# Advancing Precision Medicine in PDAC: An Ethical Scoping Review and Call to Action for IHC Implementation

## TL;DR

This paper argues that immunohistochemistry (IHC) can improve pancreatic cancer treatment by enabling personalized therapies, and calls for its ethical and equitable implementation.

## Contribution

The paper presents an ethical scoping review advocating for the widespread adoption of IHC in PDAC treatment to enable precision medicine.

## Key findings

- IHC is a cost-effective and widely available method for molecular subtyping in PDAC.
- IHC provides more accurate protein-level biomarker assessment than mRNA analysis.
- Standardized IHC protocols are essential for translating molecular subtyping into actionable treatment strategies.

## Abstract

Pancreatic cancer is among the deadliest cancers, with few patients qualifying for surgery, the only potential cure. For everyone else, treatments remain limited, and survival rates are disturbingly low. While expensive genetic tests only help a small fraction of patients, this review examines how a widely available and affordable laboratory test—immunohistochemistry (IHC)—could transform cancer care by matching patients with the most effective treatments. Instead of relying on a one-size-fits-all treatment approach for pancreatic cancer, using IHC to detect specific biomarkers can help guide clinicians in tailoring therapies to each patient’s unique tumor, potentially improving outcomes while minimizing side effects. We analyze the ethical imperative to expand clinical trials of IHC-based testing, ensuring this life-saving technology reaches all communities, regardless of their resources or location. By implementing this cost-effective approach in hospitals worldwide, we could dramatically improve how we treat pancreatic cancer, saving lives and reducing healthcare expenditure while offering hope to patients and families facing this aggressive disease. This practical solution could become a model for delivering more equitable and effective cancer care across the healthcare system.

Pancreatic ductal adenocarcinoma (PDAC) presents significant challenges in diagnosis, prevention, and treatment. Predictive biomarkers offer the potential to revolutionize clinical management, particularly in the preoperative setting, but their implementation requires careful consideration of ethical implications. This scoping review analyzes the ethical landscape of using immunohistochemistry (IHC) for molecular subtyping in PDAC, focusing on its utility, accessibility, and potential impact on patient care. We conducted a systematic literature search in the PubMed, Scopus and Google Scholar databases (2015–2025) using COVIDENCE, which identified 130 references. Of these, 79 were reviewed in a full-text format, and 9 ultimately met the inclusion criteria for our analysis. IHC offers several advantages as a companion diagnostic tool. It is relatively inexpensive, widely available in most pathology laboratories, and can be readily integrated into existing clinical workflows. This contrasts with more complex molecular subtyping methods, such as gene expression profiling, which can be costly, require specialized equipment and expertise, and may not be readily accessible in all clinical settings. Furthermore, accurate analysis of gene expression requires the localized targeting of individual cells; therefore, digesting the sample for bulk analysis would be less informative than using spatial localization techniques such as IHC. Because biomarker regulation can occur at the level of transcription or translation, protein-level assessment via IHC is often more accurate than mRNA analysis. Standardized IHC protocols for biomarker assessment are therefore essential for translating the molecular subtyping of PDAC into clinically actionable treatment strategies, especially for aggressive subtypes like basal-like tumors. This readily deployable IHC-based approach can optimize therapy selection, maximizing patient benefits and minimizing exposure to ineffective and potentially toxic treatments. This review critically analyzes the ethical dimensions of this method, grounded in the principles of autonomy, beneficence, non-maleficence, and justice. The review urges the medical community to fully utilize the potential of IHC-driven molecular subtyping to improve outcomes in PDAC, while ensuring equitable and responsible access to the benefits of precision oncology for all patients.