Clinical activity of pembrolizumab in refractory MDM2-amplified advanced intimal sarcomas.

Intimal sarcoma (InS) is an ultra-rare and aggressive subtype of soft tissue sarcoma (STS). It usually arises in large mediastinal arteries and the heart. In the advanced setting, sequential cytotoxic chemotherapy is often used, mainly based on retrospective studies and case series but with modest benefit. The use of immune checkpoint inhibitors is a promising strategy for some STS, but identifying biomarkers of response remains challenging due to disease rarity and heterogeneity. A reactive and pro-inflammatory tumor microenvironment (TME) is believed to be associated with better outcomes for patients receiving anti-PD-1-based regimens, generating the rationale to explore this strategy in malignancies with this characteristic, such as InS. We report three cases of advanced InS patients experiencing partial response to pembrolizumab-based therapy despite low tumor mutational burden and absence of mismatch-repair deficiency. We hypothesize that TME-related characteristics such as PD-L1 expression and the presence of tertiary lymphoid structures might explain this phenomenon.

Pembrolizumab in advanced intimal sarcomas Intimal sarcomas are ultra-rare and highly aggressive malignant tumours that most frequently arise in mediastinal arteries or the heart. Besides arising in challenging areas of the thoracic cavity, their rarity directly interferes with the development of new therapies, which negatively impacts patients' prognosis, especially after disease progression on chemotherapy regimens. We reported three cases successfully treated with immunotherapy (represented by pembrolizumab-based regimens), as well as a potential explanation for their outcomes.

The Role of Adjuvant Radiotherapy for the Treatment of Resected High-Risk Stage III Cutaneous Melanoma in the Era of Modern Systemic Therapies.

Modern adjuvant systemic therapies (STs) have revolutionized the management of stage III melanoma. Currently, the role of adjuvant radiotherapy (RT) remains unclear. In this single-center retrospective study, patients with clinically detectable stage III melanoma with high-risk features for lymph node basin (LNB) recurrence and whose tumors were fully resected with complete lymphadenectomy (CLD) between 2010 and 2019 were assessed. We determined the cumulative incidence (CIF) of LNB recurrence and any disease recurrence or progression using competing risk analysis. A total of 108 patients were identified; the median age was 59 years (24-92), and 74 (69%) were men. A total of 51 (42%) received adjuvant RT, 22 (20%) received adjuvant ST, and 35 (32%) received no adjuvant therapy. The advent of ST changed clinical practice, with a significant increase in the use of adjuvant ST and a decrease in the use of RT when comparing practice patterns before and after 2015 (p < 0.001). The 3-year CIF of LNB recurrence was similar in patients treated with adjuvant RT (6.3%) and adjuvant ST (9.8%). The 3-year CIF of any disease recurrence or progression was lower in patients receiving adjuvant ST (24%) compared to those receiving adjuvant RT (52%) or no adjuvant therapy (55%, p = 0.06). Three-year overall survival (OS) was not significantly different in patients treated with ST compared to those not treated with any ST (p = 0.118). Despite ST replacing RT as the dominant adjuvant treatment modality, this change in practice has not resulted in increased LNB recurrence for patients at high risk of LNB recurrence following CLD.

Clinico-demographic characteristics and outcomes of radiation-induced sarcomas (RIS): a CanSaRCC study.

Background: Radiation-induced sarcomas (RIS) tend to have aggressive behaviour and because of their rarity, the most appropriate management for these malignancies is uncertain. Objectives: Using the Canadian Sarcoma Research and Clinical Collaboration (CanSaRCC) database, a national sarcoma registry, we aimed to investigate prognostic factors and outcomes for RIS. Design: Retrospective study of RIS patients treated from 1996 to 2021 at three Canadian centres. Methods: RIS was defined as a sarcoma arising in a previously irradiated field following a 3+ year latency period, whose histology was distinct from the initially irradiated tumour. Clinicopathologic and treatment-related information was extracted from the CanSaRCC database. Overall survival (OS) was defined as the time from RIS diagnosis to death from any cause. Response rate (RR) to neoadjuvant chemotherapy (NACT) was based on physician assessment. Time-to-event analyses were estimated using the Kaplan-Meier method, with Cox regression for multivariate analysis. We considered a two-tailed p-value of <0.05 as statistically significant. Results: One hundred seven tumours met the criteria for RIS and were divided into three subgroups: breast angiosarcoma (BAS, n = 54), osteosarcoma (OST, n = 16), and other soft-tissue sarcomas (STS, n = 37). Patients were mostly female (n = 85, 79%), treated initially for breast carcinomas (n = 54, 50.5%), and diagnosed with high-grade tumours (n = 61/71, 86%). None had evidence of synchronous metastasis. Patients with OST were younger (median age: 48 years, p < 0.001), and BAS had the shortest latency interval (8 versus 18 years for OST/STS, p < 0.001). Most patients underwent surgery, 76% (n = 76/100) R0; 24% (n = 26) received radiation therapy, mostly (n = 15, 57.7%) neoadjuvant. Among those receiving chemotherapy, 30 (75%) underwent NACT; among patients with documented response assessment, the RR was 68% (n = 17/25), being even higher in the BAS population (89.5%, n = 13/17). Median OS was 53 months (95% CI 34-101), with a 5-year OS of 47.6%; larger tumour size, high histologic grade and older age were independent prognostic factors for worse OS. Conclusion: Surgery is standard, and NACT might be useful to downsize large lesions, especially in BAS patients. Raising RIS awareness is fundamental to promoting appropriate management and fostering research through multi-institutional collaborations.

Real-world treatment outcomes in HR+ HER2- metastatic breast cancer patients treated with CDK4/6 inhibitors: Results from a reference center in Brazil.

BACKGROUND: Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) have been recently developed and introduced into clinical practice. METHODS: We retrospectively analyzed data from patients with confirmed HR+/HER2 metastatic breast cancer treated with hormonal therapy in combination with ribociclib (R), palbociclib (P), or abemaciclib (A). OUTCOMES: median progression-free survival (mPFS), time to treatment discontinuation (mTTD), and objective response rate (ORR). RESULTS: Between January 2016 - June 2021, 142 patients were treated with an CDK4/6i (79 P, 42 R, 21 A). The median age was 59 years and 67.6% had recurrent disease. Roughly 35.2%, 36.6%, 28.2% of the patients had 1, 2 or 3+ metastatic sites, respectively, and 55.6% of the patients received CDK4/6i as a first-line treatment. The mPFS was 28m(R) vs. 14m(P) vs. 6m(A) (P = 0.002), with a higher proportion of patients receiving R in the first-line setting. However, no difference was seen when the analysis was restricted to the first-line scenario (P = 0.193). Sixty-four patients required one dose reduction, and 19 patients required two. ORR was 76.2% (R) vs 62% (P) vs 42.9% (A). More patients achieved a complete response with R and P, with no difference in the incidence of partial response and stable disease. Adverse events occurred in 94.4% of the population, with the most common grade 3-4 AE being neutropenia (59.1%). CONCLUSIONS: Our results confirm the efficacy and tolerability of CDK4/6i in routine clinical practice. This is the first real-world data describing and comparing the efficacy and toxicity of CDK4/6i in the Brazilian population.

Unique SLC12A2-ROS1 fusion is associated with marked response to crizotinib in lung adenocarcinoma.

Chromosomal rearrangements involving the c-ros oncogene 1 (ROS1) gene define a subset of non-small cell lung cancers highly sensitive to small-molecule tyrosine kinase inhibitors. However, little is known about the impact of different fusion partners on tyrosine kinase inhibitor efficacy. We herein describe a case of a 26-year-old never-smoker patient from southern Africa with metastatic lung adenocarcinoma driven by SLC12A2-ROS1 fusion, who had a pronounced and durable response to crizotinib. The present case underscores the importance of pursuing actionable alterations in patients with similar clinical and epidemiological characteristics. In addition, provides the second report of crizotinib activity against lung malignancies harboring the unique SLC12A2-ROS1 fusion and highlights the importance of a deeper understanding of molecular alterations in underrepresented subgroups of patients to tailor the decision-making in daily practice.

Identification of the TP53 p.R337H Variant in Tumor Genomic Profiling Should Prompt Consideration of Germline Testing for Li-Fraumeni Syndrome.

PURPOSE: Li-Fraumeni syndrome (LFS) is rare in the worldwide population, but it is highly prevalent in the Brazilian population because of a founder mutation, TP53 p.R337H, accounting for 0.3% of south and southeastern population. Clinical criteria for LFS may not identify all individuals at risk of carrying the Brazilian founder mutation because of its lower penetrance and variable expressivity. This variant is rarely described in databases of somatic mutations. Somatic findings in tumor molecular profiling may give insight to identify individuals who might be carriers of LFS and allow the adoption of risk reduction strategies for cancer. MATERIALS AND METHODS: We determined the frequency of the TP53 p.R337H variant in tumor genomic profiling from 755 consecutive Brazilian patients with pan-cancer. This is a retrospective cohort from January 2013 to March 2020 at a tertiary care center in Brazil. RESULTS: The TP53 p.R337H variant was found in 2% (15 of 755) of the samples. The mutation allele frequency ranged from 30% to 91.7%. A total of seven patients were referred for genetic counseling and germline testing after tumor genomic profiling results were disclosed. All the patients who proceeded with germline testing (6 of 6) confirmed the diagnosis of LFS. Family history was available in 12 cases. Nine patients (9 of 12) did not meet LFS clinical criteria. CONCLUSION: The identification of the TP53 p.R337H variant in tumor genomic profiling should be a predictive finding of LFS in the Brazilian population and should prompt testing for germline status confirmation.

Impressive response to dabrafenib, trametinib, and osimertinib in a metastatic EGFR-mutant/BRAF V600E lung adenocarcinoma patient.

The survival outcomes of the FLAURA trial support osimertinib as the new standard of care for untreated patients harboring activating mutations in the epidermal growth factor receptor (EGFR). Despite the initial response, disease progression invariably occurs. Although uncommon, BRAF V600E mutation arises as a unique mechanism of resistance, and thus far, no prospective studies are available to support concurrent EGFR/BRAF blockade. We report a case of impressive radiological and ctDNA response under dabrafenib, trametinib, and osimertinib in an advanced EGFR-mutant lung adenocarcinoma patient who developed BRAF V600E as one of the acquired resistance mechanisms to second-line osimertinib. Moreover, the patient experienced remarkable clinical improvement and good tolerance to combination therapy. The present case suggests the importance of prospective studies evaluating both efficacy and safety of the combination in later line settings and points towards the potential of ctDNA to monitor resistance mechanisms and treatment benefit in clinical practice.

Circulating Tumour DNA Sequencing Identifies a Genetic Resistance-Gap in Colorectal Cancers with Acquired Resistance to EGFR-Antibodies and Chemotherapy.

Epidermal growth factor receptor antibodies (EGFR-Abs) confer a survival benefit in patients with RAS wild-type metastatic colorectal cancer (mCRC), but resistance invariably occurs. Previous data showed that only a minority of cancer cells harboured known genetic resistance drivers when clinical resistance to single-agent EGFR-Abs had evolved, supporting the activity of non-genetic resistance mechanisms. Here, we used error-corrected ctDNA-sequencing (ctDNA-Seq) of 40 cancer genes to identify drivers of resistance and whether a genetic resistance-gap (a lack of detectable genetic resistance mechanisms in a large fraction of the cancer cell population) also occurs in RAS wild-type mCRCs treated with a combination of EGFR-Abs and chemotherapy. We detected one MAP2K1/MEK1 mutation and one ERBB2 amplification in 2/3 patients with primary resistance and KRAS, NRAS, MAP2K1/MEK1 mutations and ERBB2 aberrations in 6/7 patients with acquired resistance. In vitro testing identified MAP2K1/MEK1 P124S as a novel driver of EGFR-Ab resistance. Mutation subclonality analyses confirmed a genetic resistance-gap in mCRCs treated with EGFR-Abs and chemotherapy, with only 13.42% of cancer cells harboring identifiable resistance drivers. Our results support the utility of ctDNA-Seq to guide treatment allocation for patients with resistance and the importance of investigating further non-canonical EGFR-Ab resistance mechanisms, such as microenvironmentally-mediated resistance. The detection of MAP2K1 mutations could inform trials of MEK-inhibitors in these tumours.

Takotsubo syndrome induced by brachytherapy in a patient with endocervical adenocarcinoma.

BACKGROUND: Takotsubo syndrome (TTS), also known as stress cardiomyopathy, apical ballooning syndrome and broken heart syndrome, is characterized by acute-onset chest pain, electrocardiographic (ECG) abnormalities and reversible left ventricular (LV) disfunction in the absence of a culprit obstructive lesion in the coronary arteries; therefore, myocardial infarction is the most important differential diagnosis. Usually induced by emotional/physical stress, its treatment consists in hemodynamic support until complete and spontaneous recovery occurs, which is generally achieved within a few days to weeks. Cervical malignancies are an important public health issue in low/middle-income countries and, in the setting of locally advanced disease, concurrent chemoradiation followed by brachytherapy is considered the standard treatment, harboring curative potential. CASE REPORT: We report a case of a 38-year-old woman who underwent concurrent chemoradiotherapy and developed cardiopulmonary arrest in ventricular fibrillation during a brachytherapy session. Complementary tests disclosed altered ECG and cardiac biomarkers, no evidence of coronary artery obstruction, as well as LV disfunction consistent with TTS on echocardiogram and cardiac MRI. After few days of supportive therapy, complete recovery of heart function was observed. CONCLUSIONS: Especially for cancer patients, who usually experience intense emotional/physical stress intrinsically associated with their diagnosis and aggressive treatments, considering TTS as a differential diagnosis is warranted. Intracavitary brachytherapy procedure may represent a trigger for TTS.

Alectinib activity in chemotherapy-refractory metastatic RET-rearranged non-small cell lung carcinomas: A case series.

OBJECTIVES: to report outcomes of four cases of chemo-refractory RET-rearranged non-small cell lung carcinomas (NSCLCs) treated with alectinib in a single center. MATERIALS AND METHODS: we retrospectively assessed and reported the activity and tolerability of alectinib 600 mg twice daily in advanced and chemo-refractory RET-rearranged NSCLC patients treated in a Brazilian institution. Identification of RET rearrangements was performed using the FoundationOne® next-generation sequencing (NGS) platform. RESULTS: The four patients herein reported were white, female and non-smokers, ranging between 59-66 years of age. All patients had been previously treated with chemotherapy and were TKI naïve; three of them presented disease progression to nivolumab as well. Molecular tumor profiling showed a KIF5B-RET fusion in three patients and a CCDC6-RET in the fourth. One patient exhibited disease progression and clinical deterioration two months after treatment initiation. Disease control was documented in two patients with PFS ranging from 4 to 5 months (one partial metabolic response and one stable disease). In one of the cases, which developed oligoprogression on alectinib, radiation therapy plus post-progression alectinib were able to provide additional disease control for 9 more months. No grade 3/4 adverse events, dose reductions or discontinuation due to toxicity were documented. CONCLUSION: Although this is a small single center evaluation, alectinib was well tolerated and demonstrated clinical activity against advanced RET-rearranged NSCLCs, suggesting its potential role in this specific subset of malignancies. Clinical trials addressing its efficacy and the optimal dosing schedule in the present context are underway, and results are eagerly awaited.

Tumor Reduction with Pazopanib in a Patient with Recurrent Lumbar Chordoma.

INTRODUCTION: Chordomas are rare malignancies of bone origin that occur in the axial skeleton, typically the skull base and lumbar/sacral regions. Although often classified as low-grade neoplasms, its locally infiltrative behavior may result in significant morbidity and mortality. Optimal surgical resection may be curative, but up to 50% of the cases relapse within 5 years, and currently there are no systemic treatments approved in this setting. A large proportion of these tumors express stem-cell factor receptor (c-KIT) and platelet-derived growth factor receptors (PDGFRs), providing a rationale for the use of tyrosine-kinase inhibitors (TKIs). CASE REPORT: A 27-year-old male presented with recurrent chordoma of the lumbar spine 4 years after initial diagnosis. Salvage therapies in the interval included repeat resections and radiation therapy. He ultimately developed multifocal recurrence not amenable to complete excision or reirradiation. A comprehensive genomic profiling assay was performed and revealed nondrugable alterations. Decision was made to proceed with systemic treatment with pazopanib 800 mg/day, resulting in tumor reduction (-23.1% reduction in size) and prolonged disease control. CONCLUSION: For this patient with a multiple recurrent chordoma and limited treatment options, pazopanib resulted in sustained clinical benefit following initial tumor reduction.