Primary tumor of pancreatic cancer as a measurable target lesion in chemotherapy trials

Risk Stratification of Pancreatic Ductal Adenocarcinoma Patients Undergoing Curative-Intent Surgery after Neoadjuvant Therapy

PURPOSE

Clinical prognostic criteria using preoperative factors were not developed for post-neoadjuvant therapy (NAT) surgery of pancreatic ductal adenocarcinoma (PDAC). We aimed to identify preoperative factors associated with overall survival (OS) in PDAC patients who underwent post-NAT curative-intent surgery and develop risk stratification criteria.

MATERIALS AND METHODS

Consecutive PDAC patients who underwent post-NAT curative-intent surgeries between 2007 and 2020 were retrospectively analyzed. Demographic, laboratory, surgical, and histopathologic variables were collected. Baseline, preoperative, and interval changes of computed tomography (CT) findings proposed by the Society of Abdominal Radiology and the American Pancreatic Association were analyzed. Cox proportional hazard analysis was used to select preoperative variables associated with OS. We developed risk stratification criteria composed of the significant preoperative variables, i.e., post-NAT response criteria. We compared the discrimination performance of post-NAT response criteria with that of post-NAT pathological (yp) American Joint Cancer Committee TNM staging system.

RESULTS

One hundred forty-five PDAC patients were included. Stable or increased tumor size on CT (hazard ratio [HR], 2.58; 95% confidence interval [CI], 1.58 to 4.21; p < 0.001) and elevated preoperative carbohydrate antigen 19-9 (CA19-9) level (HR, 1.98; 95% CI, 1.11 to 3.55; p=0.021) were independent factors of OS. The OS of the patient groups stratified by post-NAT response criteria which combined changes in tumor size and CA19-9 showed significant difference (p < 0.001). Such stratification was comparable to ypTNM staging in discrimination performance (difference of C-index, 0.068; 95% CI, -0.012 to 0.142).

CONCLUSION

"Any degree of decrease in tumor size on CT" and CA19-9 normalization or staying normal were independent favorable factors of OS. The combination of the two factors discriminated OS comparably to ypTNM staging.

Analysis of prognostic factors for borderline resectable pancreatic cancer after neoadjuvant chemotherapy: the importance of CA19-9 decrease in patients with elevated pre-chemotherapy CA19-9 levels

BACKGROUND

Neoadjuvant chemotherapy (NAC) is widely used to treat borderline resectable pancreatic cancer. This study aimed to evaluate the serum carbohydrate antigen (CA)19-9 response, in association with survival, after four cycles of NAC-gemcitabine plus nab-paclitaxel.

METHODS

From 2015 to 2018, patients with borderline resectable pancreatic cancer were treated with NAC. Patients were stratified into two groups after excluding CA19-9 non-secretor: Group L (CA19-9 ≥2 and ≤500 U/mL) and Group H (CA19-9 >500 U/mL). The CA19-9 decrease during NAC was evaluated as a response of NAC and was assessed in association with survival concomitant with other prognosis factors.

RESULTS

Eighty-seven patients were evaluated (Group L: n = 43, Group H: n = 44). In intention-to-treat-based analysis, Group L exhibited significantly better progression-free survival (PFS) than Group H (median PFS: 24 vs 14months). In resection cohort, no correlation was detected between the CA19-9 decrease and survival in Group L. In Group H, the CA19-9 decrease ≤80% was associated with unfavorable survival in multivariate analysis [Hazard ratio: 4.738 (P = 0.007)].

CONCLUSION

In patients with pre-treatment CA19-9 >500 U/mL, the CA19-9 decrease ≤80% was strongly associated with poor survival and new strategy should be reconsidered for these patients.

Borderline Resectable and Locally Advanced Pancreatic Cancer: FDG PET/MRI and CT Tumor Metrics for Assessment of Pathologic Response to Neoadjuvant Therapy and Prediction of Survival

BACKGROUND. Imaging biomarkers of response to neoadjuvant therapy (NAT) for pancreatic ductal adenocarcinoma (PDA) are needed to optimize treatment decisions and long-term outcomes. OBJECTIVE. The purpose of this study was to investigate metrics from PET/MRI and CT to assess pathologic response of PDA to NAT and to predict overall survival (OS). METHODS. This retrospective study included 44 patients with ¹⁸F-FDG-avid borderline resectable or locally advanced PDA on pretreatment PET/MRI who also underwent post-NAT PET/MRI before surgery between August 2016 and February 2019. Carbohydrate antigen 19-9 (CA 19-9) level, metabolic metrics from PET/MRI, and morphologic metrics from CT (n = 34) were compared between pathologic responders (College of American Pathologists scores 0 and 1) and nonresponders (scores 2 and 3). AUCs were measured for metrics significantly associated with pathologic response. Relation to OS was evaluated with Cox proportional hazards models. RESULTS. Among 44 patients (22 men, 22 women; mean age, 62 ± 11.6 years), 19 (43%) were responders, and 25 (57%) were nonresponders. Median OS was 24 months (range, 6-42 months). Before treatment, responders and nonresponders did not differ in CA 19-9 level, metabolic metrics, or CT metrics (p > .05). After treatment, responders and nonresponders differed in complete metabolic response (CMR) (responders, 89% [17/19]; nonresponders, 40% [10/25]; p = .04], mean change in SUV_max (ΔSUV_max; responders, -70% ± 13%; nonresponders, -37% ± 42%; p < .001), mean change in SUV_max corrected to serum glucose level (ΔSUV_gluc) (responders, -74% ± 12%; nonresponders, -30% ± 58%; p < .001), RECIST response on CT (responders, 93% [13/14]; nonresponders, 50% [10/20]; p = .02)], and mean change in tumor volume on CT (ΔTvol) (responders, -85% ± 21%; nonresponders, 57% ± 400%; p < .001). The AUC of CMR for pathologic response was 0.75; ΔSUV_max, 0.83; ΔSUV_gluc, 0.87; RECIST, 0.71; and ΔTvol 0.86. The AUCs of bivariable PET/MRI and CT models were 0.83 (CMR and ΔSUV_max), 0.87 (CMR and ΔSUV_gluc), and 0.87 (RECIST and ΔTvol). OS was associated with CMR (p = .03), ΔSUV_max (p = .003), ΔSUV_gluc (p = .003), and RECIST (p = .046). CONCLUSION. Unlike CA 19-9 level, changes in metabolic metrics from PET/MRI and morphologic metrics from CT after NAT were associated with pathologic response and OS in patients with PDA, warranting prospective validation. CLINICAL IMPACT. Imaging metrics associated with pathologic response and OS in PDA could help guide clinical management and outcomes for patients with PDA who undergo emergency therapeutic interventions.

Circulating Biomarkers for Prediction of Objective Response to Chemotherapy in Pancreatic Cancer Patients

Pancreatic cancer is a lethal disease with increasing incidence. Most patients present with advanced disease, for which palliative systemic chemotherapy is the only therapeutic option. Despite improved median survival rates with FOLFIRINOX or gemcitabine chemotherapy compared to the best supportive care, many individual patients may not benefit from chemotherapy. Biomarkers are needed to predict who will benefit from chemotherapy and to monitor a patient’s response to chemotherapy. This review summarizes current research and future perspectives on circulating biomarkers for systemic chemotherapy response.

Assessment of response to chemotherapy in pancreatic ductal adenocarcinoma: Comparison between diffusion-weighted MR quantitative parameters and RECIST

PURPOSE

To prospectively assess chemotherapy-induced changes in pancreatic ductal adenocarcinoma (PDA) with diffusion-weighted (DW)-MR quantitative metrics, including apparent diffusion coefficient (ADC) and histogram-derived parameters, compared with RECIST 1.1.

METHODS

24 patients underwent DW-MR at baseline, week-2 and week-8 after chemotherapy initiation. Tumour diameter was assessed on T2-weighted images. Regions-of-interest (ROI) were drawn on ADC map for ROI-ADC. Volume segmentation (b = 1000 s/mm² images) provided DW-volume and histogram-derived diffusion parameters (H-ADC, H-D and H-PF). All variables and their relative change were compared to baseline or between responders and non-responders. Discriminant analysis was performed.

RESULTS

15/24 patients were responders. RECIST 1.1 correctly characterized 6/15 responders at week-8. At week-2, in responders DW-volume decreased (P = .002); ROI-ADC mean H-D increased (P = .047; P = .048;). The 25th percentile H-D increased in responders and decreased in non-responders (P = .016; P = .048). At week-8 in responders DW-volume decreased and ROI-ADC mean, 25th, 50th, 75th percentiles of H-ADC and H-D increased (P < .05). No changes were observed in non-responders (P > .05). At week-2, 25th percentile of H-D and H-PF relative change correctly classified 20/24 patients (P = .003); at week-8, DW-volume relative change correctly classified 22/24 patients (P < .0001).

CONCLUSIONS

ROI-ADC, DW-volume and histogram-derived diffusion parameters are more accurate to categorize responding and non-responding PDA patients treated with chemotherapy compared with RECIST 1.1.

CT evaluation after neoadjuvant FOLFIRINOX chemotherapy for borderline and locally advanced pancreatic adenocarcinoma

AIM

To assess anatomic changes on computed tomography (CT) after neoadjuvant FOLFIRINOX (5-fluorouracil/leucovorin/irinotecan/oxaliplatin) chemotherapy for secondary resected borderline resectable (BR) and locally advanced (LA) pancreatic adenocarcinoma and their accuracy to predict resectability and pathological response.

METHODS

Thirty-six patients with secondary resected BR/LA pancreatic adenocarcinoma after neoadjuvant FOLFIRINOX chemotherapy (± chemoradiotherapy) were retrospectively included. Two radiologists reviewed baseline and pre-surgical CTs in consensus. NCCN (National Comprehensive Cancer Network) classification, largest axis, product of the three axes (P3A), and arterial/venous involvement were studied and compared to pathological response and resection status and to disease-free survival (DFS).

RESULTS

Thirty-one patients had R0 resection, including only six exhibiting a downstaging according to the NCCN classification. After treatment, the largest axis and P3A decreased (P < 0.0001). The pre-surgical largest axis and P3A were smaller in case of R0 resection (P = 0.019/P = 0.021). The largest axis/P3A variations were higher in case of complete pathological response (P = 0.011/P = 0.016). A decrease of the arterial/venous involvement was not able to predict R0 or ypT0N0 (P > 0.05). Progression of the vascular involvement was seen in two (5 %) patients and led to a shorter DFS.

CONCLUSION

In BR/LA pancreatic adenocarcinoma after the neoadjuvant FOLFIRINOX regimen (± chemoradiotherapy), significant tumour size decreases were observed on CT. However, CT staging was not predictive of resectability and pathological response.

KEY POINTS

• Significant tumour size decreases were observed on CT after FOLFIRINOX (± chemoradiotherapy). • CT is not able to predict R0 resection accurately after FOLFIRINOX (± chemoradiotherapy). • CT is not able to predict complete response accurately after FOLFIRINOX (± chemoradiotherapy). • Even with a stable NCCN classification, BR/LA pancreatic adenocarcinoma could have R0 resection.

Tumour-stroma interactions in pancreatic ductal adenocarcinoma: rationale and current evidence for new therapeutic strategies

Most patients with pancreatic cancer present with advanced/metastatic disease and have a dismal prognosis. Despite the proven albeit modest benefits of gemcitabine demonstrated over a decade ago, subsequent advances have been slow, suggesting it may be time to take a different approach. It is thought that some key characteristics of pancreatic cancer, such as the desmoplasia, restricted vasculature and hypoxic environment, may prevent the delivery of chemotherapy to the tumour thereby explaining the limited benefits observed to-date. Moreover, there is evidence to suggest that the stroma is not only a mechanical barrier but also constitutes a dynamic compartment of pancreatic tumours that is critically involved in tumour formation, progression and metastasis. Thus, targeting the stroma and the tumour represents a promising therapeutic strategy. Currently, several stroma-targeting agents are entering clinical development. Among these, nab-paclitaxel appears promising since it combines cytotoxic therapy with targeted delivery via its proposed ability to bind SPARC on tumour and stromal cells. Preclinical data indicate that co-treatment with nab-paclitaxel and gemcitabine results in stromal depletion, increased tumour vascularization and intratumoural gemcitabine concentration, and increased tumour regression compared with either agent alone. Phase I/II study data also suggest that a high level of antitumor activity can be achieved with this combination in pancreatic cancer. This was recently confirmed in a Phase III study which showed that nab-paclitaxel plus gemcitabine significantly improved overall survival (HR 0.72) and progression-free survival (HR 0.69) versus gemcitabine alone for the first-line treatment of patients with metastatic pancreatic cancer.

Value of carbohydrate antigen 19-9 in predicting response and therapy control in patients with metastatic pancreatic cancer undergoing first-line therapy

BACKGROUND

Serum carbohydrate antigen 19-9 (CA 19-9) has been shown to be a sensitive and specific serum marker for pancreatic cancer. Little has been published about correlations between baseline CA 19-9 level or changes to CA 19-9 level and median overall survival (mOS). Its impact on monitoring treatment efficacy remains under discussion, however.

METHODS

CA 19-9 serum level was measured in 181 consecutive patients with advanced pancreatic cancer (APC) being treated with gemcitabine-based first-line chemotherapy. We separated the patients into several groups depending on baseline CA 19-9 levels and the CA 19-9 response after 6-8 weeks of treatment. Evaluations were made using SPSS 19.9.

RESULTS

Median baseline CA 19-9 level was 1,493 U/ml (range 40-1,043,301). Patients with baseline CA 19-9 ≤1,000 U/ml had a mOS of 14.9 months (95% CI: 11.36:18.44), whereas patients with CA 19-9>1,000 U/ml had a mOS of 7.4 months [(95% CI: 5.93:8.87) p < 0.001, HR 2.12]. With regard to the change in CA 19-9 after 6-8 weeks of treatment: patients with increased CA 19-9 levels had a mOS of 8.1 months, those with stabilized CA 19-9 levels 11.6 months, and those with decreased CA 19-9 levels 11.1 months (p < 0.019).

CONCLUSION

CA 19-9 levels can separate patients with differing mortality risks at baseline. Patients with stabilization or high response of CA 19-9 after 6-8 weeks of treatment had no significant differences in survival rates, whereas patients with increased CA 19-9 had significantly lower survival rates, indicating an early treatment failure.

Imaging evaluation of therapeutic response in patients with pancreatic cancer: recent advances

Chemoradiotherapy is the primary choice of non-surgical treatment of advanced pancreatic cancer, and diagnostic imaging plays an important role in objectively assessing early therapeutic response. This article systematically reviews the criteria for evaluation of therapeutic response in solid tumors and their application in pancreatic cancer, highlighting some key contents in imaging evaluation of therapeutic response in patients with pancreatic cancer.

Phase II trial of S-1 and concurrent radiotherapy in patients with locally advanced pancreatic cancer

PURPOSE

S-1 has a favorable effect in unresectable pancreatic cancer and a potential radiosensitizer. In addition, daily oral administration of S-1 is more convenient than continuous infusion of 5-fluorouracil. This study was designed to evaluate the efficacy and safety of S-1 and concurrent radiotherapy in patients with locally advanced pancreatic cancer.

METHODS

Eligibility criteria were histologically proven pancreatic adenocarcinoma, locally advanced disease, and no previous treatment. S-1 was administered orally at a dose of 40 mg/m(2) twice daily from day 1 to 14 and from day 22 to 35, and concurrent radiotherapy (a total dose of 50.4 Gy) was delivered in 28 fractions. One month after treatment completion, tumor response was evaluated by computed tomography (CT).

RESULTS

A total of 25 patients were evaluable for efficacy and toxicity on the basis of the intention-to-treat analysis. The response rate and disease control rate were 24.0 and 68.0%, respectively. There was no treatment-related death or grade 4 toxicity. The most common grade 3 hematologic and non-hematologic toxicities were thrombocytopenia (4.0%) and anorexia (20%), respectively. All toxicities were tolerable and transient. The median time-to-progression and median overall survival were 6.5 months (95% confidence interval, 4.1-9.0 months) and 12.9 months (95% confidence interval, 6.7-19.0 months), respectively, and the 1-year survival rate was estimated to be 43%.

CONCLUSIONS

S-1 and concurrent radiotherapy shows favorable efficacy for disease control against locally advanced pancreatic cancer and was well tolerated with no severe toxicities.