Tumor size related to probability of node involvement

chocomousse

I had a simple mastectomy with a SLN biopsy on 8.18 and my SLN tested negative, thank God. Those were the words I prayed to hear. I am now calcification-free and get to avoid rads. But, my BS told me something that I hadn't read before or maybe overlooked which is that the larger the DCIS tumor, the higher the chance that invasive cells will be found in the lymph nodes. I knew that grade and size increased the risk for microinvasion in the tumor but not in the nodes. He said that a 4cm tumor like mine or larger increases the risk of node involvement by 30%-40%. I haven't had my follow-up visit yet so I haven't had the chance to ask him if microinvasion was present in the tumor or if it was even tested.

Just wanted to pass that along.

april485

All you can do is wait for pathology unfortunately. Try not to "go there" in your head. Hoping that it stays pure DCIS with no micro-invasion and absolutely 0 nodal involvement. I know it is hard and your doctor probably should not have told you that cause now you can't "un-know" it. But, try to put it out of your mind as much as you can (and I know it is easier said than done) and enjoy your weekend. Hugs and my fingers are crossed for you.

chocomousse

Thank you April!

I'm fine though, nothing invasive was found in my sentinel node so I'm free and clear.

Annette47

I had never heard that. The only thing I can think of is that the larger the DCIS, the higher the odds of an invasive component which in turns raises the risk of lymph node involvement. Increasing the risk by 30-40% isn’t really all that much - he wasn’t saying the risk of lymph node involvement was 30-40%. What I was told was that there is (overall) a 20% risk of invasion with DCIS - higher with larger, higher grade DCIS, lower with smaller, lower grade (ignore the fact that I had a micro invasion with a tiny area of Grade 2, LOL). Once you have an invasive component, then the odds according to my surgeon are about 10% of lymph node involvement, although she said with a micro invasion it’s probably more like 5% or less.

So, 20% risk of invasion and then 10% risk of lymph node involvement is .20*.10 = .02 chance of lymph node involvement overall. 40% of .02 is .0008, so your risk might go from 2% with a small/average DCIS to 2.08% with a larger one.

CAMommy

ditto Annette. 30-40% increase of a very small number remains a very small number. I wish Drs would be more careful when they throw statistics around

dtad

Maybe Im missing something but the DCIS tumor must first become invasive in the breast before you would have node involvement