BC 1990 - breast cancer - data structure and protocols

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BC 1990 data preparation: brief written protocol

Strict confidentiality of trial results is observed. Information is held in the Clinical Trial Service Unit computers in a form which can be accessed only by known individuals.

All patient records are converted into 'pink form' (1990) format (described below) if not already supplied in it. Results received as tables are converted into sets of synthetic records. The following routine checks (where appropriate) are performed on every compilation:

The total numbers of patients and the distributions of randomisation age, menopausal status, axillary nodal status, oestrogen receptor status and progesterone receptor status are checked for any significant imbalance between treatment groups. These five distributions are compared as follows. Patients are grouped into three categories according to randomisation age (below 50 years; 50 - 69 years or unknown; 70 years or above) and a chi-squared test is applied to the population of the three categories found in each treatment group. Similarly, three categories are formed for menopausal status (pre- or perimenopausal; unknown; postmenopausal), for axillary nodal status (negative; unknown; positive), for oestrogen receptor status (poor; unknown; positive) and for progesterone receptor status (poor; unknown; positive) and these are tested in the same way as the categories formed for randomisation ages.

If an event such as the recurrence of disease is reported at a date later than the quoted last follow-up date, the last follow-up date is automatically changed to the later date. The completeness of follow-up is then calculated for the end of each calendar year. The distributions of randomisation dates, randomisation ages and time elapsed since last follow-up are checked for any significant imbalance between treatment groups in two ways as follows. Firstly, a t-test is applied to the difference between the mean value of each distribution for patients in each group with the corresponding mean for patients in the remainder. Secondly, an F-ratio is calculated for each distribution by comparing the variance between the groups with the variance within the groups. The distribution of time elapsed since last follow-up is also checked in these two ways for any significant imbalance between those patients with and those patients without a recorded recurrence of disease. Finally, the distribution of time elapsed since last follow-up is checked in the same two ways for any significant imbalance between patients in two categories of menopausal status (pre- or perimenopausal; postmenopausal), two categories of axillary nodal status (negative; positive), two categories of oestrogen receptor status (poor; positive) and two categories of progesterone receptor status (poor; positive).

Where patient serial numbers form an obvious sequence it is checked for missing numbers.

A tabulated breakdown of variables is produced for each trial, together (where relevant) with lists of patents in 'problematical' categories such as those with lapsed follow-up. In some cases Kaplan-Meier life-table curves are produced. Before trial data are finally incorporated into the overview, the analyses described above are sent to the participating trialist(s) for checking and approval.


Please address inquiries concerning data preparation and checking to:

Specification of BC 1990 'pink form' format

Item Description FORTRAN Columns Details Abbreviation
Study number I6  1 - 6  Trial 
Patient number A6  8 - 13  Patient 
Randomisation date  I6  15 - 20  DDMMYY  Rand. Date 
Treatment group I1  22  Trt. Grp 
Randomisation age  I2  24 - 25  years  Age 
5 Menopausal status on entry  I1  27 
Value Description Abbreviation
Pre-menopausal  Pre 
Peri-menopausal  Peri 
Post-menopausal  Post 
"Post-meno. surg." - NEW Arti 
Surgery: first mastectomy  I2  28 - 29 
Value Description Abbreviation
Radical  Rdcl 
Total  Totl 
Simple Simp 
Partial Part 
None None 
Total Simple - NEW T/S
Lumpectomy - NEW Lump 
Subcutaneous - NEW Subc 
Simple with clearance - NEW SC 
10  Patey P. minor only - NEW PPm
11  Other - NEW Othe 
Axillary status on entry  I2  30 - 31 
Value Description Abbreviation
N0 (clearance)  N0 
N1-3 (clearance)  N1-3 
N4+ (clearance)  N4+ 
N- (sample only)  N- 
N+ (sample only)  N+ 
N- (clinical)  N- 
N+ (clinical)  N+ 
N- (method unknown) - NEW N- 
N+ (method unknown) - NEW N+ 
10  N+ (clearance) - NEW N+ 
11  N > 1 (clearance ) - NEW N > 1 
12  N1-3 (method unknown) - NEW N1-3
13  N4+ (method unknown) - NEW N4+
14  Benign lesion - NEW Benign
15  N? (clinical) N0 (clearance)   
16  N? (clinical) N1-3 (clearance)
17 N? (clinical) N4+ (clearance)
18 N? (clinical) N0 (clearance)
19 N- (clinical) N1-3 (clearance)
20 N- (clinical) N4+ (clearance)
21 N- (clinical) N0 (clearance)
22 N- (clinical) N1-3 (clearance)
23 N+ (clinical) N4+ (clearance)
24 N+ (clinical) N0 (clearance)
25 N+ (clinical) N1-3 (clearance)
26 N+ (clinical) N4+ (clearance)
Oestrogen receptor status I2  32 - 33 
Value Description Abbreviation
Negative  ER- 
Marginal  ER- 
Positive  ER+ 
< 10 fmol/mg protein  ER- 
10 - 19 fmol/mg protein  ER+ 
20 - 29 fmol/mg protein  ER+ 
30 - 49 fmol/mg protein  ER+ 
50 - 99 fmol/mg protein  ER+ 
100+ fmol/mg protein  ER++ 
10  10 - 29 fmol/mg protein - NEW ER+ 
11  30 - 100 fmol/mg protein - NEW ER+ 
12  10 - 99 fmol/mg protein - NEW ER+ 
13  0 fmol/mg protein - NEW ER- 
14  10 - 49 fmol/mg protein - NEW ER+ 
Est. Rec., E.R. 
Progesterone receptor status I2  34 - 35 
Value Description Abbreviation
Negative  PR- 
Marginal  PR- 
Positive  PR+ 
< 10 fmol/mg protein  PR- 
10 - 19 fmol/mg protein  PR+ 
20 - 29 fmol/mg protein  PR+ 
30 - 49 fmol/mg protein  PR+ 
50 - 99 fmol/mg protein  PR+ 
100+ fmol/mg protein  PR++ 
10  10 - 29 fmol/mg protein - NEW PR+ 
11  30 - 100 fmol/mg protein - NEW PR+ 
12  10 - 99 fmol/mg protein - NEW PR+ 
13  0 fmol/mg protein - NEW PR- 
14  10 - 49 fmol/mg protein - NEW PR+ 
Prg.Rec., P.R. 
10  Contralateral breast cancer I1  37
Value Description Abbreviation
No  No
Yes Contra
3 Ipsilateral Ipsi - NEW
4 Both Both - NEW
11  Date of second primary breast cancer I6  39 - 44 DDMMYY  2-P. Date 
12  Recurrence I1  46 
Value Description Abbreviation
No  No
Yes Yes
13  Date of first recurrence  I6  48 - 53  DDMMYY  Rec. Date 
14  Distant recurrence  I1  55 
Value Description Abbreviation
No  No
Yes Yes
D-Rec. Date
15  Date of first distant recurrence  I6  57 - 62  DDMMYY  L-Rec. Date 
16  State when last traced  I2  63 - 64
Value Description Abbreviation
Alive  Alive 
Dead  Dead 
Lost  Lost 
Utterly lost - NEW Lost+ 
Alive?, ineligible for protocol - NEW A/in. 
Dead, ineligible for protocol - NEW D/in. 
Lost, presumed dead - NEW LostD 
10  Lost and ineligible - NEW L/in. 
11  Utterly lost and ineligible - NEW L+/in. 
17  Date died or last traced  I6  66 - 71  DDMMYY  L.F.U. 
18  Cause of death (extra category)  I2  72 - 73 
Value Description Abbreviation
Iatrogenic - NEW Iatro 
Infective Infec 
Lymphatic and haematopoietic - NEW Leuk 
Other second neoplasm - NEW Neop2 
Heart - NEW Heart 
Thrombotic or embolic - NEW ThEmb 
Other vascular - NEW Ovasc 
Extraneous cause - NEW Extra 
Not 1 - 8 and not breast cancer - NEW NotBC 
10  Not breast cancer - NEW NotBC 
11  Breast cancer or its metastases - NEW BCMet 
12  Unknown cause - NEW Unkn. 
19  Name and comments  75 - end  Name 
Missing or unknown items are left blank or set to zero.

BC 1990 data form rubric



Special coding conventions


Patient identifier


2nd prim?

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[End of document, updated to 3 June 2000]