Behavior Code Changes

Perhaps the most important change between ICD-O-2 and ICD-O-3 involves a small number of disease entities that have changed behavior codes.

Terms Changing from Borderline to Malignant Behavior

Eleven diagnoses are changing from borderline to malignant to reflect current medical understanding about the behavior of these neoplasms. They include all of the refractory anemia types, polycythemia vera, a number of other hematopoietic diseases, and papillary meningioma,. The change from behavior code 1 (borderline) to behavior code 3 (malignant) will make these diseases reportable to cancer registries that do not currently require their collection. The impact on cancer registries that must add these cases to their databases is not believed to be substantial. SEER estimates 5,000 to 10,000 new cases per year in the U.S., about the frequency of pharynx, gallbladder, or testicular cancer or Hodgkin's disease or chronic lymphocytic leukemia. It will, however, be necessary to add new codes to current casefinding code lists in order to identify these newly reportable diagnoses from the medical record disease indices.

Terms that Changed to Malignant Behavior

ICD-O-2 Code Primary term as it appeared in ICD-O-2 ICD-O-3 Code
8931/1 Endolymphatic stromal myosis (C54.1) 8931/3
9134/1 Intravascular bronchial alveolar tumor (C34._) 9133/3
9393/1 Papillary ependymoma 9393/3
9538/1 Papillary meningioma 9538/3
9950/1 Polycythemia vera 9950/3
9960/1 Chronic myeloproliferative disease, NOS 9960/3
9961/1 Myelosclerosis with myeloid metaplasia 9961/3
9962/1 Idiopathic thrombocythemia 9962/3
9980/1 Refractory anemia, NOS 9980/3
9981/1 Refractory anemia without sideroblasts 9980/3
9982/1 Refractory anemia with sideroblasts 9982/3
9983/1 Refractory anemia with excess blasts 9983/3
9984/1 Refractory anemia with excess blasts in transformation 9984/3
9989/1 Myelodysplastic syndrome, NOS 9989/3

Terms Changing from Malignant to Borderline Behavior

Five neoplasms previously coded as malignant (/3) will revert to borderline status: the cystadenomas of the ovary. A careful review of survival rates for the cystadenomas, which had been considered malignant while ICD-O-2 was in effect, indicated that their behavior was much closer to benign rather than malignant and the overall survival rate for them was nearly 100%. In most registries, these neoplasms will now be considered non-reportable and it will not be necessary to collect them. Cystadenomas of the ovary collected during the period when ICD-O-2 was in effect may be deleted from registry databases at the discretion of the database manager or standard-setting agency. One additional term, pilocytic or juvenile astrocytoma, and one obsolete term (spongioblastoma, NOS) will also revert to borderline behavior. However, for the sake of continuity, pilocytic astrocytoma will continue to be collected in many registries for the next few years.

Terms that Changed from Malignant to Borderline

ICD-O-2 Code Primary term as it appeared in ICD-O-3 ICD-O-3 Code
8442/3 Serous cystadenoma, borderline malignancy (C56.9) 8442/1
8451/3 Papillary cystadenoma, borderline malignancy (C56.9) 8451/1
8462/3 Serous papillary cystic tumor of borderline malignancy (C56.9) 8462/1
8472/3 Mucinous cystic tumor of borderline malignancy (C56.9) 8472/1
8473/3 Papillary mucinous cystadenoma, borderline malignancy (C56.9) 8473/1
9421/3 Pilocytic astrocytoma (C71._) 9421/1
9422/3 Spongioblastoma, NOS (C71._) 9421/1

Terms that Changed from Borderline to Benign Behavior

ICD-O-2 Code Primary term as it appeared in ICD-O-3 ICD-O-3 Code
8120/0 Transitional cell papilloma, NOS 8120/1
8152/0 Glucagonoma, NOS (C25._) 8152/1
8580/0 Thymoma, NOS (C37.9) 8580/1
8640/0 Sertoli cell tumor, NOS 8640/1
9506/0 Neurocytoma 9506/1