Elsevier

Surgery

Volume 162, Issue 1, July 2017, Pages 104-111
Surgery

Pancreas
Presented at the Academic Surgical Congress 2016
Implications of inaccurate clinical nodal staging in pancreatic adenocarcinoma

Presented at the 11th Annual Academic Surgical Congress, February 3, 2016, Jacksonville, FL.
https://doi.org/10.1016/j.surg.2016.12.029Get rights and content

Background

Many patients with stage I-II pancreatic adenocarcinoma do not undergo resection. We hypothesized that (1) clinical staging underestimates nodal involvement, causing stage IIB to have a greater percent of resected patients and (2) this stage-shift causes discrepancies in observed survival.

Methods

The Surveillance, Epidemiology, and End Results (SEER) research database was used to evaluate cause-specific survival in patients with pancreatic adenocarcinoma from 2004–2012. Survival was compared using the log-rank test. Single-center data on 105 patients who underwent resection of pancreatic adenocarcinoma without neoadjuvant treatment were used to compare clinical and pathologic nodal staging.

Results

In SEER data, medium-term survival in stage IIB was superior to IB and IIA, with median cause-specific survival of 14, 9, and 11 months, respectively (P < .001). Seventy-two percent of stage IIB patients underwent resection vs 28% in IB and 36% in IIA (P < .001). In our institutional data, 12.4% of patients had clinical evidence of nodal involvement vs 69.5% by pathologic staging (P < .001). Among clinical stage IA–IIA patients, 71.6% had nodal involvement by pathologic staging.

Conclusion

Both SEER and institutional data support substantial underestimation of nodal involvement by clinical staging. This finding has implications in decisions regarding neoadjuvant therapy and analysis of outcomes in the absence of pathologic staging.

Section snippets

SEER research database cohort

Patients aged ≥18 years who were diagnosed between January 1, 2004, and December 31, 2012, with PDAC (the International Classification of Diseases for Oncology, third edition histology codes 8140-2, 8144, 8490, 8500-1, 8503-4, and 8507) were extracted from the SEER research database. The SEER Program contains approximately 26% of the population in the United States.5 Patients with previous cancers and those with unknown stage were not included in the data extraction. Patients with unknown

Lack of discrimination of survival in stage IB-IIA

A total of 45,147 patients diagnosed between 2004 and 2012 with a first cancer diagnosis of PDAC were identified from the SEER database and 20.7% of patients underwent resection (Table I). Patients were followed from diagnosis until time of death or to a median of 9 months (interquartile range, 3, 23) after diagnosis for the 13.8% for patients who were still alive at the time of last follow-up. The expected inverse relationship between increasing stage and survival was observed when resected

Discussion

The major finding in this study is that inaccuracy of clinical N-staging causes stage IIB to be comprised of a disproportionately high number of resected patients compared with IA to IIA (Fig 2). The number of resected patients in IIB was 1.8 times greater than the number in IA to IIA added together. This explains why stage IIB patients have better early to medium-term survival. PDAC is unique among other common solid organ tumors in that only about half of patients with early stage, resectable

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Cited by (0)

Supported by the University of Utah Study Design and Biostatistics Center, with funding in part from the National Center for Research Resources and the National Center for Advancing Translational Sciences, National Institutes of Health, through Grant 5UL1TR001067-02 (formerly 8UL1TR000105 and UL1RR025764).

The authors have no financial or other potential conflicts of interest to disclose.

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