Postoperative Imaging and Tumor Marker Surveillance in Resected Pancreatic Cancer

Routine Imaging or Symptomatic Follow-Up After Resection of Pancreatic Adenocarcinoma

Importance

International guidelines lack consistency in their recommendations regarding routine imaging in the follow-up after pancreatic resection for pancreatic ductal adenocarcinoma (PDAC). Consequently, follow-up strategies differ between centers worldwide.

Objective

To compare clinical outcomes, including recurrence-focused treatment and survival, in patients with PDAC recurrence who received symptomatic follow-up or routine imaging after pancreatic resection in international centers affiliated with the European-African Hepato-Pancreato-Biliary Association (E-AHPBA).

Design, Setting, and Participants

This was a prospective, international, cross-sectional study. Patients from a total of 33 E-AHPBA centers from 13 countries were included between 2020 and 2021. According to the predefined study protocol, patients who underwent PDAC resection and were diagnosed with disease recurrence were prospectively included. Patients were stratified according to postoperative follow-up strategy: symptomatic follow-up (ie, without routine imaging) or routine imaging.

Exposures

Symptomatic follow-up or routine imaging in patients who underwent PDAC resection.

Main Outcomes and Measures

Overall survival (OS) was estimated with Kaplan-Meier curves and compared using the log-rank test. To adjust for potential confounders, multivariable logistic regression was used to evaluate the association between follow-up strategy and recurrence-focused treatment. Multivariable Cox proportional hazard analysis was used to study the independent association between follow-up strategy and OS.

Results

Overall, 333 patients (mean [SD] age, 65 [11] years; 184 male [55%]) with PDAC recurrence were included. Median (IQR) follow-up at time of analysis 2 years after inclusion of the last patient was 40 (30-58) months. Of the total cohort, 98 patients (29%) received symptomatic follow-up, and 235 patients (71%) received routine imaging. OS was 23 months (95% CI, 19-29 months) vs 28 months (95% CI, 24-30 months) in the groups who received symptomatic follow-up vs routine imaging, respectively (P = .01). Routine imaging was associated with receiving recurrence-focused treatment (adjusted odds ratio, 2.57; 95% CI, 1.22-5.41; P = .01) and prolonged OS (adjusted hazard ratio, 0.75; 95% CI, 0.56-.99; P = .04).

Conclusion and Relevance

In this international, prospective, cross-sectional study, routine follow-up imaging after pancreatic resection for PDAC was independently associated with receiving recurrence-focused treatment and prolonged OS.

Surveillance after surgery for pancreatic cancer: a global scoping review of guidelines and a nordic Survey of contemporary practice

OBJECTIVES

Most patients with pancreatic cancer who have undergone surgical resection eventually develop disease recurrence. ‍This study aimed to investigate whether there is evidence to support routine surveillance after pancreatic cancer surgery, with a secondary aim of analyzing the implementation of surveillance strategies in the Nordic countries.

MATERIALS AND METHODS

A scoping review was conducted to identify clinical practice guidelines globally and research studies relating to surveillance after pancreatic cancer resection. This was followed by a survey among 20 pancreatic units from four Nordic countries to assess their current practice of follow-up for operated patients.

RESULTS

Altogether 16 clinical practice guidelines and 17 research studies were included. The guidelines provided inconsistent recommendations regarding postoperative surveillance of pancreatic cancer. The clinical research data were mainly based on retrospective cohort studies with low level of evidence and lead-time bias was not addressed. Active surveillance was recommended in Sweden and Denmark, but not in Norway beyond the post-operative/adjuvant period. Finland had no national recommendations for surveillance. The Nordic survey revealed a wide variation in reported practice among the different units. About 75% (15 of 20 units) performed routine postoperative surveillance. Routine CA 19-9 testing was used by 80% and routine CT by 67% as part of surveillance. About 73% of centers continued follow-up until 5 years postoperatively.

CONCLUSION

Evidence for routine long-term (i.e. 5 years) surveillance after pancreatic cancer surgery remains limited. Most pancreatic units in the Nordic countries conduct regular follow-up, but protocols vary.

Organ-specific variations in tumor marker dynamics in postoperative pancreatic cancer recurrence: Trends in lung and liver recurrence highlighting biological heterogeneity

BACKGROUND/OBJECTIVES

Although tumor recurrence after surgical resection in pancreatic cancer (PC) is generally considered incurable, it is well-accepted that clinical presentations and outcomes vary according to the recurrent sites (e.g., liver vs. lung recurrence), suggesting a possible biological inhomogeneity of PC recurrence. Understanding the behavior of biological factors, specifically tumor markers (TMs), at different recurrence sites may contribute to individualized treatment strategies. Therefore, this study aimed to compare the dynamics of pre-recurrence TMs at liver and lung recurrence sites.

METHODS

Patients with isolated postoperative liver or lung recurrence as their first recurrence were enrolled. Starting from the recurrence date confirmed by imaging examinations, the values of TMs (carbohydrate antigen 19-9: CA19-9; carcinoembryonic antigen: CEA) were retrospectively evaluated 6 and 3 months before recurrence and at the time of recurrence.

RESULTS

Patients with liver recurrence displayed a significant increase in CA19-9 and CEA levels from as early as 6 months before recurrence. Contrastingly, patients with lung recurrence demonstrated a significant elevation of CA19-9 levels starting from 3 months before recurrence, with no increase in CEA levels, even at the time of recurrence. The relative change in CA19-9 and CEA levels during each period were significantly lower in patients with lung recurrence.

CONCLUSIONS

Both TMs exhibited organ-specific variations in patients with postoperative PC recurrence. This disparity may reflect the biological heterogeneity of PC between recurrence patterns, thereby highlighting the importance of conducting postoperative follow-up with consideration of this fact.

Identifying Optimal Candidates for Primary Tumor Resection Among Metastatic Pancreatic Cancer Patients: A Population-Based Predictive Model

BACKGROUND

There is a controversy about whether surgery should proceed among metastatic pancreatic cancer (mPC) patients. A survival benefit was observed in mPC patients who underwent primary tumor resection; however, determining which patients would benefit from surgery is complex. For this purpose, we created a model to identify mPC patients who may benefit from primary tumor excision.

METHODS

Patients with mPC were extracted from the Surveillance, Epidemiology, and End Results database, and separated into surgery and nonsurgery groups based on whether the primary tumor was resected. Propensity score matching (PSM) was applied to balance confounding factors between the two groups. A nomogram was developed using multivariable logistic regression to estimate surgical benefit. Our model is evaluated using multiple methods.

RESULTS

About 662 of 14,183 mPC patients had primary tumor surgery. Kaplan-Meier analyses showed that the surgery group had a better prognosis. After PSM, a survival benefit was still observed in the surgery group. Among the surgery cohort, 202 patients survived longer than 4 months (surgery-beneficial group). The nomogram discriminated better in training and validation sets under the receiver operating characteristic (ROC) curve (AUC), and calibration curves were consistent. Decision curve analysis (DCA) revealed that it was clinically valuable. This model is better at identifying candidates for primary tumor excision.

CONCLUSION

A helpful prediction model was developed and validated to identify ideal candidates who may benefit from primary tumor resection in mPC.

Clinical Features and Outcomes of Patients with Pancreaticobiliary Malignancies in Los Angeles County and Their Association with CA 19-9 Levels

Although CA 19-9 is a commonly used tumor marker in the management of PBMs, the literature describing outcomes in patients with PBMs who have undetectable or low (hereinafter “low”) CA 19-9 levels remains scarce. In this study, we sought to compare clinical features and outcomes in patients with PBMs and low CA 19-9 levels to those with normal and elevated CA 19-9 levels. Methods: We retrospectively collected data on patients with biopsy-confirmed PBMs and stratified patients into categories based on their CA 19-9 level at diagnosis. Survival curves were estimated for patients in each of the three aforementioned CA 19-9 groups using the Kaplan–Meier method and compared using a Cox proportional hazards regression model. Results: Of the 283 patients identified, 23 (8.1%) had low, 70 (24.7%) had normal, and 190 (67.1%) had elevated CA 19-9 levels. After controlling for sex, age, BMI, the presence of metastases at the time of diagnosis, and treatment with curative intent, the hazard ratio for death in the elevated CA 19-9 group compared to the low CA 19-9 group was 1.993 (95% CI 1.089–3.648; p = 0.025). Conclusion: The elevated CA 19-9 level compared to the low CA 19-9 level and the presence of metastases were associated with an increased hazard of death, while treatment with curative intent was associated with a decreased hazard of death.

Patterns of disease relapse and posttreatment follow-up of patients with resected pancreatic adenocarcinoma: A single-center analysis

BACKGROUND AND OBJECTIVES

To describe the patterns of disease relapse and follow-up of patients with resected pancreatic adenocarcinoma. Additionally, we looked at patients' characteristics at relapse and survival.

METHODS

We included patients with potentially resectable pancreatic adenocarcinoma diagnosed from 2008 to 2018 who were submitted to resection with clear macroscopic margins and started posttreatment surveillance.

RESULTS

The study population consists of 73 patients. The median interval between imaging studies was 3.2 months during the first 2 years of follow-up and 5.1 months thereafter. Forty-eight patients (65.8%) experienced disease relapse. The most frequent single site of relapse was locoregional (N = 21; 43.8%). At relapse, 31 patients (64.6%) were symptomatic and forty-two patients (87.6%) had Eastern Cooperative Oncology Group performance status 0 or 1. Most patients were able to undergo additional anticancer therapy (N = 41; 85.4%). Patients with asymptomatic relapses experienced longer median postrelapse survival (25.4 vs. 11.3 months; p = 0.015).

CONCLUSIONS

A follow-up protocol that included imaging studies every 3 months in the first 2 years and every 6 months thereafter is able to diagnose disease relapse when patients have adequate performance status and are still able to undergo additional anticancer treatment.

Prognostic Significance of Microvascular Invasion in Pancreatic Ductal Adenocarcinoma: A Systematic Review and Meta-Analysis

BACKGROUND The incidence, pathogenesis, and prognostic effect of microvascular invasion on pancreatic ductal adenocarcinoma (PDAC) remain controversial. This study aimed to summarize the incidence, pathogenesis, role in clinical management, recurrence, and prognostic significance of microvascular invasion in PDAC. MATERIAL AND METHODS A literature review and meta-analysis were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Systematic literature searches were conducted using PubMed and Google Scholar up to February 2021. RESULTS Seventeen studies were included in the meta-analysis. The incidence of microvascular invasion was 49.0% (95% confidence interval [CI], 43.8-54.5%) among PDAC patients who underwent surgery. The weighted multivariate Cox proportional hazards model hazard ratio for disease-free survival of 8 studies was 1.78 (95% CI 1.53-2.08, P<0.001), and there was no statistically significant difference between the subgroups (P=0.477). The hazard ratio for overall survival of 14 studies was 1.49 (95% CI 1.27-1.74, P<0.001), and there was no statistically significant difference between the subgroups (P=0.676). CONCLUSIONS Microvascular invasion occurred in nearly half of PDAC patients after surgery and was closely related to disease-free and overall survival. Understanding the role of microvascular invasion in PDAC will help provide more personalized and effective preoperative or postoperative strategies to achieve better survival outcomes.

Impact of surveillance among patients with resected pancreatic cancer following adjuvant chemotherapy

Background

Pancreatic adenocarcinoma carries a high risk of recurrence even after surgery and adjuvant chemotherapy. Current guidelines do not endorse routine surveillance imaging due to lack of evidence supporting a survival benefit. With current first-line palliative chemotherapy options, it is unclear whether surveillance allows for early detection of asymptomatic disease and therefore an improved opportunity to offer chemotherapy to fit patients. We sought to describe patterns of surveillance of resected pancreatic cancer at British Columbia (BC) Cancer and determine whether utilization of computerized tomography (CT) scans affected likelihood of receiving palliative chemotherapy at the time of recurrence.

Methods

A retrospective review was completed to identify patients treated at BC Cancer centres between 2010-2016 who had undergone curative intent resection and received at least one cycle of adjuvant chemotherapy. Information was collected on baseline characteristics, imaging scans done between adjuvant chemotherapy and recurrence, and receipt of palliative chemotherapy. Two cohorts were defined based on number of scans done between completion of adjuvant chemotherapy and recurrence: those with only 1 scan were defined as "symptomatic" recurrences and patients who had undergone more than 1 scan were considered "surveillance" recurrences.

Results

In total, 142 patients were included of which 115 (81%) patients developed recurrence. There were 22 patients (19%) in the "symptomatic" cohort and 93 patients (81%) in the "surveillance" cohort. Median time to recurrence 274 days (9.1 months) in the symptomatic cohort compared to 471 days (15.7 months) in the surveillance group. Patients who underwent surveillance scans were more likely to receive palliative chemotherapy at the time of recurrence, though statistical significance was not reached: 51% in surveillance group versus 27% in symptomatic group [odds ratio (OR) 2.11, 95% confidence interval (CI): 0.75-6.58, P=0.17].

Conclusions

Despite the absence of surveillance recommendations, the majority of patients underwent surveillance imaging. We demonstrated a non-significant increase in the likelihood of receiving palliative chemotherapy among patients who underwent surveillance scans. With more efficacious palliative chemotherapy options available, studies to determine whether receipt of chemotherapy in asymptomatic recurrences translates into improved survival and/or quality of life are warranted.

Tumor conspicuity significantly correlates with postoperative recurrence in patients with pancreatic cancer: a retrospective observational study

BACKGROUND

There has been scanty data regarding the clinical significance of tumor conspicuity in pancreatic cancer. In this study, we attempted to investigate the prognostic significance of pancreatic tumor conspicuity and determine prognostic factors for postoperative recurrence in patients with surgically resected pancreatic cancer.

METHODS

Between January 2011 and September 2019, 62 patients who underwent preoperative computed tomography (CT) for pancreatic cancer were retrospectively included. Two reviewers evaluated various clinical, imaging, and pathologic variables and reviewed all available medical records to determine patient outcomes after surgery. Tumor conspicuity was defined as the attenuation ratio between normal parenchyma and tumor lesions on dynamic-enhanced CT images and represented the conspicuity score. Recurrence-free survival and overall survival were investigated using Cox regression analysis.

RESULTS

Patient mean age was 65.9 (±11.6) years, and 56.5% were male. The median follow-up period was 11 months (range 2-138). Forty patients (64.5%) experienced postoperative recurrence, and the median time to recurrence was 6 months (range 1-101). Tumor conspicuity scores were positively correlated with both radiologic and pathologic tumor sizes (r = 0.252, 0.321, p < 0.01). Conspicuity score ≥ 2 (HR 3.8, 95% CI 1.73-8.47), elevated preoperative (HR 1.15, 95% CI; 1.02-1.28) and postoperative CA19-9 (HR 1.11, 95% CI 1.01-1.23), pathologic tumor size (HR 1.61, 95% CI 1.06-2.45), and lymphatic invasion (HR 2.76, 95% CI 1.22-6.21) were significant factors for recurrence-free survival in the multivariate analysis.

CONCLUSIONS

Over half of the patients with pancreatic cancer experienced postoperative recurrence (64.5%). Increased tumor conspicuity correlated with larger tumor size and postoperative recurrence.

Predictive value of CONUT score combined with serum CA199 levels in postoperative survival of patients with pancreatic ductal adenocarcinoma: a retrospective study

Background

The preoperative controlling nutritional status (CONUT) score and serum carbohydrate antigen 199 (CA199) levels are individually correlated with the prognosis of pancreatic ductal adenocarcinoma (PDAC). The objective of this study aimed to investigate the efficacy of CONUT score and CA199 (CONUT-CA199) combination in predicting the prognosis of PDAC patients undergoing radical surgery.

Methods

We retrospectively analyzed the preoperative CONUT scores and serum CA199 levels of 294 patients with PDAC who underwent radical resection at the Affiliated Hospital of Southwest Medical University between March 2012 and July 2019. Patients were divided into four groups on the basis of their preoperative CONUT scores and serum CA199 levels: CONUT^low/CA199^low (1), CONUT^low/CA199^high (2), CONUT^high/CA199^low (3) and CONUT^high/CA199^high (4). The prognostic effects were compared among the groups.

Results

CONUT^high was more frequent in patients with positive peripancreatic infiltration and Clavien–Dindo classification of ≥IIIa (P < 0.001). Kaplan–Meier analysis revealed obvious difference in overall survival (OS) and recurrence-free survival (RFS) among patients with PDAC having CONUT-CA199 scores of 1, 2, 3 and 4 (P < 0.001). Peripancreatic infiltration, lymph node metastasis, pTNM stage, CONUT score, serum CA199 levels and CONUT-CA199 classification were found to be the independent prognostic factors for OS and RFS in multivariate analyses. In time-dependent receiver operating characteristic (ROC) analyses, the area of the CONUT-CA199 score under the ROC curve (AUC) was higher than that of the preoperative CONUT score or serum CA199 levels for the prediction of OS and RFS.

Conclusion

CONUT-CA199 classification may be more effective in predicting the postoperative prognosis of PDAC patients.