Nascimbeni et al studied risk factors associated with lymph node metastases in patients with T1 adenocarcinomas of the colon and rectum. These can help identify patients who may require more extensive therapy. The authors are from the Mayo Clinic.
NOTE: T1 lesions in the TNM classification scheme indicates tumors involving the submucosa without extension into the muscularis propria.
Parameters:
(1) depth of invasion in submucosa
(2) lymphovascular spread
(3) anatomic segment
|
Parameter |
Finding |
Points |
|
depth of invasion in the submucosa |
upper third (beneath muscularis mucosae) |
0 |
|
|
middle third |
0.5 |
|
|
lower third (adjacent to muscularis propria) |
1 |
|
lymphovascular spread |
absent |
0 |
|
|
present |
1 |
|
anatomic segment |
lower third of rectum |
1 |
|
|
anywhere else |
0 |
where:
• The point assignment is not from the article but something I did to simplify the analysis.
• Poor differentiation to the adenocarcinoma was a risk factor in univariate but not on multivariate analysis.
• The risk of nodal metastasis relative to depth of invasion was 3% in upper third, 8% in middle third and 23% in lower third. The rate for the lower third seems a bit high to me; I wonder if this could have included most of the poorly differentiated tumors.
number of risk factors =
= SUM(points for each parameter)
|
Risk Factor |
Odds Ratio |
95% CI |
p value |
|
lower third vs upper third |
5.0 |
2.3 – 10.6 |
< 0.001 |
|
lymphovascular involvement |
3.5 |
1.4 – 8.9 |
< 0.009 |
|
lower third rectum |
6.0 |
2.2 – 14.2 |
< 0.001 |
from Table 6, page 203
Interpretation:
• If no risk factors are present, then the risk of lymph node metastases is low.
• If all 3 risk factors are present, then the patient is at risk for lymph node metastases.
Specialty: Hematology Oncology, Surgery, general, Gastroenterology
ICD-10: ,
