Ploidy/DNA and S-phase markers

[tousled1]

I notice on the board that the majority of women are HER2 positive. I am stage III metastatic infiltrating ductal, axillary node positive. Going through neoadjunct chemo (had 4 rounds A/C 1 round Taxatore and 3 more Taxatore to go). My pathology reports reads:

HER2/neu by FISII: Ratio = 3.1
Ploidy/DNA index: Aneuploid/1.61
S-phase: 24.2%
Estrogen receptors: negative
Progesterone receptors: negative

I was wondering if anyone else on this board knows what their Ploidy/DNA index and S-phase is. I know that these 2 markers have a great bearing on treatment/recurrence.

[Alice]

I don't know about the other markers but I think the s phase refers to the mitotic rate. I'm not real sure though.

[Bev]

1.98 tetraploid
low S phase, no accurate s phase population can be determined due to aneuploid cell population.

Somewhere on this site or in The Breast Book you can decipher somewhat what this means. Lower S phase, how fast tumor cells are dividing, is better. Ploidys are how much DNA is present. Aneuploid means abnormal I think, tetraploid means twice as much. I don't know exactly how the ratio is calculated. I suspect higher numbers are worse but don't know for sure.

Overall I think these figures are used to determine how aggressive the tumor is. I think they would be more significant for a stage 1 or 2 to determine if chemo is called for.

[tousled1]

Breast tumors that are diploid, tetraploid and aneuploid have a favorable, intermediate and unfavorable prognosis, respectively.

Breast tumors that have an S-phase of <7%, 7-12%, and >12% have a favorable, intermediate and unfavorable prognonsis respectively.