Code indicates the sequence of all reportable neoplasms over the lifetime of the person. This data item differs from Sequence Number-Hospital [560], because the definitions of reportable neoplasms often vary between a hospital and a central registry. Each neoplasm is assigned a different number. Sequence Number 00 indicates that the person has had only one in situ or one malignant neoplasm as defined by the Federal reportable list (regardless of central registry reference date). Sequence Number 01 indicates the first of two or more reportable neoplasms, but 02 indicates the second of two or more reportable neoplasms, and so on. Because the time period of Sequence Number is a person’s lifetime, reportable neoplasms not included in the central registry (those that occur outside the registry catchment area or before the reference date) also are allotted a sequence number. For example, a registry may contain a single record for a patient with a sequence number of 02 because the first reportable neoplasm preceded the central registry’s reference date.

Reporting Requirements: Federally Required and State/Province Defined
The Federal or SEER/NPCR standard defining the reportable neoplasms is described in Chapter III, Standards For Tumor Inclusion and Reportability. It is assumed that this shared standard is the “minimum” definition of reportability. Individual central cancer registries may define additional neoplasms as reportable.

Numeric codes in the 00-59 range indicate the sequence of neoplasms of in situ or malignant behavior (2 or 3) at the time of diagnosis, which SEER/NPCR standards require to be reported. Codes 60 to 87 indicate the sequence of non-malignant tumors (as defined in Chapter III) and any other neoplasms that the central registry has defined as reportable. Neoplasms required by SEER/NPCR with an in situ or malignant behavior at the time of diagnosis are sequenced completely independently of this higher-numbered category. Sequence Number-Hospital does not affect Sequence Number-Central. The two notational systems are independent but central registries should take Sequence Number-Hospital [560] into account when coding Sequence Number Central.

The purpose of sequencing based on the patient’s lifetime is to truly identify the 00s, the people who only had one malignant primary in their lifetimes for survival analysis. If a central registry sequences by just what is reported to them, then it will be unclear whether 00 means the person only had one malignant primary in his lifetime or the person had one malignant primary since the central registry started collecting data. The Federally required reportable list has changed throughout the years, so the registry must use the appropriate reportable list for the year of diagnosis. The central registry reference date will not affect Sequence Number-Central.

The table that follows shows which sequence number series to use by type of neoplasm.

Neoplasm	SeqNum-Central
In Situ/Malignant as Federally Required based on Diagnosis Year	(Numeric Series)
In Situ (behavior code = 2) (Cervix CIS/CIN III, Diagnosis Year before 1996) (includes VIN III, VAIN III, AIN III)	00 -- 59
Malignant (behavior code = 3)	00 -- 59
Juvenile Astrocytoma, Diagnosis Year 2001+ (*)	00 -- 59
Invasive following In Situ--New primary as defined by CoC	00 -- 59
Invasive following In Situ--New primary as defined by SEER	00 -- 59
Unspecified Federally Required Sequence Number  or Unknown	99
Non-malignant Tumor as Federally Required based on Diagnosis Year or State/Province Registry-Defined
Examples:
Non-malignant Tumor/Benign Brain	60 -- 87
Borderline Ovarian, Diagnosis Year 2001+	60 -- 87
Other Borderline/Benign	60 -- 87
Skin SCC/BCC	60 -- 87
PIN III	60 -- 87
Cervix CIS/CIN III, Diagnosis Year 2003+	60 -- 87
Unspecified Non-malignant Tumor or Central Registry-Defined Sequence Number	88
Cervix CIS/CIN III, Diagnosis Year 1996-2002	98

Note: See the section on Sequence Number--Central in The SEER Program Code Manual.

Note: Conversion Guidance: The sequence numbers for neoplasms whose histologies were associated with behavior codes that changed from in situ/malignant to benign/borderline or vice versa during the conversion from ICD-O-2 to ICD-O-3 should not be re-sequenced.