Person with cancer—most valid basis of diagnosis of the first recurrence, code N

Guide for use:

Record the most valid basis of diagnosis that identifies the first recurrence of locoregional cancer or a distant metastasis.

The term recurrence refers to the return, reappearance or metastasis of cancer of the same histology after a disease-free period. It may be locoregional or a distant metastasis.

The information is collected for the first recurrence of cancer at any site.

The coding system is based on that recommended by the International Agency for Research on Cancer (IARC) and the International Association of Cancer Registries (IACR). The value "3" is not represented.

If more than one investigation identifying the recurrence is conducted at the same time, select the higher number code from 1 to 8 reflecting the most definitive method of diagnosis. For example, if the patient has both imaging (Code 2) and histology of a primary tumour (Code 7) to verify the cancer, record Code 7 as the most valid basis of diagnosis.

When considering the most valid basis of diagnosis, the minimum requirement of a cancer registry is differentiation between neoplasms that are verified microscopically and those that are not. To exclude the latter group means losing valuable information; the feasibility of making a morphological (histological) diagnosis is dependent upon a variety of factors, such as the health and age of the patient, accessibility of the tumour, availability of medical services, and the beliefs and decisions of the patient.

A biopsy of the primary tumour should be distinguished from a biopsy of a metastasis, for example, at laparotomy; a biopsy of cancer of the head of the pancreas versus a biopsy of a metastasis in the mesentery. However, when insufficient information is available to determine whether the site of the biopsy is primary or metastatic, Code 8. Cytological and histological diagnoses should also be distinguished.

Morphological confirmation of the clinical diagnosis of malignancy depends on the successful removal of a piece of tissue that is cancerous. When using endoscopic procedures such as bronchoscopy, gastroscopy or laparoscopy, the clinician may miss the tumour with the biopsy forceps. These cases must be registered on the basis of endoscopic diagnosis and not excluded through lack of a morphological diagnosis.

Care must be taken in the interpretation and subsequent coding of autopsy findings, which may vary as follows:

(a) The post-mortem report includes the post-mortem histological diagnosis (in which case, one of the histology codes should be recorded instead);

(b) The autopsy is macroscopic only, histological investigations having been carried out only during life (in which case, one of the histology codes should be recorded instead);

(c) The autopsy findings are not supported by any histological diagnosis.

Origin:

International Agency for Research on Cancer (IARC)

Comments:
Information regarding the basis of diagnosis is important for determining how definitively the malignancy was confirmed and subsequently the reliability of cancer statistics.