AJCC 7th edition staging classification is more applicable than AJCC 8th edition staging classification for invasive IPMN

Prognostic performance of microscopic size measurements in small invasive carcinomas arising in intraductal papillary mucinous neoplasms of the pancreas

AIMS

Small invasive carcinomas arising in intraductal papillary mucinous neoplasms (IPMNs) of the pancreas can present as multiple, small foci. In such cases, there is no clear optimal measurement method for determining the invasive size for tumour staging and prognostication.

METHODS

In all, 117 small invasive IPMNs (size of largest invasive component ≤2 cm) from seven institutions (2000-2016) were reviewed, and all individual foci of invasive carcinoma were measured. T stages (AJCC 8th edition) based on the largest single focus size (LS), average size of all foci (AS), and total sum of all foci (TS) were examined in association with clinicopathologic parameters and patient outcomes.

RESULTS

The cohort comprised IPMNs with invasive tubular-type (n = 82, 70%) and colloid-type (n = 35, 30%) carcinomas. The mean LS, AS, and TS were 0.86, 0.71, and 1.32 cm, respectively. Based on the LS, AS, and TS, respectively, 48, 65, and 39 cases were classified as pT1a; 22, 18, and 11 cases as pT1b; and 47, 34, and 50 cases as pT1c. Higher pT stages based on all measurements were significantly associated with small vessel, large vessel, and perineural invasion (P < 0.05). LS-, AS-, and TS-based pT stages were not significantly associated with recurrence-free survival (RFS) or overall survival (OS) by univariate or multivariate analyses. However, among tubular-type carcinomas, higher LS-, AS-, and TS-based pT stages trended with lower RFS (based on 1-, 3-, and 5-year survival rates). All microscopic measurement methods were most predictive of RFS and OS using a 1.5-cm cutoff, with LS significantly associated with both RFS and OS by univariate and multivariate analysis.

CONCLUSIONS

For invasive tubular-type carcinomas arising in IPMN, microscopic size-based AJCC pT stages were not significant predictors of patient outcomes. However, for LS, a size threshold of 1.5 cm was optimal for stratifying both RFS and OS. The AJCC 8th ed. may not be applicable for stratifying small invasive IPMNs with colloid-type histology that generally portend a more favourable prognosis.

[Malignant Pancreatic Intraductal Papillary Mucinous Neoplasm with Splenic Invasion: A Case Report]

Intraductal papillary mucinous neoplasm (IPMN) is a tumor originating from pancreatic ductal epithelial cells, leading to excessive mucus secretion and dilation of the pancreatic duct. Pathologically, IPMNs display a wide range of dysplasia, ranging from low-grade dysplasia to invasive carcinoma. Invasion into surrounding organs, especially into spleen, is rare and has not been reported in Korean journals. Worldwide, only two cases have been reported. Here, the authors report their experience with a rare case of IPMN in the pancreas that invaded the spleen.

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.

Systematic review of challenging issues in pathology of intraductal papillary mucinous neoplasms

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) are a cystic precursor to pancreatic cancer. IPMNs deemed clinically to be at high-risk for malignant progression are frequently treated with surgical resection, and pathological examination of the pancreatectomy specimen is a key component of the clinical care of IPMN patients.

METHODS

Systematic literature reviews were conducted around eight topics of clinical relevance in the examination of pathological specimens in patients undergoing resection of IPMN.

RESULTS

This review provides updated perspectives on morphological subtyping of IPMNs, classification of intraductal oncocytic papillary neoplasms, nomenclature for high-grade dysplasia, assessment of T stage, distinction of carcinoma associated or concomitant with IPMN, role of molecular assessment of IPMN tissue, role of intraoperative assessment by frozen section, and preoperative evaluation of cyst fluid cytology.

CONCLUSIONS

This analysis provides the foundation for data-driven approaches to several challenging issues in the pathology of IPMNs.

The prognostic significance of duodenal wall invasion in pancreatic adenocarcinoma

OBJECTIVE

The most recent edition of the American Joint Committee on Cancer Staging Manual (AJCC, 8th edition) relies only on tumor size for staging resectable pancreatic adenocarcinoma, and the presence of duodenal wall invasion (DWI) no longer has an impact on staging. However, very few studies have evaluated its significance. In this study, we aim to evaluate the prognostic significance of DWI in pancreatic adenocarcinoma.

METHODS

We reviewed 97 consecutive internal cases of resected pancreatic head ductal adenocarcinoma, and clinicopathologic parameters were recorded. All cases were staged according to the 8th edition of AJCC, and the patients were divided into two groups based on the presence or absence of DWI.

RESULTS

Out of our 97 cases, 53 patients had DWI (55%). In univariate analysis, DWI was significantly associated with lymphovascular invasion and lymph node metastasis (AJCC 8th edition pN stage). In univariate analysis of overall survival, age > 60, absence of DWI, and African American race were associated with worse overall survival. In multivariate analysis, age > 60, absence of DWI, and African American race were associated with worse progression-free survival and overall survival.

CONCLUSION

Although DWI is associated with lymph node metastasis, it is not associated with inferior disease-free/overall survival.

IPMN-associated pancreatic cancer: Survival, prognostic staging and impact of adjuvant chemotherapy

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN)-associated carcinoma is a subtype of pancreatic cancer for which prognostic factors, the validity of the AJCC/UICC staging system and the role of adjuvant chemotherapy remain unknown.

MATERIALS AND METHODS

Clinicopathological, treatment and follow-up data of patients with IPMN-associated carcinoma undergoing resection between 2002 and 2018 were analyzed. Uni- and multivariable survival analyses were performed to identify prognostic factors.

RESULTS

Of 424 patients undergoing resection for IPMN-associated carcinoma, 77% patients had pancreatic ductal adenocarcinoma (IPMN-PDAC) and 23% had colloid carcinoma (IPMN-CC). Compared to IPMN-CC, IPMN-PDAC was diagnosed at more advanced tumor stages, more frequently involved lymph nodes, more frequently showed poor differentiation and were associated with higher rates of R1 resections. Resected IPMN-PDAC showed markedly shorter median overall survival than IPMN-CC (26.7 months vs. 91.3 months). The current AJCC/UICC staging system was validated for IPMN-associated carcinoma and for both of its subtypes. In multivariable analysis age ≥70 years, diabetes mellitus, high levels of Ca 19-9, IPMN-PDAC subtype, G3 tumors and higher AJCC/UICC stage were independently associated with shorter survival. Adjuvant therapy was not associated with improved survival in IPMN-associated carcinoma. Overall survival was comparable in patients receiving vs. not receiving adjuvant therapy.

CONCLUSIONS

Survival after resection of IPMN-associated carcinoma depends on tumor stage, on histologic tumor subtype, grading, and Ca 19-9 levels. The current 8th edition of the AJCC/UICC staging system is applicable for IPMN-associated carcinoma and for both of its subtypes IPMN-PDAC and IPMN-CC. The role of adjuvant therapy for IPMN-associated carcinoma remains unclear.

Prognostic Analysis of Different Metastatic Patterns in Invasive Intraductal Papillary Mucinous Neoplasm: A Surveillance, Epidemiology, and End Results Database Analysis

OBJECTIVE

To evaluate the impacts of different metastatic patterns on the prognosis of patients with invasive intraductal papillary mucinous neoplasm (IPMN).

MATERIALS AND METHODS

All patients who were diagnosed with invasive IPMN in the Surveillance, Epidemiology, and End Results SEER database (2010-2015) were included in this study. They were grouped according to different metastatic patterns. Kaplan-Meier analysis and log-rank test were used for the comparison of their survival rates. The hazard ratio (HR) with 95% confidence interval (CI) was analyzed using the Cox proportional-hazards model.

RESULTS

A total of 2264 cases were included in this study. The most common metastatic site was the liver. The patients with the nonorgan metastasis demonstrated the best survival outcomes, while those with multiple metastases showed the worst survival outcomes. As compared to the patients with isolated liver metastasis, those with isolated lung and other organ metastases showed better overall survival rates and tumor-specific survival rates. The patients with liver, lung, multiple, and other organ metastases or of age >60 years were the independent predictors of poor prognosis.

CONCLUSIONS

The patients with isolated lung and other organ metastases demonstrated better survival outcomes as compared to those with isolated liver metastasis. The patients with nonorgan metastasis demonstrated the best survival outcomes, while those with multiple metastases showed the worst survival outcomes. Further studies are needed to determine a highly selected subset of patients, who might benefit from surgery or chemotherapy.

The 8th Edition American Joint Committee on Cancer Staging for Hepato-pancreato-biliary Cancer: A Review and Update

CONTEXT.—

Cancer staging provides critical information for patients and treating physicians to battle against cancer, predict prognosis, and guide treatment decisions. The American Joint Committee on Cancer (AJCC) staging system uses a tumor, node, metastasis (TNM) scoring algorithm and is the foremost classification system for adult cancers. This system is updated every 6 to 8 years to allow sufficient time for implementation of changes and for relevant examination and discussion of data validating those changes in staging.

OBJECTIVE.—

To review the updates in the 8th edition American Joint Committee on Cancer staging system on hepato-pancreato-biliary cancer.

DATA SOURCES.—

Literature review.

CONCLUSIONS.—

The 8th edition, published in 2016 and implemented on January 1, 2018, has been in use for approximately 3 years. Compared with the 7th edition, some of the changes are quite radical. This review aims to provide a summary of the changes/updates of the 8th edition with focus on hepato-pancreato-biliary cancers, and evaluate its performance through literature review.

Validation of American Joint Committee on Cancer 8th edition of TNM staging in resected distal pancreatic cancer

BACKGROUND

In order to improve risk stratification and clinical management of the pancreatic ductal adenocarcinoma (PDAC), the American Joint Committee on Cancer (AJCC) has published its eighth edition staging manual. Some major changes have been introduced in the new staging system for both T and N categories. Given the rarity of resectable disease, distal pancreatic cancer is likely underrepresented in the published clinical studies, and how the impact of the staging system actually reflects on to clinical outcomes remain unclear.

AIM

To validate the AJCC 8^th edition of TNM staging in distal PDAC.

METHODS

A retrospective cohort study was performed in seven academic medical centers in the United States. Clinicopathological prognostic factors associated with progression-free survival (PFS) and overall survival (OS) were evaluated through univariate and multivariate analyses.

RESULTS

Overall, 454 patients were enrolled in the study, and were divided into 2 subgroups: Invasive intraductal papillary mucinous neoplasms (IPMN) (115 cases) and non-IPMN associated adenocarcinoma (339 cases). Compared to invasive IPMN, non-IPMN associated adenocarcinomas are more common in relatively younger patients, have larger tumor size, are more likely to have positive lymph nodes, and are associated with a higher tumor (T) stage and nodal (N) stage, lymphovascular invasion, perineural invasion, tumor recurrence, and a worse PFS and OS. The cohort was predominantly categorized as stage 3 per AJCC 7^th edition staging manual, and it’s more evenly distributed based on 8^th edition staging manual. T and N staging of both 7^th and 8^th edition sufficiently stratify PFS and OS in the entire cohort, although dividing into N1 and N2 according to the 8^th edition does not show additional stratification. For PDAC arising in IPMN, T staging of the 7^th edition and N1/N2 staging of the 8^th edition appear to further stratify PFS and OS. For PDAC without an IPMN component, T staging from both versions fails to stratify PFS and OS.

CONCLUSION

The AJCC 8^th edition TNM staging system provides even distribution for the T staging, however, it does not provide better risk stratification than previous staging system for distal pancreatic cancer.