Immense changes have occurred over the past decade in techniques for diagnosing neoplasms. As a result, pathologists have been able to provide much more specific information about certain cancers. In particular, cytogenetic techniques have added considerably to the body of knowledge about malignant lymphomas and leukemias. In some cases, the names of the diseases have changed to reflect the additional information. As a consequence, cancer registries and pathology departments using the International Classification of Diseases for Oncology, second edition (ICD-O-2) have been unable to code these new entities satisfactorily.

Responding to requests for assignment of new code numbers for these entities, in 1998, the International Agency for Research on Cancer (IARC), the cancer division of the World Health Organization, gathered a task force to assess whether a revision or new edition of ICD-O was necessary. It was

initially thought that only the lymphomas and leukemias would be revised. However, when questionnaires sent to every national registry in the world indicated that new diagnostic terms had been identified in all

categories of neoplasms, it was decided to update the entire book. It was not necessary to revise the topography section of ICD-O-2, since it is based on the International Classification of Diseases, tenth revision.

In addition, there was a desire that the next edition of ICD-O be compatible with other World Health Organization publications such as the series Histological Typing of Tumours, known to pathologists around the world as the Blue Books. In a coordinated effort with the editors of the Blue Books, all terms in existing fascicles were reviewed to assure that the histologic terminology was included in ICD-O-3. Further, fascicles in preparation have been reviewed to assign ICD-O-3 codes to the terms listed in their type lists.

ICD-O-3 underwent a limited but comprehensive field trial last summer. The editors met in October 1999 and again in January 2000 to finalize the lists of terms and codes and to add any additional terms found during the field trial. Additional committee work has been conducted by conference call and electronic mail.

ICD-O-3 will be implemented in North America effective with cases diagnosed on or after January 1, 2001. The advent of a new edition of ICD-O offers the opportunity to review important aspects of coding guidelines that have not changed, to highlight the enhancements provided by the editors, and to underscore what is new and what is different in the third edition.

The Good News
Borderline tumors of ovary (cystadenomas) revert to /1.

• serous
• serous papillary
• mucinous
• papillary mucinous
• papillary

In other words, you won't have to collect borderline tumors of the ovary any more. SEER looked at survival rates for these tumors, and the survival rate was nearly 100%--making their behavior much closer to benign rather than malignant. However...

The Not-So-Good News

• Polycythemia vera
• Refractory anemias
• Chronic myeloproliferative disease
• Idiopathic thrombocythemia
• Myelosclerosis with myeloid metaplasia
• Essential thrombocythemia

...become reportable

You will have to start collecting some of the blood diseases:

• polycythemia vera
• the myelodysplastic syndromes (refractory anemia)
• myeloproliferative disorders.

The impact of adding these cases is not believed to be substantial. We estimate 5000 to 10,000 new cases per year in the U.S., about the frequency of pharynx or gallbladder, or testis or Hodgkin's disease or CLL.

SEER plans additional training efforts to help registrars recognize and abstract these blood diseases.