CRC 1991 - colorectal cancer - analysis details: endpoints, steering files and strata

Contents List

• CRC 1991 - colorectal cancer
• CRC 1991 run-time diktats
• List of CRC 1991 endpoints
• CRC 1991 endpoint definitions (awaiting re-write)
• List of CRC 1991 strata
• Data structure and protocols for CRC 1991

CRC 1991 run-time diktats

• Run-time re-staging from Astler-Coller (not data edit)

• 'Inoperable' and 'metastasis at entry' (any given stage) are analysed as stage 'D'.
• Run-time estimation of unknown randomisation date
• Set randomisation date to the earliest known date of:
• Today
• Cutoff date (if any)
• LFU/death date
• Recurrence date
• Run-time estimation of unknown endpoint/censoring date
• Set endpoint/censoring date to the latest known date of:
• Randomisation date
• Recurrence date
• Run-time application of cut-off date, where relevant
• If the randomisation date is later than the cut-off date, omit the case.
• If the endpoint/censoring date is after the cut-off date, censor at the cut-off date instead.
• Run-time estimation of unknown entry age (except for the detailed-age-stratified analysis)
• Unknown: 65
• Run-time definition of 'probable colorectal cancer deaths'
• Includes all deaths with stage 'D', stage 'Y' or recurrence, and those with 'unknown cause'

Note on simultaneity of events

List of CRC 1991 endpoints

CRC 1991 endpoint definitions (should be read in conjunction with Diktats)

Run-time strategy for data errors

• In addition to cases with 'first recurrence' flags set, a first recurrence is taken to be present if a date of first recurrence is present, or if a site of first recurrence other than 'unknown, but not liver' is given.

DD: MORTALITY

• death has occurred.

If an event is not taken to have occurred, the case is censored at the date last traced.

DDCC: COLORECTAL CANCER MORTALITY

• death has occurred; and
• the cause of death is 'colorectal cancer', 'unknown' or is not stated; or
• tumour stage is D, W or Y; or
• a recurrence is reported.

If an event is not taken to have occurred, the case is censored at the date last traced.

DDCCO365: COLORECTAL CANCER MORTALITY, AFTER 30 DAYS FROM SURGERY BUT WITHIN FIRST YEAR

• the surgery and randomisation dates exist; and
• death has occurred after day 30 from surgery and before day 366 from randomisation; and
• the cause of death is 'colorectal cancer', 'unknown' or is not stated; or
• tumour stage is D, W or Y; or
• a recurrence is reported.

If an event is not taken to have occurred, the case is censored at 365 days after the randomisation date, or the date died or last traced if earlier.

DDCCR365S : COLORECTAL CANCER MORTALITY BEFORE SURGERY

• surgery was not performed; and
• the randomisation date exists and death has occurred before day 366 after randomisation, or on an unknown date; and
• the cause of death is 'colorectal cancer', 'unknown' or is not stated; or
• tumour stage is D, W or Y; or
• a recurrence is reported.

If an event is not taken to have occurred, the case is censored at 365 days, or the earlier of the date died or last traced and the surgery date (if non-null), if earlier that 365 days.

DDCCS30: COLORECTAL CANCER MORTALITY WITHIN 30 DAYS AFTER SURGERY

• the surgery date exists; and
• death has occurred before day 31 after surgery, or on an unknown date; and
• the cause of death is 'colorectal cancer', 'unknown' or is not stated; or
• tumour stage is D, W or Y; or
• a recurrence is reported.

If an event is not taken to have occurred, the case is censored at 365 days after the surgery date (if non-null, otherwise on the randomisation date), or the date died or last traced if earlier.

DDO365: MORTALITY AFTER 30 DAYS FROM SURGERY BUT WITHIN FIRST YEAR

• the surgery and randomisation dates exist; and
• death has occurred after day 30 from surgery and before day 366 from randomisation.

If an event is not taken to have occurred, the case is censored at 365 days after the randomisation date, or the date died or last traced if earlier.

DDPOSTREC: MORTALITY OMITTING DEATHS FROM KNOWN NON-COLORECTAL-CANCER CAUSES WITHOUT RECURRENCE

DDR365S: MORTALITY BEFORE SURGERY

• surgery was not performed; and
• the randomisation date exists and death has occured before day 366 after randomisation, or on an unknown date.

If an event is not taken to have occurred, the case is censored at 365 days, or the earlier of the date died or last traced and the surgery date (if non-null), if earlier that 365 days.

DDS30: MORTALITY WITHIN 30 DAYS AFTER SURGERY

• the surgery date exists; and
• death has occurred before day 31 after surgery, or on an unknown date.

If an event is not taken to have occurred, the case is censored at 30 days after the surgery date (if non-null, otherwise on the randomisation date), or the date died or last traced if earlier.

DDUKRL: MORTALITY FROM UNKNOWN CAUSES WITHOUT RECORDED RECURRENCE

• death has occurred; and
• the cause of death is 'unknown' or is not stated; and
• tumour stage is not D, W or Y; and
• a recurrence is not reported.

If an event is not taken to have occurred, the case is censored at the randomisation date if tumour stage is D, W or Y; or, otherwise, at the earlier of the date last traced and the date of first recurrence (if non-null).

DD90: MORTALITY WITHIN 90 DAYS

• the randomisation date exists and death has occurred during days 0-90 after randomisation.

If an event is not taken to have occurred, the case is censored at 90 days, or the date died or last traced if earlier.

NONCC: MORTALITY FROM KNOWN NON-COLORECTAL-CANCER CAUSES WITHOUT RECURRENCE

• death has occurred and the cause of death is stated as anything except 'colorectal cancer' or 'unknown'; and
• tumour stage is not D, W or Y; and
• a recurrence not is reported.

If an event is not taken to have occurred, the case is censored at the randomisation date if tumour stage is D, W or Y; or, otherwise, at the earlier of the date last traced and the date of first recurrence (if non-null).

NONCCO365: MORTALITY FROM NON-COLORECTAL-CANCER CAUSES, AFTER 30 DAYS FROM SURGERY BUT WITHIN FIRST YEAR

• the surgery and randomisation dates exist; and
• death has occurred after day 30 from surgery and before day 366 from randomisation; and
• the cause of death is stated as anything except 'colorectal cancer' or 'unknown'; and
• tumour stage is not D, W or Y; and
• a recurrence not is reported.

If an event is not taken to have occurred, the case is censored at the randomisation date if tumour stage is D, W or Y; or, otherwise, at 365 days after the randomisation date, or at the earlier of the date last traced and the date of first recurrence (if non-null).

NONCCR365S: MORTALITY FROM NON-COLORECTAL-CANCER CAUSES BEFORE SURGERY

• surgery was not performed; and
• the randomisation date exists and death has occured before day 366 after randomisation, or on an unknown date; and
• the cause of death is stated as anything except 'colorectal cancer' or 'unknown'; and
• tumour stage is not D, W or Y; and
• a recurrence not is reported.

If an event is not taken to have occurred, the case is censored at the surgery date (if non-null); or, otherwise, the randomisation date if tumour stage is D, W or Y; or, otherwise, at the earliest of 365 days after the randomisation date, the date last traced and the date of first recurrence (if non-null).

NONCCS30: MORTALITY FROM NON-COLORECTAL-CANCER CAUSES WITHIN 30 DAYS AFTER SURGERY

• the surgery date exists; and
• death has occurred before day 31 after surgery, or on an unknown date; and
• the cause of death is stated as anything except 'colorectal cancer' or 'unknown'; and
• tumour stage is not D, W or Y; and
• a recurrence not is reported.

If an event is not taken to have occurred, the case is censored at the randomisation date if tumour stage is D, W or Y; or, otherwise, at the earliest of 30 days after the surgery date (if non-null, otherwise on the randomisation date), the date last traced and the date of first recurrence (if non-null).

RL: RECURRENCE-FREE SURVIVAL

• tumour stage is D, W or Y; or
• death has occurred; or
• a recurrence is reported.

If an event is not taken to have occurred, the case is censored at the date last traced.

RLD: DISTANT RELAPSE AS FIRST EVENT

• a distant first recurrence type is reported regardless of local recurrence status. Hepatic relapses are included as events.

If an event is not taken to have occurred, the case is censored at the date of randomisation if tumour stage is D, W or Y; otherwise at the date died or last traced.

RLF: RECURRENCE OR COLORECTAL CANCER DEATH AS FIRST EVENT

• tumour stage is D, W or Y; or
• death has occurred and the cause of death is 'colorectal cancer', 'unknown' or is not stated; or
• a recurrence is reported.

If an event is not taken to have occurred, the case is censored at the date last traced.

RLH: HEPATIC RELAPSE AS FIRST EVENT

RLL: LOCAL RECURRENCE AS FIRST EVENT

An event is taken to have occurred if:

• a local first recurrence type is reported regardless of distant recurrence status.

If an event is not taken to have occurred, the case is censored at the date of randomisation if tumour stage is D, W or Y; otherwise at the date died or last traced.

RLLI: ISOLATED LOCAL RECURRENCE AS FIRST EVENT

• a local first recurrence type is reported in the absence of known distant recurrence status.

If an event is not taken to have occurred, the case is censored at the date of randomisation if tumour stage is D, W or Y; otherwise at the date died or last traced.

RLNONH: NON-HEPATIC RELAPSE AS FIRST EVENT

• a first recurrence type specifically excluding liver is reported; or
• tumour stage is D, W or Y or a first recurrence is reported; and
• recurrence type is 'unknown, but not liver'.

If an event is not taken to have occurred, the case is censored at the date of randomisation if tumour stage is D, W or Y; otherwise at the date died or last traced.

RLUH: RECURRENCE OR COLORECTAL CANCER DEATH AS FIRST EVENT, WITH UNKNOWN HEPATIC INVOLVEMENT

• a first recurrence of unknown or distant type without mention of hepatic status is reported; or
• a recurrence is not reported and tumour stage is not D, W or Y; and
• death from colorectal cancer or from an unknown cause is reported.

If an event is not taken to have occurred, the case is censored at the date of randomisation if tumour stage is D, W or Y; otherwise at the date died or last traced.

Additional qualifiers (add after endpoint mnemonic, e.g. DDHF for time from hepatic metastases to death):

H1: Patients with no metastasis at entry

• Tumour stage is not D, W or Y; and
• a recurrence is not reported, or is known to have occurred more than 30 days after randomisation.

H2: Patients with malignant colorectal tumours and no metastasis at entry

• Tumour stage is not D, N, O, W, X, Y or Z; and
• a recurrence is not reported; or
• a recurrence has occurred; and
• the randomisation date is unknown; or
• recurrence occurred more than 30 days after randomisation; or
• the date of first recurrence is unknown and the date died or last traced is unknown or more than 30 days after randomisation.

H3: Patients with hepatic metastases at entry

• A site of first recurrence including the liver is reported (or is 'unknown, liver sometime'); and
• tumour stage is D, W or Y; or
• recurrence occurred less than 31 days after randomisation; or
• the date of randomisation or of first recurrence is unknown.

H4: Patients with non-hepatic metastases at entry

• A site of first recurrence excluding the liver is reported (or is 'unknown, but not liver'); and
• tumour stage is D, W or Y; or
• recurrence occurred less than 31 days after randomisation; or
• the date of randomisation or of first recurrence is unknown.

H5: Stage D patients

• Tumour stage is D or W.

H6: Inoperable patients

• Tumour stage is Y.

HF: Patients with metastatic disease with unknown hepatic involvement at presentation

• The site of first recurrence is unknown, or includes 'distant' with unspecified liver involvement; and
• tumour stage is D, W or Y; or
• recurrence occurred less than 31 days after randomisation; or
• the date of randomisation or of first recurrence is unknown.

H8: Analysis of time from hepatic metastases

• A site of first recurrence including the liver is reported (or is 'unknown, liver sometime'); and
• tumour stage is D, W or Y; or
• a recurrence is reported (in which case, time is counted from the date of first recurrence instead of from the randomisation date).

H9: Patients with benign tumours or without colorectal cancer at entry

• Tumour stage is N or X; and
• tumour stage is not also D, W or Y; and
• recurrence occurred less than 31 days after randomisation; or
• the date of randomisation or of first recurrence is unknown.

HA: Patients with benign tumours at entry

• Tumour stage is X; and
• tumour stage is not also D, W or Y; and
• recurrence occurred less than 31 days after randomisation; or
• the date of randomisation or of first recurrence is unknown.

HB: Patients "without colorectal cancer" at entry

• Tumour stage is N; and
• tumour stage is not also D, W or Y; and
• recurrence occurred less than 31 days after randomisation; or
• the date of randomisation or of first recurrence is unknown.

HC: Dukes stage A-C patients

• Tumour stage is A, B or C.

HD: (Include patients of all stages in A, A2, CR and G analyses)

• Override the normal restriction to stages A, B and C.

List of CRC 1991 strata

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[End of document, updated to 3 June 2000]