Talk Cancer

Question:

Hi, My (47 year old) wife underwent lumpectomy for 1.5cm ductal invasive grade 2 tumor.  While doing surgery they removed a nearby suspicious cyst which proved to be a small ductal in situ.  All margins were found to be clear and both sentinal nodes and axillary dissection lymph nodes also proved clear. All her other tests proved clear.  ER+   PR+ and Her2Nu Negative  I think basically good stuff considering the situation. We visited two oncologists and are ready to begin chemo.  The way they look at the tumor size is to take the distance from the end of the invasive to the end of the in situ and add together to get 2.5cm and treat based on that size. One oncologist said 4 cycles of AC and then radiation and tamoxefin.  The other oncologist said 6 cycles of FEC and then radiation and tamoxefin. My question is what is the difference between 4 X AC and 6 X FEC?  Is one more potentially harmful than the other?  Is one really better?  Also, any comments on how they figure tumor size?  I would think the In Situ would be considered totally gone after surgery so there would be no need to add it’s location dimension to figure tumor size. Nervous Husband

Response:

FEC?  Is one more potentially harmful than the other?  Is one really better? The irony is that I don’t believe that a direct comparison between those drugs and cycles has  been done.  I am not one to comment on which is better and I don’t recall all the details—but the way 4 AC treatnebts was adopted was based on comparing 6 CMF with 6 FAC.  The 6 FAC was better.  I recall reading that the decision of 4 cycles was based on convenience and um can’t recall off the top of my head but it was another word that started with "c"  I renember now–compromise.  I saved that reference somewhere but am not sure I can still get to it.  The last time I tried to find that reference I was told that the page was no longer available (if in fact that was the ‘right’ page–which I am pretty sure it was, although not 100% certain).  If I ever come across the article/report I willl post that again.  Anyway, I do remember reading that not all those involved or who gave input agreed with the decision.   That does not mean it isn’t as good or even better than 6 FEC though.  I just recall reading about the comparison between AC and CMF and how they decided on the 4 cycles in relation to only the above combination of drugs.  I know that isn’t the question you asked but thought it might help lead you to find out more as to whether any comparison between FEC and AC has been done…

Response:

The way they look at the tumor size is to take the distance from the end of the invasive to the end of the in situ and add together to get 2.5cm and treat based on that size.

Is that really the way the AJCC (American Joint Committee on Cancer) says to do it? Not that the AJCC has the last say on matters of risk. Does anyone with a large body of evidence recommend this? My understanding of DCIS (ductal carcinoma insitu) is that it is often multifocal and so measuring the size of invasive cancer by the entire length from one end of an invasive tumor to the most distant end of DCIS seems excessive. This strategy would result in a large number of women being upstaged. — David "just asking" Winsemius If the statistics are boring, then you’ve got the wrong numbers.                           -Edward Tufte

Response:

The way they look at the tumor size is to take the distance from the end of the invasive to the end of the in situ and add together to get 2.5cm and treat based on that size. Is that really the way the AJCC (American Joint Committee on Cancer) says to do it? Not that the AJCC has the last say on matters of risk. Does anyone with a large body of evidence recommend this? My understanding of DCIS (ductal carcinoma insitu) is that it is often multifocal and so measuring the size of invasive cancer by the entire length from one end of an invasive tumor to the most distant end of DCIS seems excessive. This strategy would result in a large number of women being upstaged.

I does seem a bit odd.  I haven’t seen any consistent rules for sizing multifocal cancers, and oncologists seem to vary.  Generally taking the size of the largest tumour will give only a fairly small underestimate of the total volume and probably a better measure of metastasis.  I can’t see the logic in measuring the extent of the DCIS for staging purposes, as staging is primarily about assessing the amount and range of metastasis and DCIS is supposed to be non-metastatic and so shouldn’t contribute. Tim Jackson

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