HPV Circulating Cell-Free DNA Kinetics in Cervical Cancer Patients Undergoing Definitive Chemoradiation

PURPOSE/OBJECTIVE(S)

The human papilloma virus (HPV) is a significant cause of cervical cancer and viral DNA can be detected in the blood of patients with cervical cancer (cfHPV-DNA). We hypothesized that detecting HPV cfDNA before, during and after chemoradiation (CRT) could provide insights into disease extent, clinical staging, and treatment response.

MATERIALS/METHODS

Forty-seven patients with cervical cancer were enrolled on this study between 2017 and 2022, either as part of a standard-of-care (SOC) treatment banking protocol (33 patients) or as part of a clinical trial combining a therapeutic HPV vaccine (PDS0101; Immunocerv, 14 patients). Longitudinal plasma samples were collected from each patient as baseline, during week 1, 3 or 5 of CRT. cfHPV-DNA was quantified using droplet digital PCR targeting the HPV E6/E7 oncogenes of 13 high-risk types based on analysis of cervical tumor genotype (AmpFire). Clinical covariates, including FIGO stage, primary tumor size, and treatment response were studied using appropriate statistical tests.

RESULTS

All 47 patients had detectable HPV cfDNA during CRT with 38 out of 47 having HPV type 16 detected. The median cfDNA at baseline was 24.5 copies/mL, with a range of 0 to 157,638 copies/mL. Of the 35 patients with at least three measurements, 20 (57%) had peak cfDNA counts at week 3, and 30 out of 35 showed a decline in cfDNA counts at week 5 compared to week 3. The proportion of patients who cleared cfDNA (<16 copies/mL) increased with each week of CRT, reaching 75% at week 5. Baseline cfDNA counts were associated with para-aortic nodal involvement (p<0.0001) but not with FIGO stage or gross tumor volume. A greater proportion of patients treated with therapeutic HPV-directed vaccine had clearance of cfDNA counts as compared to those treated with SOC (at week 3, 38% vs 5%, P = 0.02 and week 5, 79% vs 22%, P = 0.0054) CONCLUSION: HPV cfDNA levels change dynamically throughout definitive CRT and peak during the first 3 weeks for the majority of patients. Treatment with a therapeutic HPV vaccine was associated with a more rapid decline in cfHPV DNA. Further analysis of cfDNA kinetics could provide valuable information on the relationship between cfDNA levels, treatment response, and clinical outcomes.

Evaluation of overall survival and barriers to surgery for patients with breast cancer treated without surgery: a National Cancer Database analysis

Surgery remains the foundation of curative therapy for non-metastatic breast cancer, but many patients do not undergo surgery. Evidence is limited regarding this population. We sought to assess factors associated with lack of surgery and overall survival (OS) in patients not receiving breast cancer surgery. Retrospective cohort study of patients in the US National Cancer Database treated in 2004-2016. The dataset comprised 2,696,734 patients; excluding patients with unknown surgical status or stage IV, cT0, cTx, or pIS, metastatic or recurrent disease resulted in 1,192,294 patients for analysis. Chi-square and Wilcoxon rank-sum tests were used to assess differences between groups. OS was analyzed using the Kaplan-Meier method with a Cox proportional hazards model performed to assess associated factors. In total 50,626 (4.3%) did not undergo surgery. Black race, age >50 years, lower income, uninsured or public insurance, and lower education were more prevalent in the non-surgical cohort; this group was also more likely to have more comorbidities, higher disease stage, and more aggressive disease biology. Only 3,689 non-surgical patients (7.3%) received radiation therapy (RT). Median OS time for the non-surgical patients was 58 months (3-year and 5-year OS rates 63% and 49%). Median OS times were longer for patients who received chemotherapy (80 vs 50 (no-chemo) months) and RT (85 vs 56 (no-RT) months). On multivariate analysis, age, race, income, insurance status, comorbidity score, disease stage, tumor subtype, treatment facility type and location, and receipt of RT were associated with OS. On subgroup analysis, receipt of chemotherapy improved OS for patients with triple negative (HR 0.66, 95% CI 0.59-0.75, P < 0.001) and HER2+ (HR 0.74, 95% CI 0.65-0.84, P < 0.001) subgroups while RT improved OS for ER+ (HR 0.72, 95% CI 0.64-0.82, P < 0.001) and favorable-disease (ER+, early-stage, age >60) (HR 0.61, 95% CI 0.45-0.83, P = 0.002) subgroups. Approximately 4% of women with breast cancer do not undergo surgery, particularly those with more aggressive disease and lower socioeconomic status. Despite its benefits, RT was underutilized. This study provides a benchmark of survival outcomes for patients who do not undergo surgery and highlights a potential role for use of RT.