Breast Case

[BraggPeak]

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65 yo with 1.7 cm right breast IDC, Grade 2, +LVSI, ER/PR/HER2/neu+, s/p lumpectomy and SLND. 1/1 SLN+ with micromet (1.9 mm). No further LND.
Patient received and completed adjuvant chemo.

For RT: Tangents alone, high-tangents, or regional nodal

MSK Nomogram says 23% risk of additional lymph nodes
MDACC: 40%

but patient would have technically also qualified for Z11 (Her2/neu was not used to exclude patients)

Thoughts?

 

[Gfunk6]

I would do high tangents.

Based on retrospective analysis of the Dutch MIRROR trial (http://meetinglibrary.asco.org/content/32586-65) there is a small but statistically significant increase of axillary nodal failure in cases of N1mi (~6.2%) without dedicated ALND or axillary radiation.

 

[medgator]

High-tangents +/- SCV field (it's low morbidity IMO).

 

[Neuronix]

1.9mm is right on the borderline for micromets. This case makes me nervous because it is triple positive disease with LVSI. Are you pretty confident in the surgeon/SLNBx? I like to read the op note and see if it sounds like a solid SLNBx rather than just the equivalent of "no dye was identified, so I plucked a lymph node out of the axilla" that I see sometimes . I imagine she was clinically node negative prior to surgery, though was there any other imaging and was the mammogram at least of sufficient quality so that we're pretty sure there's no gross nodes?

What quadrant was it in? I'm aggressive. So assuming she's a good 65 year old, if it's in an outer quadrant, I'd cover axilla and SCV/ICV. If it's in an inner quadrant, I'd do full nodal including IMN.

 

[thesauce]

Tangents + SCV

 

[iradi8u]

I'd err on the side of caution with a 1.9 mm micromet - too close for comfort, and with only 1 SLN, I'd treat the SCLVs. Unless it's an inner quadrant tumor, I wouldn't go out of my way to catch the IMs, but if I could get them easily, I'd include them.

 

[ShirleyT]

I would probably do high tangents +/- SCV.

 

[drnick098]

I'd be conservative and treat normal tangents alone.

Re: axillary field / high tangents

IBSG 23-01 was a non-inferiority trial randomizing 500 pts with T<5cm, cN0, pN1mi(sn) to completion axillary dissection vs no completion axillary dissection and there was non-inferior 5y DFS without completion axillary dissection.

Z0011 showed the same with macromets included.

(The speculation by Hafty that high tangent RT made up for the lack of axillary dissection is at this stage merely speculation. As far as I'm aware (correct me if I'm wrong) an analysis of the fields in Z0011 has not been presented.)

Both of these trials did not show any advantages to completion dissection and there is no evidence that RT is any better than surg in terms of local recurrence or OS.

As far as I'm aware, the MIRROR study RT/CLND analysis is only available in abstract form, and furthermore is a retrospective analysis of a national database so should be interpreted with caution.

Therefore, I wouldn't give an axillary field or high tangents.

Re: supraclav RT:

We've traditionally used >3 nodes as the cutoff for treating the supraclav based on the postmastectomy data.

Justification for treating N1 comes from MA20 which is also only available in abstract form and only has 5y followup so also should be interpreted with caution.

Therefore, I wouldn't give supraclav RT either.

The systemic agents may be enough to treat any further disease in the axilla. If anything, I would've argued for completion axillary dissection before the chemo was given for the purposes of prognostication and guiding adjuvant chemo and adjuvant RT.

 

[medgator]

We've traditionally used >3 nodes as the cutoff for treating the supraclav based on the postmastectomy data.

Justification for treating N1 comes from MA20 which is also only available in abstract form and only has 5y followup so also should be interpreted with caution.

A combined analysis of the 2 dutch PMRT trials looking strictly at patients who had 8+ nodes removed still found a survival benefit to post-mastectomy RT (which included regional nodal RT) in patients with any LN+. Systemic therapy was given to many pts (albeit it was CMF). I extrapolate that to give SCV RT in this situation (it is low morbidity IMO, outside of the temporary skin changes)

 

[thesauce]

A combined analysis of the 2 dutch PMRT trials looking strictly at patients who had 8+ nodes removed still found a survival benefit to post-mastectomy RT (which included regional nodal RT) in patients with any LN+. Systemic therapy was given to many pts (albeit it was CMF). I extrapolate that to give SCV RT in this situation (it is low morbidity IMO, outside of the temporary skin changes)

Right - and it makes sense. The patients with 1-3+ nodes are less likely than those with 4+ to have subclinical distant mets, so they would stand to benefit from aggressive local therapy.

 

[Neuronix]

Justification for treating N1 comes from MA20 which is also only available in abstract form and only has 5y followup so also should be interpreted with caution.

Also in abstract form, with 10y follow up from the EORTC: "“Irradiation of the internal mammary and medial supraclavicular lymph nodes in stage I to III breast cancer: 10 years results of the EORTC Radiation Oncology and Breast Cancer Groups phase III trial 22922/10925”" (this was previously discussed on SDN here: http://forums.studentdoctor.net/threads/treating-imns.1037757/ )

http://web.oncoletter.ch/kongressbe...ma-ipilimumab-ecco-38th-esmo-32nd-estro-.html

Conclusion slide at the end of the video sells the point again for me at 6:18.

With regards to the patient presented, I'm not certain if they would have been eligible for the trial (depends on primary location in breast and how N+ is defined and/or pathology was performed to determine N1 vs N1mi). Based in part on that abstract (and the old dissection data), I would not hesitate to radiate IMNs/regional nodal for medial tumors with any evidence of axillary involvement. What I can't fully justify is how to handle lateral N1 (+SCV +/- axilla +/- IMN) or tiny favorable risk medial tumors (WB alone typically for now). It also will be interesting to see subgroup analysis of the EORTC trial and MA-20 trial when published.

 

[BraggPeak]

Also in abstract form, with 10y follow up from the EORTC: "“Irradiation of the internal mammary and medial supraclavicular lymph nodes in stage I to III breast cancer: 10 years results of the EORTC Radiation Oncology and Breast Cancer Groups phase III trial 22922/10925”" (this was previously discussed on SDN here: http://forums.studentdoctor.net/threads/treating-imns.1037757/ )

http://web.oncoletter.ch/kongressbe...ma-ipilimumab-ecco-38th-esmo-32nd-estro-.html

Conclusion slide at the end of the video sells the point again for me at 6:18.

With regards to the patient presented, I'm not certain if they would have been eligible for the trial (depends on primary location in breast and how N+ is defined and/or pathology was performed to determine N1 vs N1mi). Based in part on that abstract (and the old dissection data), I would not hesitate to radiate IMNs/regional nodal for medial tumors with any evidence of axillary involvement. What I can't fully justify is how to handle lateral N1 (+SCV +/- axilla +/- IMN) or tiny favorable risk medial tumors (WB alone typically for now). It also will be interesting to see subgroup analysis of the EORTC trial and MA-20 trial when published.

Thanks for all the replies and great discussion.

It was outer quadrant. I ended up doing high tangents.