Inherited alterations of TGF beta signaling components in Appalachian cervical cancers

PURPOSE

This study examined targeted genomic variants of transforming growth factor beta (TGFB) signaling in Appalachian women. Appalachian women with cervical cancer were compared to healthy Appalachian counterparts to determine whether these polymorphic alleles were over-represented within this high-risk cancer population, and whether lifestyle or environmental factors modified the aggregate genetic risk in these Appalachian women.

METHODS

Appalachian women's survey data and blood samples from the Community Awareness, Resources, and Education (CARE) CARE I and CARE II studies (n = 163 invasive cervical cancer cases, 842 controls) were used to assess gene-environment interactions and cancer risk. Polymorphic allele frequencies and socio-behavioral demographic measurements were compared using t tests and χ2 tests. Multivariable logistic regression was used to evaluate interaction effects between genomic variance and demographic, behavioral, and environmental characteristics.

RESULTS

Several alleles demonstrated significant interaction with smoking (TP53 rs1042522, TGFB1 rs1800469), alcohol consumption (NQO1 rs1800566), and sexual intercourse before the age of 18 (TGFBR1 rs11466445, TGFBR1 rs7034462, TGFBR1 rs11568785). Interestingly, we noted a significant interaction between "Appalachian self-identity" variables and NQO1 rs1800566. Multivariable logistic regression of cancer status in an over-dominant TGFB1 rs1800469/TGFBR1 rs11568785 model demonstrated a 3.03-fold reduction in cervical cancer odds. Similar decreased odds (2.78-fold) were observed in an over-dominant TGFB1 rs1800469/TGFBR1 rs7034462 model in subjects who had no sexual intercourse before age 18.

CONCLUSIONS

This study reports novel associations between common low-penetrance alleles in the TGFB signaling cascade and modified risk of cervical cancer in Appalachian women. Furthermore, our unexpected findings associating Appalachian identity and NQO1 rs1800566 suggests that the complex environmental exposures that contribute to Appalachian self-identity in Appalachian cervical cancer patients represent an emerging avenue of scientific exploration.

Abstract B57: Inherited alterations of Transforming Growth Factor Beta signaling components in Appalachian Cervical Cancers

Introduction: Invasive cancer of the uterine cervix (ICC) is a leading cause of cancer death in women worldwide. ICC incidence and mortality rates are especially high among women from Appalachia. In addition to lifestyle and social-behavioral factors and HPV infections, hereditary predispositions may mediate cervical cancer risk. Polymorphic alleles within the Transforming Growth Factor Beta (TGFB) signaling cascade, an important regulator of epithelial cell growth, have been implicated in modifying cancer susceptibility. The contributions of these factors within a gene-environment model have not been well characterized in Appalachian ICC patients. Hypothesis: High-risk genomic variants of TGFB signaling pathway components will be overrepresented in Appalachian women diagnosed with ICC compared to their healthy Appalachian counterparts. Methods: A case-control study was conducted with 163 cases, women diagnosed with ICC, and 842 controls, women with normal Pap tests from Appalachia Ohio, West Virginia, and Kentucky. Inclusion criteria were (i) women residing in Appalachian counties who were ≥18 years, (ii) spoke English, (ii) not cognitively impaired, (iii) able to provide informed consent. Three distinct groups were considered, representing (i) prevalent invasive cervical cancer cases, (ii) newly diagnosed invasive cervical cancer cases, and (iii) healthy controls. Targeted genomic variance analysis of 9 SNPs (rs1800469, rs1800470, rs3917200, rs7034462, rs11568785, rs868, rs1042522, rs750749, rs1800566) and a polymorphic repeat variant was conducted on blood DNA. Behavioral and environmental factors were collected using a comprehensive, self-administered questionnaire completed at the time of enrollment. Characteristics between cases and controls were compared by a two sample t-test, assuming unequal variance for continuous variables and by Fisher's exact test for categorical variables. Associations between disease status, polymorphism and behavioral or environmental characteristics were estimated via multivariable logistic regression. Results: Never smokers with TGFB1 rs1800469 overdominant allele types A/A-G/G had 0.4 (95% CI: 0.22-0.73, p=0.003) times the odds of cervical cancer compared to never smokers with A/G genotype. This effect was not observed in ever smokers (interaction p=0.02). While there was a suggestion of an increased risk of cervical cancer for never smokers with TGFB1 rs1800469 recessive A/G-A/A genotypes compared to G/G non9A genotype CD83 dominant T/T compared to C/C-C/T, or overdominant C/C -T/T compared to C/T alleles, there were no strong interaction effects identified. The effect of dominant TP53 rs1042522 allele type (C/C C/G versus G/G) differed by smoking status. There was a significant 3-fold increase in the odds of cervical cancer (aOR: 3.1, 95% CI: 1.1-8.5, p=0.03) for never smokers with TP53 rs1042522 G/G compared to never smokers with C/C-C/G genotypes. A similar increase was not observed in ever-smokers (smoking status by genotype interaction effect p=0.02). In codominant types, there was a similar increased adjusted odds (aOR: 3.65, 95% CI: 1.21-11.0, p=0.021) of cervical cancer for never smokers with G/G genotypes compared to never smokers with C/G genotypes. This effect was not observed in ever smokers (interaction effect p=0.06). Conclusions: Genetic susceptibility may contribute to the overall cervical cancer risk associated with the Appalachian population, especially among non-smokers. Inclusion of additional demographic and social-behavioral features, as well as other genetic events, may further define this evolving cervical cancer risk model.

Citation Format: Thomas J. Knobloch, Steve Oghumu, Marta Sears, Zhaoxia Zhang, Blessing Ogbemudia, Joe Perrault, David Cohn, Cecilia R. DeGraffinreid, Bo Lu, Juan Peng, Erinn M. Hade, Michael A. Schiano, Byron C. Calhoun, William McBee, Jr., Jamie Lesnock, Holly Gallion, Jondavid Pollock, Mack T. Ruffin, IV, Christopher M. Weghorst, Electra D. Paskett. Inherited alterations of Transforming Growth Factor Beta signaling components in Appalachian Cervical Cancers. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr B57.

A retrospective study of tamoxifen and endometrial cancer in breast cancer patients

OBJECTIVE

To assess the relationship between low-dose tamoxifen, usage and endometrial cancer in breast cancer patients.

METHODS

In this case-control study, the records of the 1017 patients treated at Wilford Hall Medical Center for primary breast cancer between 1978 and 1989 were reviewed. Dose and duration of tamoxifen therapy were recorded as well as the presence of a uterus. Potential confounding variables including diabetes mellitus, hypertension, age, weight, tobacco use, and family history of breast or gynecologic cancer were recorded.

RESULTS

Of the 1017 patients in the study, 56 had inadequate records and 375 had undergone a prior hysterectomy and these patients were excluded from the study, leaving 586 eligible patients. Of these 586 women with primary breast cancer and no previous hysterectomy, 108 patients had received tamoxifen, 10 mg twice a day for greater than 1 year. Four of the 108 patients subsequently developed endometrial adenocarcinoma. Four hundred seventy-eight breast cancer patients did not receive tamoxifen and 4 later developed endometrial adenocarcinoma. The odds ratio for the development of endometrial cancer when exposed to tamoxifen was 15.2 with a 95% confidence interval of 2.8-84.4. The patients exposed and not exposed to tamoxifen were compared for potential confounding variables and after controlling for the potential confounders, tamoxifen was found to be an independent risk factor for the development of endometrial cancer.

CONCLUSIONS

Low-dose tamoxifen when given for greater than 1 year is associated with secondary endometrial cancer in patients with primary breast cancer.

A phase II trial of neoadjuvant chemotherapy prior to radical hysterectomy and/or radiation therapy in the management of advanced carcinoma of the uterine cervix

OBJECTIVE

This prospective trial was designed to access the efficacy and safety of neoadjuvant chemotherapy followed by radical hysterectomy and/or radiation therapy in women with advanced carcinoma of the uterine cervix.

METHODS

Thirty women, clinical stages IIb-IVa, were enrolled in this clinical trial. Initial treatment consisted of three cycles of bleomycin, cisplatin, and vincristine administered every 10 days. Depending on the extent of disease after chemotherapy, patients then either underwent radical hysterectomy with bilateral pelvic and periaortic lymphadenectomy or surgical staging. Following review of the surgical findings, tailored radiotherapy was administered.

RESULTS

Only 10 women (34%) had tumor regression from neoadjuvant chemotherapy sufficient to allow radical hysterectomy prior to tailored adjuvant radiotherapy; the remainder received primary radiotherapy after surgical staging. Two-year disease-free survival was 68, 43, and 0% for women with clinical stages II, III, and IV, respectively. Four women experienced acute toxicity from chemotherapy requiring medical intervention and eight women suffered chronic toxicities requiring hospitalization and/or surgery.

CONCLUSION

The neoadjuvant chemotherapy utilized in this trial was generally ineffective in converting patients from inoperable to operable, had no apparent effect on survival, and was associated with significant toxicity.

In vitro enhancement of cis-platinum antitumor activity by caffeine and pentoxifylline in a human ovarian cell line

Cell kinetic perturbations measuring DNA and nuclear protein with dual-parameter flow cytometry were studied in vitro after cis-platinum (DDP) treatment of a DDP-resistant human ovarian cell line (BG-1). Cell viability (trypan blue exclusion) and the cell's ability to replicate (replicating potential) are also reported. A dose-dependent G2 arrest and concomitant increase in cytotoxicity were observed. We also observed a marked increase in cytotoxicity of 2.5 micrograms/ml DDP with the addition of 1 mM of caffeine (CAF) or pentoxifylline (PTX). Additionally, the cells treated with DDP and CAF or DDP and PTX demonstrated a markedly diminished ability to replicate. Cell cycle perturbations, especially the G2-phase arrest, were markedly enhanced in the cells treated with DDP and CAF or DDP and PTX, when compared to that in cells treated with DDP alone. We conclude that the cytotoxicity of DDP is enhanced by CAF and PTX in vitro by inhibiting DNA repair during the S and G2 phases.

Cell kinetic perturbations after irradiation and caffeine in the BG-1 ovarian carcinoma cell line

The treatment of ovarian carcinoma includes maximum surgical removal of the tumor tissue followed by irradiation or chemotherapy. In this study, the effects of caffeine on cell cycle traverse have been studied over a 168-hr period after X irradiation in BG-1 cells, an ovarian carcinoma cell line. The results were obtained with dual-parameter flow cytometric measurements of DNA and nuclear protein, using propidium iodide and fluorescein isothiocyanate. After radiation alone, a dose-related arrest of cells in G2 phase and cell kill were observed. Irradiating BG-1 cells with 5 Gy produced an accumulation of the cells in G2 at 24-72 hr postirradiation. When G2 was divided into low nuclear protein (G2A) and high nuclear protein (G2B) compartments, there was a G2A peak accumulation at 24 hr and a G2B peak accumulation at 48-72 hr. The addition of 1 mM caffeine to the culture media, starting immediately postirradiation, prevented G2 arrest, promoting a rapid traverse of cells through G2A to G2B to G1, which was associated with diminished survival.

Second-stage fetal tachycardia and neonatal infection

Forty fetuses who had mild or marked tachycardia during the final 10 minutes of the second stage of labor were evaluated for neonatal infection. Prolonged sepsis/pneumonia occurred in 10 of the 40 infants (25%), three of eight (38%) with marked tachycardia, seven of 32 (22%) with mild tachycardia, and in only one of 167 control infants who had a normal second-stage fetal heart rate (0.6%). None of the 40 women with fetal tachycardia or the 167 control subjects had any intrapartum fever or other evidence of acute chorioamnionitis. Persistent fetal tachycardia during the second stage of labor defines a population at increased risk for subsequent neonatal sepsis/pneumonia. This population will require prolonged, expert neonatal care.