Cancer Modifier. Staging and Grading

Cancer Modifier: Staging/Grading Concept Class

Overview

The Staging/Grading Concept Class was designed as part of the Cancer Modifier Vocabulary and was primarily developed to represent facts of staging related parameters and grading attributes of each cancer.

Not only pure staging and grading parameters were added but also additional parameters that complement outcomes and responses to therapy such as “partial response” over “complete response” and additional descriptions that go beyond the normal numeric stage definition such as “extensive disease”.

Concept Names

Concept names are constructed as combinations of several data attributes retrieved by source name parsing with deduplication and alignment through look-up tables.

The examples are listed below

Concept Name	Attribute1 (staging system)	Attribute2 (system version)	Attribute3 (prefix)	Attribute4 (suffix)	Attribute5 (staging parameter)
AJCC/UICC 6th clinical T2a Category	AJCC/UICC	6th	clinical	T2a	Category
CHOI: complete response	CHOI				complete response
Pathological Gleason Score 4+3	Gleason		Pathological	4+3	Score

Concept Code

Staging/Grading concept codes are built in the same fashion as their names.

In general, the atomic attributes of conсept codes are concatenated by ‘-’. The ‘_’ symbol is used to separate the version of the staging system.

Concept Code	Attribute1 (staging system)	Attribute2 (system version)	Attribute3 (prefix)	Attribute4 (suffix)	Attribute5 (staging parameter)
c-6th_AJCC/UICC-T2a	AJCC/UICC	6th	c	T2a
CHOI-CR	CHOI				CR
p-Gleason-Score-4+3	Gleason		p	4+3	Score

Concept Relationships

Hierarchy

Cancer Modifier Staging/Grading Concepts are aligned in hierarchical structure according to step-wise loss of an attribute and/or within a suffix-prefix level.

Hierarchical type	Concept-Relationship-Concept	Concept Name	Attribute1 (staging system)	Attribute2 (system version)	Attribute3 (prefix)	Attribute4 ( suffix)	Attribute5 (staging parameter)
Suffix Hierarchy	Concept 1	AJCC/UICC 6th clinical T2a Category	AJCC/UICC	6th	clinical	T2a	Category
	Relationship	Is a
	Concept 2	AJCC/UICC 6th clinical T2 Category	AJCC/UICC	6th	clinical	T2	Category
Attribute loss	Concept 1	AJCC/UICC 6th clinical T2a Category	AJCC/UICC	6th	clinical	T2a	Category
	Relationship	Is a
	Concept 3	AJCC/UICC clinical T2a Category	AJCC/UICC		clinical	T2a	Category

Instructions for ETL

1. Stages should be used as comprehensive and self-sufficient concept (by default no need to add any type of value)
2. Concepts designed to trigger the Extent Episode and Dynamic Episode

a) Episodes can not be defined by a Stage for different cancer types. E.g. A 4a stage for a patient with tonsillar HPV-positive cancer is not the same as a 4 stage Melanoma (“4th stage is not always Metastatic”).

b) A more general rule may be applied only for TNM descriptors and should look like

i) N≥1 ⇒ [Invasive Disease](https://athena.ohdsi.org/search-terms/terms/32943)


ii) M≥1 ⇒ [Metastatic Disease](https://athena.ohdsi.org/search-terms/terms/32944)

c) Upstaging and Downstaging (the increase/reduction of the numeric value of a staging parameter) may be used to define the Progression Episode or Remission episode, respectively. This particular case should be treated with caution with high compliance to study protocol, as definition of specific disease extent episodes may vary from one protocol to other.