Dissimilar survival and clinicopathological characteristics of mucinous adenocarcinoma located in pancreatic head and body/tail

Abstract

Background: Growing evidence shows that pancreatic tumors in different anatomical locations have different characteristics, which have a significant impact on prognosis. However, no study has reported the differences between pancreatic mucinous adenocarcinoma (PMAC) in the head vs the body/tail of the pancreas.

Aim: To investigate the differences in survival and clinicopathological characteristics between PMAC in the head and body/tail of pancreas.

Methods: A total of 2058 PMAC patients from the Surveillance, Epidemiology, and End Results database diagnosed between 1992 and 2017 were retrospectively reviewed. We divided the patients who met the inclusion criteria into pancreatic head group (PHG) and pancreatic body/tail group (PBTG). The relationship between two groups and risk of invasive factors was identified using logistic regression analysis. Kaplan-Meier analysis and Cox regression analysis were conducted to compare the overall survival (OS) and cancer-specific survival (CSS) of two patient groups.

Results: In total, 271 PMAC patients were included in the study. The 1-year, 3-year, and 5-year OS rates of these patients were 51.6%, 23.5%, and 13.6%, respectively. The 1-year, 3-year, and 5-year CSS rates were 53.2%, 26.2%, and 17.4%, respectively. The median OS of PHG patients was longer than that of PBTG patients (18 vs 7.5 mo, P < 0.001). Compared to PHG patients, PBTG patients had a greater risk of metastases [odds ratio (OR) = 2.747, 95% confidence interval (CI): 1.628-4.636, P < 0.001] and higher staging (OR = 3.204, 95% CI: 1.895-5.415, P < 0.001). Survival analysis revealed that age < 65 years, male sex, low grade (G1-G2), low stage, systemic therapy, and PMAC located at the pancreatic head led to longer OS and CSS (all P < 0.05). The location of PMAC was an independent prognostic factor for CSS [hazard ratio (HR) = 0.7, 95%CI: 0.52-0.94, P = 0.017]. Further analysis demonstrated that OS and CSS of PHG were significantly better than PBTG in advanced stage (stage III-IV).

Conclusion: Compared to the pancreatic body/tail, PMAC located in the pancreatic head has better survival and favorable clinicopathological characteristics.

Keywords: Anatomical location; Pancreatic body/tail; Pancreatic head; Pancreatic mucinous adenocarcinoma; Survival.

Figure 1

Logistic regression analysis of aggressive factors. A: Risk analysis of metastasis; B: Risk analysis of higher staging. PHG: Pancreatic head group; PBTG: Pancreatic body/tail group; OR: Odds ratio.

Figure 2

Kaplan-Meier survival analysis of the two groups. A: Analysis for overall survival; B: Analysis for cancer-specific survival.

Figure 3

Kaplan-Meier survival analysis of the two groups without surgical resection. A: Analysis for overall survival; B: Analysis for cancer-specific survival.

Figure 4

Analysis of systemic therapy. Survival of patients receiving and not receiving systemic therapy (A: Overall survival; B: Cancer-specific survival). Survival of pancreatic head group patients with and without systemic therapy (C: Overall survival; D: Cancer-specific survival). Survival of pancreatic body/tail group patients with and without systemic therapy (E: Overall survival; F: Cancer-specific survival).

Figure 5

Survival analysis of pancreatic head group and pancreatic body/tail group patients without systemic therapy. (A: Overall survival; B: Cancer-specific survival). Survival analysis of pancreatic head group and pancreatic body/tail group patients with systemic therapy (C: Overall survival; D: Cancer-specific survival).

Figure 6

Survival analysis of stages between the two groups. Survival curves of all patients in stage I-IV (A: Overall survival; B: Cancer-specific survival). Different survival of pancreatic head group (PHG) and pancreatic body/tail group (PBTG) patients in early stage (stage I-II) (C: Overall survival; D: Cancer-specific survival). Different survival of PHG and PBTG patients in advanced stage (stage III-IV) (E: Overall survival; F: Cancer-specific survival).

Figure 7

Ratio of surgery in pancreatic head group and pancreatic body/tail group.