Please clarify tumor size.

I am 43 years old. Please tell me the correct way to calculate tumor size. Oncologist says biopsy (stereotactic) remval size, plus some due to the fact that cells were found along length of needle, but cannot figure in residual tumor found when partial mastectomy was done. Radiation oncologist says all findings need to be totaled when calculating tumor size. Mine may make a difference in deciding chemo vs. no chemo since 1 cm seems to be the recommended size to consider chemo tx.
Findings: biopsy - .8 cm tumor, infiltrating poorly differentiated ductal carcinoma and focal intraductal carcinoma.
oncologist said she is adding about .2 - .3 due to needle findings, but it is incorrect to add in the residual infiltrating ductal carcinoma, 0.5. (Have 1 cm. clean margins after this .5 cm). Please share your thoughts, and should this amount in fact make a difference on whether I take chemo. (Adriamycin) or not? I plan to have radiation tx followed by tamoxofen (ER/PR is 90%/>90%)either way. Also am grade3. Thank you.

[CCF-RN,MSN-rf]

Dear KeRe:  Tumor size is based on the largest dimension when measured.  It should include all invasive/infiltrating tumor.  From your entry, I cannot tell if there is an additional 0.5 or what this number represents.  If the tumor is over 1.0cm chemo is a definite.  If under 1.0cm there are other factors that play into whether or not chemotherapy would be recommended.  It is not a simple "no."  Ask your oncologist what type of benefit (risk reduction) you could expect from chemotherapy.  Then decide if the benefit is worth the risks - from your point of view.

[ritavv]

I understand that this forum is moderated by the Cleveland Clinic and the recommendations are consistent with their advice.  But to say that chemo is a "definite" if a tumor is over 1cm seems to me to be misinformation.  It may be the 'standard', but some oncologists consider other factors.  My tumor was 1.6cm, 98%ER+/PR+, very slow growing, and barely grade 2 so my oncologist felt that the risks of chemo out weighed the gains.  I'm currently 3 years NED.

[rkmsim]

I was diagnosed with a second primary in the other breast last October.  The first was in 1998.  This time the tumor was 1.1cm, lymph nodes clear.  The doctors had conflicting opinions about chemo.  Statistically, anything over 1cm chemo is recommended.  But, as one oncologist put it - he takes into consideration ALL aspects of the patient to include chemo side effects as well as the pathology of the tumor and the overall benefits of chemo.  In the case of my second primary, we decided to forego the chemo since the general consensus was that it may give an additional 1 1/2 - 3 percent benefit.  My feelings were that knowing the lasting effects I have from the AC chemo that I had in 1998 and the possible effects from Taxotere, I was willing to go without the chemo.  HOWEVER - I wouldn't have hesitated to go with the chemo if the circumstances had been different (positive lymph nodes, larger tumor, more aggressive tumor, etc.).  In other words, you have to make decisions based on knowledge of the statistics as well as what you are comfortable with.