Survival effect of tumor size and extrapancreatic extension in surgically resected pancreatic cancer: proposal for improved T classification

Pancreatic mucinous adenocarcinoma has different clinical characteristics and better prognosis compared to non-specific PDAC: A retrospective observational study

Background

Pancreatic mucinous adenocarcinoma (PMAC) is a rare malignant tumour, and there is limited understanding of its epidemiology and prognosis. Initially, PMAC was considered a metastatic manifestation of other cancers; however, instances of non-metastatic PMAC have been documented through monitoring, epidemiological studies, and data from the Surveillance, Epidemiology, and End Results (SEER) database. Therefore, it is crucial to investigate the epidemiological characteristics of PMAC and discern the prognostic differences between PMAC and the more prevalent pancreatic ductal adenocarcinoma (PDAC).

Methods

The study used data from the SEER database from 2000 to 2018 to identify patients diagnosed with PMAC or PDAC. To ensure comparable demographic characteristics between PDAC and PMAC, propensity score matching was employed. Kaplan-Meier analysis was used to analyse overall survival (OS) and cancer-specific survival (CSS). Univariate and multivariate Cox regression analyses were used to determine independent risk factors influencing OS and CSS. Additionally, the construction and validation of risk-scoring models for OS and CSS were achieved through the least absolute shrinkage and selection operator-Cox regression technique.

Results

The SEER database included 84,857 patients with PDAC and 3345 patients with PMAC. Notably, significant distinctions were observed in the distribution of tumour sites, diagnosis time, use of radiotherapy and chemotherapy, tumour size, grading, and staging between the two groups. The prognosis exhibited notable improvement among married individuals, those receiving acceptable chemotherapy, and those with focal PMAC (p < 0.05). Conversely, patients with elevated log odds of positive lymph node scores or higher pathological grades in the pancreatic tail exhibited a more unfavourable prognosis (p < 0.05). The risk-scoring models for OS or CSS based on prognostic factors indicated a significantly lower prognosis for high-risk patients compared to their low-risk counterparts (area under the curve OS: 0.81-0.82, CSS: 0.80-0.82).

Conclusion

PMAC exhibits distinct clinical characteristics compared to non-specific PDAC. Leveraging these features and pathological classifications allows for accurate prognostication of PMAC or PDAC.

Inadequacy of the eighth edition of the American Joint Committee on Cancer pancreatic cancer staging system for invasive carcinoma associated with premalignant lesions in the pancreas: an analysis using the National Cancer Database

BACKGROUND

Invasive carcinomas arising from premalignant lesions are currently staged by the same criteria as conventional pancreatic ductal adenocarcinoma.

METHODS

Clinicopathologic information and survival data were extracted through a thorough search of histology codes from National Cancer Database (2006-2016). A total of 723 patients with invasive intraductal papillary mucinous neoplasm and mucinous cystic neoplasm were analyzed.

RESULTS

The median age was 67 years, and 351 patients (48.5%) were male. There were 212 (29.3%), 232 (32.1%), 272 (37.6%), and 7 (1.0%) patients with T1, T2, T3, and T4 classification. Extrapancreatic extension (EPE) was present in 284 (39.3%). Age (HR = 1.504, 95% CI 1.196-1.891), R1 or R2 resection (HR = 1.585, 95% CI 1.175-2.140), and EPE (HR = 1.598, 95% CI 1.209-2.113) were independent prognostic factors for overall survival. Size criteria did not significantly affect survival. The median survival was 115.9 months for patients without EPE, compared to 34.2 months for those with EPE. EPE discriminated survival better than tumor size.

DISCUSSION

The T classification of the eighth edition AJCC staging system is not adequate for invasive carcinomas associated with premalignant lesions of the pancreas. They merit a separate, dedicated staging system that uses appropriate prognostic factors.

WHO histological classification and tumor size are predictors of the locally aggressive behavior of thymic epithelial tumors

OBJECTIVE

The aim of this study was to explore the influencing factors that affect the local invasive behavior of thymic epithelial tumors (TETs).

METHOD

We retrospectively analyzed 524 patients with TETs who underwent surgical treatment at our center from January 2010 to January 2022. Cox regression analysis was applied to identify predictors associated with the prognosis of TET. Logistic regression analysis was used to analyze the factors associated with the locally invasive behavior of TETs. Receiver operating characteristic analysis and the Youden index were applied to determine the predictive efficiency and cutoff value.

RESULTS

There were 275 males and 249 females with a median age of 56 years. Seventy-seven patients had locally invasive behavior. The prognosis of local invasive TETs was significantly worse that of noninvasive TETs (P < 0.001). WHO classification and tumor size were two hazard factors for tumor invasive behavior. The risk of local invasion increased by 2.196 (OR (95 % CI): 1.813-2.659) times for each grade in WHO classification with a change from type A to thymic carcinoma. The tumor size cutoff of 6 cm represented a distinct boundary in predicting the hazard of local invasion (AUC: 0.784, specificity: 0.711, sensitivity: 0.726).

CONCLUSION

WHO classification and tumor size are important factors in predicting the locally aggressive behavior of TETs. The invasion capability of TETs is constantly increasing with an escalation in WHO classification. Tumors greater than 6 cm in size have a higher risk for local invasion.

Rim Enhancement and Peripancreatic Fat Stranding in Preoperative MDCT as Predictors for Occult Metastasis in PDAC Patients

RATIONALE AND OBJECTIVE

To identify the radiological features and clinical biomarkers that could predict the occult metastasis (OM) of pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

This retrospective study included PDAC patients who were radiologically diagnosed resectable (R) or borderline resectable (BR) and underwent surgical exploration from January 2018 to December 2021. Depending on whether distant metastases were found during the exploration, patients were divided into OM and non-OM groups. Univariate and multivariable logistic regression analyses were performed to determine the radiological and clinical predictive factors for occult metastasis. Model performance was determined by discrimination and calibration.

RESULTS

A total of 502 patients (median age, 64 years; interquartile range, 57-70 years; 294 men) were enrolled, among which 68 (13.5%) patients were found with distant metastases, with 45 liver-only, 19 peritoneal-only, four patients had both liver and peritoneal metastases. Rim enhancement and peripancreatic fat stranding were more frequent in the OM group than in the non-OM group. Tumor size (p = 0.028), tumor resectability (p = 0.031), rim enhancement (p < 0.001), peripancreatic fat stranding (p < 0.001) and level of CA125 (p = 0.021) were independent predictors of occult metastasis according to the multivariable analyses, and the areas under the curve (AUCs) of these characteristics were 0.703, 0.594, 0.638, 0.655, 0.631, respectively. The combined model showed the highest AUC of 0.823.

CONCLUSIONS

Rim enhancement, peripancreatic fat stranding, tumor size, tumor resectability and level of CA125 are risk factors for OM of PDAC. The combined model of radiological and clinical features may help the preoperative prediction of OM in PDAC.

Reconsidering the absence of extrapancreatic extension in T staging for pancreatic adenocarcinoma in the AJCC (8th ed) Staging Manual using the National Cancer Database

PURPOSE

Although the concept of extrapancreatic extension (EPEx) was removed in the eighth edition of the American Joint Committee on Cancer pancreatic cancer staging system, several studies have supported the prognostic significance of EPEx. This study aimed to investigate the significance of EPEx in pancreatic ductal adenocarcinoma (PDAC) using the National Cancer Database (NCDB).

METHODS

Data of patients who underwent resection for PDAC between 2006 and 2016 were extracted and analyzed from the NCDB. Cases arising from premalignant lesions, those with metastases, and those treated with neoadjuvant therapy were excluded.

RESULTS

Among 37,634 patients, the median overall survival was 23 months and the 5-year survival rate was 22.7%. The EPEx prevalence was the lowest for T1 stage (63.2%) and increased with each T-stage (T2:83.4%, T3:85.8%). The overall survival was better in EPEx-negative patients than in EPEx-positive patients (median 33.7 vs. 21.5 months; p<0.001). When the T-stages were stratified by EPEx, EPEx-positive patients showed worse survival in all T-stages than EPEx-negative patients. Survival was comparable between T1 EPEx-positive and T2 or T3 EPEx-negative patients (p=0.088 and p=0.178, respectively). Furthermore, T2 and T3 EPEx-negative patients had similar survival to each other (p=0.877), and distinctly superior survival compared to T2 and T3 EPEx-positive patients (p<0.001).

CONCLUSIONS

EPEx was an important prognostic factor in the overall cohort and in differentiating between T stages. This study strongly suggests that staging systems should reinstate EPEx and apply it to all T-stages, especially in T1, where EPEx was absent in 36% of patients.

The Effects of Radiotherapy on Pancreatic Ductal Adenocarcinoma in Patients with Liver Metastases

BACKGROUND

While radiotherapy has been studied in the treatment of locally advanced pancreatic ductal adenocarcinoma (PDAC), few studies have analyzed the effects of radiotherapy on PDAC in patients with liver metastases. This study aimed to determine whether PDAC patients with liver metastases have improved survival after radiotherapy treatment.

METHODS

The data of 8535 patients who were diagnosed with PDAC with liver metastases between 2010 and 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Survival analysis and Cox proportional hazards regression analysis of cancer-specific mortality and overall survival were performed, and propensity score matching (PSM) was used to reduce selection bias.

RESULTS

After PSM, the median overall survival (mOS) and median cancer-specific survival (mCSS) in the radiotherapy group were longer than those in the nonradiotherapy group (OS: 6 months vs. 4 months; mCSS: 6 months vs. 5 months, both p < 0.05), respectively. The multivariate analysis showed that cancer-specific mortality rates were higher in the nonradiotherapy group than in the radiotherapy group (HR: 1.174, 95% CI: 1.035-1.333, p = 0.013). The Cox regression analysis according to subgroups showed that the survival benefits (OS and CSS) of radiotherapy were more significant in patients with tumor sizes greater than 4 cm (both p < 0.05).

CONCLUSIONS

PDAC patients with liver metastases, particularly those with tumor sizes greater than 4 cm, have improved cancer-specific survival (CSS) rates after receiving radiotherapy.

Extended lymphadenectomy benefits patients with borderline resectable pancreatic head cancer-a single-center retrospective study

Background

Whether standard lymphadenectomy or extended lymphadenectomy should be performed is still under debate during pancreaticoduodenectomy (PD). We aimed to compare their morbidity and mortality rates among patients with pancreatic head cancer (PHC).

Methods

In this retrospective study, a total of 322 patients were enrolled. According to the scope of intraoperative lymph node dissection, patients were divided into extended lymphadenectomy group (n=120) and standard lymphadenectomy group (n=202). Based on the resectability of the tumor, there were 198 cases of resectable PHC and 124 cases of borderline resectable PHC, respectively, in which further stratified analysis was carried out according to the extent of lymph node dissection.

Results

All patients completed the operation successfully, with a perioperative morbidity rate of 27.9% and mortality rate of 0.9%. As for the overall patients, patients in the extended lymphadenectomy group had higher neutrophil-to-lymphocyte ratio (NLR), longer operation time, more intraoperative blood loss, lymph node dissection and patients with borderline resectable pancreatic head cancer (BRPHC) (P<0.05). The 1-, 2- and 3-year overall survival rates of patients with extended lymphadenectomy and standard lymphadenectomy were 71.9%, 50.6%, 30.0% and 70.0%, 32.9%, 21.5%, respectively (P=0.068). With regards to patients with BRPHC, the number of lymph node dissection in the extended lymphadenectomy group was more (P<0.05), and the 1-, 2- and 3-year overall survival rates of patients with extended lymphadenectomy and standard lymphadenectomy were 60.7%, 43.3%, 27.4% and 43.2%, 17.7%, 17.7%, respectively (P=0.007).

Conclusions

Patients with BRPHC tended to have vast lymph node metastasis. Extended lymphadenectomy can improve their long-term survival.

Lymph Node Metastatic Patterns and Survival Predictors Based on Tumor Size in Pancreatic Ductal Adenocarcinoma

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies. Larger tumor size is widely acknowledged to be associated with increased lymph node (LN) metastatic potential. However, the quantitative relationships between tumor size and LN metastasis or survival remain unclear. This study aims to quantify the objective relationship between tumor size and the prevalence of LN metastases across a spectrum primary tumor size.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to identify 9958 patients with resected PDAC without distant metastasis. The prevalence of LN metastases, LN ratio (LNR), and N2/N1 ratio were assessed amongst different tumor sizes, and the relationships were displayed by matched curves.

RESULTS

In the enrolled cohort, age, tumor site, grade, American Joint Committee on Cancer (AJCC) 8th node staging, tumor size, chemotherapy, and radiotherapy were identified as significant independent predictors for overall survival (OS) and cancer-specific survival (CSS). For tumors within 1-40 mm in size, the prevalence of node-positive disease is closely modelled using a logarithmic formula [0.249 × ln (size) + 0.452] × 100%. The prevalence plateaued between 70% and 80% beyond 40 mm. The mean LNR increased in a stepwise manner as tumor size increased from 1-5 mm (LNR = 0.024) to 41-45 mm (LNR = 0.177); then, beyond 45 mm, it plateaued near 0.170. N2/N1 ratio gradually increased along with tumor size from 1-5 mm (N2/N1 = 0.286) to 41-45 mm (N2/N1 = 1.016), and when tumor size reached to 41-45 mm or more, the ratio stabilized around 1.000. In addition, significant survival prediction by AJCC N staging was observed when tumors ranging between 16 and 45 mm in size.

CONCLUSION

Regional LN involvement demonstrated a logarithmic growth with increasing tumor sizes in patients with resected PDAC . The probability of metastasis in each regional LN for resected PDAC with tumors greater than 40 mm in size was near 17.0% and their overall prevalence of LN metastasis was 70-80%. Among which, 50% of patients had an N2 stage. Such prediction may be a potential and promising tool for guiding lymphadenectomy in PDAC surgery.

CT-diagnosed extra-pancreatic extension of pancreatic ductal adenocarcinoma is a more reliable prognostic factor for survival than pathology-diagnosed extension

OBJECTIVES

To determine the correlation between CT-diagnosed extra-pancreatic extension of pancreatic ductal adenocarcinoma (PDAC), pathology-diagnosed extra-pancreatic extension, and survival in patients with PDAC.

METHODS

This retrospective study included 87 patients with resected PDAC. Two radiologists evaluated negative ((i) tumours surrounded by the pancreatic parenchyma and (ii) tumours contacting the pancreatic surface) or positive ((iii) tumours with peri-pancreatic strand appearances and/or with expansive growth) CT-diagnosed extra-pancreatic extension. Clinical, pathological, and CT imaging characteristics predicting disease-free survival (DFS) and overall survival (OS) were assessed using Cox proportional-hazards models. Diagnostic accuracy for pathology-diagnosed extra-pancreatic extension was also assessed.

RESULTS

CT-diagnosed extra-pancreatic extension (42/87 tumours, 48.3%; κ = 0.82) had a higher hazard ratio (HR) for the DFS (HR, 5.30; p < 0.01) and OS (HR, 5.31; p < 0.01) rates than pathology-diagnosed extension in univariable analyses. It was also an independent prognostic factor for the DFS (HR, 4.22; p < 0.01) and OS (HR, 4.38; p < 0.01) rates in multivariable analyses. Of 45 tumours without CT-diagnosed extra-pancreatic extension, pathology-diagnosed extra-pancreatic extension was observed in 2/8 (25.0%) and 32/37 (86.5%) tumours with CT categories (i) and (ii), respectively. However, the differences in the survival rates between patients with CT categories (i) and (ii) were insignificant, although those in the latter category had significantly better survival rates than those with CT-diagnosed extra-pancreatic extension (category (iii)).

CONCLUSIONS

CT-diagnosed extra-pancreatic extension was a better prognostic factor than pathology-diagnosed extension and considered an independent factor for the postoperative DFS and OS rates with reasonable frequency and high reproducibility, despite the low diagnostic accuracy for predicting pathology-diagnosed extra-pancreatic extension.

KEY POINTS

• A CT-diagnosed extra-pancreatic extension had a higher hazard ratio for both disease-free survival and overall survival compared to pathology-diagnosed extension in univariable survival analyses. • A CT-diagnosed extra-pancreatic extension was a significant independent predictor of both disease-free survival and overall survival, as observed in multivariable survival analyses. • Patients with tumours contacting with the pancreatic surface on CT images (CT category (ii)) showed similar survival rates to those whose tumours were surrounded by the pancreatic parenchyma (CT category (i)), although many tumours with CT category (ii) extended pathologically beyond the pancreas.

Pancreatic mucinous cystadenocarcinoma in a patient harbouring BRCA1 germline mutation effectively treated with olaparib: A case report

BACKGROUND

Pancreatic mucinous cystadenocarcinoma (MCAC) is a rare malignancy with a poor prognosis when it presents metastases at diagnosis. Due to its very low incidence, there are no clear recommendations for the treatment of advanced disease. Olaparib (an oral PARP inhibitor) has been approved for the maintenance treatment of patients with metastatic pancreatic adenocarcinoma harbouring germline BRCA1/2 mutations. Herein, we report the first case of a germline BRCA1 mutated unresectable MCAC which was effectively treated with olaparib.

CASE SUMMARY

A 41-year-old woman, without personal or family history of cancer, was diagnosed with ovarian and peritoneal metastases of MCAC. She underwent 12 cycles of gemcitabine plus oxaliplatin (GEMOX) obtaining a partial response and allowing radical surgery. One year later, local recurrence was documented, and other 12 cycles of GEMOX were administered obtaining a complete response. Seven years later, another local recurrence, not amenable to surgical resection, was diagnosed. She started FOLFIRINOX (oxaliplatin, irinotecan, leucovorin and fluorouracil), obtaining a partial response after 8 cycles. Given the excellent response to platinum-based chemotherapy, BRCA testing was performed, and a BRCA1 germline mutation was detected. She was switched to maintenance olaparib due to chemotherapy-related toxicities and achieved an almost complete metabolic response, with a reduction in the diameter of the lesion, after three months of therapy.

CONCLUSION

The current case suggests the beneficial effect of olaparib in BRCA mutated MCAC. However, further studies are required.

Nanoparticle-enabled blood tests for early detection of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is often detected too late to allow adequate treatments with the result that patients are condemned to sufferings and early death. Most efforts have been therefore aimed at identifying sensitive PDAC biomarkers. Although biomarkers have numerous advantages, sample size, intra-individual variability, existence of several biases and confounding variables and cost of investigation make their clinical application challenging. In recent years, nanotechnology is providing new options for early cancer detection. Among recent discoveries, the concept is emerging that the protein corona, i.e. the layer of plasma proteins that surrounds nanomaterials in bodily fluids, is personalized. In particular, the protein corona of cancer patients is significantly different from that of healthy individuals. Herein, we review this concept with a particular focus on clinical relevance. We also discuss the recently developed nanoparticle-enabled blood (NEB) tests that demonstrated to be promising in discriminating PDAC patients from healthy volunteers by global change of the nanoparticle-protein corona. We conclude with a critical discussion of research perspectives aimed at further improving the prediction ability of the test.

Proposed Modification of the 8th Edition of the AJCC Staging System for Pancreatic Ductal Adenocarcinoma

OBJECTIVE

The aim of this study was to improve the 8th edition (8th) of the American Joint Committee on Cancer (AJCC) staging system for pancreatic ductal adenocarcinoma (PDAC).

BACKGROUND

The new 8th AJCC staging system for PDAC was released in October, 2016, and will be applied in clinical practice in 2018.

METHODS

Two large cohorts were included in this analysis. One consisted of 45,856 PDAC patients in the Surveillance, Epidemiology, and End Results (SEER) database (2004-2014), and the other consisted of 3166 PDAC patients in the Fudan University Shanghai Cancer Center (FUSCC) database (2005-2015).

RESULTS

Using the 8th AJCC staging system, the median overall survival of the patients in the same stage varied widely among the different substages. We proposed a modified staging system based on median OS in which we maintained the T, N, and M definitions, but regrouped the substages. In the SEER cohort, the concordance index was higher for local disease with the modified staging system [0.637; 95% confidence interval (CI) 0.631-0.642] than with the 8th AJCC staging system (0.620, 95% CI 0.615-0.626). Similar findings were also observed in the FUSCC cohort. In addition, we verified the reliability of the modified staging system in an analysis of patients with different examined lymph node counts (≥15 or 1-14).

CONCLUSIONS

The modified 8th AJCC staging system for PDAC proposed in this study provides improvements and may be evaluated for potential adoption in the next edition.

Impact of Changes in the American Joint Committee on Cancer Staging Manual, Eighth Edition, for Pancreatic Ductal Adenocarcinoma

OBJECTIVE

Consistent and reliable tumor staging is a critical factor in determining treatment strategy, selection of patients for adjuvant therapy, and for therapeutic clinical trials. The aim of this study was to evaluate the number and extent of pancreatic ductal adenocarcinoma (PDAC) cases that would have a different pT, pN, and overall stages based on the new eighth edition American Joint Committee on Cancer staging system when compared with the seventh edition.

METHODS

Patients diagnosed with PDAC who underwent pancreaticoduodenectomy, total pancreatectomy, or distal pancreatectomy from 2007 to 2017 were retrospectively reviewed. A total of 340 cases were included.

RESULTS

According to the seventh edition, the vast majority of tumors in our cohort were staged as pT3 tumors (88.2%). Restaging these cases with the new size-based pT system resulted in a more equal distribution among the 3 pT categories, with higher percentage of pT2 cases (55%).

CONCLUSIONS

The newly adopted pT stage protocol for PDAC is clinically relevant, ensures a more equal distribution among different stages, and allows for a significant prognostic stratification. In contrast, the new pN classification (pN1 and pN2) based on the number of positive lymph nodes failed to show survival differences and remains controversial.

Validation of the American Joint Committee on Cancer 8th edition staging system for the pancreatic ductal adenocarcinoma

BACKGROUND & AIMS

The American Joint Commission on Cancer (AJCC) 8th edition staging system for pancreatic ductal adenocarcinoma (PDA) contains several significant changes. This study aimed to validate the AJCC 8th edition staging system of PDA.

METHODS

We analyzed patients with resected PDA between 2001 and 2017 using the Korean Pancreatic Cancer (K-PaC) registry. Overall survival (OS) was estimated using the Kaplan-Meier survival curves and compared via the log-rank test.

RESULTS

In total, 701 resected PDA patients were identified. During a median follow-up of 24.5 months, the median OS was 21.7 months. Meanwhile, the median OS of each stage according to the AJCC 8th edition was 73.5 months (stage IA), 41.9 months (stage IB), 24.2 months (stage IIA), 18.3 months (stage IIB), and 16.8 months (stage III). However, the new N-category (pN1 vs. pN2) did not subdivide prognosis, although the lymph node ratio (i.e., the ratio of the number of LN involved to the number of examined LN) did. Although pT3 and pN2 belong under stage III, pN2 has a significantly longer median OS than pT3 (16.9 months vs 11.2 months; p < 0.01).

CONCLUSION

The AJCC 8th edition staging system appropriately stratifies the prognosis of PDA patients. However, the cutoff of the N-category is not statistically valid, and the new stage III includes a heterogeneous category (pN2 and pT4). Therefore, we propose that stage III be divided into stage IIIA (Tany N2 M0) and stage IIIB (T4 Nany M0).

Multinational validation of the American Joint Committee on Cancer 8th edition pancreatic cancer staging system in a pancreas head cancer cohort

BACKGROUND

The aim of the present study was to compare the 7th and 8th editions of the American Joint Committee on Cancer (AJCC) staging system for pancreas head cancer and to validate the 8th edition using three multinational tertiary center data.

METHODS

Data of 2,864 patients with pancreas head cancer were collected from Korea (571), Japan (824), and the USA (1,469). Survival analysis was performed to compare the 7th and 8th editions. Validation was performed by log-rank tests and test for trend repeated 1,000 times with random sets.

RESULTS

In the 7th edition, 4.1%, 3.1%, 18.6%, 67.5%, 3.6%, and 3.1% were stage IA, IB, IIA, IIB, III, and IV. In the 8th edition, 8.8%, 13.9%, 3.1%, 38.2%, 32.9%, and 3.1% were stage IA, IB, IIA, IIB, III, and IV, respectively. The change in T category downstaged 459 patients from IIA to the new IA and IB. The new N2 category upstaged 856 patients from the former IIB to III. The 7th edition reversely stratified IA and IB. The 8th edition corrected this mis-stratification of the 7th edition, but lacked discriminatory power between IB and IIA (P = 0.271). Validation using the log-rank showed that the 8th edition provided better discrimination in 6.387 test sets among 10 tests. The test for trend validated the 8th edition to stratify stages in correct order more often (7.815/10).

CONCLUSION

The 8th edition provides more even distribution with more powerful discrimination compared to the 7th edition.

Correlation of tumor size and survival in pancreatic cancer

Background

Neoadjuvant therapy (NT) for resectable pancreatic adenocarcinoma (PAC) continues to be debated. We sought to establish the relationship between pancreatic tumor size, neoadjuvant chemotherapy (NCT), neoadjuvant chemoradiation (NCRT), and definitive surgery (DS) on survival.

Methods

Utilizing the National Cancer Database we identified patients with PAC who underwent NT and DS. Patient characteristics and survival were compared with Mann-Whitney U, Pearson's Chi-square, and the Kaplan-Meier method. Multivariable analysis (MVA) was developed to identify predictors of survival. All tests were two-sided and α <0.05 was significant.

Results

We identified 11,707 patients: 9,722 patients with tumors >2 cm and 1,985 with tumors ≤2 cm. There were 523 patients treated with NCT, 559 treated with NCRT, and 10,625 DS. Patients with tumors >2 cm were more likely to have higher T-stage, P<0.001, positive lymph nodes, P<0.001, poor histologic grade, P<0.001, and R1 resections, P<0.001. The median survival for patients with tumors ≤2 cm was 30.6 months compared to 20.5 months for those whose tumors were >2 cm, P<0.001. In the >2 cm groups the median survival for NCT, NCRT, and DS was 22.9, 25.8 and 21.3 months, P=0.01. MVA revealed that age, Charlson/Deyo score, N-stage, grade, tumor size >2 cm, R0 resection, and NT were predictors of survival. Ninety-day mortality was worse in both the NCT and NCRT compared to DS, P<0.001.

Conclusions

The size of pancreatic cancer correlates to pathologic stage and overall survival. Tumors >2 and <2 cm benefited from a NT. However, the 90-operative mortality was significantly worse in those patients receiving NT.

Dilemmas for the pathologist in the oncologic assessment of pancreatoduodenectomy specimens : An overview of different grossing approaches and the relevance of the histopathological characteristics in the oncologic assessment of pancreatoduodenectomy specimens

A pancreatoduodenectomy specimen is complex, and there is much debate on how it is best approached by the pathologist. In this review, we provide an overview of topics relevant for current clinical practice in terms of gross dissection, and macro- and microscopic assessment of the pancreatoduodenectomy specimen with a suspicion of suspected pancreatic cancer. Tumor origin, tumor size, degree of differentiation, lymph node status, and resection margin status are universally accepted as prognostic for survival. However, different guidelines diverge on important issues, such as the diagnostic criteria for evaluating the completeness of resection. The macroscopic assessment of the site of origin in periampullary tumors and cystic lesions is influenced by the grossing method. Bi-sectioning of the head of the pancreas may offer an advantage in this respect, as this method allows for optimal visualization of the periampullary area. However, a head-to-head comparison of the assessment of clinically relevant parameters, using axial slicing versus bi-sectioning, is not available yet and the gold standard to compare both techniques prospectively might be subject of debate. Further studies are required to validate the various dissection protocols used for pancreatoduodenectomy specimens and their specific value in the assessment of pathological parameters relevant for prognosis.

Assessment of the American Joint Commission on Cancer 8th Edition Staging System for Patients with Pancreatic Neuroendocrine Tumors: A Surveillance, Epidemiology, and End Results analysis

Although several staging systems have been proposed for pancreatic neuroendocrine tumors (pNETs), the optimal staging system remains unclear. Here, we aimed to assess the application of the newly revised 8th edition American Joint Committee on Cancer (AJCC) staging system for exocrine pancreatic carcinoma (EPC) to pNETs, in comparison with that of other staging systems. We identified pNETs patients from the Surveillance, Epidemiology, and End Results (SEER) database (2004–2014). Overall survival was analyzed using Kaplan–Meier curves with the log‐rank test. The predictive accuracy of each staging system was assessed by the concordance index (c‐index). Cox proportional hazards regression was conducted to calculate the impact of different stages. In total, 2424 patients with pNETs, including 2350 who underwent resection, were identified using SEER data. Patients with different stages were evenly stratified based on the 8th edition AJCC staging system for EPC. Kaplan–Meier curves were well separated in all patients and patients with resection using the 8th edition AJCC staging system for EPC. Moreover, the hazard ratio increased with worsening disease stage. The c‐index of the 8th edition AJCC staging system for EPC was similar to that of the other systems. For pNETs patients, the 8th edition AJCC staging system for EPC exhibits good prognostic discrimination among different stages in both all patients and those with resection.

Thymoma size significantly affects the survival, metastasis and effectiveness of adjuvant therapies: a population based study

Background

Thymoma, though a rare tumor disease, is the most common tumor of the anterior mediastinum. However, tumor size, as a critical factor, has been underestimated.

Results

Age, advanced tumor stage, and preoperative radiotherapy were poor prognostic factors of overall survival (OS) and disease specific survival (DSS) (P < 0.05 for all). Besides, tumor size was significantly related to survival. The larger tumor size indicated the less OS and DSS (P < 0.001 for all). Multivariate analysis revealed elder age, advanced stage, larger size were independent adverse predictors for survival (P < 0.05 for all). Logistic analysis revealed larger tumor size had greater rate of metastasis (P < 0.001). In the group with tumors smaller than 90mm, chemotherapy was a negative predictive factor of DSS (P < 0.05 for all), and it significantly decreased OS especially with tumor sizes between 50 and 90 mm (P < 0.001).

Materials and Methods

A total of 1,272 thymoma patients were enrolled from the Surveillance, Epidemiology, and End Results (SEER) database. Survival based on thymoma size and other characteristics of tumors were analyzed by univariate and multivariate analysis. Correlation between thymoma size and thymoma metastatic status was contributed by logistic regression analysis. The efficiency of adjuvant therapy was analysis by stratification analysis.

Conclusions

Thymoma size could predict postoperative survival and guide chemotherapeutic regimens of patients. Larger tumor size indicated worse survival and higher metastatic rate. If thymoma is smaller than 90mm, traditional chemotherapy should be prohibited. While chemotherapy could be performed moderately when thymoma larger than 90 mm.

Prognostic Significance of New AJCC Tumor Stage in Patients With Pancreatic Ductal Adenocarcinoma Treated With Neoadjuvant Therapy

The American Joint Committee for Cancer has adopted a size-based T stage system (eighth edition) for pancreatic ductal adenocarcinoma (PDAC), defined as follows: pT1≤2 cm (pT1a≤0.5 cm, pT1b>0.5 and<1 cm, and pT1c 1-2 cm); pT2>2 and ≤4 cm; and pT3> 4 cm. However, the prognostic value of this new T staging system has not been validated in patients who underwent pancreaticoduodenectomy (PD) after neoadjuvant therapy. In this study, we analyzed 398 PDAC patients who underwent neoadjuvant therapy and PD at our institution from 1999 to 2012. The results were correlated with clinicopathologic parameters and survival. The new T stage correlated with lymph nodes metastasis (P<0.001), tumor response grade (P<0.001), disease-free survival (DFS, P<0.001) and overall survival (OS, P<0.001). None of the patients with ypT0 had recurrence or died of disease. Among the patients with ypT1 disease, patients with ypT1a and ypT1b had better DFS (P=0.046) and OS (P=0.03) than those with ypT1c. However, there was no significant difference in either DFS or OS between ypT1c and ypT2 or between ypT2 and ypT3 groups (P>0.05). In multivariate analysis, new ypT3 stage was associated with shorter OS (P=0.04), but not DFS (P=0.16). Our results show that the new ypT stage better stratify survival than the ypT stage in American Joint Committee for Cancer seventh edition for PDAC patients who received PD after neoadjuvant therapy, and that tumor size cutoff of 1.0 cm work better for ypT2 than the proposed tumor size cutoff of 2.0 cm in this group of patients.

Refining the American Joint Committee on Cancer Staging Scheme For Resectable Pancreatic Ductal Adenocarcinoma Using Recursive Partitioning Analysis

Purpose: It remains unclear whether the recently proposed 8^th edition of the American Joint Committee on Cancer (AJCC) staging scheme for pancreatic ductal adenocarcinoma (PDAC) outperforms the 7^th edition. We assessed the prognostic performance of both these schemes and performed recursive partitioning analysis (RPA) to objectively regroup the 7^th and 8^th AJCC stages and derive a refined staging scheme. Methods: We examined 8542 patients with resectable PDAC from the 2004-2012 Surveillance, Epidemiology, and End Results database. The dataset was randomly divided into training and validation sets. The performance of different staging schemes was evaluated in terms of prognostic stratification, discriminatory ability, and prognostic homogeneity. Results: The 7^th and 8^th T classifications showed prominent heterogeneity within each subcategory when assessed against each other in the case of node-negative disease. RPA divided resectable PDAC into RPA-IA (8^th T1N0 limited to the pancreas), RPA-IB (8^th T1N0 extending beyond the pancreas, or 8^th T2-T3N0 limited to the pancreas), RPA-IIA (8^th T2N0 extending beyond the pancreas, or 8^th T1N1-N2), RPA-IIB (8^th T3N0 extending beyond the pancreas, or 8^th T2-T3N1), and RPA-III stages (8^th T2-T3N2) (median survival in the training set: 47, 28, 20, 16, and 14 months, respectively; P < 0.001). The RPA staging scheme outperformed the 7^th and 8^th AJCC classifications in terms of prognostic stratification, discriminatory ability, and prognostic homogeneity for both the training and validation sets. Conclusions: The proposed RPA staging is a superior risk-stratified tool to the 7^th and 8^th AJCC classifications and is not substantially more complex.

pT but not pN stage of the 8th TNM classification significantly improves prognostication in pancreatic ductal adenocarcinoma

The UICC TNM (tumour-node-metastasis) staging system for pancreatic ductal adenocarcinoma (PDAC) has been a matter of debate over decades because survival prediction based on T stages was weak and unreliable. To improve staging, the recently published 8th TNM edition (2016) introduced a conceptually completely changed strictly size-based T staging system and a refined N stage for PDAC. To investigate the clinical value of the novel TNM classification, we compared the prognostic impact of pT and pN stage between the 7th and 8th edition in two well-characterised independent German PDAC cohorts from different decades, including a total number of 523 patients. Former UICC T staging (7th edition 2009) resulted in a clustering of pT3 cases (72% and 85% of cases per cohort, respectively) and failed to show significant prognostic differences between the four stages in one of the investigated cohorts (p = 0.074). Application of the novel size-based T stage system resulted in a more equal distribution of cases between the four T categories with a predominance of pT2 tumours (65% and 60% of cases). The novel pT staging algorithm showed greatly improved discriminative power with highly significant overall differences between the four pT stages in both investigated cohorts in univariate and multivariate analyses (p < 0.001, each). In contrast, no prognostic differences were observed between the recently introduced pN1 and pN2 categories in both cohorts (p = 0.970 and p = 0.061). pT stage of resected PDAC patients according to the novel UICC staging protocol (8th edition) significantly improves patient stratification, whereas introduction of an extended N stage protocol does not demonstrate high clinical relevance in our cohorts.

Laparoscopic distal pancreatectomy for pancreatic ductal adenocarcinoma: Long-term oncologic outcomes after standard resection

BACKGROUND

Surgical resection is the only curative option in patients with pancreatic ductal adenocarcinoma. Little is known about the oncologic outcomes of laparoscopic distal pancreatectomy. This bi-institutional study aimed to examine the long-term oncologic results of standard laparoscopic distal pancreatectomy in a large cohort of patients with pancreatic ductal adenocarcinoma.

METHODS

From January 2002 to March 2016, 207 patients underwent standard laparoscopic distal pancreatectomy for pancreatic ductal adenocarcinoma at Oslo University Hospital-Rikshospitalet (Oslo, Norway) and Asan Medical Centre (Seoul, Republic of Korea). After the exclusion criteria were applied (distant metastases at operation, conversion to an open operation, loss to follow-up), 186 patients were eligible for the analysis. Perioperative and oncologic variables were analyzed for association with recurrence and survival.

RESULTS

Median overall and recurrence-free survivals were 32 and 16 months, while 5-year overall and recurrence-free survival rates were estimated to be 38.2% and 35.9%, respectively. Ninety-six (52%) patients developed recurrence: 56 (30%) extrapancreatic, 27 (15%) locoregional, and 13 (7%) combined locoregional and extrapancreatic. Thirty-seven (19.9%) patients had early recurrence (within 6 months of operation). In the multivariable analysis, tumor size >3 cm and no adjuvant chemotherapy were associated with early recurrence (P = .017 and P = .015, respectively). The Cox regression model showed that tumor size >3 cm and lymphovascular invasion were independent predictors of decreased recurrence-free and overall survival.

CONCLUSION

Standard laparoscopic distal pancreatectomy is associated with satisfactory long-term oncologic outcomes in patients with pancreatic ductal adenocarcinoma. Several risk factors, such as tumor size >3 cm, no adjuvant chemotherapy, and lymphovascular invasion, are linked to poor prognosis after standard laparoscopic distal pancreatectomy.

Is Pancreatic Head Cancer with Portal Venous Involvement Really Borderline Resectable? Appraisal of an Upfront Surgery Series

BACKGROUND

It remains controversial whether the degree of venous involvement really is associated with borderline resectability of pancreatic cancer.

METHODS

A single-center retrospective review of patients who underwent upfront pancreaticoduodenectomy for T3 pancreatic cancer without arterial involvement was performed. The patients were classified as having resectable tumors without venous contact (R group), resectable tumors with venous contact of 180° or less (R-PV group), and borderline resectable tumors with venous contact greater than 180° (BR-PV group). The unresectable group included those who had unresected tumors with paraaortic lymph node metastasis, positive peritoneal lavage cytology, or locally advanced disease. The overall survival and prognostic factors were analyzed.

RESULTS

The study enrolled 299 resected patients, including 141 patients in the R group, 119 patients in the R-PV group, and 39 patients in the BR-PV group. The overall survival did not differ significantly between the R-PV group and the BR-PV group (median survival, 20.7 vs 18.6 months; P = 0.807). Among the 158 patients who had tumors with venous contact, only a tumor size of 50 mm or larger (P = 0.041) was an independent prognostic factor in a multivariate analysis, and the overall survival for the patients with both venous contact and tumor size 50 mm or larger was comparable with that for the unresectable group (P = 0.547).

CONCLUSIONS

The degree of venous involvement may not be associated with the resectability of pancreatic head cancer, whereas tumors 50 mm in size or larger that develop venous invasion may be categorized as borderline resectable pancreatic cancers.

Pancreatic mucinous cystadenocarcinoma: Epidemiology and outcomes

BACKGROUND

Pancreatic mucinous cystadenocarcinoma is a rare malignancy. Our aim was to investigate the demographic, pathological characteristics, treatment modalities and survival of patients with mucinous cystadenocarcinoma via the National Cancer Institute's Surveillance Epidemiology and End Results (SEER) database analysis.

MATERIALS AND METHODS

This was a retrospective study of SEER database's records on patients with mucinous cystadenocarcinoma diagnosed from 1988 to 2012. Primary outcome measures were clinico-pathological characteristics, observed and disease-specific survival.

RESULTS

A total of 507 patients were identified. Median age at diagnosis was 67 years and most patients were female (68.4%). The tumors were mainly low grade (82.9%, grade I-II) and frequently localized (42.8%) in the body/tail of the pancreas (45.6%). According to Kaplan-Meier curves observed survival was 111 months (95%CI: 82.5, 139.5) vs 14 months (95% CI: 10.9, 17.1) vs 4 months (95%CI: 2.9, 5.1) for patients with localized, regional and distant disease, respectively. One-year disease-specific survival for patients with localized disease was 90.1%, vs. 56.7% for those with regional and 18.7% with distant tumor spread.

CONCLUSIONS

Mucinous cystadenocarcinomas tend to be low grade tumors, localized to the pancreatic body/tail. Surgery as the primary therapeutic intervention and tumor stage are independent predictors of disease-specific survival.

Pancreatic Ductal Adenocarcinoma is Spread to the Peripancreatic Soft Tissue in the Majority of Resected Cases, Rendering the AJCC T-Stage Protocol (7th Edition) Inapplicable and Insignificant: A Size-Based Staging System (pT1: ≤2, pT2: >2-≤4, pT3: >4 cm) is More Valid and Clinically Relevant

BACKGROUND

Most studies have failed to identify any prognostic value of the current T-stage protocol for pancreatic ductal adenocarcinoma (PDAC) by the American Joint Committee on Cancer and the Union for International Cancer Control unless some grouping was performed.

METHODS

To document the parameters included in this T-stage protocol, 223 consecutive pancreatoduodenectomy specimens with PDAC were processed by a uniform grossing protocol.

RESULTS

Peripancreatic soft tissue (PST) involvement, the main pT3 parameter, was found to be inapplicable and irreproducible due to lack of a true capsule in the pancreas and variability in the amount and distribution of adipose tissue. Furthermore, 91 % of the cases showed carcinoma in the adipose tissue, presumably representing the PST, and thus were classified as pT3. An additional 4.5 % were qualified as pT3 due to extension into adjacent sites. The T-stage defined as such was not found to have any correlation with survival (p = 0.4). A revised T-stage protocol was devised that defined pT1 as 2 cm or smaller, pT2 as >2-4 cm, and pT3 as larger than 4 cm. This revised protocol was tested in 757 consecutive PDACs. The median and 3-year survival rates of this size-based protocol were 26, 18, 13 months, and 40 %, 26 %, 20 %, respectively (p < 0.0001). The association between higher T-stage and shorter survival persisted in N0 cases and in multivariate modeling. Analysis of the Surveillance, Epidemiology, and End Results database also confirmed the survival differences (p < 0.0001).

CONCLUSIONS

This study showed that resected PDACs are already spread to various surfaces of the pancreas, leaving only about 4 % of PDACs to truly qualify as pT1/T2, and that the current T-stage protocol does not have any prognostic correlation. In contrast, as shown previously in many studies, size is an important prognosticator, and a size-based T-stage protocol is more applicable and has prognostic value in PDAC.

Impact of delay between imaging and treatment in patients with potentially curable pancreatic cancer

Background

Locoregional pancreatic ductal adenocarcinoma (PDAC) may progress rapidly and/or disseminate despite having an early stage at diagnostic imaging. A prolonged interval from imaging to resection might represent a risk factor for encountering tumour progression at laparotomy. The aim of this study was to determine the therapeutic window for timely surgical intervention.

Methods

This observational cohort study included patients with histologically confirmed PDAC scheduled for resection with curative intent from 2008 to 2014. The impact of imaging-to-resection/reassessment (IR) interval, vascular involvement and tumour size on local tumour progression or presence of metastases at reimaging or laparotomy was evaluated using univariable and multivariable regression. Risk estimates were approximated using hazard ratios (HRs).

Results

Median IR interval was 42 days. Of 349 patients scheduled for resection, 82 had unresectable disease (resectability rate 76·5 per cent). The unresectability rate was zero when the IR interval was 22 days or shorter, and was lower for an IR interval of 32 days or less compared with longer waiting times (13 versus 26·2 per cent; HR 0·42, P = 0·021). It was also lower for tumours smaller than 30 mm than for larger tumours (13·9 versus 32·5 per cent; HR 0·34, P &lt; 0·001). Tumours with no or minor vascular involvement showed decreased rates of unresectable disease (20·6 per cent versus 38 per cent when there was major or combined vascular involvement; HR 0·43, P = 0·007). However, this failed to reach statistical significance on multivariable analysis (P = 0·411), in contrast to IR interval (P = 0·028) and tumour size (P &lt; 0·001).

Conclusion

Operation within 32 days of diagnostic imaging reduced the risk of tumour progression to unresectable disease by half compared with a longer waiting time. The results of this study highlight the importance of efficient clinical PDAC management.

Hereditary Pancreatic Cancer Syndromes

Despite decades of scientific and clinical research, pancreatic ductal adenocarcinoma (PDAC) remains a lethal malignancy. The clinical and pathologic features of PDAC, specifically the known environmental and genetic risk factors, are reviewed here with special emphasis on the hereditary pancreatic cancer (HPC) syndromes. For these latter conditions, strategies are described for their identification, for primary and secondary prevention in unaffected carriers, and for disease management in affected carriers. Nascent steps have been made toward personalized medicine based on the rational use of screening, tumor subtyping, and targeted therapies; these have been guided by growing knowledge of HPC syndromes in PDAC.