The benefit of adjuvant radiotherapy on overall survival in resected stage I to II pancreatic cancer: A propensity-adjusted analysis

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.

Carbohydrate Antigen 19-9 Response to Initial Adjuvant Chemotherapy Predicts Survival and Failure Pattern of Resected Pancreatic Adenocarcinoma but Not Which Patients Are Suited for Additional Adjuvant Chemoradiation Therapy: From a Prospective Randomized Study

PURPOSE

The predictive value of carbohydrate antigen 19-9 (CA19-9) for adjuvant chemo(radiation) therapy of resected pancreatic adenocarcinoma (PDAC) is undefined.

METHODS AND MATERIALS

We analyzed CA19-9 levels in patients with resected PDAC in a prospective randomized trial of adjuvant chemotherapy with or without additional chemoradiation therapy (CRT). Patients with postoperative CA19-9 ≤92.5 U/mL and serum bilirubin ≤2 mg/dL were randomized to 2 arms: patients in 1 arm received 6 cycles of gemcitabine, whereas those in the other received 3 cycles of gemcitabine followed by CRT and another 3 cycles of gemcitabine. Serum CA19-9 was measured every 12 weeks. Those who had CA19-9 levels always <3 U/mL were excluded from the exploratory analysis.

RESULTS

One hundred forty-seven patients were enrolled in this randomized trial. Twenty-two patients with CA19-9 levels always ≤3 U/mL were excluded from the analysis. For the 125 participants, median overall survival (OS) and recurrence-free survival were 23.1 and 12.1 months, respectively, with no significant differences between the study arms. Postresection CA19-9 levels and, to a lesser extent, CA19-9 change predicted OS (P = .040 and .077, respectively). For the 89 patients who completed the initial 3 cycles of adjuvant gemcitabine, the CA19-9 response was significantly correlated with initial failure over the distant site (P = .023) and OS (P = .0022). Despite a trend of less initial failure over the locoregional area (P = .031), neither postoperative CA19-9 level nor CA19-9 response helped to select patients who might have a survival benefit from additional adjuvant CRT.

CONCLUSIONS

CA19-9 response to initial adjuvant gemcitabine predicts survival and distant failure of PDAC after resection; however, it cannot select patients suited for additional adjuvant CRT. Monitoring CA19-9 levels during adjuvant therapy for postoperative patients with PDAC may guide therapeutic decisions to prevent distant failure.

The level of agreement between rapid-on-site evaluation of endoscopic ultrasound fine needle aspirate and surgical histological diagnosis in gastrointestinal lesions

OBJECTIVE

Endoscopic ultrasound (EUS) is the main tool for biopsy via fine needle aspiration (FNA) from gastrointestinal (GI) lesions including pancreatic, upper gastrointestinal, and adjacent lesions. The variable diagnostic yield and delay until the final pathological results can affect treatment planning and cause patient anxiety. We aimed to assess the agreement of rapid on-site evaluation (ROSE) of EUS-FNA with the surgical histological diagnosis of patients who underwent resection.

METHOD

A retrospective study was performed including all patients 18 years or older who underwent EUS-FNA with ROSE for GI lesions. For patients who underwent surgical resection, the correlation between ROSE and the surgical histological diagnosis was evaluated with the kappa coefficient.

RESULTS

Overall, 73 patients who underwent EUS-FNA with ROSE were included, of whom 22 (30.1%) had curative resection. The final pathological diagnosis from surgery showed 17 malignant and 5 benign lesions. Among the benign lesions, ROSE correctly identified 2 (diagnostic accuracy of 40%), while among the malignant lesions, ROSE correctly identified 14 (diagnostic accuracy of 82.4%), yielding a fair kappa coefficient of 0.366 (95% CI 0.035-0.697). When classifying the lesions as either malignant vs benign or suspicious of malignancy, the kappa coefficient increased to 0.58 (95% CI 0.180-0.975) for the subgroup of pancreatic lesions, with diagnostic accuracy of 81.2% for the malignant category.

CONCLUSIONS

A high level of agreement for malignancy was found between FNA-EUS with ROSE and the final surgical histological diagnosis. ROSE can be used as an adjuvant diagnostic tool to optimise patient management and decrease delay-related anxiety.