Abstract P4-14-08: Serum concentrations of tamoxifen and Z-endoxifen may predict sexual dysfunction in the 2nd year of adjuvant endocrine treatment

Background and rationale: Side effects of adjuvant treatment with tamoxifen (tam) may impair Quality of Life (QoL) and have been suggested as an independent variable for discontinuation of tam1. There are large inter-patient variabilities in prevalence and severance of side effects among tam users. Therefore, there is a need for biological markers that can predict side effects. A potential biological predictor is the serum concentrations of tam and/or its metabolites. In this prospective observational study we have analyzed serum concentrations of tam and 9 metabolites over 3 years. Patients Reported Outcome Measures (PROM) were obtained to elucidate possible associations between side effects, adherence and tam metabolism.

Methods: Breast cancer patients using adjuvant tam (20mg/d) were recruited through the Prospective Breast Cancer Biobank project between 2011 and 2016. Inclusion criteria were ER positive status, ≥ 6 months tam use, tumor size of ≥0.1 cm and being able to read and write Norwegian. Concentration levels of tam and metabolites in serum were analyzed by LC-MS/MS2 and adherence data were collected through the Norwegian prescription database. PROM-data comprised of validated questioners reporting side effects of endocrine treatment and QoL. Statistical analyses comprised non-parametric tests, logistic regression, chi square tests and the Benjamin-Hochberg procedure to correct for multiple testing.

Results: Associations between metabolite concentrations and side effects were run as a cross sectional analysis (N=149) and separate analysis of each year of follow-up with 85, 77 and 65 patients at the 1st, 2nd and 3rd year respectively. We found that 78 % of patients reported side effects, 66 % reported mood swings, 21 % reported severe hot flushes and 71 % reported decreased libido. When analyzing years separately, we found that on the 2nd year patients experiencing vaginal dryness had significantly higher levels of tamoxifen (P=0.032, after correction for multiple testing and adjustment for clinical relevant variables) compared to patients not experiencing vaginal dryness. Also, on year 2 the patients in the lower quartile of Z-endoxifen (≤17.9 nM) had significantly lower libido (p=0.015) compared to patients with Z-endoxifen levels >17.9 nM after adjustment for clinical relevant variables and correction for multiple testing. Analyses regarding adherence are not complete and more results will be presented in the poster.

Discussion: Our data indicates that high serum concentrations of tam and low concentrations of Z-endoxifen are associated with vaginal dryness and sexual dysfunction. Patients reporting “very low libido” had the highest levels of tam, suggesting that slow metabolic conversion and accumulation of tam may contribute to sexual dysfunction. Our results were only significant in the second year of follow-up, possibly because patients wait to resume sexual activity after diagnosis, chemo and surgery. After receiving advice (i.e. lubricants), the symptoms are often reduced in the subsequent follow-up (3rd year). In conclusion, our results indicate that monitoring tam serum concentrations may be used to predict side effects.

1 Owusu C. et al. JCO. 2008

2 Helland T. et al. BCR. 2017

Citation Format: Helland T, Haugstøyl ME, Hagen KB, Kvaløy JT, Lunde S, Lode K, Lind RA, Gripsrud BH, Bifulco E, Gebreslase NS, Jonassen J, Hustad SS, Aas T, Lende TH, Lien EA, Janssen EA, Mellgren G, Søiland H. Serum concentrations of tamoxifen and Z-endoxifen may predict sexual dysfunction in the 2nd year of adjuvant endocrine treatment [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 P4-14-08.

The Role of MicroRNAs as Predictors of Response to Tamoxifen Treatment in Breast Cancer Patients

Endocrine therapy is a key treatment strategy to control or eradicate hormone-responsive breast cancer. However, resistance to endocrine therapy leads to breast cancer relapse. The recent extension of adjuvant tamoxifen treatment up to 10 years actualizes the need for identifying biological markers that may be used to monitor predictors of treatment response. MicroRNAs are promising biomarkers that may fill the gap between preclinical knowledge and clinical observations regarding endocrine resistance. MicroRNAs regulate gene expression by posttranscriptional repression or degradation of mRNA, most often leading to gene silencing. MicroRNAs have been identified directly in the primary tumor, but also in the circulation of breast cancer patients. The few available studies investigating microRNA in patients suggest that seven microRNAs (miR-10a, miR-26, miR-30c, miR-126a, miR-210, miR-342 and miR-519a) play a role in tamoxifen resistance. Ingenuity Pathway Analysis (IPA) reveals that these seven microRNAs interact more readily with estrogen receptor (ER)-independent pathways than ER-related signaling pathways. Some of these pathways are targetable (e.g., PIK3CA), suggesting that microRNAs as biomarkers of endocrine resistance may have clinical value. Validation of the role of these candidate microRNAs in large prospective studies is warranted.

Structured data collection improves the diagnosis of acute appendicitis

BACKGROUND

Structured preoperative data collection and computer-assisted methods are claimed to improve diagnostic accuracy in patients with acute abdominal pain. The aim of this study was to evaluate a possible age- and sex-related effect of using structured data collection in the preoperative diagnosis of patients with suspected acute appendicitis.

METHODS

Between 1989 and 1994, clinical and demographic data from 1764 consecutive patients were recorded. In 1990 and 1992, various detailed symptom, clinical and laboratory data were collected prospectively on a structured registration form. Age- and sex-specific diagnostic accuracy as well as perforation rate were calculated for each year.

RESULTS

Diagnostic accuracy increased significantly by 5 (95 per cent confidence interval (c.i.) 1-9) per cent when structured data registration was applied. In female patients aged between 13 and 40 years, diagnostic accuracy increased by 16 (95 per cent c.i. 8-24) per cent. Significant changes in diagnostic accuracy were not seen in other subgroups. Perforation rates remained unchanged during the entire study period.

CONCLUSION

In this population-based study, diagnostic accuracy in patients operated on for suspected acute appendicitis increased for all patients when structured preoperative data collection was used. However, the only subgroup with a significant increase in diagnostic accuracy was female patients aged between 13 and 40 years. Perforation rate was unaffected by structured data collection.

Incidence of acute nonperforated and perforated appendicitis: age-specific and sex-specific analysis

This prospective study was performed to investigate epidemiological characteristics in terms of the age- and sex-specific incidence in patients with perforated and nonperforated appendicitis. The study population comprised 1486 consecutive patients who underwent appendectomy for suspected acute appendicitis between 1989 and 1993. Two patient cohorts [n = 544 (37%)] were analyzed with regard to prehospitalization duration of symptoms and in-hospital observation time. The crude incidence of acute appendicitis was 86 per 100,000 per year. Although the incidence of nonperforated appendicitis was highest among adolescents and young adults (13-40 years of age), perforated appendicitis occurred at almost the same incidence in all sex and age groups. The diagnostic accuracy was 76%. Perforated appendicitis occurred in 19%, with higher rates in small children and the elderly, irrespective of gender. A high diagnostic accuracy was not associated with an increased rate of perforation. In small children and the elderly, the diagnostic accuracy was low and the perforation rate high. Patients with perforation had a significantly longer duration of symptoms as well as in-hospital observation time than did patients with nonperforated appendicitis. Perforated appendicitis showed a different incidence pattern than nonperforated appendicitis and was associated with a significantly longer duration of symptoms and in-hospital observation time, probably due to patient-related factors. We suggest this observation deserves attention regarding clinical diagnosis and treatment decision-making for patients with suspected acute appendicitis.