Amivantamab plus Lazertinib in Previously Untreated EGFR-Mutated Advanced NSCLC.

BACKGROUND: Amivantamab plus lazertinib (amivantamab-lazertinib) has shown clinically meaningful and durable antitumor activity in patients with previously untreated or osimertinib-pretreated EGFR (epidermal growth factor receptor)-mutated advanced non-small-cell lung cancer (NSCLC). METHODS: In a phase 3, international, randomized trial, we assigned, in a 2:2:1 ratio, patients with previously untreated EGFR-mutated (exon 19 deletion or L858R), locally advanced or metastatic NSCLC to receive amivantamab-lazertinib (in an open-label fashion), osimertinib (in a blinded fashion), or lazertinib (in a blinded fashion, to assess the contribution of treatment components). The primary end point was progression-free survival in the amivantamab-lazertinib group as compared with the osimertinib group, as assessed by blinded independent central review. RESULTS: Overall, 1074 patients underwent randomization (429 to amivantamab-lazertinib, 429 to osimertinib, and 216 to lazertinib). The median progression-free survival was significantly longer in the amivantamab-lazertinib group than in the osimertinib group (23.7 vs. 16.6 months; hazard ratio for disease progression or death, 0.70; 95% confidence interval [CI], 0.58 to 0.85; P<0.001). An objective response was observed in 86% of the patients (95% CI, 83 to 89) in the amivantamab-lazertinib group and in 85% of those (95% CI, 81 to 88) in the osimertinib group; among patients with a confirmed response (336 in the amivantamab-lazertinib group and 314 in the osimertinib group), the median response duration was 25.8 months (95% CI, 20.1 to could not be estimated) and 16.8 months (95% CI, 14.8 to 18.5), respectively. In a planned interim overall survival analysis of amivantamab-lazertinib as compared with osimertinib, the hazard ratio for death was 0.80 (95% CI, 0.61 to 1.05). Predominant adverse events were EGFR-related toxic effects. The incidence of discontinuation of all agents due to treatment-related adverse events was 10% with amivantamab-lazertinib and 3% with osimertinib. CONCLUSIONS: Amivantamab-lazertinib showed superior efficacy to osimertinib as first-line treatment in EGFR-mutated advanced NSCLC. (Funded by Janssen Research and Development; MARIPOSA ClinicalTrials.gov number, NCT04487080.).

Pembrolizumab with or Without Lenvatinib as First-line Therapy for Patients with Advanced Urothelial Carcinoma (LEAP-011): A Phase 3, Randomized, Double-Blind Trial.

BACKGROUND: Pembrolizumab plus lenvatinib has shown antitumor activity and acceptable safety in patients with platinum-refractory urothelial carcinoma (UC). OBJECTIVE: To evaluate pembrolizumab plus either lenvatinib or placebo as first-line therapy for advanced UC in the phase 3 LEAP-011 study. DESIGN, SETTING, AND PARTICIPANTS: Patients with advanced UC who were ineligible for cisplatin-based therapy or any platinum-based chemotherapy were enrolled. INTERVENTION: Patients were randomly assigned (1:1) to pembrolizumab 200 mg intravenously every 3 wk plus either lenvatinib 20 mg or placebo orally once daily. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Dual primary endpoints were progression-free survival (PFS) and overall survival (OS). An external data monitoring committee (DMC) regularly reviewed safety and efficacy data every 3 mo. RESULTS AND LIMITATIONS: Between June 25, 2019 and July 21, 2021, 487 patients were allocated to receive lenvatinib plus pembrolizumab (n = 245) or placebo plus pembrolizumab (n = 242). The median time from randomization to the data cutoff date (July 26, 2021) was 12.8 mo (interquartile range, 6.9-19.3). The median PFS was 4.5 mo in the combination arm and 4.0 mo in the pembrolizumab arm (hazard ratio [HR] 0.90 [95% confidence interval {CI} 0.72-1.14]). The median OS was 11.8 mo for the combination arm and 12.9 mo for the pembrolizumab arm (HR 1.14 [95% CI 0.87-1.48]). Grade 3-5 adverse events attributed to trial treatment occurred in 123 of 241 patients (51%) treated with lenvatinib plus pembrolizumab and in 66 of 242 patients (27%) treated with placebo plus pembrolizumab. This trial was terminated earlier than initially planned based on recommendation from the DMC. CONCLUSIONS: The benefit-to-risk ratio for first-line lenvatinib plus pembrolizumab was not considered favorable versus pembrolizumab plus placebo as first-line therapy in patients with advanced UC. PATIENT SUMMARY: Lenvatinib plus pembrolizumab was not more effective than pembrolizumab plus placebo in patients with advanced urothelial carcinoma.

A Phase II Study of the Combination of Oxaliplatin, Capecitabine, and Trastuzumab and Chemoradiotherapy in the Adjuvant Setting in Operated Patients With HER2-positive Gastric or Gastroesophageal Junction Cancer (TOXAG Study): A Turkish Oncology Group Study.

BACKGROUND: Trastuzumab prolonged the overall survival in patients with advanced gastric cancer with human epidermal growth factor receptor 2 (HER2) overexpression in combination with chemotherapy. In this phase II open-label prospective study, the tolerability and safety of trastuzumab with chemotherapy, and chemoradiotherapy for curatively resected patients with HER2-positive gastric carcinoma was investigated. METHODS: The patients with HER2-positive gastric, or gastroesophageal junction adenocarcinoma, after gastrectomy plus D2 dissection, were included. They received 3 cycles of oxaliplatin (100 mg/m2 intravenously day 1) plus capecitabine (850 mg/m2 orally days 1 to 14), trastuzumab (8 mg/kg intravenously day 1 in cycle 1, 6 mg/kg thereafter) every 21 days, followed by chemoradiotherapy. Trastuzumab was given for 1 year. RESULTS: Of the 212 patients screened, 35 were eligible, and 34 were treated. The median age was 56 years (minimum to maximum: 35 to 75 y), male patients constituted 73.5% (n=25), and 33 (97.1%) had gastric adenocarcinoma. R0 resection was performed in 30 (88.2%). The majority (26, 61.7%) were in stage III disease. Most of the adverse events were grade I/II, the most frequent grade III side effects were nausea (3, 8.8%), vomiting (3, 8.8%), diarrhea (2, 5.9%), and weight loss (n=2, 5.9%). Two patients died during the first 3 cycles of chemotherapy and chemoradiotherapy; 1 secondary to pulmonary thromboembolism, and the other due to cerebral ischemia. After excluding 2 with early progression and 1 consent withdrawal, of the remaining 31 patients, 28 (90.3%) were able to complete the chemotherapy and chemoradiotherapy part of the trial. After the 25 months follow-up period, 21 patients (61.8%) were alive. Overall survival at 12 and 24 months was 75.0% and 58.0%, while disease-free survival at 12 and 24 months was 65.7% and 55.0%, respectively. CONCLUSIONS: Trastuzumab in combination with capecitabine, oxaliplatin following chemoradiotherapy as the adjuvant therapy for gastric or gastroesophageal junction adenocarcinoma was considered as safe and tolerable. The frequency of HER2 overexpression in curatively resected patients is comparable to that in patients with metastatic disease (trial registration: clinicaltrials.gov the identifier: NCT01748773, December 13, 2012, https://clinicaltrials.gov/ct2/show/NCT01748773).

Pembrolizumab Plus Ipilimumab or Placebo for Metastatic Non-Small-Cell Lung Cancer With PD-L1 Tumor Proportion Score ≥ 50%: Randomized, Double-Blind Phase III KEYNOTE-598 Study.

PURPOSE: Pembrolizumab monotherapy is standard first-line therapy for metastatic non-small-cell lung cancer (NSCLC) with programmed death ligand 1 (PD-L1) tumor proportion score (TPS) ≥ 50% without actionable driver mutations. It is not known whether adding ipilimumab to pembrolizumab improves efficacy over pembrolizumab alone in this population. METHODS: In the randomized, double-blind, phase III KEYNOTE-598 trial (ClinicalTrials.gov identifier: NCT03302234), eligible patients with previously untreated metastatic NSCLC with PD-L1 TPS ≥ 50% and no sensitizing EGFR or ALK aberrations were randomly allocated 1:1 to ipilimumab 1 mg/kg or placebo every 6 weeks for up to 18 doses; all participants received pembrolizumab 200 mg every 3 weeks for up to 35 doses. Primary end points were overall survival and progression-free survival. RESULTS: Of the 568 participants, 284 were randomly allocated to each group. Median overall survival was 21.4 months for pembrolizumab-ipilimumab versus 21.9 months for pembrolizumab-placebo (hazard ratio, 1.08; 95% CI, 0.85 to 1.37; P = .74). Median progression-free survival was 8.2 months for pembrolizumab-ipilimumab versus 8.4 months for pembrolizumab-placebo (hazard ratio, 1.06; 95% CI, 0.86 to 1.30; P = .72). Grade 3-5 adverse events occurred in 62.4% of pembrolizumab-ipilimumab recipients versus 50.2% of pembrolizumab-placebo recipients and led to death in 13.1% versus 7.5%. The external data and safety monitoring committee recommended that the study be stopped for futility and that participants discontinue ipilimumab and placebo. CONCLUSION: Adding ipilimumab to pembrolizumab does not improve efficacy and is associated with greater toxicity than pembrolizumab monotherapy as first-line treatment for metastatic NSCLC with PD-L1 TPS ≥ 50% and no targetable EGFR or ALK aberrations. These data do not support use of pembrolizumab-ipilimumab in place of pembrolizumab monotherapy in this population.

A historical turning point for the treatment of advanced renal cell carcinoma: inhibition of immune checkpoint.

Background: Renal cell carcinoma (RCC) is the most common type of renal malignancy with 87% frequency. As a global health problem, kidney cancer is responsible for 2.2% of new cancer cases. One of the highly effective mechanisms that renal cancer cells avoid in the immune system is PD-1 and PD-L1 interaction.Scope: Literature search is made from PubMed, Medline, and ASCO and ESMO Annual Meeting abstracts using the following search keywords: "nivolumab," "pembrolizumab," "atezolizumab," "avelumab," "durvalumab," and "renal cell cancer." The last search was on November 1, 2019.Findings: The combination of nivolumab and ipilimumab have better survival results than sunitinib for intermediate and poor risk patients but not for favorable risk groups. In 2019, two combination regimens with pembrolizumab plus axitinib and avelumab plus axitinib demonstrated efficacy over sunitinib for every risk group. The overall survival data of these trials are still immature.Conclusions: Advanced RCC has high morbidity and mortality with an increasing prevalence. Following tyrosine kinase inhibitors, checkpoint inhibitors have a great influence on treatment of advanced RCC, especially the combination of these two strategies. In 2019 these combined strategies demonstrated 5% complete remission with up to 60% objective response rate. While not immediately, but perhaps in the near future, advanced RCC will become a manageable chronic disease, even if a cure is not possible.

An update on immunotherapy options for urothelial cancer.

Introduction: The efficacy of immune checkpoint inhibitors has been shown in many malignancies. Urothelial cancers have a high mutational load and also express a high level of PD-L1. Therefore, the use of immune checkpoint inhibitors (ICIs) in various treatment lines is being intensively investigated in urothelial cancers.Area covered: In this review article, we aimed to summarize the development of immune checkpoint inhibition in urothelial cancers. We also provide updated and comprehensive data about the use of ICIs in the second-line and first-line treatment of patients who are ineligible for cisplatin. We also summarize ongoing trials and the results of published trials. A literature search was made using PubMed, Medline, and ASCO and ESMO Annual Meetings abstracts by using the following search terms: nivolumab, pembrolizumab, atezolizumab, avelumab, durvalumab, and urothelial cancer.Expert opinion: ICIs as a monotherapy are effective for the first-line treatment of the patients with advanced urothelial carcinoma who are ineligible for cisplatin, and also patients who are pre-treated with platinum-based chemotherapy. The results of trials investigating the efficacy of the combination of ICIs and chemotherapy in the first-line setting are awaited; it remains unclear as to whether this combination may become the standard first-line treatment in advanced urothelial cancer.

The frequency and predictors of persistent amenorrhea in premenopausal women with colorectal cancer who received adjuvant chemotherapy.

The purpose of this study was to identify the frequency of chemotherapy-induced amenorrhea and associated factors thereof in premenopausal female patients diagnosed with colon cancer. Premenopausal female patients under the age of 50 years who were diagnosed with stages I, II, and III colon cancer were included. A questionnaire surveying personal history including menarche, comorbidities, drugs, other clinical features, and menstrual history during and after completion of chemotherapy was filled by the patients during outpatient visits. Patients who received pelvic radiotherapy were excluded from the study. A total of 60 patients were included in the study. Eleven patients had been treated with surgery alone, and 49 patients had received adjuvant chemotherapy with either fluorouracil (5-FU) alone (n=22) or 5-FU+oxaliplatin (n=27). The frequency of persistent amenorrhea 1 year after receiving chemotherapy was 20% in the whole group, 18% in patients who had received adjuvant chemotherapy with 5-FU alone, and 22% in patients who had received chemotherapy with 5-FU+oxaliplatin. Frequency of persistent amenorrhea was 3.5% in patients under the age of 44 years and 42.8% in patients aged 44 years and older. Multivariate analysis showed that age of 44 years and older (hazard ratio: 29.3; 95% confidence interval: 2.8-309.2, P=0.005) and menarche age of 14 years and older (hazard ratio: 7.6; 95% confidence interval: 1.2-49, P=0.076) were significantly associated with increased risk of persistent amenorrhea. In this study, we found that the frequency of persistent amenorrhea was 20% in patients who received 5-FU monotherapy or oxaliplatin-based adjuvant chemotherapy protocols in colon cancer treatment. Older age and later menarche were the factors that increased the risk of persistent amenorrhea 1 year after chemotherapy.

A current and comprehensive review of cyclin-dependent kinase inhibitors for the treatment of metastatic breast cancer.

BACKGROUND: Resistance to endocrine treatment generally occurs over time, especially in the metastatic stage. In this paper, we aimed to review the mechanisms of cyclin-dependent kinase (CDK) 4/6 inhibition and clinical usage of new agents in the light of recent literature updates. SCOPE: A literature search was carried out using PubMed, Medline and ASCO and ESMO annual-meeting abstracts by using the following search keywords; "palbociclib", "abemaciclib", "ribociclib", "cyclin-dependent kinase inhibitors" and "CDK 4/6" in metastatic breast cancer (MBC). The last search was on 10 June 2017. FINDINGS: CDKs and cyclins are two molecules that have a key role in cell cycle progression. Today, there are three highly selective CDK4/6 inhibitors in clinical development - palbociclib, ribociclib and abemaciclib. Palbociclib and ribociclib were recently approved by the US FDA in combination with letrozole for the treatment of MBC in a first-line setting, as well as palbociclib in combination with fulvestrant for hormone-receptor (HR)-positive MBC that had progressed while on previous endocrine therapy according to the PALOMA-1, MONALEESA-2 and PALOMA-3 trials, respectively. In the recently published randomized phase III MONARCH 2 trial, abemaciclib plus letrozole had longer progression-free survival and higher objective response rates with less serious adverse events in advanced HR-positive breast cancer previously treated with hormonal treatment. CONCLUSION: CDK4/6 inhibition is a new and promising target for patients with hormone-receptor-positive MBC. Both palbociclib and ribociclib showed significant additive benefit for patients receiving first-line treatment for HR-positive, epidermal growth factor receptor-2-negative advanced breast cancer. Palbociclib and abemaciclib also had significant activity in combination with fulvestrant for patients with MBC that progressed on previous endocrine therapy.

Targeting the PD-1 pathway: a new hope for gastrointestinal cancers.

BACKGROUND: VEGF, HER2 and EGFR targeted agents are currently used in gastric, esophageal and colorectal cancers. However, treatment outcomes are still poor in most gastrointestinal (GI) cancers. Immune checkpoints are one of the most promising immunotherapy approaches. In this review article, we aim to discuss the efficacy and safety of anti-PD-1/PD-L1 therapies in GI cancers, including gastric, esophageal and colorectal cancer in published or reported recent studies. SCOPE: A literature search was made from PubMed and ASCO Annual Meeting abstracts by using the following search keywords: "nivolumab", "pembrolizumab", "avelumab", "GI cancers" "anti-PD1 therapy" and "anti-PD-L1 therapy". The last search was on 2 November 2016. The most important limitation of our review is that most of the data on anti-PD-1/PD-L1 therapies in GI cancers relies on phase 1 and 2 trials. FINDINGS: Currently, there are two anti-PD-1 (nivolumab and pembrolizumab) and one anti-PDL1 (atezolizumab) agents approved by FDA. After the treatment efficacy of immune checkpoint blockade was shown in melanoma, renal cell cancer and non-squamous lung cancer, trials which evaluate immune checkpoint blockade in GI cancers are ongoing. Early results of trials have been promising and encouraging for patients with advanced stage gastroesophageal cancer. According to early results of published trials, response to anti-PD1/PD-L1 agents appears to be associated with tumor PD-L1 levels. According to two recently published phase 2 trials, the clinical benefits of immune checkpoint blockade with both nivolumab and pembrolizumab were limited in patients with microsatellite instability (MSI) positive advanced colorectal cancer. However, several phase 2/3 trials are still ongoing. CONCLUSION: Both pembrolizumab and nivolumab show promising efficacy with acceptable safety data in published trials in GI cancers, especially in refractory MSI positive metastatic colorectal cancer.

Effect of body mass index on the efficacy of adjuvant tamoxifen in premenopausal patients with hormone receptor-positive breast cancer.

PURPOSE: Obesity has been confirmed to be an adverse prognostic factor in patients who were treated with aromatase inhibitors; however, such relationship has never been thoroughly investigated in patients treated with tamoxifen. The purpose of this study was to examine the effect of body mass index (BMI) on the efficacy of adjuvant tamoxifen in premenopausal patients with hormone receptor-positive breast cancer. METHODS: Newly diagnosed premenopausal and non-metastatic hormone receptor-positive breast cancer patients were enrolled in the study. Patients with BMI ranging between 18.5 and 24.9 kg/m(2) were considered as normal weight patients (Arm A, n = 408), and/patients with a BMI ≥ 25 kg/m(2) were considered as overweight and obese patients (Arm B, n = 418). RESULTS: In both normal weight and overweight patients, the baseline clinicopathologic properties and the treatment history with radiotherapy and chemotherapy were similar and no statistical significant difference could be detected. Tamoxifen in combination with luteinizing hormone-releasing hormone (LHRH) agonist was used in 33% (136/408) of the patients in Arm A and in 22% (91/418) of patients in Arm B (p<0.001). Three-year disease free survival (DFS) rates were 89% and 87% in arm A and arm B, respectively (p=0.39). Three-year overall survival (OS) rates were 99% in arm A and 94% in arm B which appeared to be of significance (p=0.028). In univariate analysis no statistical significant effect of LHRH agonist usage on DFS (p=0.58) and OS (p=0.96) was found. CONCLUSION: Although BMI had no negative effect on recurrence risk, poor OS was observed in overweight and obese premenopausal breast cancer patients with hormone-receptor positive tumors who were treated with tamoxifen.

A comprehensive review of denosumab for bone metastasis in patients with solid tumors.

BACKGROUND: Denosumab is fully human monoclonal antibody that specifically binds and inactivates receptor activator of NF-kB ligand (RANKL), an important ligand that regulates bone remodeling. In this review, we aimed to show the clinical data about denosumab treatment and discuss its advantages for the management of patients with solid tumors and bone metastasis. SCOPE: Denosumab showed positive results in clinical studies of solid tumors with bone metastasis. PubMed database and ASCO Symposium Meeting abstracts were searched until August 2015 by using the terms 'denosumab', 'RANKL inhibitor' and 'bone metastasis'. The last search was on 21 August 2015. All resulting studies were retrieved and were also checked for related publications. Clinical trials in this review fulfilled the following criterion: inclusion of sufficient data to allow estimation of the efficacy and safety of denosumab. FINDINGS: The effects of denosumab on skeletal-related events (SREs) were investigated in three large randomized trials: one in patients with breast cancer, one in patients with prostate cancer, and one in patients with multiple myeloma or solid tumors other than breast or prostate cancer. In the breast cancer and prostate cancer studies denosumab was non-inferior and also superior to zoledronic acid in terms of the primary outcome time to first on-study SRE. In the third study denosumab was non-inferior to zoledronic acid but was not superior to zoledronic acid in solid tumors excluding breast and prostate cancer with bone metastases. In the three studies median overall survival and disease progression rates were similar between zoledronic acid and denosumab. Denosumab has also been studied in bone loss associated with hormonal therapy in both breast and prostate cancer. Adjuvant denosumab significantly reduced the risk of clinical fracture risk by 50% in breast cancer patients and by 62% in non-metastatic prostate cancer patients treated with adjuvant aromatase inhibitors or androgen deprivation therapy. In addition, biochemical markers of bone turnover and fractures were significantly reduced in patients under denosumab treatment. CONCLUSION: The promising outcomes in the initial trials with denosumab have shown clinical activity and a favorable safety profile in patients with solid tumors and bone metastasis. Denosumab significantly reduced treatment-related osteoporosis associated with breast and prostate cancer and was superior to zoledronic acid in prevention or delaying of SRE.

Which sequence best protects the heart against trastuzumab and anthracycline toxicity? An electron microscopy study in rats.

BACKGROUND/AIM: Two effective cytotoxic agents, doxorubicin and trastuzumab, are associated with potentially life-threatening cardiotoxicity. The present study was designed to investigate cardiotoxicity aggravated by the timing of administration of trastuzumab and doxorubicin in rats. MATERIALS AND METHODS: Twenty-four rats were randomly assigned to one of four groups. These received one of the following treatment drug regimens administered via intraperitoneal injection: (i) 0.9% saline control (n=6); (ii) doxorubicin (5 mg/kg) on day 1 then trastuzumab 10 mg/kg on day 15 (n=6); (iii) trastuzumab 10 mg/ kg on day 1 then doxorubicin (5 mg/kg) on day 15 (n=6) or (iv) doxorubicin (5 mg/kg) on day 1 and trastuzumab 10 mg/ kg on day 1 (n=6). On the 30th day, the hearts were processed for pathological analysis by electron microscopy. RESULTS: Electron microscopy revealed an ultrastructurally normal heart tissue in the control group. At electron microscopic examination of the tissue samples in the second and fourth group, a mild degree of dilation was observed in the peri-nuclear cisternae of some heart muscle cells. In the third group, pathological changes were detected in mitochondria. These exhibited prominent cristae, which also showed a mild degree of ultrastructural pathology in mitochondria. CONCLUSION: Based on electron microscopy findings, sequential administration of anthracycline first, followed by trastuzumab is safer in terms of cardiotoxicity, while the most toxic schedule for the rat heart was trastuzumab first, followed by anthracycline.

Impact of acetylsalicylic Acid on the clinicopathological characteristics and prognosis of patients with invasive breast cancer.

BACKGROUND: The impact of acetylsalicylic acid (ASA) on the clinicopathological characteristics of breast cancer has not yet been elucidated in detail; we therefore aimed to investigate the effects of ASA on the clinicopathological characteristics of patients with breast cancer. PATIENTS AND METHODS: Patients diagnosed with breast cancer were retrospectively analyzed. Breast cancer patients who were taking ASA at the time of breast cancer diagnosis were enrolled as ASA users (n = 84); matching patients with the same age who were not taking ASA were included as control group (n = 890). RESULTS: The median age was 56 (range 34-82) years in both groups. ASA users had a significantly lower incidence of grade II-III tumors compared to non-users (P = 0.02). The other clinicopathological characteristics and treatment histories were similar in both groups. In patients using ASA, the disease-free survival (DFS) rate was 97.3%, 89.4%, and 79.9% and in non-users it was 94.1%, 81.8%, and 70.9% in the 1rst, 3rd, and 5th year, respectively (P = 0.01). In aspirin users, the overall survival rate was 95.0%, 90.6%, and 87.6% and in non-users it was 98.1%, 91.2%, and 85.5% in the 1rst, 3rd, and 5th year, respectively (P = 0.50). CONCLUSION: Using ASA at the time of breast cancer diagnosis was associated with significantly improved DFS in breast cancer patients.

The efficacy of adjuvant trastuzumab in HER-2 positive breast cancer with axillary lymph node metastases according to the treatment duration.

INTRODUCTION: Trastuzumab is the first anti-HER-2 humanized monoclonal antibody. The benefit of adjuvant trastuzumab has been shown in randomized phase III trials. Despite trastuzumab being recommended for 52 weeks in the adjuvant treatment of HER-2 positive breast cancer according to the current breast cancer guidelines, there is still no consensus on the optimal duration of adjuvant trastuzumab. The aim of our study is to investigate the efficacy and safety of adjuvant trastuzumab for 9 weeks and 52 weeks in axillary lymph node positive HER-2 positive breast cancer patients. PATIENTS AND METHODS: A total of 271 HER-2 and axillary node positive breast cancer patients who received trastuzumab in adjuvant treatment between the years 2005 and 2013 were retrospectively analyzed. Patients with axillary node positive HER-2 positive breast cancer who were non-metastatic were enrolled to the study. Patients were allocated to the 9 week trastuzumab group (n = 155) or the 52 week trastuzumab group (n = 116). Kaplan-Meier survival analysis was carried out for disease free survival (DFS) and overall survival (OS). Two-sided p values of <0.05 were considered statistically significant. The most important limitation of our manuscript is the retrospective design. RESULTS: The median follow-up time for this analysis was 34 (4-95) months. Patients' clinical and pathological characteristics were well balanced between the two treatment arms. In the 9 week trastuzumab treatment group, the DFS rate was 96.7%, 84.8% and 74.9% in the first, third and fifth years respectively, whereas in the 52 week trastuzumab treatment group it was 94.3%, 80.0% and 80.0% (P = 0.76). In the 9 week trastuzumab treatment group, the OS rate was 99.3%, 92.2% and 88.3% in the first, third and fifth years respectively, whereas in the 52 week trastuzumab treatment group it was 99.0%, 94.7% and 78.6% (P = 0.99). In both groups, symptomatic heart failure was not reported but asymptomatic left ventricular ejection fraction (LVEF) decline was observed 3 (1.9%) and 18 (15.5%) patients in the 9 week and 52 week trastuzumab treatment groups, respectively (P < 0.001). CONCLUSION: In our study, the efficacy of trastuzumab for 52 weeks and 9 weeks was similar in node-positive HER-2 positive breast cancer. Cardiotoxicity was significantly increased in the 52 week trastuzumab arm compared to the 9 week trastuzumab arm.