Patient selection: thymic epithelial tumor that has undergone complete resection
Parameters identified on multivariate analysis:
(1) age of the patient at the time of surgical resection
(2) recurrent
(3) WHO histologic type
(4) Masaoka stage
|
Parameter
|
Finding
|
Points
|
|
WHO histologic type
|
A, AB, B1
|
0
|
|
|
B2, B3
|
1
|
|
Masaoka stage
|
I
|
0
|
|
|
II, III or IV
|
1
|
|
recurrence
|
no
|
0
|
|
|
yes
|
1
|
where:
• The survival in patients with Masaoka Stage IV disease was better than that for patients with Stage III disease. This may be due to selection bias (requirement for complete resection) and/or more aggressive management.
• The WHO histologic type and Masaoka stage were strongly correlated. Multivariate analysis was conducted excluding one or the other.
The risk increased with increasing age at the time of surgery (hazard ratio 1.03 per year). The mean age for patients who died was 58 years (Table 4, page 1060). The minimum age in the group was 17 years, which may be the baseline for determining risk. There are several possible choices for determining a cutoff for age. I will use the mean age (58) in the implementation.
number of prognostic factors adversely affecting survival =
= SUM(points for all 4 parameters)
Interpretation:
• minimum number of adverse prognostic factors: 0
• maximum number of adverse prognostic factors: 3 or 4 (depending on whether or not the WHO histologic type and Masaoka grade are counted separately)
• The lower the number of risk factors the better the survival.
