Breast

NRG-BR008 - A Phase iii randomized trial of radiotherapy optimization for low risk her2 positive breast cancer (hero)

Description:   This Phase III trial compares the recurrence-free interval (RFI) among patients with early-stage, low risk HER2+ breast cancer who undergo breast conserving surgery and receive HER2-directed therapy, and are randomized to not receive adjuvant breast radiotherapy versus those who are randomized to receive adjuvant radiotherapy per the standard of care.

The landmark trials that established breast conservation therapy (BCT) (breast-conserving surgery followed by adjuvant breast irradiation) as a suitable alternative to mastectomy were conducted in an era that predated biological subtyping of breast cancer and the use of HER2-directed therapies in patients with HER2+ cancers. These trials established adjuvant radiotherapy following breast-conserving surgery as necessary to maximize local control, yet, in the intervening years, overall outcomes have improved significantly owing to widespread adoption of screening mammography, resulting in a substantial reduction in average tumor size at diagnosis, as well as improvements in surgical techniques and, crucial for this proposal, the development of highly active systemic therapies.

Before the development of HER2-targeted therapies, patients with HER2-driven localized breast cancer had among the highest rates of local recurrence. However, with improved identification of these patients and the advent of HER2-directed therapies, outcomes have improved significantly, and trials have sought to optimize treatment to reduce the morbidity of both local and systemic treatment. Among the most salient of these examples is the APT trial, a single-arm adjuvant study that enrolled 410 breast cancer patients with HER2+ tumors ≤ 3cm in size and negative axillary nodes, who received adjuvant systemic therapy with weekly paclitaxel and trastuzumab for 12 weeks (TH) followed by 9 months of trastuzumab monotherapy. In addition to demonstrating a very low incidence of distant recurrence, among those on the trial who underwent BCT (lumpectomy and radiation, n = 244), only 2 local recurrence (LR) events have been reported after 7 years of follow-up (7-year LR = 1.2%), representing among the most favorable local outcomes of any breast cancer cohort studied to date. Confirmatory results are forthcoming from the ATEMPT trial, which evaluated the antibody-drug conjugate T-DM1 (ado-trastuzumab emtansine) (n=383) vs the TH regimen from the APT trial (n = 114), thus far showing only 3 LRs in each arm with a median 3-years of follow-up. Importantly, per the current standard of care for HER2+ patients undergoing BCT, all patients presumably received adjuvant breast radiotherapy.

The balance of the BCT literature, including a landmark meta-analysis by the Early Breast Cancer Trialists' Collaborative Group, suggests that adjuvant radiotherapy approximately halves the risk of local recurrence following lumpectomy across all analyzable subgroups. While the relative benefit appears constant across subgroups, the absolute benefit of adjuvant radiotherapy varies with the underlying risk. Taking the favorable results of the APT trial (1.2% 7-year LR), if one presumes that omission of radiotherapy yields a doubling or tripling of local recurrence (based on the observed RR of 0.5 - 0.66 for those receiving radiotherapy across the preponderance of historical trials), this population might have manifested a LR rate of 2.4 - 3.6% with the omission of radiotherapy. That is to say, the hypothesis is that administration of RT to APT patients undergoing BCT may have reduced the 7-year absolute risk of LR by only 1.2-2.4%. Through the identification of patients who are at low risk of LR, it may be acceptable for such patients to forego radiation. This hypothesis will be studied by evaluating omission of radiotherapy among patients with pT1N0 disease at breast-conserving surgery who receive adjuvant HER2-directed therapy (trastuzumab/paclitaxel preferred, other options per protocol), or with clinical tumors ≤ 3 cm and clinically negative axillary nodes (cN0) who achieve a pathologic complete response (pCR; ypT0N0) following preoperative (neoadjuvant) administration of HER2-directed therapy (trastuzumab/paclitaxel preferred, other options per protocol). It is expcted that the 5-year LR rate for this population omitting radiotherapy will be 2% or less, and that omission of radiation will not have a measurable impact on regional and distant recurrences or overall survival.

The practice of breast radiation oncology has benefited immensely from practice-changing trials that have refined the application of adjuvant radiotherapy since the early surgical studies determined whole breast radiotherapy to be necessary following lumpectomy. There are now several favorable breast cancer subtypes in which patients routinely forego radiotherapy after trials demonstrating modest benefits in terms of local recurrence and no impact on distant recurrence or survival, such as among small, low grade luminal cancers in older women and "good-risk" DCIS. Therefore, this will study the omission of radiotherapy among a population of HER2+ breast cancer patients who are now appreciated to also have favorable risk, so as to similarly weigh the attendant inconveniences, cost and morbidity of radiotherapy in light of an established absolute benefit, which may prove to be modest.

Clinicaltrials.gov/study/NCT05705401

NRG-BR009 - A phase III adjuvant trial evaluating the addition of adjuvant chemotherapy to ovarian function suppression plus endocrine therapy in premenopausal patients with Pn0-1, er-positive/her2-negative breast cancer and an oncotype recurrence score

Description:   This Phase III Trial will determine whether adjuvant chemotherapy (ACT) added to ovarian function suppression (OFS) plus endocrine therapy (ET) is superior to OFS plus ET in improving invasive breast cancer-free survival (IBCFS) among premenopausal, early- stage breast cancer (EBC) patients with estrogen receptor (ER)-positive, HER2-negative tumors and 21-gene recurrence score (RS) between 16-25 (for pN0 patients) and 0-25 (for pN1 patients).

Younger age at diagnosis is an adverse prognostic factor in early breast cancer: women who are less than 35 years of age at diagnosis are more likely to die from their disease than their older counterparts following standard treatments. There remains a pressing need for advancements in therapeutic options for this patient population. One increasingly utilized option is ovarian suppression, which was first reported as treatment for advanced breast cancer in 1896 and has been examined in a multitude of clinical trials over the past century. As chemotherapeutic options became more commonplace for breast cancer therapy, however, the role of ovarian suppression became uncertain.

In the pre-genomic era, several studies evaluated the role of ovarian suppression compared to chemotherapy, with conflicting results. These studies either looked at ovarian suppression alone or at tamoxifen compared to chemotherapy. A meta-analysis examining LHRH-agonists (luteinizing hormone-releasing hormone) in the Early Breast Cancer Overview group (LHRH-agonists in Early Breast Cancer Overview group 2007) showed that when LHRH-agonists were added to tamoxifen, chemotherapy, or both, there was a 12.7% reduction in the risk of recurrence and a 15.1% reduction in the risk of death. When compared to chemotherapy, LHRH-agonists appeared to be equally as effective, especially if patients were less than 40 years of age. These older studies, conducted in the pre-taxane/anthracycline era, typically used CMF (cyclophosphamide, methotrexate, and fluorouracil) chemotherapy, and were designed prior to the use of genomic assays .

Clinicaltrials.gov/study/NCT05879926

swog-s2206 - phase III trial of neoadjuvant durvalumab plue chemotherapy versus chemotherapy alone for adults with mammaprint ultrahigh (mp2) hormone receptor (HR) positive/human epidermal growth factor receptor (her2) negative stage ii-iii breast cancer

Description:   This phase III trial compares the addition of an immunotherapy drug (durvalumab) to usual chemotherapy versus usual chemotherapy alone in treating patients with MammaPrint Ultrahigh (MP2) stage II-III hormone receptor positive, HER2 negative breast cancer. Immunotherapy with monoclonal antibodies, such as durvalumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Chemotherapy drugs, such as paclitaxel, doxorubicin, and cyclophosphamide work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. There is some evidence from previous clinical trials that people who have a MammaPrint Ultrahigh Risk result may be more likely to respond to chemotherapy and immunotherapy. Adding durvalumab to usual chemotherapy may be able to prevent the cancer from returning for patients with MP2 stage II-III hormone receptor positive, HER2 negative breast cancer.

Clinicaltrials.gov/study/NCT06058377

swog-s2212 - a randomized phase iii study of shorter anthracycline-free chemo immunotherapy adapted to pathological response in early triple negative berast cancer (scarlet)

Description:   This phase III trial compares the effects of shorter chemotherapy (chemo)-immunotherapy without anthracyclines to usual chemo-immunotherapy for the treatment of early-stage triple negative breast cancer. Paclitaxel is in a class of medications called anti-microtubule agents. It stops cancer cells from growing and dividing and may kill them. Carboplatin is in a class of medications known as platinum-containing compounds. It works in a way similar to the anticancer drug cisplatin, but may be better tolerated than cisplatin. Carboplatin works by killing, stopping or slowing the growth of cancer cells. Cyclophosphamide is in a class of medications called alkylating agents. It works by damaging the cell's deoxyribonucleic acid (DNA) and may kill cancer cells. It may also lower the body's immune response. Docetaxel is in a class of medications called taxanes. It stops cancer cells from growing and dividing and may kill them. Doxorubicin is an anthracycline chemotherapy drug that damages DNA and may kill cancer cells. Pembrolizumab may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Shorter treatment without anthracycline chemotherapy may work the same as the usual anthracycline chemotherapy treatment for early-stage triple negative breast cancer.

Clinicaltrials.gov/study/NCT05929768

SWOG-s1703 - Randomized Non-Inferiority Trial Comparing Overall Survival of Patients Monitored with Serum Tumor Marker Directed Disease Monitoring (STMDDM) versus Usual Care in Patients with Metastatic Hormone Receptor Positive HER-2 Negative Breast Cancer

Description:  This randomized research trial studies how well serum tumor marker directed disease monitoring works in monitoring patients with hormone receptor positive Her2 negative breast cancer that has spread to other places in the body. Using markers to prompt when scans should be ordered may be as good as the usual approach to monitoring disease.

Clinicaltrials.gov/study/NCT03723928