Does radiologic response correlate to pathologic response in patients undergoing neoadjuvant therapy for borderline resectable pancreatic malignancy?

FOLFIRINOX or Gemcitabine-based Chemotherapy for Borderline Resectable and Locally Advanced Pancreatic Cancer: A Multi-institutional, Patient-Level, Meta-analysis and Systematic Review

BACKGROUND

Pancreatic cancer often presents as locally advanced (LAPC) or borderline resectable (BRPC). Neoadjuvant systemic therapy is recommended as initial treatment. It is currently unclear what chemotherapy should be preferred for patients with BRPC or LAPC.

METHODS

We performed a systematic review and multi-institutional meta-analysis of patient-level data regarding the use of initial systemic therapy for BRPC and LAPC. Outcomes were reported separately for tumor entity and by chemotherapy regimen including FOLFIRINOX (FIO) or gemcitabine-based.

RESULTS

A total of 23 studies comprising 2930 patients were analyzed for overall survival (OS) calculated from the beginning of systemic treatment. OS for patients with BRPC was 22.0 months with FIO, 16.9 months with gemcitabine/nab-paclitaxel (Gem/nab), 21.6 months with gemcitabine/cisplatin or oxaliplatin or docetaxel or capecitabine (GemX), and 10 months with gemcitabine monotherapy (Gem-mono) (p < 0.0001). In patients with LAPC, OS also was higher with FIO (17.1 months) compared with Gem/nab (12.5 months), GemX (12.3 months), and Gem-mono (9.4 months; p < 0.0001). This difference was driven by the patients who did not undergo surgery, where FIO was superior to other regimens. The resection rates for patients with BRPC were 0.55 for gemcitabine-based chemotherapy and 0.53 with FIO. In patients with LAPC, resection rates were 0.19 with Gemcitabine and 0.28 with FIO. In resected patients, OS for patients with BRPC was 32.9 months with FIO and not different compared to Gem/nab, (28.6 months, p = 0.285), GemX (38.8 months, p = 0.1), or Gem-mono (23.1 months, p = 0.083). A similar trend was observed in resected patients converted from LAPC.

CONCLUSIONS

In patients with BRPC or LAPC, primary treatment with FOLFIRINOX compared with Gemcitabine-based chemotherapy appears to provide a survival benefit for patients that are ultimately unresectable. For patients that undergo surgical resection, outcomes are similar between GEM+ and FOLFIRINOX when delivered in the neoadjuvant setting.

Imaging Recommendations for Diagnosis, Staging, and Management of Pancreatic Cancer

Pancreatic cancer is the fourth most prevalent cause of cancer-related death worldwide, with a fatality rate equal to its incidence rate. Pancreatic cancer is a rare malignancy with a global incidence and death ranking of 14th and 7th, respectively. Pancreatic cancer cases are divided into three categories without metastatic disease: resectable, borderline resectable, or locally advanced disease. The category is determined by the tumor's location in the pancreas and whether it is abutting or encasing the adjacent arteries and/or vein/s.

The stage of disease and the location of the primary tumor determine the clinical presentation: the pancreatic head, neck, or uncinate process, the body or tail, or multifocal disease. Imaging plays a crucial role in the diagnosis and follow-up of pancreatic cancers. Various imaging modalities available for pancreatic imaging are ultrasonography (USG), contrast-enhanced computed tomography (CECT), magnetic resonance imaging (MRI), and 18-fluoro-deoxy glucose positron emission tomography (FDG PET).

Even though surgical resection is possible in both resectable and borderline resectable non-metastatic cases, neoadjuvant chemotherapy with or without radiotherapy has become the standard practice for borderline resectable cases as it gives a high yield of R0 resection.

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.

Retrospective Evaluation of Treatment Response in Patients with Nonmetastatic Pancreatic Cancer Using CT and CA 19-9

Background Imaging studies have limitations in evaluating pancreatic ductal adenocarcinoma (PDAC) treatment response. Purpose To investigate the effectiveness of combined CT and carbohydrate antigen 19-9 (CA 19-9) evaluation at 8 weeks after first-line treatment to predict overall survival (OS) of patients with nonmetastatic PDAC. Materials and Methods Patients with nonmetastatic PDAC who received first-line treatment with either chemotherapy or concurrent chemoradiation in a single-center PDAC cohort registry were retrospectively enrolled in the study between January 2013 and December 2016. Follow-up CT images obtained 8 weeks after treatment were evaluated according to Response Evaluation Criteria in Solid Tumors. Patients with partial response (PR) or stable disease (SD) were defined as CT responders, and those with progressive disease (PD) were defined as CT nonresponders. Patients with a normalized CA 19-9 level at 8-week follow-up were defined as CA 19-9 responders, and those with a nonnormalized or nonelevated CA 19-9 level were defined as CA 19-9 nonresponders. OS was compared using the Kaplan-Meier method with Breslow analysis. Results A total of 197 patients (mean age ± standard deviation, 65 years ± 10; 107 men) were evaluated. Patients with PD (n = 17) showed shorter OS than those with SD (n = 147; P < .001) or PR (n = 33; P = .003). OS did not differ between the patients with PR and those with SD (P = .60). When the CT and CA 19-9 responses were integrated, OS was longest in CT and CA 19-9 responders (group 1, n = 27; median OS, 26.6 months [95% CI: 9.0, 44.1]), followed by CT responders but CA 19-9 nonresponders (group 2, n = 153; median OS, 15.9 months [95% CI: 13.3, 18.5]; P = .007 vs group 1) and CT and CA 19-9 nonresponders (group 3, n = 17; median OS, 6.5 months [95% CI: 0.8, 12.2]; P < .001 vs group 2). Conclusion Integrated evaluation with CT and carbohydrate antigen 19-9 response allowed more accurate stratification of survival in patients with pancreatic ductal adenocarcinoma in the early treatment period than did evaluation according to Response Evaluation Criteria in Solid Tumors. © RSNA, 2022 Online supplemental material is available for this article.

Arterial involvement and resectability scoring system to predict R0 resection in patients with pancreatic ductal adenocarcinoma treated with neoadjuvant chemoradiation therapy

OBJECTIVES

To derive a CT-based scoring system incorporating arterial involvement and resectability status to predict R0 resection in patients with pancreatic ductal adenocarcinoma (PDAC) undergoing neoadjuvant chemoradiation therapy (CRT).

METHODS

This retrospective study included 112 patients with PDAC who underwent dynamic contrast-enhanced CT before and after neoadjuvant CRT. A 5-point score was used to determine arterial involvement (A score; 1 = no involvement, 2 = haziness, 3 = abutment, 4 = encasement, 5 = deformity) and 4-point score evaluating resectability status (R score; 1 = resectable, 2 = borderline resectable [BR] with venous involvement, 3 = BR with arterial involvement, 4 = locally advanced [LA]). A score before and after CRT were summed with R score before and after CRT to compute the AR score (AR_total). The associations between AR_total, R0 resection, overall survival (OS), and disease-free survival (DFS) were assessed.

RESULTS

The AR_total was associated with R0 resection (p < .001) and showed area under the ROC curve of 0.79 for differentiating R0 and R1 resections. Median OS was significantly lower for patients with AR_total  > 9 (median: 35.2 months) compared to patients with AR_total ≤ 9 (median: not estimable) (p < .001). Similar results were observed for DFS (median, 16.8 months in > 9 vs median, not estimable in ≤ 9; p < .001).

CONCLUSIONS

A composite score which incorporates degree of arterial involvement and resectability status before and after neoadjuvant CRT is associated with R0 resection and discriminates between R0 and R1 resections in PDAC.

KEY POINTS

• A scoring system incorporating arterial involvement and resectability status was associated with R0 resection. • AR_total >  9 could predict patients' overall and disease-free survival.

Pancreatic cancer in 2021: What you need to know to win

Pancreatic cancer is one of the solid tumors with the worst prognosis. Five-year survival rate is less than 10%. Surgical resection is the only potentially curative treatment, but the tumor is often diagnosed at an advanced stage of the disease and surgery could be performed in a very limited number of patients. Moreover, surgery is still associated with high post-operative morbidity, while other therapies still offer very disappointing results. This article reviews every aspect of pancreatic cancer, focusing on the elements that can improve prognosis. It was written with the aim of describing everything you need to know in 2021 in order to face this difficult challenge.

Multimodality Imaging for the Staging of Pancreatic Cancer

Imaging plays a key role in the diagnosis, staging, and follow-up of pancreatic ductal adenocarcinoma. The pancreatic protocol dual-phase multidetector computed tomography scan is the imaging modality of choice. A computed tomography scan is highly accurate for pancreatic tumor detection, assessment of resectability, and detection of metastatic disease. This article reviews key principles of the acquisition, interpretation, and reporting of pancreatic ductal adenocarcinoma imaging with computed tomography scanning and highlights potential roles for newer and supplemental imaging technologies. We discuss the importance of structured interpretation and reporting for providing the most complete and accurate assessment of tumor stage and resectability.

Four-Tier Pathologic Tumor Regression Grading System Predicts the Clinical Outcome in Patients Who Undergo Surgical Resection for Locally Advanced Pancreatic Cancer after Neoadjuvant Chemotherapy

Background/Aims

Neoadjuvant chemotherapy is increasingly utilized in patients with borderline or locally advanced pancreatic cancer (LAPC). However, the pathologic evaluation of tumor regression is not routinely performed or well established. We aimed to evaluate the prognostic value of three tumor regression grading systems frequently used in LAPC and to determine the correlation between pathologic and clinical response.

Methods

We included a total of 38 patients with LAPC who were treated with neoadjuvant chemotherapy and subsequent resection. Pathologic tumor regression was graded based on the College of American Pathologists (CAP), Evans, and MD Anderson grading systems.

Results

One out of 38 patients (2.6%) achieved a pathologic complete response. Unlike other grading systems (Evans, p=0.063; MD Anderson, p=0.110), the CAP grading system was a significant prognostic factor for overall survival (p=0.043). Pathologic N stage (p=0.023), margin status (p=0.044), and radiologic response (p=0.016) correlated with overall survival. In the multivariate analysis, CAP 3 was an independent predictor of shorter overall survival (p=0.026). The CAP grading system correlated with the radiologic response (p=0.007) but not the carbohydrate antigen 19-9 level (p=0.333).

Conclusions

The four-tier CAP pathologic tumor regression grading system predicted the clinical outcome in LAPC patients who underwent resection after neoadjuvant chemotherapy. Therefore, a more comprehensive pathologic evaluation is warranted in these patients.

Radiographic and Serologic Predictors of Pathologic Major Response to Preoperative Therapy for Pancreatic Cancer

OBJECTIVE

We sought to identify potential radiologic and serologic markers of pancreatic tumor response to therapy, using pathologic major response (pMR) as the objective endpoint.

BACKGROUND

We previously demonstrated that a pMR to preoperative therapy, defined as detection of <5% viable cancer cells in the surgical specimen on histopathological analysis, is an important prognostic factor for patients with pancreatic ductal adenocarcinoma (PDAC).

METHODS

Pretreatment and posttreatment computed tomography scans of consecutive patients who received preoperative chemotherapy and/or (chemo)radiation before pancreatectomy for PDAC between January 2010 and December 2018 were rereviewed. Response per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1, other radiographic changes in tumor size and anatomic extent, and posttreatment CA 19-9 levels were compared between patients who did and did not have a pMR on final histopathologic analysis of their surgical specimens.

RESULTS

A total of 290 patients with localized PDAC underwent pancreatectomy between 2010 and 2018 after receiving preoperative chemotherapy (n = 36; 12%), (chemo)radiation (n = 87; 30%), or both (n = 167; 58%). Among them, 28 (10%) experienced pMR, including 9 (3.1%) who experienced pathologic complete response. On multivariable logistic regression, low posttreatment CA 19-9 level, RECIST partial response, and reduction in tumor volume were confirmed to be independently associated with pMR (P < 0.01).

CONCLUSIONS

We identified serologic and radiographic indicators of pMR that could help inform the delivery of preoperative therapy to patients with PDAC.

The utility of Multi-Detector Computed Tomography criteria after neoadjuvant therapy in Borderline Resectable Pancreatic cancer: Prospective, bi-institutional study

OBJECTIVES

To evaluate the utility of MDCT criteria for the determination of resectability and tumor response in borderline resectable pancreatic cancer (BRPC) following neoadjuvant therapy (NAT).

METHODS

This prospective study includes 90 consecutive BRPC patients who underwent surgery following NAT. Two radiologists assessed baseline and pre-surgical CTs for (largest tumor axis, size, attenuation, and vascular criteria). Logistic regression was used to determine which CT criteria independently associated with R0 resection and pathologic major response (pMR). Median survival and overall survival (OS) were calculated.

RESULTS

Seventy-three/90 (81.1 %) patients had R0 resection, and 11/90 (12.2 %) had pMR. After NAT, there were significant interval changes in the largest tumor axis, size, attenuation, and venous burden index (VBI) (P < 0.02). On the multivariable analysis, regression of the VBI and low VBI at the pre-surgical CT were independently associated with an increased likelihood of R0 resection (OR 1.82; 95 % CI 1.44-5.33) (OR 1.91; 95 % CI 1.83-6.14). The assessment of VBI at the pre-surgical CT showed moderate reproducibility (k-value, 0.56 - 0.60). On the multivariable analysis, partial response (PR) was found to be independently associated with an increased likelihood of pMR (OR 1.71; 95 % CI 1.31-3.45). The median survival was longer in patients who had R0 (P = 0.01). The overall survival was longer in patients who had pMR compared to those who did not (P = 0.02).

CONCLUSION

Surgical exploration could be indicated in patients who had regression of the VBI and low VBI at the pre-surgical CT. PR response is associated with pMR.

[Radiologic Evaluation for Resectability of Pancreatic Adenocarcinoma]

Imaging studies play an important role in the detection, diagnosis, assessment of resectability, staging, and determination of patient-tailored treatment options for pancreatic adenocarcinoma. Recently, for patients diagnosed with borderline resectable or locally advanced pancreatic cancers, it is recommended to consider curative-intent surgery following neoadjuvant or palliative therapy, if possible. This review covers how to interpret imaging tests and what to consider when assessing resectability, diagnosing distant metastasis, and re-assessing the resectability of pancreatic cancer after neoadjuvant or palliative therapy.

Importance of Normalization of CA19-9 Levels Following Neoadjuvant Therapy in Patients With Localized Pancreatic Cancer

OBJECTIVE

Carbohydrate antigen 19-9 (CA19-9) is a prognostic marker for patients with pancreatic cancer (PC), but its value as a treatment biomarker is unclear.

SUMMARY BACKGROUND DATA

Although CA19-9 is an established prognostic marker for patients with PC, it is unclear how CA19-9 monitoring should be used to guide multimodality treatment and what level of change in CA19-9 constitutes a meaningful treatment response.

METHODS

CA19-9 measurements at diagnosis (pretx), after completion of all planned neoadjuvant therapy (preop), and after surgery (postop) were analyzed in patients with localized PC who had an elevated CA19-9 (≥35 U/dL) at diagnosis. Patients were classified by: 1) quartiles of pretx CA19-9 (Q1-4); 2) proportional changes in CA19-9 (ΔCA19-9) after the completion of neoadjuvant therapy; 3) normalization (CA19-9 <35 U/dL) of preop CA19-9; and 4) normalization of postop CA19-9.

RESULTS

Among 131 patients, the median overall survival (OS) was 30 months; 68 months for the 33 patients in Q1 of pretx CA19-9 (<80 U/dL) compared with 25 months for the 98 patients in Q2-4 (P = 0.03). For the 98 patients in Q2-4, preop CA19-9 declined (from pretx) in 86 (88%), but there was no association between the magnitude of ΔCA19-9 and OS (P = 0.77). Median OS of the 98 patients who did (n = 29) or did not (n = 69) normalize their preop CA19-9 were 46 and 23 months, respectively (P = 0.02). Of the 69 patients with an elevated preop CA19-9, 32 (46%) normalized their postop CA19-9. Failure to normalize preop or postop CA19-9 was associated with a 2.77-fold and 4.03-fold increased risk of death, respectively (P < 0.003) as compared with patients with normal preop CA19-9.

CONCLUSIONS

Following neoadjuvant therapy, normalization of CA19-9, rather than the magnitude of change, is the strongest prognostic marker for long-term survival.

Serum CA19-9 Response to Neoadjuvant Therapy Predicts Tumor Size Reduction and Survival in Pancreatic Adenocarcinoma

BACKGROUND

The optimal cutoffs for carbohydrate antigen 19-9 (CA19-9) response after neoadjuvant therapy (NT) for pancreatic adenocarcinoma (PDAC) are not well characterized. This study aimed to analyze the relationship of serum CA19-9 to other markers of response and to identify thresholds correlating to outcomes.

METHODS

A retrospective review of resected PDAC patients from 2010 to 2017 at an academic tertiary referral center was conducted.

RESULTS

The analysis enrolled 250 subjects. Normalization and multiple cutoff points for CA19-9 response were assessed. Normalization was not associated with improved survival (35.17 vs. 29.43 months; p = 0.173). Although a response 45% or higher was associated with longer survival (35 vs. 20 months; p = 0.018), a response of 85% or higher was optimal (55.7 vs. 25.97 months; p < 0.0001). A response of 85% or higher remained a strong independent predictor of survival [hazard ratio (HR), 0.47; p = 0.007]. Subjects with a response of 85% or higher had received more NT cycles [3 (range 2-6) vs. 3 (range 2-4) cycles; p = 0.006] and fewer adjuvant cycles [4 (range 3-6) vs. 5 (range 3-6) cycles; p = 0.027]. Reduction in T-size correlated with a drop in CA19-9 and a size reduction of 25% or higher (56.97 vs. 28.17 months; p = 0.016) improved survival. A serum CA19-9 response of 85% or higher was a strong independent predictor of a reduction in T-size of 25% or higher (HR 2.40; p = 0.007).

CONCLUSION

A CA19-9 response of 85% or higher is the optimal threshold for predicting survival. It is predictive of T-size reduction. Future NT trials should incorporate CA19-9 response as an end point.

Reduced and Normalized Carbohydrate Antigen 19-9 Concentrations after Neoadjuvant Chemotherapy Have Comparable Prognostic Performance in Patients with Borderline Resectable and Locally Advanced Pancreatic Cancer

Background: The association between optimal carbohydrate antigen (CA) 19-9 concentration after neoadjuvant chemotherapy (NACT) and prognosis has not been confirmed in patients with borderline resectable (BRPC) and locally advanced pancreatic cancer (LAPC). Methods: This retrospective study included 122 patients with BRPC and 103 with LAPC who underwent surgery after NACT between 2012 and 2019 in a tertiary referral center. Prognostic models were established based on relative difference of the CA 19-9 (RDC), with their prognostic performance compared using C-index and Akaike information criterion (AIC). Results: CA 19-9 concentrations of 37–1000 U/mL before NACT showed prognostic significance in patients with BRPC and LAPC (hazard ratio [HR]: 0.262; 95% confidence interval [CI]: 0.092–0.748; p = 0.012). Prognostic models in this subgroup showed that RDC was independently prognostic of better overall survival (HR: 0.262; 95% CI: 0.093–0.739; p = 0.011) and recurrence free survival (HR: 0.299; 95% CI: 0.140–0.642; p = 0.002). The prognostic performances of RDC (C-index: 0.653; AIC: 227.243), normalization of CA 19-9 after NACT (C-index: 0.625; AIC: 230.897) and surgery (C-index: 0.613; AIC: 233.114) showed no significant differences. Conclusion: RDC was independently associated with better prognosis after NACT in patients with BRPC or LAPC. Decreased CA19-9 after NACT was a prognostic indicator of better survival and recurrence, as was normalization of CA 19-9 after both NACT and surgery.

Clinical Significance of Neoadjuvant Chemotherapy With Gemcitabine Plus S-1 for Resectable Pancreatic Ductal Adenocarcinoma

BACKGROUND/AIM

Little is known about the efficacy of neoadjuvant chemotherapy (NAC) with gemcitabine plus S-1 (GS) for patients with resectable pancreatic ductal adenocarcinoma (R-PDAC). The aim of this study was to investigate differences in the long-term outcome of patients with R-PDAC undergoing pancreatectomy with and without NAC-GS to clarify the clinical significance of NAC-GS.

PATIENTS AND METHODS

A total of 77 patients with R-PDAC who were scheduled for pancreatectomy between January 2012 and December 2017 were enrolled. Of these patients, 39 received NAC-GS (GS group) and 38 had upfront surgery (UFS group).

RESULTS

Among the 77 patients, one patient in each group did not undergo pancreatectomy due to intraoperative non-curative factors. Median tumor size and the number of lymph nodes with metastasis were significantly lower in the GS group than in the UFS group (p=0.002 and p=0.017). However, the 5-year overall survival rate was similar in the two groups (26.1% versus 21.5%, p=0.930).

CONCLUSION

NAC-GS may not be recommended for patients with R-PDAC since it does not seem to offer any survival benefits.

Intraoperative Near-infrared Imaging Can Identify Neoplasms and Aid in Real-time Margin Assessment During Pancreatic Resection

OBJECTIVE

To determine if intraoperative near-infrared (NIR) imaging carries benefit in resection of pancreatic neoplasms.

BACKGROUND

Resection of pancreatic malignancies is hindered by high rates of local and distant recurrence from positive margins and unrecognized metastases. Improved tumor visualization could improve outcomes. We hypothesized that intraoperative NIR imaging with a clinically approved optical contrast agent could serve as a useful adjunct in assessing margins and extent of disease during pancreatic resections.

METHODS

Twenty patients were enrolled in an open-label clinical trial from July 2016 to May 2018. Subjects received second window indocyanine green (ICG) (2.5-5 mg/kg) 24 hours prior to pancreatic resection. NIR imaging was performed during staging laparoscopy and after pancreas mobilization in situ and following resection ex vivo. Tumor fluorescence was quantified using tumor-to-background ratio (TBR). Fluorescence at the specimen margin was compared to pathology evaluation.

RESULTS

Procedures included 9 pancreaticoduodenectomies, 10 distal pancreatectomies, and 1 total pancreatectomy; 21 total specimens were obtained. Three out of 8 noninvasive tumors were fluorescent (mean TBR 2.59 ± 2.57). Twelve out of 13 invasive malignancies (n = 12 pancreatic adenocarcinoma, n = 1 cholangiocarcinoma) were fluorescent (mean TBR 4.42 ± 2.91). Fluorescence at the transection margin correlated with final pathologic assessment in 12 of 13 patients. Following neoadjuvant therapy, 4 of 5 tumors were fluorescent; these 4 tumors showed no treatment response on pathology assessment. One tumor had a significant treatment response and showed no fluorescence.

CONCLUSIONS

Second window ICG reliably accumulates in invasive pancreatic malignancies and provides real-time feedback during pancreatectomy. NIR imaging may help to assess the response to neoadjuvant therapy.

Preoperative Imaging Evaluation after Downstaging of Pancreatic Ductal Adenocarcinoma: A Multi-Center Study

Introduction: Evaluation of pancreatic ductal adenocarcinoma (PDAC) after chemoradiotherapy downstaging is challenging due to computed tomography (CT) overestimation of tumor extension and residual vascular involvement, limiting access to surgery to some patients with potentially resectable tumors. With this study, we wanted to assess which radiological findings are most reliable at pre-operative imaging in the evaluation of PDAC after chemoradiotherapy in order to achieve complete resection. Methods: We retrospectively enrolled 71 patients with locally advanced and borderline resectable PDAC who underwent neoadjuvant chemoradiotherapy. Pre-operative CT or magnetic resonance (MR) have been evaluated by three radiologists to assess major qualitative and quantitative parameters of lesions. Accuracy, sensitivity, and specificity compared to anatomopathological results were evaluated for each parameter. Cohen’s K-coefficient has been calculated to evaluate the inter-observer agreement (IOA). Both single and consensus lecture have been tested. Different dimensional cut-offs were tested to categorize tumors according to their major axis and to compare with anatomopathological diameter, tumor persistence, and margin infiltration. Results: A 25 mm cut-off was 67% sensitive, 90% specific, and 77% accurate in assessing real tumor dimension. 25 mm cut-off reported a 64% sensitivity, 78% specificity, and 69% accuracy in assessing R0 resection. Each 5 mm increment of major axis dimension there is an odds ratio (OR) 1.79 (95% CI 1.13–2.80, p = 0.012) for R+ resection. Imaging presence of the perivascular cuff is not associated with tumor persistence and resection margin infiltration (p = 0.362). Lesion enhancement and pattern homogeneity were not accurate in determining tumor persistence. IOA was generally poor to fair, except for >25 mm cut-off classification where IOA was moderate. Diagnostic accuracy is superior in consensus lecture rather than single lecture. Conclusion: Imaging methods tend to underestimate PDAC resectability after neoadjuvant-CRT. IOA is poor to fair in evaluating most of the qualitative parameters of downstaged pancreatic adenocarcinoma. Surgery should be considered for downstaged borderline resectable PDACs, independently from perivascular cuff presence, especially for tumors smaller than 25 mm.

Outcomes after neoadjuvant treatment with gemcitabine and erlotinib followed by gemcitabine-erlotinib and radiotherapy for resectable pancreatic cancer (GEMCAD 10-03 trial)

BACKGROUND

Neoadjuvant therapy (NAT) for pancreatic adenocarcinoma (PDAC) patients has shown promising results in non-randomized trials. This is a multi-institutional phase II trial of NAT in resectable PDAC patients.

METHODS

Patients with confirmed resectable PDAC after agreement by two expert radiologists were eligible. Patients received three cycles of GEM (1000 mg/m²/week) plus daily erlotinib (ERL) (100 mg/day). After re-staging, patients without progressive disease underwent 5 weeks of therapy with GEM (300 mg/m²/week), ERL 100 mg/day and concomitant radiotherapy (45 Gy). Efficacy was assessed using tumor regression grade (TRG) and resection margin status. Using a single-arm Simon's design, considering the therapy not useful if R0 < 40% and useful if the R0 > 70% (alpha 5%, beta 10%), 24 patients needed to be recruited. This trial was registered at ClinicalTrials.gov, number NCT01389440.

RESULTS

Twenty-five patients were enrolled. Adverse effects of NAT were mainly mild gastrointestinal disorders. Resectability rate was 76%, with a R0 rate of 63.1% among the resected patients. Median overall survival (OS) and disease-free survival (DFS) were 23.8 (95% CI 11.4-36.2) and 12.8 months (95% CI 8.6-17.1), respectively. R0 resection patients had better median OS, compared with patients with R1 resection or not resected (65.5 months vs. 15.5 months, p = 0.01). N0 rate among the resected patients was 63.1%, and showed a longer median OS (65.5 vs. 15.2 months, p = 0.009).

CONCLUSION

The results of this study confirm promising oncologic results with NAT for patients with resectable PDAC. Therefore, the present trial supports the development of phase II randomized trials comparing NAT vs. upfront surgery in resectable pancreatic cancer.

Detecting tumour response and predicting resectability after neoadjuvant therapy for borderline resectable and locally advanced pancreatic cancer

BACKGROUND

This systematic review aimed to determine the accuracy of imaging modalities to predict resectability and R0 resection for borderline resectable (BRPC) or locally advanced pancreatic cancer (LAPC) after neoadjuvant therapy (NAT).

METHODS

A systematic search of major databases was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

Fifteen studies identified 995 patients of which 683 had BRPC and 312 LAPC. Computed tomography (CT) scan was the most common modality for re-staging (n = 14), followed by positron emission tomography (PET)-CT (n = 3) and endosonography (EUS) (n = 2). Stable disease on RECIST criteria was found in 67% of patients (range 53-80%) with 20% demonstrating reduction in tumour size. A total of 60% of patients underwent surgery post-NAT (range 31-85%) with a R0 rate of 88% (range 57-100%). Accuracy for predicting R0 resectability and T-stage on CT scan was 71 and 49%. A reduction in SUV_max on PET-CT and reduction of tumour stiffness on EUS elastography positively correlated with resectability.

CONCLUSIONS

More than half the patients undergo resection post-NAT for LAPC and BRPC. Stable, or reduction of, tumour disease may predict resectability. Reduction in tumour SUV_max on PET-CT and decreased tumour stiffness on EUS elastography may be potential markers of NAT response and resectability.

Pancreatic Adenocarcinoma Staging in the Era of Preoperative Chemotherapy and Radiation Therapy

Pancreatic ductal adenocarcinoma (PDA) remains among the most challenging malignancies to treat. At diagnosis, the tumor often already extends beyond the confines of the pancreas, spreading to an extent such that primary surgery with curative intent is very rarely feasible. Considerable momentum is now being given to a treatment strategy involving neoadjuvant chemotherapy or chemotherapy and radiation therapy in patients with nonmetastatic PDA. The main advantage of this strategy is better selection of patients likely to benefit from curative-intent surgery through the achievement of negative resection margins. Patients with rapidly progressive disease are identified and are spared ineffective surgery with its attendant morbidity. Neoadjuvant therapy can downstage tumors classified as locally advanced at initial imaging studies to resectable tumors. However, the imaging study evaluation of the response to neoadjuvant therapy is extremely complex. Thus, the diagnostic performance of imaging studies is not sufficient to ensure the accurate selection of patients in whom negative-margin resection is likely to be achieved. More specifically, standard criteria for predicting vascular invasion, based on the amount of tumor-vessel contact, are not valid after neoadjuvant therapy. ^©RSNA, 2018.

Modified National Comprehensive Cancer Network Criteria for Assessing Resectability of Pancreatic Ductal Adenocarcinoma

OBJECTIVE

The objective of our study was to assess the preoperative resectability of pancreatic ductal adenocarcinoma (PDAC) using the National Comprehensive Cancer Network (NCCN) guideline, the general rules of the Japan Pancreas Society (JPS), and both of them combined.

MATERIALS AND METHODS

Eighty-six consecutive patients with PDAC (50 men and 36 women; mean age ± SD, 70.8 ± 9.0 years; age range, 49-86 years) underwent dynamic contrast-enhanced CT. Following the NCCN guideline, the degree of vascular invasion was evaluated to determine the NCCN score: 0 points for absence of vascular invasion, 1 point for tumor contact ≤ 180°, and 2 points for tumor contact > 180°. Direct invasion to adjacent structures was rated according to the general rules of JPS to determine the JPS score: 0 points for absence and 1 point for presence. The NCCN score, JPS score, and sum of the two scores, which we refer to as the "combined score," were compared with histopathologic or intraoperative findings as well as for the differentiation of R0 resection (negative resection margins) from R1 (microscopic tumor infiltration) and R2 (macroscopic residual tumor) using ROC curve analysis.

RESULTS

The sensitivities, specificities, and areas under the ROC curves (AUCs) for the differentiation of R0 from R1 and R2 were 100.0%, 40.0%, and 0.725, respectively, with the NCCN score; 63.9%, 84.0%, and 0.824 with the JPS score; and 86.9%, 68.0%, and 0.874 with the combined score. The AUC of the combined score was significantly greater than that of the NCCN score (p = 0.0059).

CONCLUSION

The assessment of resectability of PDAC based on the combined criteria of the NCCN guideline and general rules of JPS was superior to that based on either criterion alone.

Response assessment in pancreatic ductal adenocarcinoma: role of imaging

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive gastrointestinal (GI) malignancy with poor 5-year survival rate. Advances in surgical techniques and introduction of novel combination chemotherapy and radiation therapy regimens have necessitated the need for biomarkers for assessment of treatment response. Conventional imaging methods such as RECIST have been used for response evaluation in clinical trials particularly in patients with metastatic PDAC. However, the role of these approaches for assessing response to loco-regional and systemic therapies is limited due to complex morphological and histological nature of PDAC. Determination of tumor resectability after neoadjuvant therapy remains a challenge. This review article provides an overview of the challenges and limitations of response assessment in PDAC and reviews the current evidence for the utility of novel morphological and functional imaging tools in this disease.