Background: The authors hypothesized that in resected pancreatic adenocarcinoma (PDAC), pathologic characteristics, oncologic outcomes, prognostic factors, and the accuracy of the American Joint Committee on Cancer (AJCC) staging system might differ based on tumor location.
Methods: Patients undergoing pancreatectomy for PDAC at two academic institutions from 2000 to 2015 were retrieved. A comparative analysis between head (H-PDAC) and body-tail (BT-PDAC) tumors was performed using uni- and multivariable models. The accuracy of the eighth AJCC staging system was analyzed using C-statistics.
Results: Among 1466 patients, 264 (18%) had BT-PDAC, which displayed greater tumor size but significantly lower rates of perineural invasion and G3/4 grading. Furthermore, BT-PDAC was associated with a lower frequency of nodal involvement and a greater representation of earlier stages. The recurrence-free survival and disease-specific survival times were longer for BT-PDAC (16 vs 14 months [p = 0.020] and 33 vs 26 months [p = 0.026], respectively), but tumor location was not an independent predictor of recurrence or survival in the multivariable analyses. The recurrence patterns did not differ. Certain prognostic factors (i.e., CA 19.9, grading, R-status, and adjuvant treatment) were common, whereas others were site-specific (i.e., preoperative pain, diabetes, and multivisceral resection). The performances of the AJCC staging system were similar (C-statistics of 0.573 for H-PDAC and 0.597 for BT-PDAC, respectively).
Conclusions: Despite differences in pathologic profile found to be in favor of BT-PDAC, tumor location was not an independent predictor of recurrence or survival after pancreatectomy. An array of site-specific prognostic factors was identified, but the AJCC staging system displayed similar prognostic power regardless of primary tumor location.