4
Diagnosis
Recommendation 1.4. Optimal internal validation procedures
(change anticipated)
➤ This topic is deferred to forthcoming CAP guideline update, Principles
of Analytic Validation of IHC Assays, once available. There should
be initial test validation/verification prior to reporting any clinical
samples. Prior to that, previously recommended principles apply.
(Strong Recommendation; EB-H)
Recommendation 1.5. Optimal internal QA procedures
➤ Ongoing quality control and equipment maintenance are required.
Initial and ongoing laboratory personnel training and competency
assessment should be performed. Standardized operating procedures
should be used that include routine use of external control materials
with each batch of testing and routine evaluation of internal normal
epithelial elements or the inclusion of normal breast sections (or
other appropriate control) on each tested slide, wherever possible.
External controls should include negative and positive samples as
well as samples with lower percentages of ER expression (such as
tonsil). On slide controls are recommended. Regular, ongoing assay
reassessment should be done at least semiannually. Revalidation is
needed whenever there is a significant change to the test system.
Ongoing competency assessment and education of pathologists is
required. (Strong Recommendation; EB-H)
Recommendation 1.6. Optimal external proficiency assessment
➤ The laboratory performing ER and PgR testing must participate in
external proficiency testing or alternative performance assessment
as required by its accrediting organization. (Strong Recommendation;
EB-H)
Recommendation 1.7. Optimal laboratory accreditation
➤ On-site inspection every other year should be undertaken with annual
requirement for self-inspection. (Moderate Recommendation; IC-I)
Recommendation 2.1
➤ Laboratories should include ongoing quality control using standard
operating procedures for test evaluation prior to scoring (readout)
and interpretation of any case as defined in the checklist in Figure 1.
(Strong Recommendation; IC-H)
