The median follow-up for patients with IPMN-associated adenocarcinoma was 24.8 months. The characteristics of the 70 patients included in the present study are listed in . The median age at surgery was 68.0 years (range, 35–85); 47% were men, and 89% were white. Of the 70 patients, 84% had undergone a Whipple procedure and 16% had undergone distal pancreatectomy with or without splenectomy. The median size of the tumor with an invasive component was 3.3 cm (range, 0.2–10.0). Invasive carcinoma at the margin was present in 11 patients (15.7%), and 50% had lymph node metastases. Perineural and perivascular invasion was present in 47% and 27% of the carcinoma specimens, respectively. One patient had Stage III disease, and most had Stage II (64%). The median survival for all patients in the present analysis was 28 months. The 2- and 5-year survival rate was 57% and 45%, respectively.
The evaluation of the histologic features of the invasive carcinoma associated with IPMN revealed that 49% of the patients had tubular adenocarcinoma and 33% had colloid carcinoma; 24% of patients had other histologic types, including undifferentiated (anaplastic) and mixed.
Of the 70 patients with an IPMN-associated invasive component, 40 underwent adjuvant therapy and 30 did not (). The patients who had not received adjuvant therapy were more likely to be ≥65 years old; however, the difference was not statistically significant (p = .095). The median size of the invasive component was 3.1 cm for those receiving CRT and 3.5 cm for those who did not (p = .859). The proportion of patients receiving CRT who had positive margins was 20%. In contrast, only 10% of patients who did not receive CRT had positive margins (p = .255). Significantly more patients who received CRT were more likely to have positive lymph nodes (65% vs. 30%), Stage II–III disease (80% vs. 47%), and perineural invasion (63% vs. 27%) than patients who did not receive CRT (all p <.007). Patients with ductal histologic tumor were more likely than those with colloid histologic tumor to have Stage II–III disease, positive lymph nodes, vascular invasion, and perineural invasion. Patients with a ductal histologic type were significantly more likely to undergo adjuvant CRT than those with a colloid histologic type (p = .005).
Tumor characteristics and survival for patients receiving or not receiving adjuvant therapy
Univariate and multivariate analyses were performed to identify the prognostic factors in patients with IPMN-associated invasive carcinoma (). Patients with lymph node positive disease had significantly inferior survival on univariate analysis (relative risk [RR] 4.06, p <.001; ). Margin-positive resections resulted in inferior survival on univariate analysis (RR 2.42, p = .023). Poor, anaplastic, or undifferentiated tumors resulted in a worse prognosis compared with well or moderate-grade tumors (RR 2.25, p = .026). Patients with colloid histologic features had a nonsignificant improvement in survival compared with those with ductal histologic features (RR 1.94, p = .120).
Univariate and multivariate analyses of prognostic variables
Survival after pancreaticoduodenectomy for intraductal papillary mucinous neoplasm with associated invasive adenocarcinoma was inferior for node-positive patients (relative risk [RR] 4.06, p <.001).
The median survival time and 2-year survival rate after surgery with and without CRT was 25.8 months and 56% and 91.9 months and 59%, respectively (p = .923; ). Node-positive patients who received adjuvant CRT had significantly improved survival compared with those who did not receive CRT (RR 0.43, p = .047; ). Although the numbers were small (n = 11), the margin-positive patients who received CRT (n = 9) had improved survival compared with those who did not (p = .042). On multivariate analysis, adjuvant CRT was associated with improved survival (RR 0.43; 95% confidence interval, 0.19–0.95; p = .044) after adjusting for nodal disease, margin status, tumor location, tumor grade, and histologic type.
Fig. 2 Survival after pancreaticoduodenectomy for intraductal papillary mucinous neoplasm with associated invasive adenocarcinoma was not significantly different statistically for those who received adjuvant chemoradiotherapy (CRT) (relative risk [RR] 1.023, (more ...)
Patients with resected intraductal papillary mucinous neoplasm with invasive component and node-positive disease benefited from adjuvant chemoradiotherapy (CRT) (relative risk [RR] 0.43, p = .044).