How to judge HER2 immunohistochemistry, FISH?3 major cancer guidelines are recommended!

*For medical professionals for reading reference

One article masters the interpretation of breast cancer, gastric cancer, and urinary epithelial cancer.

The HER2 gene plays an important role in the occurrence and development of a variety of tumors. In recent years, HER2 related therapy for HER2 -positive gastric cancer, breast cancer, and urinary epithelial cancer has also achieved good results in clinical practice. Patients and clinicians' attention to HER2 results is also increasing day by day. Therefore, the pathologist also put forward new challenges to the test of HER2. This article mainly explains and explains the HER2 interpretation of gastric cancer, breast cancer, and urinary tract cancer.

Gastric cancer

According to the "Gastric Cancer HER2 Test Guidelines (2016)" [1] and "Gastric Cancer HER2 Testing Guide (2011)" [2] suggestion, all cases that are confirmed by pathological diagnosis must be performed by HER2 testing; If the lesion and the recurrence or metastatic lesions, if a sufficient specimen can be obtained, it is recommended to re -perform HER2 testing. "Gastric Cancer HER2 Test: Recommended by the Asia -Pacific Working Group" also recommends that the recurrence and metastasis of gastric cancer patients will be re -performed.

HER2 detection process of gastric cancer

The preferred method: immunohistochemistry. According to the IHC reading situation, decide whether to cross the same place in situ.

IHC3+cases are directly judged as HER2 positive; cases of IHC1+and IHC0 are directly judged as negative.

The specific interpretation of IHC2+needs to be further combined with in -situ hybridization to ultimately clarify its state.

HER2 interpretation of gastric cancer

1

Immunohistochemistry

2

In -situ

"Gastric Cancer HER2 Detection Guide (2011)" believes that the two -color silver dye in -situ hybrid (DSISH) is more practical value than fluorescent in situ hybridization (FISH) FISH is a conventional means.

Fish interpretation of gastric cancer

Breast cancer

According to the "Breast Cancer HER2 Testing Guide (2019 Edition)" [3], all breast primary and influential cancer should be performed. Moreover, as long as the tumor tissue can be obtained, HER2 detection should be performed for recurrence and metastases.

However, it should be noted that for tissue -level infiltrated duct cancer, classical infiltrated lobular cancer, small tube cancer, mucocar cancer, screen cancer, secretion cancer, low -grade glandocarcinoma, and low levels HER2 is usually negative. If the test results are positive, you need to verify the diagnosis or re -test of tissue pathology.

Breast cancer HER2 detection process

Generally, IHC testing is performed first, and according to the situation of IHC, decide whether to do a miscellaneous auxiliary in -situ.

IHC3+is judged as HER2 positive, and IHC0 or 1+ is judged as HER2 negative.

IHC2+needs to be clear in situ, or select other tissue blocks and other laboratory re -inspection.

Breast cancer HER2 interpretation standard

1

Immunohistochemistry

It should be noted that: A interpretation standards are based on each slicing meter; the type B specimen can include surgical resection, rough needle puncture biopsy, Mermelon biopsy, and cytology specimens greater than 100 tumor cells.

2

In -situ

According to the guideline recommendation, IHC testing HER2 protein expression level is used, and the in -situ hybrid detection HER2 gene amplification level is applied. In situ hybrids include fluorescent in situ hybrid (FISH) and bright field of view, and the commonly used bright field of view includes the in situ hybrid (CISH) and silver enhanced in -situ hybrid (SISH). The most widely used in SISH is the two -color in situ hybridization (DISH), which is consistent with FISH's double -probe test results. This article will list the five results of the interpretation.

Remarks: When HER2/CEP17 ratio is <2.0, the average HER2 copy number is ≥4.0 and the <6.0 signal/cells, according to the existing evidence -based medical evidence, it is not possible to determine whether the patient can benefit in the anti -HER2 targeted drug. It is recommended to make a comprehensive analysis after re -counting. If the above situation is still the above situation, the interpretation of the results of the IHC will be made.

Urine epithelial cancer

Depending on the current research of urinary epithelial cancer, it cannot benefit from only anti -HER2 drugs, but when it is combined with other drugs, it still brings better clinical effects to patients. In the world, there is no HER2 interpretation criteria for urinary tract cancer. In order to better benefit patients, domestic experts and scholars jointly released the "Consensus on Clinical Pathological Experts in the Urinary Cancer Cancer Epidermal Growth Factors 2 in China" [4 ].

This consensus recommends that patients with advanced or metastatic urinary tract epithelial cancer should be detected by HER2 protein. At the same time, it is recommended that all postoperative diagnosis of patients with muscle layer infiltrate urinary tract cancer (phase ≥pT2) regular HER2 Protein expression testing. As a result, more patients can benefit more patients.

It should be pointed out that the HER2 interpretation of the urinary tract cancer is still in its infancy, and the standards are more referenced with breast cancer and combined with the characteristics of urinary epithelial cancer.

Her2 interpretation standard

1

immunochemistry

2

Genetic amplification detection

Remarks: Regarding the detection of HER2 protein on the urinary tract, it is recommended to use a paraffin -embedded tissue using surgical resection or biopsy, and it should not be too long to avoid affecting expression; Paraffects made of cytology specimens can also be buried, but it should be indicated. Summarize

The change of the HER2 gene plays a role in a variety of types of tumors, and the accurate HER2 test is the cornerstone of the patient's correct treatment. The standardized operation and standard interpretation of the operation and standards help improve the accuracy and repetitiveness of HER2. In the process of judgment, pathologists need to be closely linked to the clinic, attach importance to the cooperation of multidisciplinary disciplines to help the correct judgment of the results and the objective evaluation of the treatment efficacy.

references:

1. "Gastric Cancer HER2 Testing Guide (2016 Edition)" Expert Group. Stomach cancer HER2 Test Guide (2016 version) [J]. Chinese Pathological Magazine, 2016, 45 (08): 528-532.

2. "Stomach Cancer HER2 Test Guidelines" writing group. Stomach cancer HER2 test guide [J]. Chinese pathology magazine, 2011, 40 (08): 553-557.

3. Breast cancer HER2 Testing Guide (2019 version) [J]. Chinese Pathological Magazine, 2019 (03): 169-175.

4. The China Anti -Cancer Association Oncology Professional Committee, the China Clinical Oncology Society of Clinical Oncology Society of Urine Cancer Cancer. (10): 1001-1006.

First of this article: The pathological channel of the medical community

Author of this article: No. 4

Audit expert: Professor Dong Lin, Cancer Hospital of the Chinese Academy of Medical Sciences

Editor in charge: Xiao Wang

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