Surgical Drain Fluid cfDNA Sequencing for Residual Disease Detection

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Solution Overview

Problem

Current methods for detecting minimal residual disease after cancer surgery are inadequate, as they rely on non-specific plasma analytes that do not accurately indicate the presence of cancerous tissue at the surgical site, leading to delayed or inappropriate post-surgical treatments.

Innovation Solution

A method involving the collection of surgical drainage samples, isolation of tumor-associated genetic material, and sequencing to detect and quantify tumor-associated mutations or variants, which provides a more proximal and accurate indicator of residual disease.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If plasma cfDNA testing is used for early detection of recurrence, then non-specific detection capability is improved, but measurement precision at surgical site is worsened

Engineering Contradiction:

Improvedetection capabilityVSAvoidsurgical site specificity

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The invention segments the detection approach by using separate surgical drains for different anatomical compartments (e.g., ipsilateral vs. contralateral neck drains). This allows independent analysis of cfDNA from each surgical site, enabling precise localization of residual disease while maintaining comprehensive detection capability across multiple sites.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention extracts cfDNA directly from surgical drain fluid at the source of potential residual disease, rather than relying on systemic plasma circulation. This extraction approach concentrates tumor-derived DNA from the specific surgical site, improving measurement precision while maintaining detection sensitivity.

Inventive Principle:

Principle #2Taking out (Extraction)

2Adaptability or versatility

If plasma cfDNA detection is used, then systemic detection coverage is improved, but detection speed is worsened

Engineering Contradiction:

Improvesystemic detection coverageVSAvoiddetection latency

Core Design Contradiction:

Adaptability or versatilityVSSpeed

Solution Approach 1:

The invention performs preliminary detection by analyzing cfDNA in surgical drain fluid immediately post-operatively, before residual tumor cells can significantly proliferate or disseminate systemically. This early detection at the source provides rapid results within hours, enabling prompt treatment decisions without waiting for systemic circulation to accumulate detectable cfDNA levels.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If plasma cfDNA analysis is performed, then comprehensive sampling is improved, but analyte concentration is worsened

Engineering Contradiction:

Improvesampling coverageVSAvoidcfDNA concentration

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The invention uses surgical drain fluid as an intermediary medium that directly contacts the surgical site and collects tumor-derived cfDNA as it is released. This intermediary approach concentrates analytes from the local microenvironment without the dilution effect of systemic plasma circulation, achieving high cfDNA concentrations suitable for sensitive detection while maintaining site-specific information.

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method enables timely and accurate detection of minimal residual disease, allowing for personalized post-operative treatment selection, potentially reducing side effects and improving patient outcomes.

Implementation Method 1

isolating the amount of tumor-associated genetic material from the sample further includes filtering the sample, centrifuging the sample, contacting the sample with a chromatography medium

Methodology Applied

Scientific EffectCentrifuging: Centrifugal Separation

Implementation Method 2

contacting the sample with a chromatography medium

Methodology Applied

Scientific EffectChromatography: Chromatography

Implementation Method 3

sequencing the amount of tumor-associated genetic material to detect and quantify at least one tumor-associated mutation or variant

Methodology Applied

Scientific EffectDNA sequencing:

Data Source

PatentEP4077709B1Method of measuring cell-free DNA in surgical drain fluid to select adjuvant therapy

Publication Date: 2025.06.18 WASHINGTON UNIV IN SAINT LOUIS

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Figure 3A~3B

AI summary

A method for detecting minimal residual disease in a subject following a cancer surgery is disclosed. The method includes obtaining a sample from the subject. The sample includes a surgical drainage. The method also includes isolating an amount of tumor-associated genetic material from the sample, sequencing the amount of tumor-associated genetic material to detect and quantify at least one tumor-associated mutation or variant in the amount of tumor-associated genetic material, and providing the at least one quantity of the at least one tumor-associated mutation or variant to a practitioner.