Optimal Adjuvant Treatment Approach After Upfront Resection of Pancreatic Cancer: Revisiting the Role of Radiation Based on Pathologic Features

Adjuvant Chemotherapy With or Without Radiotherapy for Resected Pancreatic Cancer After Multiagent Neoadjuvant Chemotherapy

BACKGROUND

Adjuvant therapy is associated with improved pancreatic cancer survival after neoadjuvant chemotherapy and surgery. However, whether adjuvant treatment should include radiotherapy is unclear in this setting.

METHODS

This study queried the National Cancer Database for pancreatic adenocarcinoma patients who underwent curative resection after multiagent neoadjuvant chemotherapy between 2010 and 2019 and received adjuvant treatment. Adjuvant chemotherapy plus radiotherapy (external beam, 45-50.4 gray) was compared with adjuvant chemotherapy alone. Uni- and multivariable Cox regression was used to assess survival associations. Analyses were repeated in a propensity score-matched subgroup.

RESULTS

Of 1983 patients who received adjuvant treatment after multiagent neoadjuvant chemotherapy and resection, 1502 (75.7%) received adjuvant chemotherapy alone and 481 (24.3%) received concomitant adjuvant radiotherapy (chemoradiotherapy). The patients treated with adjuvant chemoradiotherapy were younger, were treated at non-academic facilities more often, and had higher rates of lymph node metastasis (ypN1-2), positive resection margins (R1), and lymphovascular invasion (LVI+). The median survival was shorter for the chemoradiotherapy-treated patients according to the unadjusted analysis (26.8 vs 33.2 months; p = 0.0017). After adjustment for confounders, chemoradiotherapy was associated with better outcomes in the multivariable model (hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.61-0.93; p = 0.008). The association between chemoradiotherapy and improved outcomes was stronger for the patients with grade III tumors (HR, 0.53; 95% CI, 0.37-0.74) or LVI+ tumors (HR, 0.58; 95% CI, 0.44-0.75). In a subgroup of 396 propensity-matched patients, chemoradiotherapy was associated with a survival benefit only for the patients with LVI+ or grade III tumors.

CONCLUSION

After multiagent neoadjuvant chemotherapy and resection for pancreatic cancer, additional adjuvant chemoradiotherapy versus adjuvant chemotherapy alone is associated with improved survival for patients with LVI+ or grade III tumors.

Photodynamic Stromal Depletion in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest solid malignancies, with a five-year survival of less than 10%. The resistance of the disease and the associated lack of therapeutic response is attributed primarily to its dense, fibrotic stroma, which acts as a barrier to drug perfusion and permits tumour survival and invasion. As clinical trials of chemotherapy (CT), radiotherapy (RT), and targeted agents have not been successful, improving the survival rate in unresectable PDAC remains an urgent clinical need. Photodynamic stromal depletion (PSD) is a recent approach that uses visible or near-infrared light to destroy the desmoplastic tissue. Preclinical evidence suggests this can resensitise tumour cells to subsequent therapies whilst averting the tumorigenic effects of tumour-stromal cell interactions. So far, the pre-clinical studies have suggested that PDT can successfully mediate the destruction of various stromal elements without increasing the aggressiveness of the tumour. However, the complexity of this interplay, including the combined tumour promoting and suppressing effects, poses unknowns for the clinical application of photodynamic stromal depletion in PDAC.

Folate receptor-positive circulating tumor cells predict survival and recurrence patterns in patients undergoing resection for pancreatic cancer

Objective

To evaluate the prognostic impact of folate receptor (FR)-positive circulating tumor cells (FR⁺ CTCs) for patients with pancreatic cancer (PC).

Background

Risk stratification before surgery for PC patients remains challenging as there are no reliable prognostic markers currently. FR⁺ CTCs, detected by ligand-targeted polymerase chain reaction (LT-PCR), have shown excellent diagnostic value for PC in our previous study and prognostic value in a variety of cancer types.

Methods

Peripheral blood samples from 44 consecutive patients diagnosed with PC were analyzed for FR⁺ CTCs. 25 patients underwent tumor resection and were assigned to the surgical group. 19 patients failed to undergo radical resection because of local advance or distant metastasis and were assigned to the non-surgical group. The impact of CTCs on relapse and survival were explored.

Results

For the prognostic stratification, the optimal cut-off value of CTCs analyzed by receiver operating characteristic (ROC) curve was 14.49 folate units (FU)/3 ml. High CTC levels (> 14.49 FU/3 ml) were detected in 52.0% (13/25) of the patients in the surgical group and 63.2% (12/19) in the non-surgical group. In the surgical group, median disease-free survival (DFS) for patients with high CTC levels versus low CTC levels (< 14.49 FU/3 ml) was 8.0 versus 26.0 months (P = 0.008). In multivariable analysis, CTCs were an independent risk factor for DFS (HR: 4.589, P = 0.012). Concerning the recurrence patterns, patients with high CTC levels showed a significantly frequent rate of distant and early recurrence (P = 0.017 and P = 0.011). CTC levels remained an independent predictor for both distant (OR: 8.375, P = 0.014) and early recurrence (OR: 8.412, P = 0.013) confirmed by multivariable logistic regression. However, CTCs did not predict survival in the non-surgical group (P = 0.220).

Conclusion

FR⁺ CTCs in resected PC patients could predict impaired survival and recurrence patterns after surgery. Preoperative CTC levels detected by LT-PCR may help guide treatment strategies and further studies in a larger cohort are warranted.

Adjuvant Chemoradiotherapy in Resected Pancreatic Ductal Adenocarcinoma: Where Does the Benefit Lie? A Nomogram for Risk Stratification and Patient Selection

INTRODUCTION

The impact of adjuvant sequential chemoradiotherapy (CRT) on survival in resected pancreatic ductal adenocarcinoma (PDAC) remains unclear and warrants further investigation.

METHODS

NCDB patients with R0/R1 resected PDAC who received adjuvant chemotherapy without CRT or followed by CRT per RTOG-0848 protocol were included. Cox regression for 5-year overall survival (OS) was performed and used to construct a pathologic nomogram in patients who did not receive CRT. A risk score was calculated and patients were divided into low-risk and high-risk groups. Patients from each risk stratum were matched for the receipt of CRT to assess the added benefit of CRT on survival. The Kaplan-Meier analysis was performed to compare OS.

RESULTS

A total of 7146 patients were selected, 1308 (18.3%) received CRT per RTOG-0848. Cox regression concluded grade, T stage, N stage, node yield < 12, R1, and LVI as significant predictors of 5-year OS which were used to construct the risk score. Matched analysis in low-risk patients (score 0-79) showed no difference in OS between CRT vs. no CRT (47.6 ± 5.7 vs. 45.1 ± 3.9 months; p = 0.847). OS benefit was 3% at 1 year, - 4% at 2 years, and 4% at 5 years. In high-risk patients (score 80-100), median OS was higher in CRT vs. no CRT (24.8 ± 0.7 vs. 21.7 ± 0.8 months; p = 0.043). Absolute OS benefit was 13% at 1 year, 5% at 2 years, and - 1% at 5 years.

CONCLUSION

CRT has a short-lived impact on OS in resected PDAC that is only evident in high-risk patients. In this subset, survival benefit peaks at 1 year and subsides at 3 to 5 years following PDAC resection.

Impact of Adjuvant Chemoradiotherapy on Survival of Resected Pancreatic Adenocarcinoma Cancer: A Surveillance, Epidemiology and End Results (SEER) Analysis

Background

The benefits of postoperative adjuvant chemoradiotherapy (CRT) for pancreatic cancer remain controversial. The purpose of this study is to determine if adjuvant CRT can improve the overall survival of postoperative pancreatic cancer patients compared to adjuvant chemotherapy (CT).

Methods

Patients with resected pancreas adenocarcinoma were identified in the Surveillance, Epidemiology, and End Results (SEER) database (2004–2016). Multivariate Cox regression was used to determine the factors related to survival rate. Selection bias was reduced to a minimum through propensity matching analysis. Subgroup analyses by clinical characteristics were performed.

Results

This study identified 10,097 patients who received adjuvant CT (n = 5,454) or adjuvant CRT (n = 4,643). On multivariate analysis, age, sex, tumor size, site, grade, stage, T stage, and lymph node metastasis were independent risk factors for OS. The basic clinical characteristics were well balanced after propensity matching. After propensity matching, CRT can improve the survival rate compared with CT [median OS: 22 months vs 23 months (HR, 0.928; 95% CI, 0.881–0.977; P = 0.004)]. Subgroup analysis indicated that the survival benefit of adjuvant chemoradiotherapy was more significant in patients with female (HR, 0.860; 95% CI, 0.798–0.926; P = 0.005 for interaction) or T3 (HR, 0.905; 95% CI, 0.855–0.957; P = 0.04 for interaction) or lymph nodes positive (HR, 0.883; 95% CI, 0.832–0.938; P = 0.005 for interaction).

Conclusion

Adjuvant CRT was associated with improved survival compared with adjuvant CT in patients with resection of pancreatic ductal adenocarcinoma. The benefit was more significant in patients with female or T3 or lymph nodes positive.

Hyperthermic intra-operative intraperitoneal chemotherapy as an adjuvant to pancreatic cancer resection

Background

Even after potentially curative resection the long-term survival of pancreatic cancer is poor. The local-regional failures are frequent. Previous studies have shown that adjuvant treatment with hyperthermic intra-operative intraperitoneal chemotherapy (HIPEC) may effectively control local disease. The objective of the study is to update the results of the prior publications by integrating data from recently accrued cases. Also, to revisit the clinical and pharmacological rationale for the intraperitoneal administration of chemotherapy in pancreatic cancer patients undergoing potentially curative resection.

Methods

This is a prospective study of pancreatic cancer patients that underwent R₀ resection in combination with HIPEC-gemcitabine. Morbidity and mortality were recorded. Survival was calculated and the sites for recurrent disease were recorded.

Results

The updated results for 33 patients that underwent treatment until 2016 and for 6 more patients that were included until 2018 were presented. The hospital mortality and morbidity rate were 5.1% (2 patients), and 28.2% (11 patients) respectively. The median and 5-year survival rate was 17 months and 24% respectively. With a median follow-up time of 13 months 23 patients (59%) were recorded with recurrence. Local regional failures were recorded in 4 patients (10.3%).

Conclusions

HIPEC following R₀ resection is a feasible and safe adjuvant treatment for pancreatic cancer. The local-regional failures appear to be significantly decreased and to result in an increased overall survival. Further studies with combined intraperitoneal and systemic perioperative chemotherapy may serve to supplement our data with an increased benefit for patients having pancreas cancer resection.