Consensus guidelines for the management of intraductal papillary mucinous neoplasms of the pancreas

This week’s discussion included information about the utility of the Fukuoka criteria.


Srinivasan N, et al. Systematic review of the clinical utility and validity of the Sendai and Fukuoka Consensus Guidelines for the management of intraductal papillary mucinous neoplasms of the pancreas.HPB (Oxford). 2018 Jun;20(6):497-504.

Free full-text. 

RESULTS: Ten studies evaluating the FCG, 8 evaluating the SCG and 4 evaluating both guidelines were included. In 14 studies evaluating the FCG, out of a total of 2498 neoplasms, 849 were malignant and 1649 were benign neoplasms. Pooled analysis showed that 751 of 1801 (42%) FCG+ve neoplasms were malignant and 599 neoplasms of 697 (86%) FCG-ve neoplasms were benign. PPV of the high risk and worrisome risk groups were 465/986 (47%) and 239/520 (46%) respectively. In 12 studies evaluating the SCG, 1234 neoplasms were analyzed of which 388 (31%) were malignant and 846 (69%) were benign. Pooled analysis demonstrated that 265 of 802 (33%) SCG+ve neoplasms were malignant and 238 of 266 SCG-ve (90%) neoplasms were benign.

CONCLUSION: The FCG had a higher positive predictive value (PPV) compared to the SCG. However, the negative predictive value (NPV) of the FCG was slightly lower than that of the SCG. Malignant and even invasive IPMN may be missed according to both guidelines.

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Signet-ring cell carcinoma: a look at the rare colorectal cancer

A discussion this week included signet ring cell carcinoma.


Reference: Nitsche U, et al. Mucinous and signet-ring cell colorectal cancers differ from classical adenocarcinomas in tumor biology and prognosis. Annals of Surgery. 2013 Nov;258(5):775-782; discussion 782-783. doi:10.1097/SLA.0b013e3182a69f7e

Additional Reading: Korphaisarn K, et al. Signet ring cell colorectal cancer: genomic insights into a rare subpopulation of colorectal adenocarcinoma. British Journal of Cancer. 2019 Sep;121(6):505-510. doi:10.1038/s41416-019-0548-9

Summary: In a study analyzing clinical, histopathological, and survival data of 3479 patients undergoing surgery for primary colorectal cancer between 1982 and 2012, Nitsche et al (2013) compared the characteristics of classical adenocarcinomas (AC) to the less common mucinous adenocarcinomas (MAC) and to the rare signet-ring cell carcinomas (SC).

SC

Approximately 10% of all colorectal cancers are MAC, and about 1% are SC. Because of their relatively rare occurrence, in particular, the evaluation of the clinical impact of SC is difficult. However, compared with AC, both MAC and SC have been shown to be associated with young age, advanced tumor stage, accumulation in female patients, and distinct molecular patterns, such as microsatellite instability and activating mutations of the BRAF gene. Although ambiguous, recent data and meta-analyses suggest that the
histological subtype MAC may be associated with worse outcome compared with AC. Poor prognosis of SC is more evident, mainly due to high rates of synchronous and metachronous distant organ metastasis associated with this histological subtype.

In describing SC, the authors state: “SC have been described as being positive for intestinal trefoil factor and MUC2, 2 peptides that are usually produced only by goblet cells. Thus, SC could arise from different cells of origin than AC. Although they can be localized in the colorectum, SC may be genetically more related to signet-ring cell cancers of other organs (eg, gastric cancer) than to AC or MAC of the colorectum. The
absence of E-cadherin/β-catenin and amplification of Bcl-2 are features typically shared with signet-ring cell cancer of the stomach but not with classical colorectal adenocarcinomas” (p.781).

The authors conclude that patients with MAC and SC could profit from closer follow-up or even intensified adjuvant therapy because of their high rates of local and distant recurrence. The biological behavior of SC differs in specific, and these patients require special awareness, despite the relatively rare prevalence.