Stage IV breast cancer found in the stomach

What a shock! I read your other postings about weight loss, etc. Has anyone suggested genetic counseling? There is a mutation in CDH-1 which leads to gastric as well as lobular breast cancer. ILC is difficult to detect because it does not form lumps like the more common ductal lesions. It can 'hide' especially in dense tissue through typical imaging such as mammograms and ultrasounds. Surprising that your MRI did not find it.

The other metastatic condition which you may want to read up on is peritoneal carcinomatosis: there is a thread on this forum populated by gals with that diagnosis. While not exactly the same clinically, they also have gut issues...

There are quite a few of us on Verzenio with some kind of anti-estrogen therapy, fulvestrant injections for me since I had a hard time tolerating aromatase inhibition. I wonder why Arimidex was selected for you. Seems as though letrozole is chosen more often. Because you are already having GI problems, I hope the diarrhea from V doesn't impact you too badly. Loperamide is usually used but it worked too well for me resulting in uncomfortable bloating and abdominal cramps. After a dose reduction, I found that control of the loose stool is possible by taking two FiberCon tablets daily. The other meds in the class Ibrance and Kisqali don't have this side effect (blood counts are their downside) so I think a second opinion is an excellent idea.

KBL- it is not uncommon for ILC to spread to anywhere in the abdominal cavity. It seems to have a predilection for GI/GU organs--and less of a likelihood for spreading to the lungs.

Most people who have ILC do have a mutation in the CDH1 gene, but most of those mutations are somatic (acquired after birth) and NOT hereditary (genetic.) BUT in a small number of patients the mutation is hereditary and having genetic testing can help you identify if you need to consider additional treatment approaches. HOWEVER, having stomach and upper GI mets does NOT confer a greater likelihood that your mutation is genetic. Primary gastric cancer from a hereditary CDH1 mutation is VERY different from an ILC breast primary spreading to the stomach.

If in addition to genetic testing you choose to do genomic testing (to identify if your cancer has certain frequently-associated with cancer mutations; this is different from genetic testing that looks to see if you have hereditary mutations) be sure to use Foundation One rather than Guardant 360 for the liquid biopsy testing. Guardant does not sequence the entire CDH1 genome, so if your mutation happens to be in an unsequened region it will not be detected. The Foundation One platform does sequence the entire CDH1 gene. I learned that after having a Guardant test and my CHD1 mutation did not show up. I had tissue testing done previously and knew the exact mutation; I sent that info to Guardant and the geneticist told me that my mutation was in a region they don't test. It was actually the Guardant geneticist (who has been VERY helpful over the two years I have done G360 testing) who suggested that I might want to use F1-- but I wanted to follow another mutations the G360 test had found using the same testing platform...

Sorry to bombard you with more information than you might be looking for... but so few oncologists see many lobular patients, and even fewer send liquid biopsies (yet) that I wanted to save you trouble if CDH1 info was part of your reason for sending that test.

I have lots of abdominal mets, but for the first four years after my diagnosis of MBC NONE of the ovarian/Fallopian tube/peritoneal/omenta/colon mets that have been discovered during surgery/colonoscopy show up on ANY imaging (not PET, MRI, CT or ultrasound.) It was only this spring that a 4 cm lesion covering the outer surface of my bladder has been detected on a CT scan. I had that biopsied and indeed it is lobular MBC. At least it was large enough to get me into a clinical trial. Thankfully my onc is a PI on that trial, and the trial is sponsored (funded) by my cancer center so she has some leeway in determining if the lesion meets the "Measurable disease" criteria. Technically, due to the very irregular edges of the lesion it is not a RECIST-measurable lesion. But since the trial is actually sponsored by our cancer center, she has the authority to determine that the lesion is indeed evaluable so that they can decide if there is a response to treatment. I was looking at two other trials at different cancer centers at the same time (both with pharma sponsors) and neither would accept my lesion as measurable and so I could not get into those trials. I am very fortunate that I got on to this one.

I hope that you get a good response to your treatment. I got 39 months on Ibrance/Letrozole and found it very tolerable once I dropped to the 75 mg dose. I have bone marrow mets as well as the soft tissue involvement and had a hard tome with the blood-count effects of the higher doses. Once I dropped to 75 mg I was able to complete all cycles and re-start the next one on time. I was on 75 mg for 39 cycles. There is current post=marketing (real-life) analysis that shows nearly-identical efficacy from all three doses-- so don't hesitate to try a lower dose if you feel that the side effects, including fatigue, are difficult to tolerate. It seems that if it works, it works at any of the three available doses.

Hope you get a very ling response from whichever regimen you choose.

Elizabeth