Features of T1 pancreatic cancer and validation of the eighth edition AJCC staging system definition using a Korean-Japanese joint cohort and the SEER database

Survival Analysis of 4 Different Age Groups of Pancreatic Ductal Adenocarcinoma After Radical Resection From Retrospective Multi-Center Analysis (YPB-003)

AIM

This study aimed to investigate the efficacy of radical resection and postoperative adjuvant chemotherapy on the survival benefit in patients with pancreatic ductal adenocarcinoma (PDAC), stratified by age, frailty, and other factors in actual clinical practice.

METHODS

We retrospectively analyzed the clinicopathological and follow-up data of 414 patients with PDAC who underwent surgical resection at nine institutions under the Yamaguchi Pancreat/Biliary Disease Study Group, between January 1997 and December 2016. Recurrence-free survival (RFS) and overall survival (OS) were calculated using the Kaplan-Meier method. Associations between survival and prognostic factors were evaluated by univariate and multivariate analyses.

RESULTS

There were 30.5% of patients with PDAC who were aged < 65 years, 37.9% aged 65-74 years, 17.6% aged 75-79 years, and 14.0% aged ≥ 80 years. Notably, RFS declined with increasing age (median RFS: 12.9, 10.2, 9.4, and 7.4 months, respectively), although the differences were not significant (p = 0.223). OS significantly decreased with age (median OS: 21.6, 21.2, 17.0, and 13.9 months, respectively; p = 0.005). In patients aged < 75 years, independent prognostic factors identified by univariate and multivariate analyses included lymph node metastasis (hazard ratio [HR], 1.598; p = 0.007), tumor size (HR, 1.489; p = 0.043), R status (HR, 1.536; p = 0.011), and serum albumin levels (HR, 1.526; p = 0.031). In patients aged ≥ 75 years, a high modified frailty index (HR, 2.446; p = 0.012) emerged as an independent prognostic factor, along with lymph node metastasis, CA19-9 level (HR, 1.897; p = 0.017), and R status (HR, 2.087; p = 0.007).

CONCLUSION

The prognosis for older patients with PDAC was shorter than that of younger patients. Frailty may contribute to their poorer prognosis in older age.

An international multi-institutional validation of T1 sub-staging of intraductal papillary mucinous neoplasm-derived pancreatic cancer

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN)-derived pancreatic ductal adenocarcinoma (PDAC) is resected at smaller sizes compared with its biologically distinct counterpart, pancreatic intraepithelial neoplasia (PanIN)-derived PDAC. Thus, experts proposed T1 sub-staging for IPMN-derived PDAC. However, this has never been validated.

METHODS

Consecutive upfront surgery patients with IPMN-derived PDAC from 5 international high-volume centers were classified by the proposed T1 sub-staging classification (T1a ≤0.5, T1b >0.5 and ≤1.0, and T1c >1.0 and ≤2.0 cm) using the invasive component size. Kaplan-Meier and log-rank tests were used to compare overall survival (OS). A multivariable Cox regression was used to determine hazard ratios (HRs) with confidence intervals (95% CIs).

RESULTS

Among 747 patients, 69 (9.2%), 50 (6.7%), 99 (13.0%), and 531 patients (71.1%), comprised the T1a, T1b, T1c, and T2-4 subgroups, respectively. Increasing T-stage was associated with elevated CA19-9, poorer grade, nodal positivity, R1 margin, and tubular subtype. Median OS for T1a, T1b, T1c, and T2-4 were 159.0 (95% CI = 126.0 to NR), 128.8 (98.3 to NR), 77.6 (48.3 to 108.2), and 31.4 (27.5 to 37.7) months, respectively (P < .001). OS decreased with increasing T-stage for all pairwise comparisons (all P < .05). After risk adjustment, older than age 65, elevated CA19-9, T1b [HR = 2.55 (1.22 to 5.32)], T1c [HR = 3.04 (1.60 to 5.76)], and T2-4 [HR = 3.41 (1.89 to 6.17)] compared with T1a, nodal positivity, R1 margin, and no adjuvant chemotherapy were associated with worse OS. Disease recurrence was more common in T2-4 tumors (56.4%) compared with T1a (18.2%), T1b (23.9%), and T1c (36.1%, P < .001).

CONCLUSION

T1 sub-staging of IPMN-derived PDAC is valid and has significant prognostic value. Advancing T1 sub-stage is associated with worse histopathology, survival, and recurrence. T1 sub-staging is recommended for future guidelines.

The role of national population-based registries in pancreatic cancer surgery research

Research and innovation are critical for advancing the multidisciplinary management of pancreatic cancer. Registry-based studies (RBSs) are a complement to randomized clinical trials (RCTs). Compared with RCTs, RBSs offer cost-effectiveness, larger sample sizes, and representation of real-world clinical practice. National population-based registries (NPBRs) aim to cover the entire national population, and studies based on NPBRs are, compared to non-NPBRs, less prone to selection bias. The last decade has witnessed a dramatic increase in NPBRs in pancreatic cancer surgery, which has undoubtedly added invaluable knowledge to the body of evidence on pancreatic cancer management. However, several methodological shortcomings may compromise the quality of registry-based studies. These include a lack of control over data collection and a lack of reporting on the quality of the source registry or database in terms of validation of coverage and data completeness and accuracy. Furthermore, there is a significant risk of double publication from the most commonly used registries as well as the inclusion of historical data that is not relevant or representative of research questions addressing current practices.