Duration of chemotherapy prior to chemoradiation affects survival outcomes for resected stage I-II or unresected stage III pancreatic cancer

Neoadjuvant Therapy Is Associated with Improved Chemotherapy Delivery and Overall Survival Compared to Upfront Resection in Pancreatic Cancer without Increasing Perioperative Complications

The role of neoadjuvant chemoradiotherapy and/or chemotherapy (neoCHT) in patients with pancreatic ductal adenocarcinoma (PDAC) is poorly defined. We hypothesized that patients who underwent neoadjuvant therapy (NAT) would have improved systemic therapy delivery, as well as comparable perioperative complications, compared to patients undergoing upfront resection. This is an IRB-approved retrospective study of potentially resectable PDAC patients treated within an academic quaternary referral center between 2011 and 2018. Data were abstracted from the electronic medical record using an institutional cancer registry and the National Surgical Quality Improvement Program. Three hundred and fourteen patients were eligible for analysis and eighty-one patients received NAT. The median overall survival (OS) was significantly improved in patients who received NAT (28.6 vs. 20.1 months, p = 0.014). Patients receiving neoCHT had an overall increased mean duration of systemic therapy (p < 0.001), and the median OS improved with each month of chemotherapy delivered (HR = 0.81 per month CHT, 95% CI (0.76-0.86), p < 0.001). NAT was not associated with increases in early severe post-operative complications (p = 0.47), late leaks (p = 0.23), or 30-90 day readmissions (p = 0.084). Our results show improved OS in patients who received NAT, driven largely by improved chemotherapy delivery, without an apparent increase in early or late perioperative complications compared to patients undergoing upfront resection.

Real-world patterns of adjuvant chemotherapy treatment for patients with resected pancreatic adenocarcinoma

The aim of the study was to analyze the real-world treatment patterns of adjuvant chemotherapy administration among patients with resected pancreatic adenocarcinoma. Cases with non-metastatic pancreatic adenocarcinoma, diagnosed 2007-2018, treated with upfront surgical resection, and recorded within Alberta Cancer registry were accessed. Multivariable logistic regression analysis was conducted to evaluate factors predicting use of adjuvant chemotherapy. Kaplan-Meier survival estimates and multivariable Cox regression analysis were used to compare overall survival among patients treated with adjuvant gemcitabine versus those treated with adjuvant gemcitabine + capecitabine. A total of 695 patients who have undergone upfront surgical treatment of pancreatic adenocarcinoma, including 445 patients (64%) who received adjuvant chemotherapy and 250 patients (36%) who did not receive adjuvant chemotherapy. The following factors were associated with lower probability to receive adjuvant chemotherapy: older age (OR 0.94; 95% CI 0.93-0.96), node negativity (OR 0.47; 95% CI 0.33-0.67), higher Charlson comorbidity index (OR 0.86; 95% CI 0.74-0.99), and living within the Northern zone of the province (OR for Calgary zone versus North zone: 2.24; 95% CI 1.29-3.90). Within patients who received adjuvant gemcitabine ± capecitabine, factors associated with worse overall survival included higher Charlson comorbidity index (HR 1.18; 95% CI 1.00-1.40), and node-positive disease (HR for node-negative versus node-positive disease: 0.51; 95% CI 0.33-0.78). Type of chemotherapy was not predictive of overall survival (HR for gemcitabine versus gemcitabine plus capecitabine: 1.40; 95% CI 0.98-2.00). P value for interaction between type of chemotherapy and nodal status was 0.038. In this real-world study, the added benefit of adjuvant gemcitabine + capecitabine (compared to adjuvant gemcitabine) seems to be limited to patients with node-positive disease.

Duration of chemotherapy prior to chemoradiation affects survival outcomes for resected stage I-II or unresected stage III pancreatic cancer

Background

For resected early stage pancreatic cancer, RTOG 9704 evaluated the outcome of 3 weeks of postoperative chemotherapy (C) followed by chemoradiation (CRT) and further C. For unresectable locally advanced pancreatic cancer, a recent literature review of prospective studies showed that the duration of induction C prior to CRT can impact survival. However, the ideal duration of C prior to CRT remains unclear for these patient cohorts. This National Cancer Database (NCDB) study was performed to compare the outcome of various durations of C prior to CRT.

Methods

The NCDB was queried for resected primary stage I‐II, cT1‐3N0‐1M0, and unresected stage III, cT4N0‐1M0 pancreatic adenocarcinoma treated with C + CRT (2004‐2015). Cohorts I‐II and III included stage I‐II and stage III cases, respectively. Patients were stratified by short (short C) and long duration (long C) of chemotherapy based on their median durations. Baseline patient, tumor, and treatment characteristics were examined. The primary endpoint was overall survival (OS). Kaplan‐Meier analysis, multivariable Cox proportional hazards method, and propensity score matching were used.

Results

Among 1577 patients, cohort I‐II had 839 patients and cohort III had 738 patients. The longer duration of chemotherapy prior to CRT showed improved OS in the multivariate analysis in both cohort I‐II (hazards ratio [HR] 0.72, P < 0.001) and cohort III (HR 0.83, P = 0.03). Using 1:1 propensity score matching, 610 patients for cohort I‐II and 542 patients for cohort III were matched. After matching, long C remained statistically significant for improved OS compared with short C in both cohort I‐II (median OS 26.1 vs 21.9 months; P = 0.003) and cohort III (median OS 16.7 vs 14.2; P = 0.02).

Conclusion

Our NCDB study using propensity score‐matched analysis showed a survival benefit for using the longer duration of chemotherapy compared to the shorter duration for both resected stage I‐II and unresected stage III pancreatic cancer.