The differential effect of neoadjuvant chemotherapy and chemoradiation on nodal downstaging in pancreatic adenocarcinoma

The known genetic variants of BRCA1, BRCA2 and NOD2 in pancreatitis and pancreatic cancer risk assessment

The single nucleotide polymorphism in NOD2 (rs2066847) is associated with conditions that may predispose to the development of gastrointestinal disorders, as well as the known BRCA1 and BRCA2 variants classified as risk factors in many cancers. In our study, we analyzed these variants in a group of patients with pancreatitis and pancreatic cancer to clarify their role in pancreatic disease development. The DNA was isolated from whole blood samples of 553 patients with pancreatitis, 83 patients with pancreatic cancer, 44 cases of other pancreatic diseases, and 116 healthy volunteers. The NOD2 (rs2066847), BRCA1 (rs80357914) and BRCA2 (rs276174813) were genotyped. The statistically significant 3-fold increased risk of pancreatic cancer was detected among the patients with rs2066847 polymorphism (OR = 2.77, p-value = 0.019). We did not find the studied polymorphisms in BRCA1 (rs80357914) and BRCA2 (rs276174813). However, the adjacent polymorphisms have been detected only in patients with pancreatic diseases. The studied variant in NOD2 occurs more frequently in pancreatic patients and significantly increases the risk of pancreatic cancer. It can be considered as a genetic risk factor that predisposes to cancer development. The analyzed regions in BRCA1 and BRCA2 may be a potential target in further search for a genetic marker of pancreatic diseases.

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.

Surgical Outcomes Following Neoadjuvant Treatment for Locally Advanced and Borderline Resectable Pancreatic Ductal Adenocarcinoma

Objective

To assess overall survival (OS), compare the effects of neoadjuvant treatment, and describe surgical outcomes for patients undergoing pancreatic resection following chemotherapy and/or chemoradiotherapy (CRT) for borderline resectable (BR) or locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC).

Background

We approach BR/LA PDAC using chemotherapy followed by selective CRT to the primary site of disease where either the surgical margin remains radiologically threatened following chemotherapy or as a further downstaging treatment.

Methods

Retrospective study of patients between December 2005 and June 2023 at the Royal Marsden Hospital, London, United Kingdom.

Results

A total of 54 patients were included. The OS between R1 and R0 patients was significantly different: 7.5 versus 23 versus 42 versus 51 months for R1 chemo, R1 chemo and CRT, R0 chemo and R0 chemo, and CRT groups, respectively, P < 0.001. Similarly, 9 versus 18 versus 42 versus 41 months for N1 chemo, N1 chemo and CRT, N0 chemo and N0 chemo, and CRT groups, respectively, P = 0.0026. Multivariable Cox regression model demonstrated that perineural invasion (hazard ratio: 2.88, 95% confidence interval: 1.06-7.81; P = 0.038) and perivascular invasion (PVI) (HR: 2.76, 95% CI: 1.24-6.13; P = 0.013) were associated with significantly worse OS. Chemo and CRT conferred OS benefit compared to chemo only (7 vs 23 months, P = 0.004) in PVI-positive patients.

Conclusions

Neoadjuvant chemotherapy followed by CRT compared to chemotherapy alone for resected BD and LA PDAC was demonstrated to significantly improve median OS, in particular, in patients with R1 resection margins, ypN1 nodal status, and perivascular invasion.

Identification of tumour regression in neoadjuvantly treated pancreatic cancer is based on divergent and nonspecific criteria

AIMS

Following the increased use of neoadjuvant therapy for pancreatic cancer, grading of tumour regression (TR) has become part of routine diagnostics. However, it suffers from marked interobserver variation, which is mainly ascribed to the subjectivity of the defining criteria of the categories in TR grading systems. We hypothesized that a further cause for the interobserver variation is the use of divergent and nonspecific morphological criteria to identify tumour regression.

METHODS AND RESULTS

Twenty treatment-naïve pancreatic cancers and 20 pancreatic cancers treated with neoadjuvant chemotherapy were reviewed by three experienced pancreatic pathologists who, blinded for treatment status, categorized each tumour as treatment-naïve or neoadjuvantly treated, and annotated all tissue areas they considered showing tumour regression. Only 50%-65% of the cases were categorized correctly, and the annotated tissue areas were highly discrepant (only 3%-41% overlap). When the prevalence of various morphological features deemed to indicate TR was compared between treatment-naïve and neoadjuvantly treated tumours, only one pattern, characterized by reduced cancer cell density and prominent stroma affecting a large area of the tumour bed, occurred significantly more frequently, but not exclusively, in the neoadjuvantly treated group. Finally, stromal features, both morphological and biological, were investigated as possible markers for tumour regression, but failed to distinguish TR from native tumour stroma.

CONCLUSION

There is considerable divergence in opinion between pathologists when it comes to the identification of tumour regression. Reliable identification of TR is only possible if it is extensive, while lesser degrees of treatment effect cannot be recognized with certainty.