Abstract P5-02-02: Genomic Landscape of ER+/HER2- metastatic breast cancer as a function of prior treatment with a CDK4/6 inhibitor

Background CDK4/6 inhibitors (CDK4/6i), like palbociclib, ribociclib, and abemaciclib, along with antiestrogens, have revolutionized treatment for ER+/HER2- metastatic breast cancer (MBC). Although most patients initially respond, almost all eventually progress, and ER+ HER2- MBC remains incurable. There is an urgent need to understand the molecular processes that drive resistance in order to improve survival. The landscape of acquired somatic alterations causal to CDK4/6i resistance remains unknown. Here we report differences in mutational landscapes between ER+ HER2- MBC patients treated with and without CDK4/6i. Methods Deidentified data from 780 and 1073 ER+ HER2- MBC patients (solid tumor or ctDNA liquid biopsy sequencing respectively) with at least 6 months between diagnosis of Stage 4 disease and biopsy were analyzed. Patients were divided into either treated or untreated with CDK4/6i prior to biopsy. Sequencing was performed using the Tempus xT tumor assay (DNA sequencing of 595-648 genes at 500x coverage) and Tempus xF liquid biopsy (ctDNA sequencing of 105-523 genes). Gene alterations (consisting of pathogenic/likely pathogenic short variants and copy number alterations) were compared between groups by Chi-squared/Fisher’s Exact tests and p-values adjusted for false-discovery. Results We first analyzed sequencing data of both solid tumor and liquid ctDNA from ER+/HER2- MBC patients. ESR1 mutations were significantly more frequent in those that received CDK4/6i than those that did not (Solid tumor 33% vs 16%, p < 0.001, q = 0.001; Liquid biopsy 32% vs 16%, p < 0.001 and q < 0.001). We also saw more frequent mutations/amplifications in the following genes in the CDK4/6i treated cohort vs. those that were not. These results trended towards significance in our solid tumor, but not in our liquid biopsy cohort: CCND1 (18% vs 11% p = 0.028 q =0 .3); FGF3 (17% vs 9.5% p = 0.010 q = 0.2); FGF4 (17% vs 11% p = 0.035 q = 0.3), GATA3 (17% vs 8.9% p = 0.008 q = 0.2), PTEN (12% vs 6.1% p = 0.030 q = 0.3) and FGF19 (8.2% vs 1.7% p = 0.002 q = 0.12). Interestingly, 96-98% of CCND1, FGF3, FGF4 and FGF19 alterations were copy number amplifications. Conversely, we saw a trend towards significance for more mutations in TP53 (37% vs 27% p=0.008 and q=0.2) in those that had not received a CDK4/6i than those that did. Conclusions Here we present the landscape of somatic alterations in ER+/HER2- MBC patients with and without prior CDK4/6i therapy from our large real world de-identified data set. Patients with prior CDK4/6i therapy harbored significantly more ESR1 somatic alterations, demonstrated in both solid tissue and liquid biopsies. In solid tissue biopsies, patients with prior CDK4/6i therapy harbored more CCND1, FGF3, FGF4, and GATA3 alterations and less TP53 alterations. These trends were not significant after adjustment for multiple testing. CCND1, FGF3, FGF4 and FGF19 alterations were copy number amplifications, which may be consistent with 11q13 amplification. Further studies will provide insights into how these trends translate towards our understanding of CDK4/6i related resistance mechanisms.

Citation Format: M Rosario Chica-Parrado, Chang-Ching Lin, Timothy Mahoney, Elizabeth Mauer, Ariella Hanker, Carlos Arteaga. Genomic Landscape of ER+/HER2- metastatic breast cancer as a function of prior treatment with a CDK4/6 inhibitor. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-02-02.

Efficient gene transfer into retinal cells using adenoviral vectors: dependence on receptor expression

PURPOSE

A number of ocular diseases are potentially amenable to gene therapy interventions if appropriate vectors for the targeted administration of therapeutic genes can be identified. In vitro and in vivo transduction efficiency of a Group C serotype 5 adenoviral vector containing the fiber domain derived from a Group B serotype 35 adenovirus and the gene encoding green fluorescent protein (AdV5/F35-GFP) was compared to an AdV5-GFP vector for transgene delivery to human retinoblastoma and to human and murine retinas.

METHODS

The distribution of the adenoviral receptors CAR and CD46 on normal and malignant retinal tissues was determined using immunohistochemistry. Human retinoblastoma cells were incubated with either AdV5-GFP or AdV5/F35-GFP, and the expression of the reporter protein was compared using quantitative fluorescence and fluorescent-activated cell sorting. Mice were given a single subretinal injection of either viral vector, and eyes were enucleated at specified times after injection for histopathologic examination. Human cadaver eyes were similarly examined ex vivo.

RESULTS

CAR was expressed in retina except in photoreceptor outer segments. CD46 was expressed in photoreceptor inner and outer segments. Both vectors efficiently transduced the human retinoblastoma cells in vitro. However, the amount of the transgene expressed using AdV5/F35-GFP was more than sixfold greater than that when AdV5-GFP was used. In vivo, AdV5/F35-GFP at doses as low as 10(5) infectious units (IU) transduced cells in all layers of the retina especially photoreceptors and occasional neuronal cells, and Müller cells as well as retinal pigment epithelial cells, whereas AdV5-GFP transduced only retinal pigment epithelial cells and occasional photoreceptors and Müller cells.

CONCLUSIONS

AdV5/F35 chimeric vectors may be superior to AdV5 for gene therapy applications targeting the photoreceptor.

Stage III colon cancers: why adjuvant chemotherapy is not offered to elderly patients

HYPOTHESIS

Adjuvant chemotherapy is not offered to elderly patients with stage III colon cancer.

DESIGN

A retrospective review of hospital and office records.

SETTING

A suburban community hospital.

PATIENTS

The medical records of 69 patients with stage III colon cancer were reviewed. All identified from the Tumor Registry at Jersey Shore Medical Center, Neptune, NJ, were included in this study.

RESULTS

Thirty-five patients (51%) did not receive adjuvant chemotherapy. After adjusting for age, women were 5.8 times less likely to receive chemotherapy (P = .002). Patients not receiving chemotherapy were significantly older (78.7 vs 70.4 years; P = .003) than those who received adjuvant chemotherapy. There was no relation found between the year of diagnosis and the administration of chemotherapy. There were 4 major reasons for not receiving chemotherapy: (1) not offered (n = 12, 34%), (2) refused (n = 11, 31%), (3) too old (n = 7, 20%), and (4) significant concomitant disease (n = 5, 14%).

CONCLUSIONS

A large group of elderly patients who had been surgically treated for colon cancer and who were eligible for adjuvant chemotherapy either were not referred for treatment or refused treatment. This suggests a bias on the part of surgeons, primary care physicians, and patients against the use of chemotherapy in elderly patients.

Mast cells and nerve fibers in interstitial cystitis (IC): an algorithm for histologic diagnosis via quantitative image analysis and morphometry (QIAM)

OBJECTIVE

To develop and evaluate a diagnostic algorithm based on the alteration of mast cell and nerve fiber observed in bladder tissue of patients with interstitial cystitis (IC).

MATERIALS AND METHODS

Non-IC samples from 6 control groups (N = 10, 10, 13, 2, 11, and 3, respectively) and nonclassic interstitial cystitis (NC-IC, N = 20) were stained with Giemsa stain in order to calculate the detrusor to mucosa mast cell ratio (DMMCR) using quantitative image analysis and morphometry (QIAM). Immunohistochemical staining for S-100 protein was also performed to quantify nerve fiber proliferation in the detrusor muscle of the bladder.

RESULTS

The average DMMCR of NC-IC was 1.19. Bacille Calmette-Guérin (BCG) cystitis was 0.84 and microscopically normal bladder tissue from patients with bladder or prostate cancer was 0.45. No case of IC that we examined had a DMMCR < 0.5. The number and percentage area of nerve fibers in the detrusor in IC were increased compared to controls and BCG (IC, 2.01%; BCG, 0.95%; control, 1.3%).

CONCLUSION

A diagnostic algorithm is proposed for IC based on the findings that indicate that: 1) if the DMMCR > 0.75, then IC is present; 2) if the DMMCR < 0.5, then IC is negative; and 3) if the DMMCR is between 0.5 and 0.75, a quantitative S-100 protein staining analysis can be employed to evaluate nerve fiber proliferation to detect those marginal cases of NC-IC. The findings of the study also suggest that a neuroimmune process or mediation may be involved in the pathogenesis of IC.

Apgar scores in the identification of sensorineural hearing loss

Apgar scores of 0-4 at 1 minute and 0-6 at 5 minutes have been investigated as risk criteria in the Utah High Risk Hearing Screening Program. The 1990 Joint Committee on Infant Hearing (JCIH) statement recommended only an Apgar score of 0-3 at 5 minutes be included in a risk registry for sensorineural hearing loss (SNHL). An analysis of live births indicates the more lenient Utah cut-off criteria are justified. It is concluded that both of the Utah Apgar scores, even when moderately depressed, are sensitive risk factors for SNHL in infants. These findings suggest serious consideration be given to expanding the 1990 JCIH Apgar recommendation.

The effects of mate removal on pregnancy success in prairie voles (Microtus ochrogaster) and meadow voles (Microtus pennsylvanicus)

The effects of removing the stud male have not been controlled in many studies relating pregnancy block to the presence of an unfamiliar male. We examined the effects of removing the male on pregnancy success in prairie voles and meadow voles, two species that differ in degree of paternal investment. Whereas prairie vole males provide extensive care to offspring and accelerate pup development, meadow vole males display little or no care and delay development of pups. We predicted that removal of the stud male would decrease pregnancy success in prairie voles and either have no effect or increase success in meadow voles. In experiment 1, females were in male-induced estrus, and their mates were either left with them or were removed 4 h, 1 day, 2 days, or 8 days after mating. In experiment 2, females were in postpartum estrus, and their mates were either left with them or were removed 1 day, 2 days, or 8 days after birth of their first litter. Removal of the male soon after mating in postpartum estrus decreased pregnancy success in prairie voles and increased success in meadow voles. Thus, although removal of the stud male influenced litter production, the direction of the effect varied with species.

Prolidase deficiency: a patient without hydroxyproline-containing iminodipeptides in urine

A 17-year-old girl was shown to have prolidase deficiency on the basis of the presence of large amounts of proline-containing dipeptides in urine and an almost complete absence of prolidase in plasma and erythrocytes. Unlike most earlier cases of this genetic defect our patient did not excrete hydroxyproline-containing dipeptides in her urine.

Acoustic reflex crossover artifacts in infants and young children

Crossover artifacts occur when the probe microphone of an impedance instrument directly responds to vibratory-acoustic energy that crosses the skull from the stimulus transducer on the contralateral ear. The resulting meter deflections are subjectively similar to and may be interpreted as actual acoustic reflexes (ARs) by unsuspecting examiners. In this study, infants and young children aged 10 days to 6 years 9 months were fit with earplugs to eliminate the AR and were examined for artifact incidence and threshold. Results indicate a high rate of occurrence of the crossover artifact in the youngest subjects, when probe tones of 220 and 660 Hz were used with stimuli of 500 and 1,000 Hz. Artifact thresholds were found as low as at a 92-dB hearing level, and an inverse relationship was shown between age and artifact incidence and threshold.

Function of the acoustic reflex in discrimination of intense speech

It is known that the middle ear acoustic reflex (AR) alters the transmission characteristics of the auditory system; however, disagreement exists on how these changes may influence the ears; transfer of speech stimuli. In this study, speech with and without a competing message was delivered at supra-AR levels to cat ears that demonstrated an active and a pharmaceutically inactivated middle ear reflex mechanism. Resulting cochlear potentials were tape recorded and subsequently presented to 18 human subjects with normal hearing. Findings suggest word and sentence discrimination is enhanced in the presence of a functioning AR, with implications for hearing aid use and stapedectomy procedure.