On-treatment derived neutrophil-to-lymphocyte ratio and survival with palbociclib and endocrine treatment: analysis of a multicenter retrospective cohort and the PALOMA-2/3 study with immune correlates.

BACKGROUND: Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors have been established as a standard treatment for hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC); however, predictive biomarkers with translational relevance have not yet been elucidated. METHODS: Data from postmenopausal women who received the CDK4/6 inhibitor palbociclib and letrozole for HR-positive, HER2-negative ABC from tertiary referral centers were analyzed (N = 221; exploratory cohort). Pre- and on-treatment neutrophil-to-lymphocyte ratio (NLR) and derived NLR (dNLR; neutrophil/[leukocyte-neutrophil]) were correlated with survival outcomes. Data from the PALOMA-2 (NCT01740427) and PALOMA-3 studies (NCT01942135) involving patients treated with endocrine treatment with or without palbociclib were also analyzed (validation cohort). Prospectively enrolled patients (N = 20) were subjected to immunophenotyping with circulating immune cells to explore the biological implications of immune cell dynamics. RESULTS: In the exploratory cohort, palbociclib administration significantly reduced leukocyte, neutrophil, and lymphocyte counts on day 1 of cycle 2. Although the baseline dNLR was not significantly associated with progression-free survival (PFS), higher on-treatment dNLRs were associated with worse PFS (hazard ratio = 3.337, P < 0.001). In the PALOMA-2 validation cohort, higher on-treatment dNLRs were associated with inferior PFS in patients treated with palbociclib and letrozole (hazard ratio = 1.498, P = 0.009), and reduction in the dNLR after treatment was predictive of a survival benefit (hazard ratio = 1.555, P = 0.026). On-treatment dNLRs were also predictive of PFS following palbociclib and fulvestrant treatment in the PALOMA-3 validation cohort. Using flow cytometry analysis, we found that the CDK4/6 inhibitor prevented T cell exhaustion and diminished myeloid-derived suppressor cell frequency. CONCLUSIONS: On-treatment dNLR significantly predicted PFS in patients with HR-positive, HER2-negative ABC receiving palbociclib and endocrine treatment. Additionally, we observed putative systemic immune responses elicited by palbociclib, suggesting immunologic changes upon CDK4/6 inhibitor treatment.

First-in-human study of IM156, a novel potent biguanide oxidative phosphorylation (OXPHOS) inhibitor, in patients with advanced solid tumors.

Preclinical models suggest anticancer activity of IM156, a novel biguanide mitochondrial protein complex 1 inhibitor of oxidative phosphorylation (OXPHOS). This first-in-human dose-escalation study enrolled patients with refractory advanced solid tumors to determine the maximum tolerated dose (MTD) or recommended phase 2 dose (RP2D). Eligible patients received oral IM156 every other day (QOD) or daily (QD) and were assessed for safety, dose-limiting toxicities (DLTs), pharmacokinetics, and preliminary signals of efficacy. 22 patients with advanced cancers (gastric, n = 8; colorectal, n = 3; ovarian, n = 3; other, n = 8) received IM156 100 to 1,200 mg either QOD or QD. There were no DLTs. However, 1,200 mg QD was not well tolerated due to nausea; 800 mg QD was determined as the RP2D. The most frequent treatment-related AEs (TRAEs) were nausea (n = 15; 68%), diarrhea (n = 10; 46%), emesis (n = 9; 41%), fatigue (n = 4; 18%) and abdominal pain, constipation, and blood lactate increased (n = 2 each; 9%). Grade 3 nausea (n = 3; 14%) was the only grade ≥ 3 TRAE. Plasma exposures increased dose proportionally; mean Day 27 area under the curve (AUC0-24) values were higher following QD administration compared to the respective QOD regimen. Stable disease (SD), observed in 7 (32%) patients (confirmed in 2 [9%]), was the best response. To our knowledge, this is the first phase 1 study of an OXPHOS inhibitor that established a RP2D for further clinical development in cancer. Observed AEs of IM156 were manageable and SD was the best response.

Blood Test for Breast Cancer Screening through the Detection of Tumor-Associated Circulating Transcripts.

Liquid biopsy has been emerging for early screening and treatment monitoring at each cancer stage. However, the current blood-based diagnostic tools in breast cancer have not been sufficient to understand patient-derived molecular features of aggressive tumors individually. Herein, we aimed to develop a blood test for the early detection of breast cancer with cost-effective and high-throughput considerations in order to combat the challenges associated with precision oncology using mRNA-based tests. We prospectively evaluated 719 blood samples from 404 breast cancer patients and 315 healthy controls, and identified 10 mRNA transcripts whose expression is increased in the blood of breast cancer patients relative to healthy controls. Modeling of the tumor-associated circulating transcripts (TACTs) is performed by means of four different machine learning techniques (artificial neural network (ANN), decision tree (DT), logistic regression (LR), and support vector machine (SVM)). The ANN model had superior sensitivity (90.2%), specificity (80.0%), and accuracy (85.7%) compared with the other three models. Relative to the value of 90.2% achieved using the TACT assay on our test set, the sensitivity values of other conventional assays (mammogram, CEA, and CA 15-3) were comparable or much lower, at 89%, 7%, and 5%, respectively. The sensitivity, specificity, and accuracy of TACTs were appreciably consistent across the different breast cancer stages, suggesting the potential of the TACTs assay as an early diagnosis and prediction of poor outcomes. Our study potentially paves the way for a simple and accurate diagnostic and prognostic tool for liquid biopsy.

Final results of the randomized phase 2 LEO trial and bone protective effects of everolimus for premenopausal hormone receptor-positive, HER2-negative metastatic breast cancer.

The phase 2 LEO study showed that everolimus (EVE) plus letrozole (LET) with ovarian suppression increased progression-free survival (PFS) in tamoxifen-exposed premenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer with visceral metastases. Here we report final survival outcomes from the LEO study, and the results of exploratory analyses of bone turnover marker changes and bone-specific progressive disease. Patients who were exposed to or progressed on tamoxifen as adjuvant/palliative treatments were randomly assigned (2:1) to the EVE (leuprorelin + LET + EVE, n = 92) or LET (leuprorelin + LET, n = 45) arm. In a median 51-months of follow-up, the median PFS was 17.5 and 13.8 months in the EVE and LET arms, respectively (P = .245). Patients in the EVE arm with baseline visceral (median PFS 16.4 vs 9.5 months, P = .040) and bone (median PFS 17.1 vs 10.9, P = .003) metastases had greater PFS compared to the LET arm. No differences in overall survival (OS) were observed (median OS, 48.3 vs 50.8 months, P = .948). The 1-year cumulative incidences of bone-specific disease progression were 6.0% and 23.4% in the EVE and LET arms, respectively (hazard ratio 0.26, P < .001). Bone turnover markers at 6 and 12 weeks after treatment decreased in the EVE arm but were increased or stationary in the LET arm. Skeletal-related events occurred in 6.5% and 11.1% of patients in the EVE and LET arms, respectively. EVE + LET with ovarian suppression prolonged PFS in patients with baseline visceral or bone metastases and offered bone-protective effects in the overall study population. However, these clinical benefits did not translate into an OS benefit.

Risk of Lymphedema Following Contemporary Treatment for Breast Cancer: An Analysis of 7617 Consecutive Patients From a Multidisciplinary Perspective.

OBJECTIVE: The aim of this study was to identify the comprehensive risk factors for lymphedema, thereby enabling a more informed multidisciplinary treatment decision-making. SUMMARY BACKGROUND DATA: Lymphedema is a serious long-term complication in breast cancer patients post-surgery; however, the influence of multimodal therapy on its occurrence remains unclear. METHODS: We retrospectively collected treatment-related data from 5549 breast cancer patients who underwent surgery between 2007 and 2015 at our institution. Individual radiotherapy plans were reviewed for regional nodal irradiation (RNI) field design and fractionation type. We identified lymphedema risk factors and used them to construct nomograms to predict individual risk of lymphedema. Nomograms were validated internally using 100 bootstrap samples and externally using 2 separate datasets of 1877 Asian and 191 Western patients. RESULTS: Six hundred thirty-nine patients developed lymphedema during a median follow-up of 60 months. The 3-year lymphedema incidence was 10.5%; this rate increased with larger irradiation volumes (no RNI vs RNI excluding axilla I-II vs RNI including axilla I-II: 5.7% vs 16.8% vs 24.1%) and when using conventional fractionation instead of hypofractionation (13.5% vs 6.8%). On multivariate analysis, higher body mass index, larger number of dissected nodes, taxane-based regimen, total mastectomy, larger irradiation field, and conventional fractionation were strongly associated with lymphedema (all P < 0.001). Nomograms constructed based on these variables showed good calibration and discrimination internally (concordance index: 0.774) and externally (0.832 for Asian and 0.820 for Western patients). CONCLUSIONS: Trimodality breast cancer treatment factors interact to promote lymphedema. Lymphedema risk can be decreased by deintensifying node dissection, chemotherapy regimen, and field and dose of radiotherapy. Deescalation strategies on a multidisciplinary basis might minimize lymphedema risk.

Phase 2 study of TAS-117, an allosteric akt inhibitor in advanced solid tumors harboring phosphatidylinositol 3-kinase/v-akt murine thymoma viral oncogene homolog gene mutations.

TAS-117 is a potent and selective allosteric pan-v-akt murine thymoma viral oncogene homolog (Akt) inhibitor. We conducted a single-arm single-center phase 2 study of TAS-117 in heavily treated patients with tumors refractory to systemic chemotherapy and harboring phosphatidylinositol 3-kinase (PI3K)/Akt mutations. Patients with gastrointestinal (GI) cancers were orally administered 16 mg TAS-117 daily, and those with non-GI tumors were administered 24 mg on a 4 days on/3 days off schedule. The primary endpoint was overall response rate (ORR). Secondary endpoints included disease control rate (DCR), progression-free survival (PFS), overall survival (OS), PFS ratio, safety, and tolerability. Thirteen patients were enrolled: eight with non-GI (breast, ovarian, endometrial, and non-small cell lung) and five with GI (colon, rectal, gastric, and gallbladder) cancers. Ten patients were treated with TAS-117 after ≥ 4 lines of therapy. Twelve patients showed PIK3 catalytic subunit alpha (PIK3CA) mutations; one harbored an Akt1E17K mutation. The median treatment duration was 1.4 months; the median number of treatment cycles was 2. The ORR was 8 %, and DCR was 23 %. The median PFS and OS were 1.4 and 4.8 months, respectively. Grade 3-4 treatment-related adverse events were anorexia (grade 3, 8 %) and hyperglycemia (grade 3, 8 %; grade 4, 8 %).Grade 3-4 treatment-related adverse events occurred in 27 % of grade 3 anorexia (9 %) and hyperglycemia (grade 3, 8 %; grade 4, 9\%). TAS-117 showed limited antitumor activity and manageable toxicity. Clinical efficacy was observed in patients with ovarian cancer harboring PIK3CA E545K mutations and in patients with breast cancer harboring PIK3CA H1047R and Akt1E17K mutations.Trial registration: This study was retrospectively registered with ClinicalTrial.gov (NCT03017521 on January 11, 2017).

Use of bevacizumab before or after radiotherapy increases the risk of fistula formation in patients with cervical cancer.

OBJECTIVE: Several reports have documented the risk of fistula formation after bevacizumab in patients previously treated with radiation therapy. The aim of this study was to investigate the risk of fistula formation with bevacizumab and radiotherapy compared with radiotherapy alone. METHODS: We retrospectively analyzed patients with stage I-IV cervical cancer between January 2013 and December 2018. Patients who had a history of pelvic radiotherapy, who were treated with intracavitary brachytherapy alone, received radiotherapy at another hospital, received concurrent bevacizumab and radiotherapy, or had missing follow-up data or a short follow-up period (<6 months) were excluded. The fistula rates were compared between the groups using the Cox proportional hazards model and propensity score analyses. RESULTS: A total of 302 patients were included in the study: 249 patients were treated with definitive or adjuvant radiotherapy, and 53 patients were treated with radiotherapy before or after bevacizumab. With a median follow-up of 35.9 (IQR 22.8-53.5) months, the 3 year cumulative fistula incidence rate was significantly higher in the radiotherapy + bevacizumab group than in the radiotherapy group (27.0% vs 3.0%, p<0.001). Bevacizumab administration was significantly associated with fistula formation in the multivariable adjusted model (HR 4.76, 95% CI 1.71 to 13.23) and three propensity score adjusted model (all p<0.05). Biologically equivalent dose in 2 Gy fractions for 2 cc of the rectum more than 76 Gy was also associated with fistula formation (HR 4.30, 95% CI 1.52 to 12.18). Additionally, a 10 month interval between radiotherapy and bevacizumab reduced the incidence of fistula formation in the radiotherapy + bevacizumab group (p=0.032). CONCLUSIONS: In patients with cervical cancer treated with pelvic radiotherapy, the addition of bevacizumab substantially increased the risk of fistula formation. Physicians should perform pelvic radiotherapy in combination with bevacizumab with caution; moreover, close monitoring for fistula formation is warranted in these patients.

Palbociclib use with grade 3 neutropenia in hormone receptor-positive metastatic breast cancer.

PURPOSE: Neutropenia is the most common toxicity of CDK4/6 inhibitors, causing frequent dose interruptions. However, CDK4/6 inhibitor-induced neutropenia shows a benign clinical course in contrast to that caused by chemotherapy. Here, we investigated the safety of a new dose scheme for palbociclib, which avoids dose delays or reductions due to afebrile grade 3 neutropenia. METHODS: A consecutive cohort of ER( +)/HER2( -) advanced breast cancer patients who received palbociclib between 2017 and 2018 was analyzed. The patients were classified into Group 1 (patients who maintained palbociclib dose with afebrile grade 3 neutropenia), Group 2 (patients who experienced any dose modification with afebrile grade 3 neutropenia), and Group 3 (patients without afebrile grade 3 neutropenia). The primary endpoint was febrile neutropenia incidence; other toxicities were compared with those of the PALOMA-2 trial. RESULTS: Among the 107 patients, 54.2%, 22.4%, and 23.4% were classified into Groups 1, 2, and 3, respectively. There was no febrile neutropenia in Groups 1 and 2 during palbociclib treatment. Group 1 showed higher incidence of thrombocytopenia (all-grade, 32.8%; grade 3-4, 8.6%) than Group 2 and the PALOMA-2 data, but there was no bleeding related to thrombocytopenia. Group 1 showed higher incidence of all-grade non-hematologic adverse events than Group 2; only one grade 3 non-hematologic toxicity was observed in Group 1. There were no treatment-related hospitalizations or deaths in Group 1. CONCLUSIONS: Thus, omitting palbociclib dose modification with afebrile grade 3 neutropenia is safe and tolerable without febrile neutropenia events. This scheme could be useful to avoid unnecessary reductions in palbociclib doses in future practice.

Intermediate HER2 expression is associated with poor prognosis in estrogen receptor-positive breast cancer patients aged 55 years and older.

PURPOSE: An antibody-drug conjugate targeting HER2, DS8201, has shown clinical activity against breast cancer with low-level HER2 expression. We aimed to evaluate the prognostic impact of intermediate HER2 expression in estrogen receptor (ER)+ early breast cancer (EBC) and metastatic breast cancer (MBC) cohorts. METHODS: We analyzed prospectively collected data from EBC and MBC cohorts at Yonsei Cancer Center. Patients with HER2 immunohistochemistry (IHC) 0 ~ 1+ were assigned to the HER2-negative group, and patients with IHC 2+ and in situ hybridization (ISH)-negativity were assigned to the HER2-intermediate group. After the exclusion of HER2 IHC 3+ or ISH+ patients, a total of 2657 EBC and 535 MBC patients were analyzed. RESULTS: In total, 654 (24.6%) EBC and 166 (31.0%) MBC patients were classified in the HER2-intermediate group. The HER2-intermediate patients more frequently tended to have progesterone receptor (PR)-negativity and higher nuclear grade in the EBC cohort, and showed a higher proportion of patients aged ≥ 55 years compared with the HER2-negative group in the MBC cohort. The HER2-intermediate patients showed significantly poorer recurrence-free survival (RFS) compared to the HER2-negative patients in the EBC cohort (p = 0.044). Notably, intermediate HER2 expression predicted poorer RFS in EBC patients aged ≥ 55 years (hazard ratio 1.95; p = 0.042) in multivariate Cox analysis but did not affect RFS in those aged < 55 years. In line with the EBC cohort results, intermediate HER2 expression predicted poorer overall survival (OS) in MBC patients aged ≥ 55 (hazard ratio 1.45; p = 0.044) without affecting OS of those aged < 55 years. CONCLUSION: Intermediate HER2 expression is an independent predictor of poor prognosis in both ER+ EBC and MBC patients aged ≥ 55 years. The clinical efficacy of new HER2-targeting antibody-drug conjugates needs to be validated in this high-risk subset of ER+ breast cancer patients.

Correction to: Palbociclib use with grade 3 neutropenia in hormone receptor-positive metastatic breast cancer.

In the original publication of the article, under the Results section, subheading "Patient survival", the second sentence that reads as "The 6-month PFS was 92.4%, 81.8%, and 93.3% and the one-year PFS was 72.0%, 88.9%, and 78.9% in Groups 1-3, respectively." should read as "The 6-month PFS was 82.8%, 75.0%, and 68.0% and the one-year PFS was 77.0%, 62.0%, and 63.8% in Groups 1-3, respectively.".

Cardiotoxicity evaluation using magnetic resonance imaging in breast Cancer patients (CareBest): study protocol for a prospective trial.

BACKGROUND: Cardiovascular disease is second only to cancer recurrence as a determinant of lifespan in cancer survivors, and cancer therapy-related cardiac dysfunction is a clinically important risk factor. We aim to investigate the use of cardiac magnetic resonance imaging (MRI) to evaluate early tissue changes and perform functional assessment of chemo- and radiation-induced cardiotoxicity and to identify MRI prognostic indicators of cardiotoxicity in breast cancer patients. METHODS: A 3-min cardiac imaging protocol will be added to the breast MRI examination to diagnose cardiotoxicity in breast cancer patients. Standardized MRI-based evaluation of breast cancer and the left ventricular myocardium will be performed at baseline and at 3, 6, and 12 months and 2 years or more after cancer treatment. We will analyze both ventricular volume and ejection fraction (EF), strain of left ventricle (LV), native T1, extracellular volume fraction (ECV), and T2 values acquired in the mid LV. DISCUSSION: The primary result of this study will be the comparison of the prognostic value of MRI parameters (native T1, ECV, both ventricular systolic function and LV strain) for cardiotoxicity. The endpoint is defined as the occurrence of a major adverse cardiac event (MACE). The secondary outcome will be an assessment of the temporal relationships between contractile dysfunction and microstructural injury over 4 years using MRI. This study will assess the usefulness of quantitative MRI to diagnose cardiotoxicity and will clarify the temporal relationships between contractile dysfunction and microstructural injury of the LV myocardium using MRI during breast cancer treatment. TRIAL REGISTRATION: The protocol was registered at clinicaltrials.gov (Clinical trial no. NCT03301389) on October 4, 2017.

Changes in taste and food preferences in breast cancer patients receiving chemotherapy: a pilot study.

PURPOSE: Cancer treatment may relate to appetite reduction and malnutrition. We investigated taste alterations and dish-type preferences during chemo- and/or radiation therapy in breast cancer patients. METHODS: Breast cancer patients (BC, n = 59) scheduled to receive cancer therapy and healthy subjects (control group or CTRL, n = 49) were voluntarily recruited. Taste detection thresholds (DTs) and recognition thresholds (RT) were compared between pre-treatment BC patients and CTRL for sweet (sucrose), salty (NaCl), bitter (caffeine), and sour (citric acid) solutions. Changes in taste thresholds and dish preferences during treatment were monitored in the BC group. Blood chemistry and anthropometric data were collected. RESULTS: At baseline, BC patients demonstrated lower sweet and salty DTs and RTs and a higher sour RT compared to CTRL. Bitter DT and RT were similar in both groups. Mild/soft dishes were preferred over fried/oily dishes by BC patients. Throughout treatment in BC patients, sweet thresholds significantly declined, while salty, bitter, and sour DTs and RTs were not affected, and there was no increase in preference for a dish. However, preference towards mild/soft dishes remained. While sweet-sour fruits and sweetened nuts were not favored during therapy. CONCLUSIONS: Sensitivities to sweet, salty, and sour but not bitter tastes differed between BC patients and CTRL. During treatment, sweet taste sensitivity increased while other tastes were unaffected. BC patients preferred mild/soft dishes over fried and sweetened dishes compared to CTRL. Our findings may contribute to developing dishes for breast cancer patients to increase food intake and thereby lower the risk of malnutrition.

Palbociclib plus exemestane with gonadotropin-releasing hormone agonist versus capecitabine in premenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer (KCSG-BR15-10): a multicentre, open-label, randomised, phase 2 trial.

BACKGROUND: Endocrine treatment is recommended by clinical guidelines as the preferred treatment option for premenopausal as well as postmenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer. In real-world clinical practice, however, a substantial number of patients are treated with chemotherapy. We aimed to compare the clinical antitumour activity and safety of palbociclib plus endocrine therapy with that of capecitabine chemotherapy in premenopausal women with hormone receptor-positive, HER2-negative metastatic breast cancer. METHODS: This multicentre, open-label, randomised, phase 2 study was done in 14 academic institutions in South Korea. Premenopausal women aged 19 years or older with hormone receptor-positive, HER2-negative breast cancer that had relapsed or progressed during previous tamoxifen therapy and with an Eastern Cooperative Oncology Group performance status of 0-2 were included. One line of previous chemotherapy for metastatic breast cancer was allowed. Patients were randomly assigned, using a random permuted block design (with a block size of two), to receive palbociclib plus combination endocrine therapy (oral exemestane 25 mg per day for 28 days and oral palbociclib 125 mg per day for 21 days every 4 weeks plus leuprolide 3·75 mg subcutaneously every 4 weeks) or chemotherapy (oral capecitabine 1250 mg/m2 twice daily for 2 weeks every 3 weeks). Randomisation was stratified by previous chemotherapy for metastatic breast cancer and visceral metastasis. The primary endpoint was progression-free survival. All analyses were done in a modified intention-to-treat population that excluded patients who did not receive study medication. This study is registered with ClinicalTrials.gov, NCT02592746, and is ongoing for follow-up of overall survival. FINDINGS: Between June 15, 2016, and Dec 10, 2018, 189 patients were enrolled, of whom 184 were randomly assigned to the palbociclib plus endocrine therapy group (n=92) or the capecitabine group (n=92). Six patients in the capecitabine group withdrew from the study before drug administration; therefore, 92 patients in the palbociclib plus endocrine therapy group and 86 patients in the capecitabine group were included in the modified intention-to-treat analyses. 46 (50%) of 92 patients in the palbociclib plus endocrine therapy group and 45 (51%) of 92 in the capecitabine group were treatment naive for metastatic breast cancer. During a median follow-up of 17 months (IQR 9-22), median progression-free survival was 20·1 months (95% CI 14·2-21·8) in the palbociclib plus endocrine therapy group versus 14·4 months (12·1-17·0) in the capecitabine group (hazard ratio 0·659 [95% CI 0·437-0·994], one-sided log-rank p=0·0235). Treatment-related grade 3 or worse neutropenia was more common in the palbociclib plus endocrine therapy group than in the capecitabine group (69 [75%] of 92 vs 14 [16%] of 86 patients). 2 (2%) patients in the palbociclib plus endocrine therapy group and 15 (17%) patients in the capecitabine group had treatment-related serious adverse events. No treatment-related deaths occurred. INTERPRETATION: Exemestane plus palbociclib with ovarian function suppression showed clinical benefit compared with capecitabine in terms of improved progression-free survival in premenopausal patients with hormone receptor-positive, HER2-negative metastatic breast cancer. Palbociclib plus exemestane with ovarian suppression is an active treatment option in premenopausal patients with hormone receptor-positive, HER2-negative metastatic breast cancer who have been pretreated with tamoxifen. FUNDING: Pfizer, Shinpoong, and Daewoong Korea and Takeda.

Molecular mechanisms of resistance to CDK4/6 inhibitors in breast cancer: A review.

Deregulation of the cyclin D-CDK4/6-INK4-RB pathway leading to uncontrolled cell proliferation, is frequently observed in breast cancer. Currently, three selective CDK4/6 inhibitors have been FDA approved: palbociclib, ribociclib and abemaciclib. Despite promising clinical outcomes, intrinsic or acquired resistance to CDK4/6 inhibitors has limited the success of these treatments; therefore, the development of various strategies to overcome this resistance is of great importance. We highlight the various mechanisms that are directly or indirectly responsible for resistance to CDK4/6 inhibitors, categorizing them into two broad groups; cell cycle-specific mechanisms and cell cycle-nonspecific mechanisms. Elucidation of the diverse mechanisms through which resistance to CDK4/6 inhibitors occurs, may aid in the design of novel therapeutic strategies to improve patient outcomes. This review summarizes the currently available knowledge regarding mechanisms of resistance to CDK4/6 inhibitors, and possible therapeutic strategies that may overcome this resistance as well.

Effect of primary tumor resection on overall survival in patients with stage IV breast cancer.

We aimed to evaluate the effect of primary tumor resection on overall survival in stage IV breast cancer patients. In total, 284 breast cancer patients presenting with breast cancer at stage IV at initial diagnosis, between 2001 and 2014, were enrolled in the study. Patients were divided into two groups based on surgical resection of the primary tumor. Overall survival (OS) between the two groups was analyzed. Patients in the surgery group (n = 92) had smaller tumors than those in the no-surgery group (n = 192, T0-1:17.7% vs 34.8%, P < 0.001). The surgery group more often had negative nodal status (5.7% vs 33.7%, P < 0.001). Multiple metastatic organ sites were more common in the no-surgery group than in the surgery group (55.7% vs 15.2%, P < 0.001). The surgery group showed a better OS than the no-surgery group (P = 0.01). Multivariate analysis showed that surgical resection of primary tumors tended to be associated with improved OS (HR = 0.67, P = 0.055). T stage, ER, HER2 and metastatic organ sites were independent prognostic factors for OS in multivariate analysis. Surgical resection of the primary tumor may be a treatment option for patients with stage IV disease and may not have a negative effect on overall survival.

A phase II trial of the pan-HER inhibitor poziotinib, in patients with HER2-positive metastatic breast cancer who had received at least two prior HER2-directed regimens: results of the NOV120101-203 trial.

Although the introduction of human epidermal growth factor receptor (HER)2-directed therapy including trastuzumab, pertuzumab, lapatinib and trastuzumab emtansine (T-DM1) in the treatment of HER2-positive metastatic breast cancers (mBCs) favorably changed the natural history of this disease, most cases of HER2-positive mBC will eventually progress. Poziotinib is an oral pan-HER kinase inhibitor showing potent activity through irreversible inhibition of these kinases. This open-label, multicenter phase II study was designed to evaluate the efficacy and safety of poziotinib monotherapy in patients with HER2-positive mBC who had progressed from more than two HER2-directed therapies. Patients received 12 mg poziotinib once daily on a 14-day on/7-day off schedule. Progression-free survival (PFS) as the primary endpoint, the objective response rate (ORR), overall survival (OS) and safety were evaluated. From April 2015 to February 2016, 106 patients were enrolled in the trial from seven institutes in South Korea. They had a median age of 51 years (range 30-76) and had received a median of four prior therapies including two HER2-directed therapies for advanced or metastatic cancers. The median follow-up duration was 12 months. The median PFS was 4.04 months (95% confidence interval [CI], 2.94-4.40 months), and median overall survival has not been reached. The most common treatment-related adverse events were (total/grade ≥3) diarrhea (96.23%/14.15%), stomatitis (92.45%/12.26%) and rashes (63.21%/3.77%). Poziotinib showed meaningful activity in these heavily treated HER2-positive mBCs. Diarrhea and stomatitis were the major toxicities. Biomarker studies analyzed are warranted to support further evaluation of this treatment in such cases.

Chemotherapy-induced irreversible alopecia in early breast cancer patients.

PURPOSE: The purpose of this work is to determine the prevalence of chemotherapy-induced irreversible alopecia (CIIA), which is defined as an alopecia that exists at least 6 months after completion of chemotherapy and factors affecting CIIA in early breast cancer patients. METHODS: We performed a cross-sectional study. We retrospectively identified breast cancer patients who had received AC (Adriamycin, Cyclophosphamide) or AC-T (AC followed by Taxane) as neoadjuvant or adjuvant chemotherapy. We conducted questionnaire survey regarding alopecia and measured hair density using phototrichogram. RESULTS: From February 2015 to May 2015, among 265 patients who responded properly to the questionnaire, the women who answered they had severe alopecia (alopecia > 50% of scalp) were 19 patients (7.2%). AC-only and AC-T treated patients reported severe alopecia in 2.7% and 10.5%, respectively, which were significantly different (p < 0.001). Mean hair density was 75 hair/cm2 (range 42-112) and 75.2/cm2 (range 48.3-102) on occipital area and vertex area, respectively. Hair loss was the most frequent in parietal area (42.6%). Half of total patients (46%) and 73% of CIIA patients regarded that their hair became thinner after chemotherapy CONCLUSIONS: We found that significant proportion of early breast cancer patients were suffering from severe CIIA, especially when they had been treated with AC followed by taxane regimen.

Effects of hormone receptor status on the durable response of trastuzumab-based therapy in metastatic breast cancer.

PURPOSE: Trastuzumab-based treatment is the standard care for patients with HER2+ metastatic breast cancer (MBC). About 10% of HER2+ MBC showed a long-term durable response (progression-free survival, PFS > 3 years) to trastuzumab-based therapy. The aim of this study is to identify clinico-pathologic factors for a durable response to trastuzumab-based therapy in HER2-positive MBC. METHODS: In the Yonsei Breast Cancer MBC Database, we identified 1218 MBC patients who were diagnosed from 2006 to 2015. Among them, 294 had HER2+ disease, and 153 received trastuzumab plus taxane chemotherapy as first-line treatment. Clinico-pathologic factors, such as hormone receptor (HR) status and metastatic sites, were reviewed. To evaluate a durable response, landmark analysis was performed. RESULTS: The median follow-up time was 28 months (95% CI 4.4-83.0 months). Of 153 HER2+ patients, there were 73 HR- patients (47.7%), and bone was the most common metastatic site. The median PFS and overall survival (OS) were 12 and 39 months, respectively. HR- patients showed a tendency toward longer PFS (median, 13 vs. 11 months, P = 0.160) compared with HR+ patients. Patients with non-visceral metastases had longer median PFS and OS than those with visceral disease (median PFS, 15 vs. 11 months, P = 0.012; median OS, 75 vs. 34 months, P = 0.03). Landmark analysis at 9 months suggested that the PFS of HR- patients was significantly longer than that of HR+ patients (median, 19 vs. 9 months, P = 0.008). CONCLUSIONS: Among patients with HER2+ MBC, HR status is a possible predictive biomarker of a durable response to trastuzumab-based therapy.

A phase 1, open label, dose escalation study to investigate the safety, tolerability, and pharmacokinetics of MG1102 (apolipoprotein(a) Kringle V) in patients with solid tumors.

Purpose MG1102 is a potent inhibitor of angiogenesis in both in vitro and in vivo models. The purpose of the study was to investigate the safety and tolerability, pharmacokinetic (PK) profile, and preliminary antitumor efficacy of MG1102. Methods Patients with refractory solid tumors were eligible. Each patient received 1 dose of MG1102 followed by a 6-day rest period, during which they underwent PK assessments and safety monitoring. If the initial dose was tolerated, the patient continued with the 21-day treatment of MG1102 (5 days on, 2 days off for 3 weeks). Dose escalation was planned in 6 cohorts (6, 12, 24, 48, 96, and 192 mg/m2). Primary objectives included safety and maximum tolerated dose (MTD) assessment. Secondary objectives included assessment of PK, pharmacodynamics, and efficacy. Results A total of 16 patients were enrolled and 12 (75%) completed the study. The most common cancer type was colorectal cancer (n = 10). There was no dose limiting toxicity and the MTD was not reached at 192 mg/m2. The most frequent treatment-emergent adverse events were gastrointestinal disorders, including nausea (30.8%), abdominal pain (23.1%), constipation (23.1%), and dyspepsia (23.1%). The PK of MG1102 was slightly less than dose proportional from Cohorts 3 to 6. Among 13 response-evaluable patients, 1 unconfirmed partial response (PR) was seen (in the 48 mg/m2 cohort) and 4 patients had stable disease. Conclusions The safety profile of MG1102 was generally manageable and the toxicities resolved quickly. Potential antitumor activity was observed with 1 unconfirmed PR (60% size reduction).

Prevalence and prognostic implications of psychological distress in patients with gastric cancer.

BACKGROUND: The aim of this study was to investigate the prevalence and prognostic significance of psychological distress in gastric cancer patients. METHODS: The study population included 229 gastric cancer patients visiting Yonsei Cancer Center between November 2009 and March 2011. The distress was measured by available tools including the Modified Distress Thermometer (MDT), Hospital Anxiety and Depression Scale (HADS), and Center for Epidemiologic Studies-Depression Scale (CES-D). Patients with psychological distress were defined as those who scored above the cut-off values in both the MDT and either one of the HADS or CES-D. RESULTS: The median age of patients was 56 (range, 20 to 86) and 97 (42.4%) patients were with stage IV disease status at enrollment. The overall prevalence of psychological distress was 33.6% (95% CI: 27.5-39.8%) in 229 gastric cancer patients. In multiple logistic regression analysis, lower education level (odds ratio [OR] 2.39; 95% confidence interval [CI] 1.11-5.17, P = 0.026) and higher disease stage (OR 2.72; 95% CI 1.47-5.03, P = 0.001) were associated with psychological distress. In stage I-III disease, patients with psychological distress had worse disease-free survival (DFS) (5-year DFS rate: 60% vs 76%, P = 0.49) compared with those without psychological distress. In stage IV disease (n = 97), patients with psychological distress showed poorer overall survival than those without psychological distress (median OS (Overall Survival): 12.2 vs. 13.8 months, P = 0.019). CONCLUSION: Psychological distress is common in patients with all stages of gastric cancer and is associated with worse outcomes.