R0 resection for ductal pancreatic cancer—Japanese experience

Microscopic Residual Tumor After Pancreaticoduodenectomy: Is Standardization of Pathological Examination Worthwhile?

OBJECTIVES

R1 resection rate after pancreaticoduodenectomy (PD) for cancer is highly variable. The aim of this study was to verify if a standardized histopathological work-up of the specimen affects the rate of R1 resection after PD for cancer.

METHODS

Two groups of specimens were managed with (standardized method [SM] group) or without (non-standardized method [NSM] group) a SM of histopathological work-up. Each group included 50 cases of PD for periampullary cancer. Differences in terms of R1 resection rate between the 2 groups were evaluated. Correlation between R1 status and local recurrence was also evaluated.

RESULTS

The cohort of 100 patients consisted of 66 pancreatic ductal adenocarcinoma, 15 cholangiocarcinoma, and 19 ampullary cancer. The R1 resection rate resulted statistically higher in the SM group (66% vs 10%). Local recurrence was more frequently related to R1 resection in the SM group (34.3% of cases) than in NSM group (20% of cases).

CONCLUSIONS

The use of the SM of pathological evaluation of the specimen after PD for cancer determines a significant increase of R1 resection. This remarkable difference seems to be due to the different definition of minimum clearance. The SM seems to better discriminate patients in terms of risk of local recurrence.

Japan Pancreatic Cancer Registry; 30th year anniversary: Japan Pancreas Society

OBJECTIVES

Since 1981, the Japan Pancreas Society has been hosting a nationwide pancreatic cancer registry. To commemorate its 30th anniversary, we review its history and latest achievement.

METHODS

During 3 decades, more than 350 leading institutions in Japan contributed voluntarily to register and periodic follow-up. The registry was modified to protect privacy by encrypting and hash algorithm.

RESULTS

From 1981 to 2007, 32,619 cumulative records were analyzed. The overall survival of invasive cancer was improved significantly. More patients with earlier stage or with intraductal and cystic neoplasms underwent resection. The strongest prognostic factor of Union for International Cancer Control (UICC) stage IIA and IIB tubular adenocarcinoma in the pancreatic head was histological grade, followed by tumor size, extent of lymph node dissection, and postoperative chemotherapy. The 5-year survival rate of Union for International Cancer Control stage 0 reached 85%. The improvement of survival of patients with invasive cancer in Japan can be attributed to the introduction of effective chemotherapies, regionalization, and the earlier diagnosis and treatment. Simple definition of "early pancreatic cancer" is needed.

CONCLUSIONS

At the 30th year anniversary, the Japan Pancreas Society nationwide pancreatic cancer registry is more shining than ever for current perspectives and for future diagnostic and treatment tactics.

Tumour growth is more dispersed in pancreatic head cancers than in rectal cancer: implications for resection margin assessment

AIMS

The UK definition of microscopic resection margin involvement (R1) in pancreatic head cancer, based on tumour lying <1 mm from the margin, has been adopted from rectal cancer, but has never been validated. The aim of this study was to assess the adequacy of the R1 definition for pancreatic head cancers by comparing the growth patterns of rectal (RC), pancreatic (PC), ampullary (AC) and distal bile duct (DBC) adenocarcinomas.

METHODS AND RESULTS

Distances between tumour cells and tumour cell density in the tumour centre and periphery were quantified by Minimum Spanning Tree (MST) analysis in 10 cases of the four cancer groups. In RC, the MST distance was similar throughout the entire width of the tumour, whereas in PC, DBC and AC it was significantly larger at the periphery than at the tumour centre (P ≤ 0.003). While results were similar for PC and DBC, however, distances at the centre and periphery of both cancers were larger compared to AC (P ≤ 0.046). Tumour cell density dropped at the periphery of PC to 31% of that at the centre, compared to 83% in RC (P < 0.0002).

CONCLUSIONS

Tumour growth in pancreatic head cancers is more dispersed than in RC, particularly in the tumour periphery. Revision of the R1 definition for pancreatic head cancer may therefore need to be considered.

Redefining resection margin status in pancreatic cancer

Curative resection is crucial to survival in pancreatic cancer; however, despite optimization and standardization of surgical procedures, this is not always achieved. This review highlights that the rates of microscopic margin involvement (R1) vary markedly between studies and, although resection margin status is believed to be a key prognostic factor, the rates of margin involvement and local tumour recurrence or overall survival of pancreatic cancer patients are often incongruent. Recent studies indicate that the discrepancy between margin status and clinical outcome is caused by frequent underreporting of microscopic margin involvement. Lack of standardization of pathological examination, confusing nomenclature and controversy regarding the definition of microscopic margin involvement have resulted in the wide variation of reported R1 rates that precludes meaningful comparison of data and clinicopathological correlation.

Impact of margin status on survival following pancreatoduodenectomy for cancer: the Leeds Pathology Protocol (LEEPP)

BACKGROUND

In a previous study we reported an 85% R1 rate for pancreatic cancer following the use of the rigorous, fully standardized Leeds Pathology Protocol (LEEPP). As this significantly exceeded R1 rates observed by others, we investigated the reproducibility of margin assessment using the LEEPP in a larger, prospective, observational cohort study and correlated clinicopathological data with survival.

METHODS

Clinicopathological features, including exact site and multifocality of margin involvement, and survival were collated from a prospective series of 83 pancreatoduodenectomies for pancreatic (n = 27), ampullary (n = 24) and bile duct cancer (n = 32). Data were compared with those of the previous study in which the same pathology protocol, based on axial slicing and extensive tissue sampling from the circumferential margin, had been used.

RESULTS

The R1 rate was high in pancreatic (82%) and bile duct (72%) cancer and significantly lower in ampullary cancer (25%). Margin positivity was often multifocal, the posterior margin being most frequently involved. Margin status correlated with survival in the entire cohort (P = 0.006) and the pancreatic subgroup (P = 0.046). These findings were consistent with observations in our previous study.

CONCLUSIONS

Margin involvement in pancreatic cancer is a frequent and prognostically significant finding when specimens are assessed using the LEEPP.

Resection margins and R1 rates in pancreatic cancer--are we there yet?

The prognosis of pancreatic cancer is poor, even for those patients who undergo surgical resection. The rate of local recurrence is high, despite the fact that in most series complete ('R0') resection is reported to be achieved in the majority of patients. The discrepancy between pathological assessment and clinical outcome indicates that microscopic margin involvement (R1) is frequently underreported, and potential causes for this are discussed in this review. Special emphasis is given to the variation that exists between currently used dissection techniques and their impact on the assessment of the resection margins in pancreatoduodenectomy specimens.