Toronto Workshop on Late Recurrence in Estrogen Receptor-Positive Breast Cancer: Part 1: Late Recurrence: Current Understanding, Clinical Considerations

The emerging predictive and prognostic role of HER2 in HER2-negative early breast cancer: a retrospective study

PURPOSE

Many patients with early breast cancer (eBC) undergoing neoadjuvant chemotherapy do not achieve pathological complete response (pCR), which is a prognostic factor. We examined the role of HER2-low expression in predicting pCR and prognosis in HER2-negative eBC.

METHODS

We evaluated patients with stage I-III HER2-negative BC, treated between 2013 and 2023 at The Royal Marsden NHS Foundation Trust, London. Tumors were classified based on estrogen receptor (ER) status and into HER2-low and HER2-zero subgroups. We analyzed pCR rates, relapse-free survival (RFS) and overall survival (OS).

RESULTS

754 patients were included in the analysis. pCR rate was 8.9% in the ER+ /HER2-low, 16.5% in the ER+ /HER2-zero, 38.9% in the ER- ER-/HER2-low and 35.9% in the ER-/HER2-zero eBC (p < 0.001). Multivariable analysis showed a significantly lower pCR rate in HER2-low compared to HER2-zero BC in the ER+ subgroup. At a median follow-up of 63.8 months (59.9-67.4), we observed longer OS in HER2-low compared to HER2-zero patients in the overall and in the ER+ population. There was no predictive or prognostic impact of HER2-low status in the ER- population.

CONCLUSION

This study supports the interpretation of HER2 status as a possible prognostic and predictive biomarker for HER2-negative eBC, especially among patients with ER+ disease.

Clinical and Genomic Risk for Late Breast Cancer Recurrence and Survival

BACKGROUND

The 21-gene recurrence score (RS) assay (Oncotype DX) is used to guide adjuvant chemotherapy use for patients with hormone receptor-positive, HER2 (human epidermal growth factor receptor 2)-negative, axillary node-negative breast cancer. Its role, however, in providing prognostic information for late distant recurrence when added to clinicopathologic prognostic factors is unknown.

METHODS

A patient-specific meta-analysis including 10,004 women enrolled in three trials was updated using extended follow-up data from TAILORx, integrating the RS with histologic grade, tumor size, and age at surgery for the RSClin tool. Cox models integrating clinicopathologic factors and the RS were compared by using likelihood ratio (LR) tests. External validation of prognosis for distant recurrence in years 0 to 10 and 5 to 10 was performed in an independent cohort of 1098 women in a real-world registry.

RESULTS

RSClin provided significantly more prognostic information than either the clinicopathologic factors (ΔLR chi-square, 86.2; P<0.001) or RS alone (ΔLR chi-square, 131.0; P<0.001). The model was prognostic in an independent cohort for distant recurrence by 10 years after diagnosis (standardized hazard ratio, 1.56; 95% confidence interval, 1.25 to 1.94), was associated with late distant recurrence risk between 5 and 10 years after diagnosis (standardized hazard ratio, 1.78; 95% confidence interval, 1.25 to 2.55), and approximated the observed 10-year distant recurrence risk (Lin concordance, 0.87) and 5- to 10-year distant recurrence risk (Lin concordance, 0.92).

CONCLUSIONS

The 21-gene RS is prognostic for distant recurrence and overall survival in early breast cancer. A model integrating the 21-gene RS and clinicopathologic factors improved estimates of distant recurrence risk compared with either used individually and stratified late distant recurrence risk. (Funded by the National Cancer Institute, National Institutes of Health [U10CA180820, U10CA180794, UG1CA189859, U10CA180868, and U10CA180822] and others.).

Epidemiology of early vs. Late recurrence among women with Early-Stage estrogen Receptor-Positive breast cancer in the pathways study

BACKGROUND

Relatively little is known about the differences in prognostic factors for early vs late recurrence among women with early-stage estrogen receptor-positive (ER+) breast cancer.

METHODS

We analyzed factors related to early (<5 years) vs late (≥5 years) recurrence in 2,992 women with stage I-IIB ER+ breast cancer in the Pathways Study, a prospective cohort of women with breast cancer enrolled between 2006 and 2013, with ascertainment of recurrence and death through December 2021.

RESULTS

After a median follow-up of 13.3 years, 341 (13.8%) women had recurrences, including 181 (53.7%) with late recurrence. Higher stage and grade were associated with recurrence regardless of timing, whereas progesterone receptor (PR) negativity was associated with early but not late recurrence. Receipt of endocrine therapy was associated with reduced risk of overall recurrence, but the length of endocrine therapy was not significant in multivariable models. Minoritized racial and ethnic groups, including Asian, Black, and Hispanic women, had higher risk of early but not late recurrence, compared with non-Hispanic White women. The trend of higher risk of early recurrence among these groups remained after adjustment for clinical, demographic, and socioeconomic factors, but was statistically significant only in Asian women.

CONCLUSIONS

Our study revealed potentially important distinctions for early vs late recurrence, including the associations with PR-negativity and self-identified race and ethnicity. Possible higher risk of early recurrence among Asian, Black, and Hispanic women provides novel evidence for the existence of disparities in cancer outcomes, even within the breast cancer subtype indicative of generally good prognosis.

Increased blood draws for ultrasensitive ctDNA and CTCs detection in early breast cancer patients

Early breast cancer patients often experience relapse due to residual disease after treatment. Liquid biopsy is a methodology capable of detecting tumor components in blood, but low concentrations at early stages pose challenges. To detect them, next-generation sequencing has promise but entails complex processes. Exploring larger blood volumes could overcome detection limitations. Herein, a total of 282 high-volume plasma and blood-cell samples were collected for dual ctDNA/CTCs detection using a single droplet-digital PCR assay per patient. ctDNA and/or CTCs were detected in 100% of pre-treatment samples. On the other hand, post-treatment positive samples exhibited a minimum variant allele frequency of 0.003% for ctDNA and minimum cell number of 0.069 CTCs/mL of blood, surpassing previous investigations. Accurate prediction of residual disease before surgery was achieved in patients without a complete pathological response. A model utilizing ctDNA dynamics achieved an area under the ROC curve of 0.92 for predicting response. We detected disease recurrence in blood in the three patients who experienced a relapse, anticipating clinical relapse by 34.61, 9.10, and 7.59 months. This methodology provides an easily implemented alternative for ultrasensitive residual disease detection in early breast cancer patients.

Validation of CTS5 Model in Large-scale Breast Cancer Population and Combination of CTS5 and Ki-67 Status to Develop a Novel Nomogram for Prognosis Prediction

BACKGROUND

More than half of patients with early-stage estrogen receptor-positive (ER+) breast cancer relapse after completing 5 years of adjuvant endocrine therapy, so it is important to determine which patients are candidates for extended endocrine therapy. The clinical treatment score after 5 years (CTS5) is a prognostic tool developed based on postmenopausal ER+ breast cancer to assess the risk of late distant recurrence (LDR) after 5 years of adjuvant endocrine therapy for breast cancer. We aimed to externally validate the prognostic value of CTS5 in premenopausal and postmenopausal patients and combined with Ki-67 to develop a new model to improve the ability of prognosis prediction.

METHODS

We included a total of 516 patients with early-stage ER+ breast cancer who had received 5 years of adjuvant endocrine therapy and were recurrence-free for 5 years after surgery. According to menopausal status, we divided the study population into 2 groups: premenopausal and postmenopausal women. The CTS5 of each patient was calculated using a previously published formula, and the patients were divided into low, intermediate, and high CTS5 risk groups according to their CTS5 values. Based on the results of the univariate analysis ( P <0.01), a multivariate COX proportional hazards regression analysis was conducted to establish a nomogram with significant variables ( P <0.05). The discriminative power and accuracy of the nomograms were assessed using the concordance index (C-index), calibration curve, and area under the time-dependent receiver operating characteristic curve. Discrimination and calibration were evaluated by bootstrapping 1000 times. Finally, we utilized decision curve analysis to assess the performance of our novel predictive model in comparison to the CTS5 scoring system with regard to their respective benefits and advantages.

RESULTS

The median follow-up time was 7 years (6 to 9 years). The 516 women were categorized by CTS5 as follows: 246(47.7%) low risk, 179(34.7%) intermediate risk, and 91(17.6%) high risk. Using the CTS5 score as a continuous variable, patients' risk score was significantly positively associated with recurrence risk in both premenopausal and postmenopausal subgroups. For HER2- premenopausal patients and HER2+ postmenopausal patients, the CTS5 score was positively correlated with LDR risk. Patients with a Ki-67≥20% had a higher risk of LDR regardless of menopausal status. Using the CTS5 score as a categorical variable, the high-risk group of HER2- premenopausal patients had a higher risk of LDR. However, the CTS5 model could not distinguish the risk of LDR in different risk groups for HER2+ postmenopausal patients. In the high-risk group, patients with Ki-67≥20% had a higher risk of LDR, regardless of menopausal status. We developed a new nomogram model by combining the CTS5 model with Ki-67 levels. The C-indexes premenopausal and postmenopausal cohorts were 0.731 and 0.713, respectively. The nomogram model was well calibrated, and the time-dependent ROC curves indicated good specificity and sensitivity. Furthermore, decision curve analysis demonstrated that the new model had a wider and practical range of threshold probabilities, resulting in an increased net benefit compared with the CTS5 model.

CONCLUSIONS

Our study demonstrated that the CTS5 model can effectively predict the risk of LDR in early-stage ER+ breast cancer patients in both premenopausal and postmenopausal patients. Extended endocrine therapy is recommended for patients with Ki-67≥20% in the CTS5 high-risk group, as well as premenopausal patients with HER2-. Compared with CTS5, the new nomogram model has better identification and calibration capabilities, and further research is required to validate its efficacy in large-scale, multicenter, and prospective studies.

Working tables on Hormone Receptor positive (HR+), Human Epidermal growth factor Receptor 2 negative (HER2-) early stage breast cancer: Defining high risk of recurrence

Hormone-receptor positive (HR+), Human-Epidermal-growth Factor negative (HER2-) breast cancer, including the Luminal A and the Luminal B subtypes, is the most common in women diagnosed with early-stage BC. Despite the advances in screening, surgery and therapies, recurrence still occurs. Therefore, it is important to identify early those factors that significantly impact the recurrence risk. Based on current evidence and their professional expertise, a Panel of oncologists discussed the definition of high risk of recurrence in early breast cancer. Histological grade, nodal involvement, genomic score, histological grade, tumor size, and Ki-67 proliferation index were rated as the most important factors to define the high risk in patients with early breast cancer. All these factors should be considered comprehensively to tailor the choice of treatment to the peculiar characteristics of each patient.

Prognostic influences of B-cell lymphoma 2-positive expression on late recurrence in breast cancer

Purpose

B-cell lymphoma 2 (BCL2) has an antiapoptotic role, however, has resulted in it being a powerful favorable prognostic factor in breast cancer. Several studies revealed BCL2 is strongly associated with a lower rate of early recurrence after initial treatment in breast cancer patients, but study of a prolonged effect after 5 years is lacking. We investigated BCL2 as a prognostic factor in breast cancer in comparison to early and late recurrence.

Methods

We retrieved data from 2,198 patients with primary breast cancer who underwent surgical treatment and adjuvant treatment at the breast cancer center between 2005 and 2015. Each molecular subtype was classified, and Ki-67 and BCL2 were also assessed by immunohistochemistry. BCL2 and the association between molecular subtypes were assessed in early and late recurrences, respectively. Five-year postrecurrence survival and BCL2 were also assessed.

Results

The BCL2-positive group was associated with favorable clinicopathologic characteristics. The time to recurrence was significantly longer in the BCL2-positive group (P = 0.035). Late recurrence after 5 years was higher in the BCL2-positive group (P = 0.029). In multivariate survival analysis, tumor size and BCL2-positive expression were the only independent prognostic factors for late recurrence (P = 0.004). In the patients with recurrence, 5-year postrecurrence survival was significantly higher in the BCL2-positive group (P < 0.001).

Conclusion

Our result showed that prognosis was better in BCL2-positive patients compared to BCL2-negative patients at late recurrence. We suggested that BCL2 expression could be used as a marker to help determine additional adjuvant therapy or extended hormone therapy in hormone-dependent breast cancer.

Local recurrence of mammary Paget's disease after nipple-sparing mastectomy and implant breast reconstruction: a case report and literature review

Objective

To provide a rare case of local recurrent Paget’s disease after nipple-sparing mastectomy (NSM) with immediate breast reconstruction with 10 years of disease-free survival and to analyze the clinical and pathological characteristics.

Background

Mammary Paget’s disease can be considered a rare type of local recurrence after breast cancer treatment, both in cases of conservative surgery and NSM with immediate breast reconstruction (Lohsiriwat et al, Ann Surg Oncol 19:1850-1855, 2012). Recurrent patients who present with nipple-areolar Paget’s disease usually have unfavorable primary pathological characteristics and different latency periods. However, the recurrent status in patients with favorable primary pathological characteristics and the latency periods after NSM with immediate breast reconstruction are unclear.

Methods

First, we present a case of local recurrent Paget’s disease in a young patient diagnosed with invasive breast carcinoma at age 30 who underwent NSM with primary silicone reconstruction. Then, the keywords “Paget’s disease” and “nipple-sparing mastectomy” were selected. Articles including the local recurrence of Paget’s disease after NSM were collected from the PubMed, Springer, and OVID databases, and the acquired relevant data were analyzed. We did not restrict our search by study design or publication date.

Results

Five studies describing 31 cases of local recurrent Paget’s disease after NSM with implant breast reconstruction were included. The mean patient age reported was 45 years, and the average latency period from NSM to the local recurrence of Paget’s disease was 40.2 months. Recurrent tumor histological features were Paget’s disease with ductal carcinoma in situ (DCIS) in 16 patients (50%), Paget’s disease without DCIS in 13 patients (40.6%), and Paget’s disease with ductal intraepithelial neoplasia (DIN) in 3 patients (9.4%). The primary tumor histological feature was estrogen receptor (ER)(−)/progesterone receptor (PR)(−)/human epidermal growth factor receptor (HER-2)(+) in 21 patients (77.8%). Neither locoregional relapse nor metastatic events were found in these recurrent patients who accepted NAC excision after 4–5 years of follow-up. Our reported case showed that the patient experienced pregnancy and lactation after primary adjuvant chemotherapy and endocrine therapy. However, she developed an eczematoid lesion in the NAC 120 months after breast surgery. The histopathological examination was consistent with Paget’s disease of the breast. Complete NAC and breast silicone prosthesis removal were performed. The patient accepted no systematic or local therapy and is currently alive. It is noteworthy that the biological features of the primary tumor were ER(+), PR(+), and HER-2(−); however, the recurrent tumor changed to ER(−), PR(−), and HER-2(+).

Conclusions

The local recurrence of Paget’s disease after NSM is uncommon; it may develop at a very early age and have a very long time to recurrence, as in our patient, who presented with recurrence 10 years after primary surgery. Surgeons should be wary of local recurrence of the nipple-areola complex after NSM in patients with ER-negative and HER-2-positive primary tumors. However, patients with ER/PR-positive and HER-2-negative tumors should not be neglected; we reported a case of an ER/PR-positive and HER-2-negative primary tumor, and ER-positive recurrent cases have the longest latency period. The local recurrence rate of Paget’s disease after NSM is low, and the prognosis is good in recurrent patients who accept further extensive NAC excision. Further systematic treatment was not considered for this patient.

HER2-low breast cancer shows a lower immune response compared to HER2-negative cases

Currently, the human epidermal growth factor receptor 2 (HER2) status of breast cancer is classified dichotomously as negative or positive to select patients for HER2-targeted therapy. However, with the introduction of novel treatment options, it is important to get more insight in the biology of cancers with low HER2 expression. Therefore, we studied several clinicopathologic characteristics in relation to the level of HER2 expression (HER2- versus HER2low). We used a well-documented cohort of breast cancer patients (n = 529), with available tissue microarrays and Affymetrix mRNA expression data. HER2 status was scored as negative (immunohistochemistry 0) or low (immunohistochemistry 1 + or 2 + without amplification). We associated HER2 status with several clinicopathologic characteristics, gene-expression data and survival, stratified for estrogen receptor (ER) status. Overall, breast cancers were scored as HER2- (n = 429) or HER2low (n = 100). Within the ER+ cohort (n = 305), no significant associations were found between the HER2 groups and clinicopathologic features. However, HER2low tumors showed several differentially expressed genes compared to HER2- cases, including genes that are associated with worse outcome and depletion of immunity. In ER- cases (n = 224), HER2low status was significantly associated with increased regional nodal positivity, lower density of tumor infiltrating lymphocyte and a lower protein expression of Ki-67 and EGFR compared to HER2- cases. After multivariate analysis, only density of tumor infiltrating lymphocytes remained significantly associated with HER2low status (P = 0.035). No difference in survival was observed between HER2low and HER2- patients, neither in the ER+ nor ER- cohort. In conclusion, our data suggests that HER2low breast cancer is associated with a lower immune response compared to HER2- breast cancer.

Therapeutic Targeting of Minimal Residual Disease to Prevent Late Recurrence in Hormone-Receptor Positive Breast Cancer: Challenges and New Approaches

While the majority of breast cancers are diagnosed at a curable stage, approximately 20% of women will experience recurrence at a distant site during their lifetime. These metastatic recurrences are incurable with current therapeutic approaches. Over the past decade, the biologic mechanisms underlying these recurrences have been elucidated, establishing the existence of minimal residual disease in the form of circulating micrometastases and dormant disease, primarily in the bone marrow. Numerous technologies are now available to detect minimal residual disease (MRD) after breast cancer treatment, but it is yet unknown how to best target and eradicate these cells, and whether clearance of detectable disease prior to the formation of overt metastases can prevent ultimate progression and death. Clinical trials to test this hypothesis are challenging due to the rare nature of MRD in the blood and bone marrow, resulting in the need to screen a large number of survivors to identify those for study. Use of prognostic molecular tools may be able to direct screening to those patients most likely to harbor MRD, but the relationship between these predictors and MRD detection is as yet undefined. Further challenges include the lack of a definitive assay for MRD with established clinical utility, difficulty in selecting potential interventions due to limitations in understanding the biology of MRD, and the emotional impact of detecting MRD in patients who have completed definitive treatment and have no evidence of overt metastatic disease. This review provides a roadmap for tackling these challenges in the design and implementation of interventional clinical trials aimed at eliminating MRD and ultimately preventing metastatic disease to improve survival from this disease, with a specific focus on late recurrences in ER+ breast cancer.

The Incidence of Breast Cancer Recurrence 10-32 Years after Primary Diagnosis

Background

Extended, more effective breast cancer treatments have increased the prevalence of long-term survivors. We investigated the risk of late breast cancer recurrence (BCR), 10 years or more after primary diagnosis, and associations between patient and tumor characteristics at primary diagnosis and late BCR up to 32 years after primary breast cancer diagnosis.

Methods

Using the Danish Breast Cancer Group clinical database, we identified all women with an incident early breast cancer diagnosed during 1987-2004. We restricted to women who survived 10 years without a recurrence or second cancer (10-year disease-free survivors) and followed them from 10 years after breast cancer diagnosis date until late recurrence, death, emigration, second cancer, or December 31, 2018. We calculated incidence rates per 1000 person-years and cumulative incidences for late BCR, stratifying by patient and tumor characteristics. Using Cox regression, we calculated adjusted hazard ratios for late BCR accounting for competing risks.

Results

Among 36 924 women with breast cancer, 20 315 became 10-year disease-free survivors. Of these, 2595 developed late BCR (incidence rate = 15.53 per 1000 person-years, 95% confidence interval = 14.94 to 16.14; cumulative incidence = 16.6%, 95% confidence interval = 15.8% to 17.5%) from year 10 to 32 after primary diagnosis. Tumor size larger than 20 mm, lymph node–positive disease, and estrogen receptor–positive tumors were associated with increased cumulative incidences and hazards for late BCR.

Conclusions

Recurrences continued to occur up to 32 years after primary diagnosis. Women with high lymph node burden, large tumor size, and estrogen receptor–positive tumors had increased risk of late recurrence. Such patients may warrant extended surveillance, more aggressive treatment, or new therapy approaches.

Validation of the Clinical Treatment Score Post-Five Years in Breast Cancer Patients for Predicting Late Distant Recurrence: A Single-Center Investigation in Korea

Background

Endocrine therapy is administered to hormone-positive breast cancer patients to prevent distant metastasis. It is important to evaluate the risk of recurrence and to determine which patients are viable candidates for such treatment because hormone therapy has side effects that can include postmenopausal symptoms. The Clinical Treatment Score post-five years (CTS5), a simple tool for identifying candidates for endocrine therapy, was recently introduced; however, CTS5 only has been applied in validation studies with postmenopausal women. We aimed to validate CTS5 among premenopausal breast cancer patients.

Methods

We identified patients treated between 1994 and 2014 at Samsung Medical Center in Seoul, Korea, and followed their treatment outcomes for more than 60 months after surgery using clinicopathologic parameters. According to menopausal status, we divided the study population into two groups: pre- and postmenopausal women. After calculating CTS5 values based on some parameters, we stratified the rate of late distant recurrence (DR) and analyzed the correlation between CTS5 value and late DR by risk.

Results

Among 16,904 patients treated surgically for breast cancer, 2,605 with hormone receptor-positive breast cancer who received endocrine therapy were included. Of these, 1,749 (67.14%) patients were premenopausal women, and the median age was 44.00 years. When categorizing study participants according to CTS5-related risk for late DR, 86.79% were categorized as low risk, 5.95% were categorized as intermediate risk, and 7.26% were categorized as high risk. The annual rate of DR was 1.41% for those in the present study and was similar between pre- and postmenopausal participants (1.40 vs. 1.42). Distant metastasis-free survival was not different between the two groups (hazard ratio: 0.817, 95% confidence interval [CI]: 0.547-1.221). The area under the receiver operating characteristic curve at 10 years for premenopausal and postmenopausal patients was 61.75 (95% CI: 52.97-70.53) and 72.71 (95% CIs: 63.30-82.12), respectively.

Conclusions

Although CTS5 was able to predict late DR, it should be applied with caution in premenopausal women. A CTS5 calculator for premenopausal women might be needed to not underestimate the risk of recurrence in Korea.

Late Recurrence in Breast Cancer: To Run after the Oxen or to Try to Close the Barn?

Simple Summary

The initial treatment of early breast cancer has achieved important clinical results over time. However, late recurrences after many years of disease-free survival remain an open question, which has recently attracted the attention of a few researchers. The authors of this commentary suggest that the approach emerging from scientific meetings regarding this subject is marred by the lack of attention to recent clinical and laboratory data. The role of tumor dormancy and the dynamics of disease recurrence are presented here and a more general reflection on therapeutic approaches to cancer is proposed.

Abstract

The problem of late recurrence in breast cancer has recently gained attention and was also addressed in an international workshop held in Toronto (ON, Canada), in which several aspects of the question were examined. This Commentary offers a few considerations, which may be useful for the ongoing investigations. A few premises are discussed: (a) clinical recurrences, especially the late ones, imply periods of tumor dormancy; (b) a structured pattern of distant metastases appearance is detectable in both early and late follow-up times; (c) the current general paradigm underlying neoplastic treatments, i.e., that killing all cancer cells is the only way to control the disease, which is strictly sprouting from the somatic mutation theory, should be re-considered. Finally, a few research approaches are suggested.

Case report: 16-yr life history and genomic evolution of an ER+ HER2- breast cancer

Metastatic breast cancer is one of the leading causes of cancer-related death in women. Limited studies have been done on the genomic evolution between primary and metastatic breast cancer. We reconstructed the genomic evolution through the 16-yr history of an ER+ HER2- breast cancer patient to investigate molecular mechanisms of disease relapse and treatment resistance after long-term exposure to hormonal therapy. Genomic and transcriptome profiling was performed on primary breast tumor (2002), initial recurrence (2012), and liver metastasis (2015) samples. Cell-free DNA analysis was performed at 11 time points (2015-2017). Mutational analysis revealed a low mutational burden in the primary tumor that doubled at the time of progression, with driver mutations in PI3K-Akt and RAS-RAF signaling pathways. Phylogenetic analysis showed an early branching off between primary tumor and metastasis. Liquid biopsies, although initially negative, started to detect an ESR1 E380Q mutation in 2016 with increasing allele frequency until the end of 2017. Transcriptome analysis revealed 721 (193 up, 528 down) genes to be differentially expressed between primary tumor and first relapse. The most significantly down-regulated genes were TFF1 and PGR, indicating resistance to aromatase inhibitor (AI) therapy. The most up-regulated genes included PTHLH, S100P, and SOX2, promoting tumor growth and metastasis. This phylogenetic reconstruction of the life history of a single patient's cancer as well as monitoring tumor progression through liquid biopsies allowed for uncovering the molecular mechanisms leading to initial relapse, metastatic spread, and treatment resistance.