HER2 response rates to AC versus THP?

Anonymous

HER2 response rates to AC versus THP?

Decker

My mom just finished 4 cycles of AC, and the tumor shrunk by only 32%. She's will start 4 cycles of THP tomorrow. Her tumor is not a strong HER2 positive as per FISH test, but still classified as HER2 positive. The tumor was initially classified as triple negative using the SISH test, but later revised to HER2 positive after a second-opinion FISH test done after 2 cycles of AC. ER/PR negative.

Is there a better chance for higher tumor shrinkage through THP compared with AC, given that THP is targeted therapy? This is pre-surgery, pre-chemo tumor size was around 2.3cm.

Also, have you seen studies / evidence showing effectiveness of adriamycin versus carboplatin for HER2 positive bc?

Thank you

MinusTwo

I think it depends on the studies you read. In any case she's already had the AC, so it's a moot point. It's unlikely they'll do back to back different chemos at this point.

Pre surgery (neo-adjuvant) I had 6 cycles of TCHP (taxotere, carboplatin, herceptin & perjeta). Unfortunately I did not have a complete response, so AFTER surgery I had 3 rounds of AC (adriamycin/cytoxan). I was scheduled for 4 rounds, but it was just more than I could handle. Then I had radiation - along with Herceptin for the rest of a year. Good luck.

cyathea

Hi Decker , I'm not a doctor so I don't have the knowledge to give you any recommendations about which treatment is better for your mom. I can only report that my chemo was very effective on my tumors. I started with Taxotere-Carboplatin-Herceptin-Perjeta, but due to issues with my liver, I was switched to just Abraxane and Herceptin after the first two cycles. I did a total of 6 cycles. My tumors were strongly HER2+. From the surgery pathology report, they found that the chemo had been completely effective on my left breast tumor and left lymph nodes and mostly effective on my right side (no large tumors, just microscopic tumors and cancer cells remaining in my right breast and right lymph nodes). The tumor on my right side was over 5 cm and the chemo turned it into fibrotic tissue.

My doctors have told me that those who are HER2+ tend to do very well on the targeted therapy treatments. So, if your doctor is recommending THP for your mom, it is probably the best treatment for her individual condition. That said, you could always ask for a second opinion on that as well.

Hugs for you and your mom and best wishes for the successful treatment of cancer in her body.

Decker

Thanks, did your oncologist discuss why you got carboplatin rather than AC?

Decker

Thanks, did your oncologist discuss why you used carboplatin neoadjuvant rather than AC neoadjuvant?

ElaineTherese

Hi!

I got AC+THP, and my lump shrank throughout my chemo. By the time I had surgery, all of the active cancer in my lump and my compromised node were gone. I can't say whether it shrank more on AC or THP, but it certainly began shrinking while I was on AC. My lump was pretty close to the skin and my oncologist could measure it shrinking with a ruler!!! Of course, my lump was 5 cm.+ to begin with, so there was a lot to shrink! I certainly preferred the THP to the AC; I just thought so much more clearly on that regimen. Best of luck to you and your Mom!

SpecialK

decker - it seems like oncologists choose either ACTH(P) or TCH(P) based on a number of factors, but often it is practice policy, regional preference, experience, philosophy. I have seen a number of oncologists add Carboplatin to the taxane portion of ACTH(P) - particularly for those ER-/PR- patients, so you receive the AC dose dense first, then Taxol, Carboplatin and targeted therapy next. One of the reasons seems to be some of those with negative hormonal receptors get improved response from the addition ofCarboplatin. It is a lot of treatment though, so the decision can be dependent on how your mom is tolerating things so far and how her blood counts are doing throughout.

MinusTwo

Most people that are HER2+ have neoadjuvant chemo. The goal is to stop the growth as fast as possible in addition to shrinking the tumor before surgery. I choose the Carboplatin because, as Special mentioned, I was ER/PR negative.

Decker

Hmm, so my mom is also ER/PR negative, but the oncologist said there wouldn't be a difference between carboplatin or AC. Are there studies showing carboplatin is better than AC for ER/PR negative, HER2 positive breast cancer?

SpecialK

decker - it is adding Carboplatin to the Taxol portion of ACTH, not in place of the AC that is sometimes used for ER-/PR-, or triple negatives. Since your mom is already well into the AC portion, the operative question is whether or not to add the Carboplatin to her remaining Taxol plus targeted therapy portion of neoadjuvent chemo, particularly in light of the perception of less effect from the AC than expected. This would be making the addition to the ACTH(P) , not making a choice of one regimen over the other. I have seen it done more in cases of triple negative breast cancer, but if your mom is tolerating chemo well, it is possible that her doc would consider adding the Carboplatin to the remaining Taxol in her regimen. It is worth discussing. Also want to caution that imaging does not always reveal the true extent of eradication - often it looks like the tumor is still there, but in fact it is a shell, with a swiss cheese effect within. Until you have surgery it is hard to be accurate about response from imaging alone. I think what your oncologist was saying was no real difference between ACTH(P) and TCH(P) in terms of efficacy. It is also hard to know which aspect is driving cancer growth, or if all are. For some it is the estrogen - of lack of - that causes growth, for others it is the Her2+ aspect, for some it is everything. Chemo does not generally work as well on ER+ cancers, seems to be better on ER-. ER+ cancers have the potential benefit from anti-hormonals medications taken adjuvently, but ER- patients do not have that option. There are also some other meds that can be taken adjuvently by Her2+ patients who do not have a pathological complete response at the time of surgery, you can ask your mom's oncologist about those - Kadcyla and Neratinib, and I have seen a few early stagers also use Xeloda, which is not a specific Her2+ drug. I don't know that any specific studies have been done to compare chemo regimens for ER-/PR-/Her2+ cancers, but in comparing chemo regimens, in general, I believe the Adriamycin/Cytoxan/Taxol and Taxotere/Carboplatin regimens, when combined with targeted therapies, are generally equal to each other. In those studies patients had both arrangements of hormonal receptors.

Decker

Thank you SpecialK, what do you mean by "both arrangements of hormonal receptors"?

SpecialK

Either ER+/PR+, or ER-/PR- as either can occur with Her2+, andyou will more rarely see a mixture like ER+/PR-.

MinusTwo

Decker - usually Adriamycin and Herceptin are not given together since both can damage the heart. Or if they are, there will likely be echocardiogram testing on a regular basis. Supposedly Herceptin damage usually resolves down the road. Adriamycin can be more permanent.

Decker

MinusTwo, did you mean adriamycin and carboplatin not given together? The treatment has been 4 cycles of AC that just finished, and now 4 cycles of THP, so adriamycin and herceptin are not given at the same time.

Sivatej

My mom had 4 doses of AC, then surgery , and then she had 4 rounds of TH continuing herceptin later for an year. There was residual tumour at the time of surgery. But now I'm sort of tensed as we don't know if it could have been killed completely if all 8 doses were given prior to the surgery. I know that sequencing of the treatment has no effect on the outcome but I wonder if some extra therapy could have been added if there was residual tumour at the end of 8 rounds.

The plan was 4-8 rounds of neo-adjuvent chemo but at the end of 4 cycles it was written that the response was very good and hence suitable for surgery

She started with a 6cm tumour and 3 nodes with a little thickening of the skin(which was completely clear at surgery). Do people report the extent of residual cancer at surgery or can they tell of how much tumour was there to start off with if the surgery was done after initial therapy?

Are there any survival stats for such a diagnosis, this fear is intense. It's really comforting and good to see you all doing well