Prediction of Metastases to Cervical Lymph Nodes from Squamous Cell Carcinoma of the Tongue and Floor of the Mouth Based on the Histologic Malignancy Score and Vascular Invasion

Parameters for histologic malignancy score (HMS):

(1) degree of keratinization

(2) nuclear differentiation

(3) mitotic rate

(4) inflammatory response

(5) stage of invasion

(6) pattern of invasion

where:

• The parameters are similar to that of Crissman et al (previous section) except that "stage of invasion" replaces "vascular-lymphatic invasion."

• Mitoses are scored based on the number in 10 high power fields, rather than an average number per field.

• Nuclear polymorphism replaces nuclear differentiation, with different descriptors.

• Pattern of invasion uses different criteria than the score in Crissman et al.

histologic malignancy score =

= (points for keratinization) + (points for nuclear polymorphism) + (points for mitotic activity) + (points for lymphoplasmacytic response)+ (points for stage of invasion) + (points for invasion pattern)

Interpretation

• minimum histologic malignancy score: 6

• maximum histologic malignancy score: 24

Logistic Regression Analysis

q =

= (-10.73) + (1.95 if vascular invasion present, else 0) + (0.64 * (histologic malignancy score))

probability of metastasis =

= (1 / (1 + EXP (-q)))

The regression equation correctly classified 87% of cases in the study set.