Chemotherapy for 77-year-old?

Herceptin and other drugs to treat HER2+ are not considered chemotherapy but called a targeted drug therapy. They generally do not have the same side effects as chemo therapy and are well tolerated in most cases. They don't cause nausea or hair loss. The most serious issue is a heart one which will be checked a couple times during treatment. After having a miserable time with chemo, I sailed through herceptin with minimal problems (I was barely + and debated going through another treatment). Treatment decisions are tough. What is her general state of health? Is she still active? The problem is that no one will tell you with 100% certainty that one plan is the best and only way to go. We are all different.

This post is in the DCIS forum, does your mom have an invasive component as well? If there is no invasive component, then chemo would not be warranted, regardless of the Her2 status.

(1) Diagnosis:

Pure DCIS is by definition non-invasive ("in situ") disease (Stage 0). By the assessment of the pathologist, it is confined to the inside of the ducts. DCIS is not typically tested for HER2 status under consensus guidelines, although such testing is sometimes done.

Invasive breast cancer has broken through the wall of duct into the surrounding breast tissue (process of invasion)(Stage IA or higher). Invasive breast cancer should always be tested for HER2 status, if possible.

Often a patient is diagnosed with DCIS, but some invasive breast cancer is also found in either the biopsy sample and/or surgical samples. The presence of an area of invasion, no matter how small (in either biopsy or surgical samples), means that the actual diagnosis is not DCIS (Stage 0) disease, but is a diagnosis of invasive breast cancer and is Stage IA disease or higher (depending on the size of the invasive tumor, lymph node status, and evidence of distant metastasis).

I doubt that a trained Medical Oncologist would ever recommend chemotherapy plus trastuzumab (Herceptin) to a patient with pure DCIS for the reasons noted above by others: Clinical consensus guidelines for the treatment of pure DCIS simply do not provide for either chemotherapy or HER2-targeted therapy in such patients (regardless of HER2 status). In current clinical practice, chemotherapy and HER2-targeted therapies are only used in certain patients with invasive breast cancer (e.g., Invasive Ductal Carcinoma ("IDC"); Invasive Lobular Carcinoma ("ILC"); other invasive histology).

This suggests to me that there is some misunderstanding about her actual diagnosis. If you have not already done so, please obtain copies of the complete pathology reports from all biopsies and surgeries (not some summary in a patient portal) for your review and records. The reports should specify the features of any DCIS separately from the features of any invasive breast cancer, and should also provide information about the margins relative to each. You can request an explanation of her final pathologic diagnosis, in light of all biopsies and surgeries, and of the key properties of any invasive component (histology; tumor size; lymph node status; ER, PR, HER2 status; grade).

(2) HER2 Testing

You mentioned conflicting HER2 test results, one positive and one negative. That is not very common.

You may wish to confirm your understanding that one result was deemed "negative". Please note that HER2 test results are deemed either: (a) negative; (b) "equivocal"; or (c) positive. In the case of an "equivocal" test result (e.g., IHC "2+"), then testing by a different method should be done (e.g., FISH). If the result of the different test method (e.g., FISH) is "positive", then HER2 status is considered "HER2-positive" under current HRE2 testing guidelines from ASCO/CAP. An "equivocal" result by one test method, and a "positive" result upon alternate or "reflex testing" is not really a conflicting result, but is an unclear result that has been clarified as positive by further testing.

If one result was deemed "negative", then it is critical to know what disease was tested. For example, it is possible to have HER2-negative DCIS and HER2-positive invasive disease at the same time. Yet, the HER2 status of the invasive disease is what is important for this treatment decision. Please be sure that the "negative" result was determined from testing an "invasive" component, and not from the associated DCIS.

Sometimes there is a discrepancy between HER2 test results on biopsy and on surgical samples. There can be issues with sample processing, limited biopsy sample size, or other technical concerns. Tumor heterogeneity could be another possible explanation for a negative and a positive result, in which different areas of the same invasive tumor have different properties and are "heterogeneous" with respect to HER2 status. If the pathologist and her Medical Oncologist consider her to have HER2-positive invasive breast cancer, they should be able to explain to you why the "positive" result should be relied upon and why any "negative" result is not determinative in her particular case.

There may be more specialized cases regarding determination of HER2 status. In such cases or if in doubt, a second opinion from a pathologist at an independent institution may be helpful.

(3) Invasive Breast Cancer Treatments:

NCCN guidelines for Breast Cancer (Version 2.2017) applicable to INVASIVE breast cancer provide different recommendations based on histology; estrogen receptor ("ER") status; progesterone receptor ("PR") status; HER2 status; tumor size; and lymph node status. These factors affect the distant recurrence risk profile of a person with invasive breast cancer. For some patients, their risk of distant (metastatic) recurrence may warrant either consideration of or a recommendation for systemic treatments, such as chemotherapy; HER2-targeted therapy (for HER2-positive disease); and/or endocrine therapy (for hormone receptor-positive disease).

To better understand her risk/benefit profile, you can request a case-specific estimate of her distant recurrence risk and the potential risk reduction benefit of chemotherapy plus trastuzumab, along with possible limitations. Then, the potential benefit should be weighed against the risk or incidence of severe adverse effects of any proposed regimen. Certain co-morbidities may increase the risk of certain adverse effects, and these should be taken into account. Life-expectancy is also a consideration.

In this regard, the 2017 St. Gallen panel recently noted: "The Panel resolutely endorsed the statement that there is no absolute age limit for adjuvant chemotherapy but rather the recommendation should depend on the health status of the patient, the risk of cancer recurrence, the likely benefit of therapy, and patient preferences."

(4) Distant recurrence Risk with INVASIVE breast cancer - Rationale for Systemic Therapy

You mentioned that your mom is "cancer-free." Sometimes surgeons say this, but it is misleading and confusing to patients. In the surgeon's opinion, the tumor has been successfully removed with adequate margins, but this is only a LOCAL treatment.

If a person has invasive breast cancer, then there is some risk of DISTANT spread, which presents a current risk of suffering an incurable distant (metastatic) recurrence. This distant recurrence risk varies depending on factors such as histology; tumor size; lymph node status; ER, PR, and HER2 status; grade, etc. The size of the distant recurrence risk affects recommendations for systemic drug treatment.

Perhaps she had some favorable pathologic findings? For example, node-negative status is a favorable pathologic finding and is generally associated with a lower likelihood of suffering distant metastatic recurrence. However, it is not a guarantee that no cells have left the primary breast tumor and reached distant sites.

Even with node-negative (N0) invasive disease and no lymphovascular invasion ("LVI"), it is still possible that in the years before surgery, some rogue cancer cells broke off from the breast tumor, and moved to distant sites via the lymphatic system or via the blood stream.

A few rogue cells or clusters of cells at a distant site(s) are a form of "micrometastatic" distant spread that is NOT detectable by conventional tumor staging procedures or whole-body scans. Thus, such undetected distant micrometastases may be present, even when scans are negative, the lymph node biopsy is negative, and there is no LVI observed. This is because these methods are not 100% accurate in determining whether any tumor cells have moved to distant sites, and cannot exclude the possibility.

The risk that current undetected micrometastases may grow and later manifest as "recurrent metastatic disease" at a later date provides the rationale for systemic therapy in the appropriate case (e.g., chemotherapy; endocrine therapy (for hormone-receptor positive disease); and/or HER2-targeted therapy (for HER2-positive disease)):

Pantel, J Natl Cancer Inst (1999) 91(13): 1113-1124 - [parenthetical notes added by me]:

"Because the goal of [post-surgical, systemic] adjuvant therapy is the eradication of occult [undetectable] micrometastatic tumor cells before metastatic disease becomes clinically evident . . ."

Even those with node-negative invasive disease may receive such systemic treatment(s), based on their distant recurrence risk.

(5) Second Opinion

If there is time, one of the best ways to probe medical advice is to seek a second opinion at an independent institution. Many look for an NCI-designated Cancer Center for a second opinion (confirm in-network):

https://www.cancer.gov/research/nci-role/cancer-centers/find

If of interest, you can ask her current team for the recommended time-frames for initiation of any further treatments (e.g., chemotherapy; radiation therapy), and if there is time to seek a second opinion. Actual pathology slides (sent overnight) and all related written reports and test results would be reviewed by a pathologist. As part of any second opinion, you may also seek consultation(s) with a surgeon, Radiation Oncologist and/or Medical Oncologist. One may seek treatment at the current hospital or second opinion hospital.

I am a layperson with no medical training. All information above should be confirmed with her team to ensure receipt of accurate, current, case-specific professional advice.

Best,

BarredOwl