Targeting RARA overexpression with tamibarotene, a potent and selective RARα agonist, is a novel approach in AML

A superenhancer at the retinoic acid receptor alpha (RARA) gene is associated with RARA mRNA overexpression in ∼30% of non-acute promyelocytic leukemia acute myeloid leukemia (AML) and in ∼50% of myelodysplastic syndromes (MDS). RARA overexpression is an actionable target for treatment with tamibarotene, an oral potent and selective RARα agonist. Sensitivity to the RARα agonist tamibarotene was demonstrated in RARA-high but not RARA-low preclinical AML models. The combination of oral tamibarotene plus azacitidine was evaluated in a phase 2 clinical study in 51 newly diagnosed unfit patients with AML identified as RARA-positive (n = 22) or RARA-negative (n = 29) for RARA mRNA overexpression in peripheral blasts using a blood-based biomarker test. In 18 response-evaluable RARA-positive patients, complete remission (CR)/CR with incomplete hematologic recovery rate was 61%, CR rate was 50%, and time to initial composite CR was rapid at 1.2 months. Transfusion independence was attained by 72% of RARA-positive patients. In contrast, 28 response-evaluable RARA-negative patients had response rates that were consistent with azacitidine monotherapy. Tamibarotene in combination with azacitidine was well tolerated. The majority of nonhematologic adverse events were low grade and hematologic adverse events were comparable to single-agent azacitidine, demonstrating that there was no additional myelosuppression when tamibarotene was combined with azacitidine. These results support further evaluation of tamibarotene-based treatment strategies in patients with AML or MDS with RARA overexpression to provide a targeted approach with the goal of improving patient outcomes. This trial was registered at www.clinicaltrials.gov as #NCT02807558.

Acute Myeloid Sarcoma: An Unusual Cause of Diarrhea

A 62-year-old man with a past medical history of hypothyroidism was admitted for diarrhea and abdominal pain for three weeks. Initial workup for diarrhea was negative. His condition deteriorated after hospitalization. He underwent sigmoidoscopy which showed rectosigmoid mucosal ulceration. Pathology showed leukemic cells infiltration of the mucosa. The patient underwent bone marrow biopsy which confirmed the diagnosis of acute myeloid leukemia (AML). He received induction chemotherapy and his symptoms improved.

Relevance of quantification in brain PET studies with 18F-FDG

The inclusion of ¹⁸F-FDG PET as a biomarker in the diagnostic criteria of neurodegenerative diseases and its indication in the presurgical assessment for drug-resistant epilepsies allow to improve specificity of these diagnosis. The traditional interpretation of neurological PET studies has been performed qualitatively, although in the last decade, several quantitative evaluation methods have emerged. This technical development has become relevant in clinical practice, improving specificity, reproducibility and reducing the interrater reliability derived from visual analysis. In this article we update/review the main imaging processing techniques currently used. This may allow the Nuclear Medicine physician to know their advantages and disadvantages when including these procedures in daily clinical practice.

The Role of Inhibition of Apoptosis in Acute Leukemias and Myelodysplastic Syndrome

Avoidance of apoptosis is a key mechanism that malignancies, including acute leukemias and MDS, utilize in order to proliferate and resist chemotherapy. Recently, venetoclax, an inhibitor of the anti-apoptotic protein BCL-2, has been approved for the treatment of upfront AML in an unfit, elderly population. This paper reviews the pre-clinical and clinical data for apoptosis inhibitors currently in development for the treatment of AML, ALL, and MDS.

Abstract P2-14-12: Impact of the time interval between neoadjuvant chemotherapy and surgery in Latin-Americans breast cancer patients

Background: Few studies have evaluated the impact of the time interval between neoadjuvant chemotherapy (NAC) and surgery in breast cancer. In Latin America, where the vast majority of hospitals are oversaturated, it is important to define which patients to give priority and to be clear about ideal time or maximum to schedule surgery after NAC without altering the prognosis. The objective of this work is to establish the ideal time interval for post-neoadjuvant surgery and evaluate the impact on patient survival.

Methods: We reviewed the clinical histories of breast cancer with clinical stage II and III who received NAC between 2005 and 2014. Patients were divided into 3 groups according to the time interval to surgery: <4, 4-8 and >8 weeks. Overall survival (OS) and recurrence-free survival (RFS) were estimated using the Kaplan-Meier method, and comparisons of survival curves using the logrank or Breslow test, both globally and by molecular subtypes. The optimal time to surgery has been determined by the Cox model.

Results: During the study period, 583 patients who had post NA surgery before six months were registered. The median age was 49 years (range: 24-85), 82% had clinical stage III, 53% histological grade III, 32.7% were luminal A, 15.6% luminal B, 24.4% Her2 and 27.3% TN. According to the time interval to surgery, 67 (11.5%) patients had surgery before 4 weeks, 204 (35.0%) between 4 to 8 weeks, and 312 (53.5%) after 8 weeks. The groups do not present differences in relation to the clinical characteristics (p> 0.05). The median follow-up time was 4.8 years. The 5-year OS rate according to the time interval was 57.9, 61.5, and 62.7% (p = 0.581) and the RFS rate was 40.6, 52.3, and 51.1% (p = 0.411). No differences were found in the survival curves by molecular subtypes , except for luminal b like . In the multivariate analysis, the effect of the time interval to surgery was not significant in OS and RFS; however, the HR curve suggests that the appropriate cut-off point for surgical time would be 8 weeks.

Table 1:Time Interval :OS - RFS  RFS  OS  MEDIAN5 - yearsPMEDIAN5 - yearsPWeeks for NAC to Surgery      <4 weeks3.240.6 6.157.9 4-8 weeks6.352.3 9.161.5 >8 weeks5.151.10.416.762.70.581       Weeks for NAC to Surgery      <8 weeks549.5 9.160.7 >8 weeks5.151.10.5856.762.70.414

Table 2 :Time Interval - Molecular Subtype  RFS  OS  MEDIAN5 - yearsPMEDIAN5 - yearsPLUMINAL A LIKE      < 8 weeks----74.1 ----84 >8 weeks7.163.80.719.973.90.236       *LUMINAL B LIKE      < 8 weeks2.336.8 5.460.5 >8 weeks5.857.60.46----820.08       HER2      <8 weeks2.228.7 3.938.4 >8weeks3.645.90.57.26.261.30.616       TRIPLE NEGATIVE      <8 weeks3.144.2 3.448.4 >8 weeks2.041.80.9143.743.90.516* ER + PR >20% KI67>14% , HER2 NEGATIVE

Conclusion: The time interval between the end of neoadjuvant period and surgery has no impact on recurrence-free survival or on overall survival, despite this we suggest that the period of time between neoadjuvant and surgery not be greater than 8 weeks. More studies will be required to determine the ideal time interval and which cases should be prioritized according to the characteristics of our patients.

Citation Format: Rebaza LP, Galarreta JA, Castañeda C, Cotrina JM, Vilchez S, de la Cruz M, Ponce J, Aguilar A, Flores C, Castillo M, Galvez M, Vigil C. Impact of the time interval between neoadjuvant chemotherapy and surgery in Latin-Americans breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-14-12.

Mutational analysis of BRCA1 and BRCA2 genes in Peruvian families with hereditary breast and ovarian cancer

Background

Breast cancer is one of the most prevalent malignancies in the world. In Peru, breast cancer is the second cause of death among women. Five to ten percent of patients present a high genetic predisposition due to BRCA1 and BRCA2 germline mutations.

Methods

We performed a comprehensive analysis of BRCA1 and BRCA2 genes by Sanger sequencing and multiplex ligation‐dependent probe amplification (MLPA) to detect large rearrangements in patients from 18 families, which met the criteria for hereditary breast cancer.

Results

In this series, we found four pathogenic mutations, three previously reported (BRCA1: c.302‐1G>C and c.815_824dup10; BRCA2: c.5946delT) and a duplication of adenines in exon 15 in BRCA1 gene (c.4647_4648dupAA, ClinVar SCV000256598.1). We also found two exonic and four intronic variants of unknown significance and 28 polymorphic variants.

Conclusion

This is the first report to determine the spectrum of mutations in the BRCA1/BRCA2 genes in Peruvian families selected by clinical and genetic criteria. The alteration rate in BRCA1/BRCA2 with proven pathogenic mutation was 22.2% (4 out 18) and this finding could be influenced by the reduced sample size or clinical criteria. In addition, we found three known BRCA1/BRCA2 mutations and a BRCA1 c.4647_4648dupAA as a novel pathogenic mutation.

Abstract P5-09-08: Molecular evaluation of Peruvian patients with hereditary breast cancer reveals a novel germline mutation in BRCA1

Background

Breast cancer is the leading cancer in women worldwide, while in Peru is the second most frequent cancer with a high incidence of triple negative breast cancers (21%). There is no previous information about BRCA1/BRCA2 mutations in Peruvian high-risk breast cancer patients. Prior studies from International diagnostic laboratories only presented results of our population as a pooled Hispanic data. Our aim was to characterize mutations in BRCA1/BRCA2 genes in Peruvian patients with breast cancer with hereditary patterns.

Methods

We evaluated mutations in BRCA1/BRCA2 genes by Sanger sequencing and large genomic rearrangements by multiplex ligation-dependent probe amplification (MLPA) in 18 families with hereditary breast cancer criteria identified at the Breast Unit of Oncosalud-AUNA (Lima-Peru). Molecular analysis was done in the facilities of Genetics and Molecular Biology Center at the San Martin de Porres University (Lima-Peru).

Results

Sequencing identified 4 pathogenic mutations in 4/18 families, three previously detected (BRCA1: c.302-1G>C y c.815_824dup10; BRCA2: c.5946delT) and a novel germline mutation in exon 15 of BRCA1 (c.4647_4648dupAA, ClinVar SCV000256598.1) producing a frameshift variant. MLPA revealed 2 amplifications in exon 7 (duplication and triplication) in BRCA1 in unrelated patients with potential pathogenic effects, one of this co-existed with the BRCA2: c.5946delT mutation. In addition, three variants of uncertain significance were found (c.140G>T, in exon 5 of BRCA1 and c.464G>A and c.938C>T in exon 5 and 10 of BRCA2, respectively).

Conclusions

After a comprehensive evaluation we found an alteration rate of 27.8% (5/18) in BRCA1/BRCA2 in families with criteria for hereditary breast cancer. We reported BRCA1 c.4647_4648dupAA as a novel mutation. Further studies including a larger sample size of Peruvian patients should evaluate the prevalence or founder effect of this mutation in our population.

Citation Format: Ponce J, Vigil C, Araujo JM, Castañeda C, Calderon G, Buleje JL, Acosta O, Danos P, Huaman F, Guevara-Fujita ML, Aguilar A, Pinto JA, Gomez HL, Fujita R. Molecular evaluation of Peruvian patients with hereditary breast cancer reveals a novel germline mutation in BRCA1 [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-09-08.

Preliminary outcome of a treatment strategy based on perioperative chemotherapy and surgery in patients with locally advanced colon cancer

AIM

Preoperative chemotherapy followed by radical surgery is an attractive treatment for locally advanced colon cancer (LACC) given the promising results of this approach in other locally advanced tumours. The study evaluates the outcome and treatment-related complications of perioperative oxaliplatin- and capecitabine-based chemotherapy and surgery for clinical Stage III colon cancer.

METHOD

Twenty-two consecutive patients with a CT-staged LACC were included. All were staged at baseline and before surgery. Surgery-related complications and oncological outcome were determined.

RESULTS

Toxicity was manageable, with 19/22 patients completing the planned chemotherapy protocol. The median time from initial diagnosis to surgery was 65.5 days. The median time from the end of chemotherapy to surgery was 22 days. After neoadjuvant treatment, tumour reduction of 69.5% was observed by CT scan and a 59.9% decrease of SUVmax (standard uptake value) was achieved on positron emission tomography/CT. No progressive disease was reported during preoperative chemotherapy and surgery was performed in all 22 patients. Four patients developed postoperative complications. After a median postoperative follow-up of 14.4 months, the actuarial overall and disease-free survival rates were 100 and 90%.

CONCLUSION

Neoadjuvant chemotherapy followed by surgery and chemotherapy for LACC is safe without apparent increase of early and medium-term complications.

[Contribution of time of flight and point spread function modeling to the performance characteristics of the PET/CT Biograph mCT scanner]

OBJECTIVE

To characterize the performance of the Biograph mCT PET/CT TrueV scanner with time of flight (TOF) and point spread function (PSF) modeling.

MATERIAL AND METHODS

The PET/CT scanner combines a 64-slice CT and PET scanner that incorporates in the reconstruction the TOF and PSF information. PET operating characteristics were evaluated according to the standard NEMA NU 2-2007, expanding some tests. In addition, different reconstruction algorithms were included, and the intrinsic radiation and tomographic uniformity were also evaluated.

RESULTS

The spatial resolution (FWHM) at 1 and 10cm was 4.4 and 5.3mm, improving to 2.6 and 2.5mm when PSF is introduced. Sensitivity was 10.9 and 10.2 Kcps/MBq at 0 and 10cm from the axis. Scatter fraction was less than 34% at low concentrations and the noise equivalent count rate (NECR) was maximal at 27.8 kBq/mL with 182 Kcps, the intrinsic radiation produced a rate of 4.42 true coincidences per second. Coefficient of variation of the volume and system uniformity were 4.7 and 0.8% respectively. The image quality test showed better results when PSF and TOF were included together. PSF improved the hot spheres contrast and background variability, while TOF improved the cold spheres contrast.

CONCLUSIONS

The Biograph mCT TrueV scanner has good performance characteristics. The image quality improves when the information from the PSF and the TOF is incorporated in the reconstruction.

[Dual time point 18F-FDOPA PET as a tool for characterizing brain tumors]

(18)F-FDOPA is an amino acid analogue used to evaluate presynaptic dopaminergic activity, which has aroused great interest in neuro-oncology. We have evaluated five (18)F-FDOPA PET studies of patients referred for study of parkinsonian syndrome. Two subjects had previously treated high-grade brain tumors, one nonspecific brain injury, and 2 subjects presented unexpected tumoral lesions. For all lesions SUVmax, time to SUVmax and tumor-to-normal grey matter SUVmax rate (T/N) were calculated, and 90 minutes (18)F-FDOPA kinetics were analyzed. Tumor lesions corresponded to three malignant neurocytomas, one meningioma, one pineocytoma and one intrasinusal hemangioma. Both malignant and benign tumors exhibited high uptake of (18)F-FDOPA well above the normal cortex. However, the analysis of the curve uptake displayed characteristic patterns that facilitate the characterization of tumor lesions. A dual phase maximum uptake was observed, with an early 10 minutes uptake in malignant lesions, and a late 60 to 90 minutes uptake in benign or low grade lesions.

HER2+ Tumors with Lack Steroid Receptors Showed a Shorter DFS but Similar OS Compared to HER2+ Tumors That Also Express ER and/or PR

Background: HER2 expression is widely measured on tumor tissue from breast cancer patients since it gives prognostic and predictive information. Data suggest that breast cancer growth is regulated by the coordinated action of the estrogen receptor (ER) and receptor tyrosine kinase signaling pathways. The aim of this retrospective analysis was to evaluate the additional prognostic value of the ER/PR status for the subset of patients with HER2-positive tumors.Methods: From 2000-2002, 203 breast tumors were tested for HER2 and steroid receptors levels. HER2-positivity was defined as ≥2 copies of the HER2 gene by FISH or 3+ by IHC. A cut-off point of 10 % was used as positivity for ER and/or progesterone receptor (PR) levels.Results: Among the 203 patients, 103 had HER2+/ER-/PR- tumors and 100 had HER2+/ER+ and/or PR+ tumors. Patients' characteristics were comparable between the two groups as far as age, menopausal status, pTNM (stage I-II-III) status and type of initial therapy. All patients had surgery followed by standard chemotherapy and radiotherapy and hormonal therapy if the tumor was ER+ or PR+. No patients received adjuvant treatment with trastuzumab. The median follow-up for the entire cohort was 73 months (range 12-110). Comparisons of disease-free survival (DFS), overall survival (OS) as well as site of first recurrence were made between the two groups. The 5-year DFS was statistically different between the two groups: 69.9% for HER2+/ER-/PR- patients and 81.0% for the HER2+/ER+ and/or PR+ (p=0.037). The 5-year OS was not different between the two groups with 82.5% for HER2+/ER-/PR- patients and 86.0% for the HER2/ER+ and/or PR+ (p=0.402).Conclusions: Patients with HER2+/ER-/PR- breast cancers treated with surgery and standard adjuvant chemotherapy exhibit a statistically worse DFS compared to patients with HER2+/ER+ and/or PR+ tumors. However, overall survival was similar in both groups; additional factors should be evaluated to explain this finding.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6052.