant Therapy Versus Upfront Surgery in Resectable Pancreatic Cancer: Systematic Review and Meta-analysis of Latest Randomized Controlled Trials

BACKGROUND

Survival and surgical benefits of neoadjuvant treatments (NAT) in resectable pancreatic cancer (RPC) remains unclear. The role of NAT in providing additional benefits to reduce biological aggressiveness and recurrence is worth elucidating. We assessed the latest randomized controlled trials (RCTs).

METHODS

A systematic review and meta-analysis was performed including trials published from inception to February 2024 to evaluate survival, surgical, and short-term oncological benefits with RCTs for RPC, comparing NAT with upfront surgery.

RESULTS

Eight RCTs with 982 patients were analyzed. RPC treated with NAT conferred better median disease-free survival (DFS) compared to upfront surgery (HR = 0.66, p = 0.01) with a significantly improved R0 resection (RR = 1.20, p = 0.04) and pN0 rate (RR = 1.68, p < 0.001). These benefits did not translate into overall survival benefits (HR = 0.81, p = 0.06). Postoperative major morbidity and mortality did not differ significantly between treatment approaches. No significant difference was noted in resection rate (RR = 0.95, p = 0.21). However, a significantly lower surgical exploration rate was exhibited in the NAT group (RR = 0.84, p = 0.007).

CONCLUSION

NAT conferred better DFS with significantly improved R0 resection rate and pN0 rate compared with upfront surgery. Our findings highlight the potential benefits of NAT in enhancing survival, surgical, and short-term oncological outcomes without increasing postoperative risks.

Bayesan Model to Predict R Status After Neoadjuvant Therapy in Pancreatic Cancer

OBJECTIVE

To build a Bayesian approach-based model to predict the success of surgical exploration post-neoadjuvant treatment.

BACKGROUND

Pancreatic cancer (PDAC) is best treated with radical surgery and chemotherapy, offering the greatest chance of survival. Surgery after neoadjuvant treatment (NAT) is indicated in the absence of progression, knowing the limits in accurately predicting resectability with traditional radiology. R Status being a pathological parameter, it can be assessed only after surgery.

METHOD

Patients successfully resected for histologically confirmed PDAC after NAT for BR and LA disease were included, with attention to the predictors of R status from the existing literature. The Bayesian logistic regression model was estimated for predicting the R1 status. The area under curve (AUC) of the average posterior probability of R1 was calculated and results were reported considering the 95% posterior credible intervals for the odds ratios, along with the probability of direction.

RESULTS

The final model demonstrated a commendable AUC value of 0.72, indicating good performance. The likelihood of positive margins was associated with older age, higher ASA score, the presence of venous and/or arterial involvement at preoperative radiology, tumor location within the pancreatic body, a lack of tumor size reduction post-NAT, and the persistence of an elevated Ca19.9 value.

CONCLUSIONS

A Bayesian approach using only preoperative items is firstly used with good performance to predict R Status in pancreatic cancer patients who underwent resection after neoadjuvant therapy.

Stepwise Analysis of Resection Margin Impact on Survival and Distant Metastasis in Pancreatic Head Ductal Adenocarcinoma

The prognostic role of tumor cells in pancreatic ductal adenocarcinoma (PDAC) of the pancreatic head with direct microscopic infiltration (DMI) or in close proximity (≤1 mm) to the resection margin (RM) remains unclear. This single-center, retrospective study included specimens from 75 patients who underwent oncological resection of pancreatic head PDAC between February 2013 and July 2020. Two pathologists independently re-measured the distance between tumors and the multiple RMs. The impact of RM involvement for DMI, tumor cells within ≤1 mm, in general, and for individual RMs on overall survival (OS) and development of distant pulmonary (PM) and hepatic (HM) metastasis was analyzed. DMI of RMs was significantly associated with a shorter OS (median 5 vs 19 months, P = .02). The presence of tumor cells within ≤1 mm of RMs yielded a negative impact on OS with a trend toward significance (median 9 vs 21 months, P = .09). DMI and tumor cells within ≤1 mm of the pancreatic transection margin (PRM), individually, had a significant negative impact on OS (median 4 vs 19 months and 6 vs 19 months, P < .05), but not for any other individual RM. RM involvement of ≤1 mm of only the vascular circumferential resection margin (VCRM) resulted in a shorter time to HM development (P = 0.05). DMI of the posterior circumferential resection margin (PCRM) and VCRM, individually, showed shorter time to PM (P < .05). Potential clinical considerations include extended intraoperative evaluation of the PRM (1 mm) and intensified preoperative prediction of R1 resection as a basis for neoadjuvant therapy.

Prognostic impact of the distance from the anterior surface to tumor cells in pancreatoduodenectomy with neoadjuvant chemoradiotherapy for pancreatic ductal adenocarcinoma

PURPOSE

Several reports have shown the importance of margins in pancreatoduodenectomy (PD) specimens; however, whether anterior surfaces are included as margins varies among reports. In this study, we aimed to examine the impact of the anterior surface on disease-free survival (DFS) and overall survival (OS).

METHOD

In total, 98 patients who underwent PD after chemoradiotherapy for pancreatic ductal adenocarcinoma at Mie University Hospital between January 1, 2012, and December 31, 2019, were included. We investigated the prognostic impact of the distance from the anterior surface to tumor cells on DFS and OS using a log-rank test. Multivariate analysis was performed using Cox proportional hazards analysis.

RESULTS

A significant difference in DFS and OS was observed up to a distance of 5 mm from the anterior surface of tumor cells. The multivariate analysis revealed that the distance from the anterior surface to tumor cells (≤5 mm) was an independent poor prognostic factor for DFS and OS.

CONCLUSION

In patients with PD treated with neoadjuvant therapy, the distance from the anterior surface to tumor cells is an important assessment and should be included in the pathology report.

Multicenter Prospective Cohort Study of Neoadjuvant Chemotherapy for Borderline Resectable Pancreatic Cancer (YPB-001)

OBJECTIVES

The present multicenter prospective observational study investigated the effectiveness and safety of neoadjuvant chemotherapy (NAC) for patients with borderline resectable pancreatic cancer (BRPC) and those with RPC contacting major vessels, with respect to a historical control of upfront surgery.

MATERIALS AND METHODS

Patients with BRPC and RPC contacting major vessels were prospectively registered and administered NAC with durations and regimens determined by the corresponding treating physician. Our primary aim was to assess the R0 resection rate, and secondary aim was to evaluate safety, resection rate, time to treatment failure, overall survival, and response rate.

RESULTS

Fifty of 52 enrolled patients were analyzed; 2 with serious comorbidities died during treatment. Thirty-one patients underwent resection, with R0 resection being achieved in 26 (52% of total and 84% of all resected cases). Univariate and multivariate analyses indicated age (≥75 years) as the only independent predictor of nonresection. Median progression-free survival and median survival time were longer in the prospective cohort than in the historical cohort.

CONCLUSIONS

Overall, NAC for BRPC in real-world setting might yield R0 resection rates similar to those reported in previous clinical studies. Development of safe regimens and management strategies that can maintain treatment intensity in geriatric patients is warranted.

Clinical and pathological factors associated with survival in patients with pancreatic cancer who receive adjuvant therapy after neoadjuvant therapy: A retrospective multi-institutional analysis

BACKGROUND

Neoadjuvant therapy is being increasingly used for patients with pancreatic cancer. The role of adjuvant therapy in these patients is unclear. The purpose of this study was to identify clinical and pathologic characteristics that are associated with longer overall survival in patients with pancreatic cancer who receive adjuvant therapy after neoadjuvant therapy.

METHODS

This study was conducted using multi-institutional data. All patients underwent surgery after at least 1 cycle of neoadjuvant therapy for pancreatic cancer. Patients who died within 3 months after surgery and were known to have distant metastasis or macroscopic residual disease were excluded. Mann-Whitney U test, χ2 analysis, Kaplan-Meier plot, and univariate and multivariate Cox regression analysis were performed as statistical analyses.

RESULTS

In the present study, 529 patients with resected pancreatic cancer after neoadjuvant therapy were reviewed. For neoadjuvant therapy, 177 (33.5%) patients received neoadjuvant chemotherapy, and 352 (66.5%) patients received neoadjuvant chemoradiotherapy. The median duration of neoadjuvant therapy was 7.0 months (interquartile range, 5.0-8.7). Patients were followed for a median of 23.0 months after surgery. Adjuvant therapy was administered to 297 (56.1%) patients and was not associated with longer overall survival for the entire cohort (24 vs 22 months, P = .31). Interaction analysis showed that adjuvant therapy was associated with longer overall survival in patients who received less than 4 months neoadjuvant therapy (hazard ratio 0.40; 95% confidence interval 0.17-0.95; P = .03) or who had microscopic margin positive surgical resections (hazard ratio 0.56; 95% confidence interval 0.33-0.93; P = .03).

CONCLUSION

In this retrospective study, there was a survival benefit associated with adjuvant therapy for patients who received less than 4 months of neoadjuvant therapy or had microscopic positive margins.

Adjuvant FOLFIRINOX in Patients with Resectable Pancreatic Cancer Is Effective but Rarely Feasible in Real Life: Is Neoadjuvant FOLFIRINOX a Better Option?

BACKGROUND

The recommended treatment for resectable pancreatic cancer (PC) is resection followed by adjuvant FOLFIRINOX. We assessed the proportion of patients that managed to complete the 12 courses of adjuvant FOLFIRINOX and compared their outcome with that of patients with borderline resectable pancreatic cancer (BRPC) who underwent resection after neoadjuvant FOLFIRINOX.

METHODS

A retrospective analysis was performed on a prospectively maintained database of all PC patients who underwent resection with (2/2015-12/2021) or without (1/2018-12/2021) neoadjuvant therapy.

RESULTS

A total of 100 patients underwent upfront resection, and 51 patients with BRPC received neoadjuvant treatment. Only 46 resection patients started adjuvant FOLFIRINOX, and only 23 completed 12 courses. The main reasons for not starting/completing adjuvant therapy were poor tolerance and rapid recurrence. Significantly more patients in the neoadjuvant group received at least six FOLFIRINOX courses (80.4% vs. 31%, p < 0.001). Patients who completed at least 6 courses, either pre- or postoperatively, had better overall survival (p = 0.025) than those who did not. In spite of having more advanced disease, the neoadjuvant group had comparable overall survival (p = 0.062) regardless of the number of treatment courses.

CONCLUSION

Only a minority of patients (23%) undergoing upfront pancreatic resection completed the planned 12 courses of FOLFIRINOX. Patients who received neoadjuvant treatment were significantly more likely to receive at least six treatment courses. Patients receiving at least six courses had better overall survival than those who received fewer than six courses, regardless of the timing of treatment relative to surgery. Potential ways to increase chemotherapy adherence, such as administering treatment before surgery, should be considered.

Innovative Imaging Techniques Used to Evaluate Borderline-Resectable Pancreatic Adenocarcinoma

A diagnosis of pancreatic cancer carries a 5-y survival rate of less than 10%. Furthermore, the detection of pancreatic cancer occurs most often in later stages of the disease due to its location in the retroperitoneum and lack of symptoms (in most cases) until tumors become more advanced. Once diagnosed, cross-sectional imaging techniques are heavily utilized to determine the tumor stage and the potential for surgical resection. However, a major determinant of resectability is the extent of local vascular involvement of the mesenteric vessels and critical tributaries; current imaging techniques have limited capacity to accurately determine vascular involvement. Surrounding inflammation and fibrosis can be difficult to discriminate from viable tumor, making determination of the degree of vascular involvement unreliable. New innovations in fluorescence and optoacoustic imaging techniques may overcome these limitations and make determination of resectability more accurate. These imaging modalities are able to more clearly discern between viable tumor tissue and non-neoplastic inflammation or desmoplasia, allowing clinicians to more reliably characterize vascular involvement and develop individualized treatment plans for patients. This review will discuss the current imaging techniques used to diagnose pancreatic cancer, the barriers that current techniques raise to accurate staging, and novel fluorescence and optoacoustic imaging techniques that may provide more accurate clinical staging of pancreatic cancer.

Impact of resection margin status on survival after operation for pancreatic head cancer with extrapancreatic nerve plexus invasion

BACKGROUND

Extrapancreatic nerve plexus (PL) invasion of pancreatic ductal adenocarcinoma (PDAC) is an important factor for determining resectability and surgical method. We sought to clarify the characteristics of PDAC with PL invasion and clinical impact of the resection margin status on prognosis for PDAC with PL invasion.

METHODS

A total of 242 patients with pancreatic head cancer who underwent pancreatectomy were evaluated. Clinicopathological data and patient survival were analyzed.

RESULTS

Pathological PL invasion was observed in 68 patients (28.1%). Patients with PL invasion had significantly shorter disease-free survival (DFS) and showed trends toward worse overall survival (OS) than those without PL invasion. While multivariate analysis revealed that PL invasion was not an independent prognostic factor, PL invasion was associated with extensive venous invasion and a high percentage of lymph node metastases, both of which were independent factors affecting DFS and OS. Among patients with PL invasion, there was no significant difference in DFS and OS between the R0 and R1 resection groups.

CONCLUSIONS

PL invasion is a common pathological feature of aggressive PDAC with high propensity for invasiveness and metastatic potential. The microscopic resection margin status may not affect the survival of pancreatic head cancer patients with PL invasion.

Efficacy and safety of laparoscopic radical resection following neoadjuvant therapy for pancreatic ductal adenocarcinoma: A retrospective study

BACKGROUND

Multiple studies have demonstrated that neoadjuvant chemotherapy (NACT) can prolong the overall survival of pancreatic ductal adenocarcinoma (PDAC) patients. However, most studies have focused on open surgery following NACT.

AIM

To investigate the efficacy and safety of laparoscopic radical resection following NACT for PDAC.

METHODS

We retrospectively analyzed the clinical data of 15 patients with pathologically confirmed PDAC who received NACT followed by laparoscopic radical surgery in our hospital from December 2019 to April 2022. All patients underwent abdominal contrast-enhanced computed tomography (CT) and positron emission tomography-CT before surgery to accurately assess tumor stage and exclude distant metastasis.

RESULTS

All 15 patients with pancreatic cancer were successfully converted to surgical resection after NACT, including 8 patients with pancreatic head cancer and 7 patients with pancreatic body and tail cancer. Among them, 13 patients received the nab-paclitaxel plus gemcitabine regimen (gemcitabine 1000 mg/m² plus nab-paclitaxel 125 mg/m² on days 1, 8, and 15 every 4 wk) and 2 patients received the modified FOLFIRINOX regimen (intravenous oxaliplatin 68 mg/m², irinotecan 135 mg/m², and leucovorin 400 mg/m² on day 1 and fluorouracil 400 mg/m² on day 1, followed by 46-h continuous infusion of fluorouracil 2400 mg/m²). After each treatment cycle, abdominal CT, tumor markers, and circulating tumor cell counts were reviewed to evaluate the treatment efficacy. All 15 patients achieved partial remission. The surgical procedures included laparoscopic pancreaticoduodenectomy (LPD, n = 8) and laparoscopic radical antegrade modular pancreatosplenectomy (L-RAMPS, n = 7). None of them were converted to a laparotomy. One patient with pancreatic head carcinoma was found to have portal vein involvement during the operation, and LPD combined with vascular resection and reconstruction was performed. The amount of blood loss and operation times of L-RAMPS vs LPD were 435.71 ± 32.37 mL vs 343.75 ± 145.01 mL and 272.52 ± 49.14 min vs 444.38 ± 68.63 min, respectively. The number of dissected lymph nodes was 16.87 ± 4.10, and 3 patients had positive lymph nodes. One patient developed grade B postoperative pancreatic fistula (POPF) after L-RAMPS, and one patient experienced jaundice after LPD. None of the patients died after surgery. As of April 2022, progressive disease was noted in 4 patients, 2 patients had liver metastasis, and one had both liver metastasis and lymph node metastasis and died during the follow-up period.

CONCLUSION

Laparoscopic radical resection of PDAC after NACT is safe and effective if it is performed by a surgeon with rich experience in LPD and in a large center of pancreatic surgery.