Accuracy of surveillance serum squamous cell carcinoma antigen for cervical cancer recurrence after definitive chemoradiation

OBJECTIVE

Recurrence remains a significant clinical problem for patients with cervical cancer, and early detection may improve outcomes. Serum squamous cell carcinoma antigen (SCCA) is a biomarker of prognosis and response to chemoradiotherapy. We hypothesized that elevated serum SCCA during surveillance is sensitive and specific for recurrence.

METHODS

Pre-treatment and follow-up serum SCCA from patients treated with definitive-intent radiotherapy were measured via enzyme-linked immunosorbent assay in a Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory and analyzed retrospectively. Follow-up SCCA was defined as the value closest to recurrence, or as last available for patients without recurrence. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of follow-up SCCA for recurrence was determined for the whole cohort (Cohort 1), for patients with elevated (Cohort 2), and normal pre-treatment SCCA (Cohort 3). Patterns of failure were also evaluated.

RESULTS

Of 227 patients in Cohort 1, 23% experienced recurrence, and 17% died of cervical cancer. Mean follow-up SCCA was 0.9 (±2.5) for patients with no recurrence and 6.0 (±18.7) for patients with recurrence (p=0.02). Sensitivity, specificity, PPV, and NPV of follow-up SCCA for recurrence in Cohort 1 were 38.5%, 97.1%, 80%, and 84.2%, and for patients in Cohort 2 were 54.5%, 95%, 78.3%, and 86.5%, respectively. Four of 86 patients in Cohort 3 had an elevated follow-up SCCA, two of these at the time of recurrence. Elevated pre-treatment SCCA and follow-up SCCA were associated with isolated pelvic recurrence.

CONCLUSIONS

Surveillance serum SCCA has high specificity and NPV for recurrence, and may be of limited utility in patients with normal pre-treatment SCCA.

Adjuvant External Beam Radiotherapy and Histopathologic Prognostic Factors in Tall Cell Papillary Thyroid Carcinoma

PURPOSE/OBJECTIVE(S)

Differentiated thyroid cancer is a diverse disease, with histopathologic characteristics contributing to prognosis and treatment decisions. Tall cell variant of papillary thyroid cancer (TCV-PTC) carries a poor prognosis relative to other histologies, with first site of failure most often in the neck. Several small studies suggest there may be a disease control benefit to adjuvant external beam radiotherapy (EBRT) for certain high-risk DTC populations; however, data is limited. In this study we aim to shed light on both histopathologic prognostic factors and survival outcomes of patients with TCV-PTC carcinoma treated with surgery followed by EBRT and Radioactive Iodine (RAI) or RAI alone. We hypothesize that EBRT with RAI leads to better disease control than RAI alone.

MATERIALS/METHODS

Patients with TCV-PTC diagnosed between 1997-2020 at a single institution were included in the analysis. TNM staging was standardized to AJCC 8th edition. Demographics, staging, and histologic characteristics were compared between the two treatment groups using T-tests and Fisher's exact tests. Kaplan-Meier survival analyses were performed between patients receiving EBRT vs. RAI alone for disease-free survival (DFS), cancer-specific survival (CSS) and overall survival (OS), along with Cox Proportional Hazards analysis.

RESULTS

A total of 93 patients were included. Of these patients, 22 received adjuvant RAI and EBRT, and 71 received RAI alone. There was no statistical difference in race, gender, tall cell percentage in the pathology specimen, TNM stage, AJCC group stage, or disease recurrence in patients receiving EBRT vs. RAI alone. However, those receiving EBRT were significantly older (RAI mean age (SD): 50.6 (18.7), EBRT mean age (SD): 59.7 (14.4), p = 0.02) and length of follow-up was shorter for the EBRT cohort (RAI mean (SD): 8.80 (5.81) years, EBRT mean (SD): 4.53 (2.14) years, p < 0.01). Multifocal disease (HR: 3.04, 95% CI: 1.30 - 7.08, p = 0.01) and soft tissue invasion (HR: 2.93, 95% CI: 1.28 - 6.75, p = 0.01) were associated with decreased DFS, whilst age (HR 1.08, 1.01 - 1.15: p = 0.03) was associated with decreased CSS; tall cell percentage in the pathology specimen, extra-thyroidal extension, vascular invasion, and positive surgical margin were not significant for either metric. There was no statistical difference in DFS (p = 0.5), CSS (p = 0.3), or OS (p = 0.6) between patients that received EBRT and RAI vs. RAI alone.

CONCLUSION

DFS, CSS, and OS were not different between patients who received EBRT compared to RAI only in this high-risk subgroup of patients. Short interval follow-up for the EBRT group and significant age differences between the EBRT and RAI cohorts may confound results. Given the significant association of advanced age with CSS, an expanded, age-matched cohort analysis is underway.

SCCA1/SERPINB3 suppresses anti-tumor immunity and blunts therapy-induced T cell responses via STAT-dependent chemokine production

Cancer patients with high serum squamous cell carcinoma antigen (SCCA1/SERPINB3) are commonly associated with treatment resistance and poor prognosis. Despite being a clinical biomarker, the modulation of SERPINB3 in tumor immunity is poorly understood. We found positive correlations of SERPINB3 with CXCL1/8, S100A8/A9 and myeloid cell infiltration through RNAseq analysis of human primary cervix tumors. Induction of SERPINB3 resulted in increased CXCL1/8 and S100A8/A9, which promoted monocyte and MDSC migration in vitro. In mouse models, Serpinb3a-tumors showed increased MDSC and TAM infiltration contributing to T cell inhibition and this was further augmented upon radiation. Intratumoral knockdown of Serpinb3a demonstrated tumor growth inhibition and reduced CXCL1, S100A8/A9, MDSC, and M2 macrophage infiltration. These changes led to enhanced cytotoxic T cell function and sensitized tumors to radiotherapy. We further revealed SERPINB3 promoted STAT-dependent suppressive chemokine expression, whereby inhibiting STAT activation by ruxolitinib or siRNA abrogated CXCL1/8 and S100A8/A9 in SERPINB3 cells. Patients with elevated pre-treatment SCCA and high pSTAT3 had increased intratumoral CD11b+ myeloid cell compared to patients with low SCCA and pSTAT3 cohort that had overall improved survival after radiotherapy. These findings provide a preclinical rationale for targeting SERPINB3 in tumors to counteract the immunosuppression and improve response to radiation.

SCCA1/SERPINB3 promotes suppressive immune environment via STAT-dependent chemokine production, blunting the therapy-induced T cell responses

Radiotherapy is a commonly used cancer treatment; however, patients with high serum squamous cell carcinoma antigen (SCCA1/SERPINB3) are associated with resistance and poor prognosis. Despite being a strong clinical biomarker, the modulation of SERPINB3 in tumor immunity is poorly understood. We investigated the microenvironment of SERPINB3 high tumors through RNAseq of primary cervix tumors and found that SERPINB3 was positively correlated with CXCL1/8, S100A8/A9 and myeloid cell infiltration. Induction of SERPINB3 in vitro resulted in increased CXCL1/8 and S100A8/A9 production, and supernatants from SERPINB3-expressing cultures attracted monocytes and MDSCs. In murine tumors, the orthologue mSerpinB3a promoted MDSC, TAM, and M2 macrophage infiltration contributing to an immunosuppressive phenotype, which was further augmented upon radiation. Radiation-enhanced T cell response was muted in SERPINB3 tumors, whereas Treg expansion was observed. A STAT-dependent mechanism was implicated, whereby inhibiting STAT signaling with ruxolitinib abrogated suppressive chemokine production. Patients with elevated pre-treatment serum SCCA and high pSTAT3 had increased intratumoral CD11b+ myeloid cell compared to patients with low SCCA and pSTAT3 cohort that had overall improved cancer specific survival after radiotherapy. These findings provide a preclinical rationale for targeting STAT signaling in tumors with high SERPINB3 to counteract the immunosuppressive microenvironment and improve response to radiation.

Expression of Potential Biomarker Targets by Immunohistochemistry in Cervical Carcinomas

There have been few clinically useful targetable biomarkers in uterine cervical carcinomas. Estrogen receptor (ER), HER2, and fibroblast activation protein (FAP) are potential therapeutic or theranostic targets in other gynecologic and genitourinary carcinoma types. We determined the immunohistochemical expression patterns of these markers in treatment-naive cervical carcinoma, and whether expression correlated with clinical outcomes after definitive chemoradiation therapy. Tissue microarrays were created from 71 patient samples taken before therapy (57 squamous cell carcinomas and 14 nonsquamous cell carcinomas) and stained for ER, HER2, and FAP. ER was positive in 25/70 cases (36%). Of 66 tumors with evaluable HER2 staining, only 1 had positive (3+) staining (3%, positive for HER2 amplification by fluorescence in situ hybridization), and 1 had equivocal (2+) staining (negative for amplification by fluorescence in situ hybridization). The remainder were negative for HER2 overexpression. FAP expression was widely variably in the tumor stroma. ER positivity and FAP expression did not correlate with cervical recurrence, pelvic recurrence, distant recurrence, or cancer death. In conclusion, HER2 amplification is very rare in nonmetastatic treatment-naive cervical carcinomas, but if present, could represent a target for antibody therapy. ER and FAP were expressed in a subset of tumors, but expression did not correlate with clinical outcomes. These immunohistochemical markers do not demonstrate prognostic significance in treatment-naive cervical cancer, but they may have utility in targeted therapy or imaging.

Abstract 3475: An 18-gene expression model predicts resistance to standard of care therapy on 3-month follow up 18FDG-PET in locally advanced cervical cancer

Introduction: As many as 30-50% of patients with locally advanced cervical cancer (LACC) experience recurrence after chemoradiation therapy (CRT), and five-year survival rates for these patients is only ~10%. While local recurrence and overall survival are useful metrics for analyzing genomic risk factors in LACC, such time to event analysis can be complicated by confounding variables which impede the elucidation of biologically relevant signals. Our group previously reported upregulation of genes from the PI3K pathway in cervical tumors with residual abnormal 18F-Fluoro-deoxy-glucose (FDG) uptake on positron emission tomography (PET) performed 3 months after CRT. Here, we analyzed whole transcriptome data using RNASeq from N=86 prospectively collected pretreatment cervix tumor biopsies to identify novel gene expression signatures associated with persistent or new FDG uptake on 3 month post-therapy FDG-PET.

Objective: To identify and validate a predictive gene expression signature able to distinguish primary tumors likely to be resistant to standard of care CRT as assessed by PET scan obtained 3-months following completion of therapy.

Methods: Whole tumor RNA-seq analysis was performed on 86 pre-treatment tumor specimens and compared with associated 3-month post-CRT FDG-PET. Response was dichotomized into metabolic complete response (mCR) and persistent/new disease (mP/N) defined as persistent or new areas of FDG-uptake on post-CRT PET per the nuclear medicine report. Differential expression analysis was conducted using the EdgeR R-package. Pathway enrichment analysis was conducted using reference libraries as specified and EnrichR software. Decision tree modeling, hyperparameter optimization, and k-fold cross-validation was performed using the sci-kitlearn python package.

Results: We identified an 18-gene expression signature predictive for mCR vs. mP/N in patients treated with definitive CRT with an overall prospective accuracy of 0.92. This model reliably identified both classes of patients (mCR F1=0.95, precision = 0.90, recall =1.0 ; mP/N F1=0.80, precision 0.67, recall =1.0). Crowd source enrichment analysis using EnrichR identified an NRF2 driven expression program (p=0.0006), and an altered inflammatory response (0.000006) within the predictive 18 gene signature.

Conclusions: We generated an 18-gene model to predict response to CRT as assessed by 3 month PET imaging. This novel expression signature further identified the NRF2 transcription factor as an important marker for resistance to CRT, consistent with previous studies showing NRF2 promotes cervical cancer growth. Our findings highlight the need for further elucidation of the NRF2 pathway in LACC, and can be used to accurately assess high risk patients who would benefit from treatment escalation.

Citation Format: Michael R. Waters, Matthew Inkman, Perry W. Grigsby, Stephanie Markovina, Julie K. Schwarz, Jin Zhang. An 18-gene expression model predicts resistance to standard of care therapy on 3-month follow up 18FDG-PET in locally advanced cervical cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3475.

Overall survival in patients with FIGO stage IVA cervical cancer

OBJECTIVE

FIGO stage IVA cervical cancer is a unique diagnosis that conveys a poor prognosis. Despite the use of PET/CT for staging, concurrent chemotherapy, and image-guided brachytherapy, overall survival (OS) in these patients is low. Treatment requires aggressive use of radiotherapy and chemotherapy. We report results of a prospective observational cohort study for patients with de novo stage IVA cervical cancer treated at a single institution.

METHODS

Patients with a new diagnosis of stage IVA cervical cancer treated at an academic institution between 1997 and 2020 were prospectively monitored. Staging was retroactively assigned using the 2018 FIGO staging system. All patients had a PET/CT prior to treatment and were treated with definitive intent radiotherapy with or without chemotherapy. The primary outcome of interest was OS. Secondary outcomes were local control, progression-free survival (PFS), and disease-specific survival (DSS).

RESULTS

32 patients with de novo stage IVA cervical cancer were treated with definitive intent radiotherapy. Median follow-up time was 4.27 years (1.31-10.35). 22/32 (69%) of patients received brachytherapy as a part of their definitive treatment, and 28/32 (88%) received chemotherapy concurrently with radiotherapy. 14/32 (44%) of patients had no evidence of disease at last follow-up. The 5-year local control, PFS, DFS, and OS estimates were 79%, 49%, 53%, and 48%, respectively. On multivariate analysis, complete metabolic response was associated with a statistically significant improvement in PFS (HR = 0.256, 95% CI = 0.078-0.836, p = 0.024) and OS (HR = 0.273, 95% CI 0.081-0.919).

CONCLUSIONS

These data demonstrate a robust OS in patients with stage IVA cervical cancer when treated with definitive chemoradiotherapy.

Phase I Trial of Stereotactic MRI-Guided Online Adaptive Radiation Therapy (SMART) for the Treatment of Oligometastatic Ovarian Cancer

PURPOSE

Stereotactic body radiation therapy is increasingly used to treat a variety of oligometastatic histologies, but few data exist for ovarian cancer. Ablative stereotactic body radiation therapy dosing is challenging in sites like the abdomen, pelvis, and central thorax due to proximity and motion of organs at risk. A novel radiation delivery method, stereotactic magnetic-resonance-guided online-adaptive radiation therapy (SMART), may improve the therapeutic index of stereotactic body radiation therapy through enhanced soft-tissue visualization, real-time nonionizing imaging, and ability to adapt to the anatomy-of-the-day, with the goal of producing systemic-therapy-free intervals. This phase I trial assessed feasibility, safety, and dosimetric advantage of SMART to treat ovarian oligometastases.

METHODS AND MATERIALS

Ten patients with recurrent oligometastatic ovarian cancer underwent SMART for oligometastasis ablation. Initial plans prescribed 35 Gy/5 fractions with goal 95% planning target volume coverage by 95% of prescription, with dose escalation permitted, subject to strict organ-at-risk dose constraints. Daily adaptive planning was used to protect organs-at-risk and/or increase target dose. Feasibility (successful delivery of >80% of fractions in the first on-table attempt) and safety of this approach was evaluated, in addition to efficacy, survival metrics, quality-of-life, prospective timing and dosimetric outcomes.

RESULTS

Ten women with seventeen ovarian oligometastases were treated with SMART, and 100% of treatment fractions were successfully delivered. Online adaptive plans were selected at time of treatment for 58% of fractions, due to initial plan violation of organs-at-risk constraints (84% of adapted fractions) or observed opportunity for planning target volume dose escalation (16% of adapted fractions), with a median on-table time of 64 minutes. A single Grade ≥3 acute (within 6 months of SMART) treatment-related toxicity (duodenal ulcer) was observed. Local control at 3 months was 94%; median progression-free survival was 10.9 months. Median Kaplan-Meier estimated systemic-therapy-free survival after radiation completion was 11.5 months, with concomitant quality-of-life improvements.

CONCLUSIONS

SMART is feasible and safe for high-dose radiation therapy ablation of ovarian oligometastases of the abdomen, pelvis, and central thorax with minimal toxicity, high rates of local control, and prolonged systemic-therapy-free survival translating into improved quality-of-life.

HPV transcript expression affects cervical cancer response to chemoradiation

Persistent HPV infection is causative for the majority of cervical cancer cases; however, current guidelines do not require HPV testing for newly diagnosed cervical cancer. Using an institutional cohort of 88 patients with cervical cancer treated uniformly with standard-of-care chemoradiation treatment (CRT) with prospectively collected clinical outcome data, we observed that patients with cervical tumors containing HPV genotypes other than HPV 16 have worse survival outcomes after CRT compared with patients with HPV 16⁺ tumors, consistent with previously published studies. Using RNA sequencing analysis, we quantified viral transcription efficiency and found higher levels of E6 and the alternative transcript E6*I in cervical tumors with HPV genotypes other than HPV 16. These findings were validated using whole transcriptome data from The Cancer Genome Atlas (n = 304). For the first time to our knowledge, transcript expression level of HPV E6*I was identified as a predictive biomarker of CRT outcome in our complete institutional data set (n = 88) and within the HPV 16⁺ subset (n = 36). In vitro characterization of HPV E6*I and E6 overexpression revealed that both induce CRT resistance through distinct mechanisms dependent upon p53–p21. Our findings suggest that high expression of E6*I and E6 may represent novel biomarkers of CRT efficacy, and these patients may benefit from alternative treatment strategies.

Targetability of cervical cancer by magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU)-mediated hyperthermia (HT) for patients receiving radiation therapy

PURPOSE

To evaluate the targetability of late-stage cervical cancer by magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU)-induced hyperthermia (HT) as an adjuvant to radiation therapy (RT).

METHODS

Seventy-nine cervical cancer patients (stage IIIB-IVA) who received RT with lesions visible on positron emission tomography-computed tomography (PET-CT) were retrospectively analyzed for targetability using a commercially-available HT-capable MRgHIFU system. Targetability was assessed for both primary targets and/or any metastatic lymph nodes using both posterior (supine) and anterior (prone) patient setups relative to the transducer. Thirty-four different angles of rotation along subjects' longitudinal axis were analyzed. Targetability was categorized as: (1) Targetable with/without minimal intervention; (2) Not targetable. To determine if any factors could be used for prospective screening of patients, potential associations between demographic/anatomical factors and targetability were analyzed.

RESULTS

72.15% primary tumors and 33.96% metastatic lymph nodes were targetable from at least one angle. 49.37% and 39.24% of primary tumors could be targeted with patient laying in supine and prone positions, respectively. 25°-30° rotation and 0° rotation had the highest rate of the posterior and anterior targetability, respectively. The ventral depth of the tumor and its distance to the coccyx were statistically correlated with the anterior and posterior targetability, respectively.

CONCLUSION

Most late-stage cervical cancer primaries were targetable by MRgHIFU HT requiring either no/minimal intervention. A rotation of 0° or 25°-30° relative to the transducer might benefit anterior and posterior targetability, respectively. Certain demographic/anatomic parameters might be useful in screening patients for treatability.

Long-Term Outcomes of Cervical Cancer Patients Treated With Definitive Chemoradiation Following a Complete Metabolic Response

AIMS

A complete metabolic response (CMR) on early post-treatment 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a positive prognostic factor for cervical cancer patients treated with definitive chemoradiation, but long-term outcomes of this group of patients are unknown. Patterns of failure and risk subgroups are identified.

MATERIALS AND METHODS

Patients who received curative-intent chemoradiation from 1998 to 2018 for International Federation of Gynecology and Obstetrics (FIGO) stage IB1-IVA cervical cancer and had a CMR on post-treatment FDG-PET within 5 months of treatment completion were included. Cox proportional hazards models determined factors associated with locoregional and distant failure. Kaplan-Meier estimates of freedom from any recurrence (FFR) of patient subgroups were compared with Log-rank tests.

RESULTS

There were 402 patients with a CMR after chemoradiation on FDG-PET. Initial T stage was T1 (38%)/T2 (40%)/T3 (20%)/T4 (2%); initial FDG-avid nodal status was no nodes (50%)/pelvic lymph nodes (40%)/pelvic and para-aortic lymph nodes (10%). After a median follow-up of 6 years, 109 (27%) recurred. The pattern of recurrence was locoregional (27%), distant (61%) or both (12%). No factors were associated with locoregional failure. Distant recurrence was more likely in patients with T3-4 lesions (hazard ratio = 2.4, 95% confidence interval 1.5-3.8) and involvement of pelvic (hazard ratio = 1.6, 95% confidence interval 1.0-2.7) or para-aortic lymph nodes (hazard ratio = 2.7, 95% confidence interval 1.4-5.0) at diagnosis. The 5-year FFR rates for T1-2 patients with no nodes, pelvic nodes alone or para-aortic nodes at diagnosis were 85, 76 and 62%, respectively (P = 0.04, none versus para-aortic nodes). The 5-year FFR for T3-4 patients with no nodes, pelvic nodes alone or para-aortic nodes at diagnosis were 68, 56 and 25%, respectively (P = 0.09, none versus para-aortic nodes).

CONCLUSIONS

T3-4 tumours and para-aortic nodal involvement at diagnosis are poor prognostic factors, even after a CMR following chemoradiation.

Standardized Uptake Value for 18F-Fluorodeoxyglucose Is a Marker of Inflammatory State and Immune Infiltrate in Cervical Cancer

PURPOSE

Chemoradiotherapy for locally advanced cervical cancer fails in over a third of patients. Biomarkers with therapeutic implications are therefore needed. We investigated the relationship between an established prognostic marker, maximum standardized uptake value (SUV_max) on ¹⁸F-fluorodeoxyglucose positron emission tomography, and the inflammatory and immune state of cervical cancers.

EXPERIMENTAL DESIGN

An SUV_max most prognostic for freedom from progression (FFP) was identified and compared with known prognostic clinical variables in a cohort of 318 patients treated with definitive radiation with prospectively collected clinical data. Gene set enrichment analysis (GSEA) and CIBERSORT of whole-transcriptome data from 68 patients were used to identify biological pathways and immune cell subpopulations associated with high SUV_max. IHC using a tissue microarray (TMA, N = 82) was used to validate the CIBERSORT findings. The impact of macrophages on cervical cancer glucose metabolism was investigated in coculture experiments.

RESULTS

SUV_max <11.4 was most prognostic for FFP (P = 0.001). The GSEA showed that high SUV_max is associated with increased gene expression of inflammatory pathways, including JAK/STAT3 signaling. CIBERSORT and CD68 staining of the TMA showed high SUV_max tumors are characterized by a monocyte-predominant immune infiltrate. Coculture of cervical cancer cells with macrophages or macrophage-conditioned media altered glucose uptake, and IL6 and JAK/STAT3 signaling contribute to this effect.

CONCLUSIONS

SUV_max is a prognostic marker in cervical cancer that is associated with activation of inflammatory pathways and tumor infiltration of myeloid-derived immune cells, particularly macrophages. Macrophages contribute to changes in cervical cancer glucose metabolism.See related commentary by Williamson et al., p. 4136.

Integrating imaging and RNA-seq improves outcome prediction in cervical cancer

Approaches using a single type of data have been applied to classify human tumors. Here we integrate imaging features and transcriptomic data using a prospectively collected tumor bank. We demonstrate that increased maximum standardized uptake value on pretreatment 18F-fluorodeoxyglucose-positron emission tomography correlates with epithelial-to-mesenchymal transition (EMT) gene expression. We derived and validated 3 major molecular groups, namely squamous epithelial, squamous mesenchymal, and adenocarcinoma, using prospectively collected institutional (n = 67) and publicly available (n = 304) data sets. Patients with tumors of the squamous mesenchymal subtype showed inferior survival outcomes compared with the other 2 molecular groups. High mesenchymal gene expression in cervical cancer cells positively correlated with the capacity to form spheroids and with resistance to radiation. CaSki organoids were radiation-resistant but sensitive to the glycolysis inhibitor, 2-DG. These experiments provide a strategy for response prediction by integrating large data sets, and highlight the potential for metabolic therapy to influence EMT phenotypes in cervical cancer.

Early posttherapy clearance of human papillomavirus and treatment response in cervical carcinoma

BACKGROUND

Among patients with cervical cancer, little is known about the significance of persistent human papillomavirus (HPV) expression after chemoradiation (CRT). This study evaluated associations between early posttreatment HPV clearance and patient outcomes with an added focus on the value of posttherapy positron emission tomography (PET) imaging.

METHODS

Included patients underwent pretreatment testing indicating a high-risk HPV infection and posttreatment testing with a messenger RNA (mRNA)-based genital swab after CRT. Posttherapy responses were stratified on the basis of HPV mRNA detection into an early clearance (EC) group (no mRNA) and a persistent expression (PE) group (detectable mRNA) on the basis of an evaluation at a median of 6 weeks after therapy. The Kaplan-Meier method was used to compare outcomes, and multivariable analysis was used to identify predictors of outcomes.

RESULTS

Seventy-two of the 97 eligible patients (74.2%) had EC. The mean follow-up time was 25 months (range, 4-56 months), and 2-year pelvic control (76.9% vs 50.2%; P = .01) and overall survival (OS; 80.9% vs 52.2%; P < .01) were superior among EC patients. In the multivariable analysis, EC predicted for improved survival (hazard ratio [HR] for mortality, 0.46; 95% confidence interval [CI], 0.21-0.96; P = .047), as did a complete response (CR) on posttherapy PET (HR for less than a CR on PET, 6.17; 95% CI, 2.58-14.72; P < .01). In a subset analysis of patients with a posttherapy PET CR, HPV clearance retained prognostic significance (2-year OS, 95.6% with EC vs 66.7% with PE; P = .04), whereas PE patients without a PET CR had the worst survival (35.9%; P < .01 for trend).

CONCLUSIONS

Early posttherapy clearance of HPV is associated with improved survival in cervical cancer. Evaluating HPV expression at this 6-week time point provides prognostic information beyond posttherapy PET imaging and may aid in risk stratification and decisions for treatment escalation.

Long-term outcomes of intensity-modulated radiation therapy (IMRT) and high dose rate brachytherapy as adjuvant therapy after radical hysterectomy for cervical cancer

OBJECTIVE

Compared with 3D-planned pelvic radiation, intensity-modulated radiation therapy (IMRT) has been shown to reduce acute toxicity in cervical cancer patients after radical hysterectomy. This study evaluated late toxicity and patterns of failure after post-operative pelvic IMRT interdigitated weekly with high dose rate brachytherapy.

METHODS

This retrospective study included 53 cervical cancer patients treated between January 2006 and August 2019 with radical hysterectomy, lymphadenectomy, and post-operative IMRT and high dose rate brachytherapy. The decision to include chemotherapy was made by the treating gynecologic oncologist based on patient-specific criteria including positive pelvic lymph nodes, positive surgical margins, or positive parametrial invasion. The actuarial rates of genitourinary and gastrointestinal toxicity, vaginal cuff/regional nodal/distant failure, and overall survival were calculated using the Kaplan-Meier method.

RESULTS

Median follow-up was 70 months (range 5.4-148) months and age at diagnosis was 47 (range 24-73) years. The 2018 International Federation of Gynecology and Obstetrics (FIGO) clinical stages were IB1 (n=19), IB2 (n=7), IIB (n=7), IIIC1 (n=19), and IIIC2 (n=1). Median radiation dose delivered in 160 cGy daily fractions was 5120 (range 4640-5120) cGy. Median brachytherapy dose prescribed to the vaginal surface delivered in six weekly fractions was 2400 (range 1200-4800) cGy. Concurrent chemotherapy was delivered in 35 (66%) patients. There were no acute grade >3 genitourinary or gastrointestinal toxicities. Late grade >3 occurred in two (3.8%) patients, including a small bowel obstruction and a ureteral stricture. The 5-year actuarial rate for gastrointestinal or genitourinary toxicity was 1.9%. There were no vaginal cuff recurrences. The 5-year actuarial rates for regional nodal failure, distant failure outside the radiation field, any failure, and overall survival were 11%, 11%, 14%, and 85%, respectively.

CONCLUSIONS

Post-operative IMRT with high dose rate brachytherapy for patients with cervical cancer is associated with excellent outcomes and limited rates of radiation-related non-hematologic toxicity.

Radiologic Assessment of Groin Lymph Nodes in Pelvic Malignancies

INTRODUCTION

Metastatic involvement of groin nodes can alter radiation therapy planning for pelvic tumors. ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) can identify nodal metastases; however, interpretation of PET/CT-positive nodes can be complicated by non-malignant processes. We evaluated quantitative metrics as methods to identify groin metastases in patients with pelvic tumors by comparison with standard subjective interpretive criteria, with pathology as the reference standard.

METHODS

We retrospectively identified patients with vulvar, vaginal, or anal cancers who underwent ¹⁸F-FDG PET/CT before pathologic evaluation of groin nodes between 2007 and 2017. Because patho-radiologic correlation was not possible for every node, one index node identified on imaging was selected for each groin. For each index node, standardized uptake value measurements, total lesion glycolysis, metabolic tumor volume, CT-based volume, and short and long axes were measured. Multivariate logistic regression was used to identify metrics predictive for pathologically positive groins and generate a probabilistic model. Area under the receiver-operating characteristic curves (AUCs) for the model were compared with clinical interpretation from the diagnostic report via a Wald's χ² test.

RESULTS

Of 55 patients identified for analysis, 75 groins had pathologic evaluation resulting in 75 index groin nodes for analysis with 35 groins pathologically positive for malignancy. Logistic regression identified mean standardized-uptake-value (50% threshold) and short-axis length as the most predictive imaging metrics for metastatic nodal involvement. The probabilistic model performed better at predicting pathologic involvement compared with standard clinical interpretation on analysis (AUC 0.91, 95% CI 0.84 to 0.97 vs 0.80, 95% CI 0.71 to 0.89; p<0.01).

DISCUSSION

Accuracy of ¹⁸F-FDG PET/CT for detecting groin nodal metastases in patients with pelvic tumors may be improved with the use of quantitative metrics. Improving prediction of nodal metastases can aid with appropriate selection of patients for pathologic node evaluation and guide radiation volumes and doses.

Decreased local immune response and retained HPV gene expression during chemoradiotherapy are associated with treatment resistance and death from cervical cancer

More than one-third of patients with locally advanced cervical cancer do not respond to chemoradiation therapy (CRT). We aimed to characterize the transcriptional landscape of paired human cervical tumors before and during CRT in order to gain insight into the evolution of treatment response and to elucidate mechanisms of treatment resistance. We prospectively collected cervical tumor biopsies from 115 patients both before and 3 weeks into CRT. RNA-sequencing, Gene Set Enrichment Analysis and HPV gene expression were performed on 20 paired samples that had adequate neoplastic tissue mid-treatment. Tumors from patients with no evidence of disease (NED) at last follow-up had enrichment in pathways related to the immune response both pretreatment and mid-treatment, while tumors from patients dead of disease (DOD) demonstrated enrichment in biosynthetic and mitotic pathways but not in immune-related pathways. Patients DOD had decreased expression of T-cell and cytolytic genes and increased expression of PD-L2 mid-treatment compared to patients NED. Histological and immunohistochemical analysis revealed a decrease in tumor-associated lymphocytes (TAL) during CRT in all patients but tumors from patients DOD had a significantly more pronounced decrease in TALs and CD8+ cells mid-treatment, which was validated in a larger mid-treatment cohort. Finally, patients DOD retained more HPV E6/E7 gene expression during CRT and this was associated with increased expression of genes driving mitosis, which was corroborated in vitro. Our results suggest that decreased local immune response and retained HPV gene expression may be acting together to promote treatment resistance during CRT in patients with cervical cancer.

Impact of tumor histology on detection of pelvic and para-aortic nodal metastasis with 18F-fluorodeoxyglucose-positron emission tomography in stage IB cervical cancer

OBJECTIVE

¹⁸F-fluorodeoxyglucose-positron emission tomography (FDG-PET) detection of metastatic nodal disease is useful for guiding cervical cancer treatment but the impact of tumor histology is unknown. This study reports the detection of FDG avid pelvic and para-aortic lymph nodes in patients with early stage cervical cancer with squamous carcinoma and adenocarcinoma tumor histology.

METHODS

Patients with International Federation of Gynecology and Obstetrics (FIGO) 2009 stage IB1-2 cervical cancer who underwent pre-surgical FDG-PET between March 1999 and February 2018 were identified in a tertiary academic center database. All patients had radical hysterectomy with pelvic and para-aortic lymph node dissection. Detection of pelvic and para-aortic lymph nodes by FDG-PET versus surgical dissection was compared. FDG-PET sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined and stratified by tumor histology.

RESULTS

We identified 212 patients with early stage cervical cancer (84% FIGO IB1, 16% IB2) who underwent pre-surgical FDG-PET; 137 (65%) patients had squamous carcinoma and 75 (35%) patients had adenocarcinoma. PET/computed tomography was performed in 189 (89%) patients and 23 (11%) had PET only. Surgical dissection revealed positive pelvic and para-aortic lymph nodes in 25% and 3.3% of patients, respectively. For squamous carcinoma, sensitivity, specificity, PPV, and NPV of FDG-PET for pelvic nodal metastasis were 44%, 99%, 95%, and 78%, respectively. For adenocarcinoma, the corresponding results for pelvic nodal metastasis were 25%, 99%, 67%, and 92%, respectively. The overall values for sensitivity, specificity, PPV, and NPV of FDG-PET for para-aortic nodal metastasis were 29%, 99%, 67%, and 98%, respectively.

DISCUSSION

Pelvic nodal metastasis was less likely to be detected by FDG-PET in patients with early stage adenocarcinoma than with squamous carcinoma.

Concurrent chemoradiation for cervical cancer: Comparison of LDR and HDR brachytherapy

PURPOSE

To compare clinical outcomes between low-dose-rate (LDR) brachytherapy and high-dose-rate (HDR) brachytherapy for cervical cancer patients.

METHODS AND MATERIALS

All consecutive newly diagnosed cervical cancer patients undergoing pretreatment 18-fluorodeoxyglucose positron emission tomography imaging and treated with curative-intent definitive chemoradiation from 1997 to 2016 at a U.S. academic center were included. Brachytherapy boost was LDR or HDR 2D treatment planning from 1997 to 2005 and HDR with MR-based 3D planning from 2005 to 2016. Local control (LC), cancer-specific survival (CSS), and late bowel/bladder complications were evaluated.

RESULTS

Tumor stages were International Federation of Gynecology and Obstetrics IB1-IIB (n = 457; 75%) and III-IVA (n = 152; 25%). Brachytherapy was LDR for 104 patients and HDR for 505 patients. Concurrent weekly cisplatin was administered to 536 patients (88%). With median followup of 9.4 years, there was no difference in LC (p = 0.24) or CSS (p = 0.50) between LDR and HDR brachytherapy. Cox multivariable regression showed that only International Federation of Gynecology and Obstetrics stage III-IVA (HR=2.4, p = 0.004) was associated with worse LC. A propensity-matched cohort (90 LDR vs. 90 HDR) was created, and the 5-year LC rates were 88% LDR and 82% HDR, p = 0.26; 5-year CSS rates were 66% LDR and 58% HDR, p = 0.19; 5-year grade ≥3 bowel/bladder toxicities were 23% LDR and 16% HDR, p = 0.44. For all patients, the 5-year late toxicity in stage III-IVA patients was higher with LDR 47% vs. HDR 15%, p = 0.03, with no difference in LC, 86% and 75%, respectively (p = 0.09).

CONCLUSIONS

There was no difference in LC with either LDR or HDR brachytherapy. The late complication rate was reduced with HDR and 3D-planned brachytherapy compared to LDR and 2D-planned brachytherapy.

Clinical outcomes after isolated pelvic failure in cervical cancer patients treated with definitive radiation

PURPOSE

To describe clinical outcomes in patients with isolated pelvic failures after definitive radiation treatment for cervical cancer.

METHODS AND MATERIALS

Cervical cancer patients with isolated pelvic failure after definitive radiation with brachytherapy boost were identified in a tertiary academic center database from 1997 to 2016. All patients received an FDG-PET scan prior to their initial treatment and at the time of their first recurrence. Isolated failures in the cervix or pelvic nodes were biopsy-proven. Distant failure and overall survival (OS) were censored outcomes.

RESULTS

Isolated pelvic failure was detected in 67(11%) out of 607 consecutive patients treated with external beam pelvic radiation and brachytherapy boost. The median time to isolated pelvic recurrence was 9 months (range 3-198). Median follow-up time for patients alive after isolated pelvic recurrence was 40 months (range 0.6-183). Of these 67 patients, 28(42%) received salvage surgery, 17(25%) received chemotherapy alone, and 22(33%) received neither surgery nor chemotherapy. The median time to distant failure after isolated pelvic failure was 20 months (95% CI 3-37), with no significant difference between patients treated surgically vs. non-surgically. FDG-avid pelvic and para-aortic nodes at initial presentation were associated with worse distant control after isolated pelvic failure (HR = 3.4, 95% CI 1.0-12). Median OS for patients treated with surgery, chemotherapy alone, and neither surgery nor chemotherapy was 29 months (95% CI 16-41), 12 months (95% CI 3-21), and 3 months (95% CI 1-5), respectively.

CONCLUSIONS

Patients who have pelvic and para-aortic nodal disease at initial presentation are at higher risk of failing distantly after isolated pelvic failure, which should be considered when counseling patients on aggressive surgical salvage. Surgical salvage was associated with prolonged survival after isolated pelvic failure.

Measurement Repeatability of 18F-FDG PET/CT Versus 18F-FDG PET/MRI in Solid Tumors of the Pelvis

Knowledge of the within-subject variability of ¹⁸F-FDG PET/MRI measurements is necessary for proper interpretation of quantitative PET or MRI metrics in the context of therapeutic efficacy assessments with integrated PET/MRI scanners. The goal of this study was to determine the test–retest repeatability of these metrics on PET/MRI, with comparison to similar metrics acquired by PET/CT. Methods: This prospective study enrolled subjects with pathology-proven pelvic malignancies. Baseline imaging consisted of PET/CT immediately followed by PET/MRI, using a single 370-MBq ¹⁸F-FDG dose. Repeat imaging was performed within 7 d using an identical imaging protocol, with no oncologic therapy between sessions. PET imaging on both scanners consisted of a list-mode acquisition at a single pelvic station. The MRI consisted of 2-point Dixon imaging for attenuation correction, standard sequences for anatomic correlation, and diffusion-weighted imaging. PET data were statically reconstructed using various frame durations and minimizing uptake time differences between sessions. SUV metrics were extracted for both PET/CT and PET/MRI in each imaging session. Apparent diffusion coefficient (ADC) metrics were extracted for both PET/MRI sessions. Results: The study cohort consisted of 14 subjects (13 female, 1 male) with various pelvic cancers (11 cervical, 2 rectal, 1 endometrial). For SUV_max, the within-subject coefficient of variation (wCV) appeared higher for PET/CT (8.5%–12.8%) than PET/MRI (6.6%–8.7%) across all PET reconstructions, though with no significant repeatability differences (all P values ≥ 0.08) between modalities. For lean body mass-adjusted SUV_peak, the wCVs appeared similar for PET/CT (9.9%–11.5%) and PET/MRI (9.2%–11.3%) across all PET reconstructions, again with no significant repeatability differences (all P values ≥ 0.14) between modalities. For PET/MRI, the wCV for ADC_median of 3.5% appeared lower than the wCVs for SUV_max (6.6%–8.7%) and SUL_peak (9.2%–11.3%), though without significant repeatability differences (all P values ≥ 0.23). Conclusion: For solid tumors of the pelvis, the repeatability of the evaluated SUV and ADC metrics on ¹⁸F-FDG PET/MRI is both acceptably high and similar to previously published values for ¹⁸F-FDG PET/CT and MRI, supporting the use of ¹⁸F-FDG PET/MRI for quantitative oncologic treatment response assessments.

Long-term outcomes of follicular variant vs classic papillary thyroid carcinoma

The majority of papillary thyroid carcinoma (PTC) cases comprise classic papillary (C-PTC) and follicular variant (FV-PTC) histologic sub-types. Historically, clinical equivalency was assumed, but recent data suggest C-PTC may have poorer outcomes. However, large single-institution series with long-term outcomes of C-PTC and FV-PTC, using modern pathologic criteria for FV-PTC, are needed. Our objective was to compare prevalence and impact of clinicopathologic factors, including BRAF mutation status, on long-term outcomes of C-PTC and FV-PTC. We hypothesized that patients with C-PTC would have higher risk disease features and worse survival outcomes. This retrospective study included 1293 patients treated at a single, US academic institution between 1943 and 2009 with mean follow-up of 8.6 years. All patients underwent either partial or total thyroidectomy and had invasive C-PTC or FV-PTC per modern pathology criteria. Primary study measurements included differences in recurrence-free survival (RFS), disease-specific survival (DSS) and associations with clinicopathologic factors including the BRAF mutation. Compared to FV-PTC, C-PTC was associated with multiple features of high-risk disease (P < 0.05) and significantly reduced RFS and DSS. Survival differences were consistent across univariate, multivariate and Kaplan-Meier analyses. BRAF mutations were more common in C-PTC (P = 0.002). However, on Kaplan-Meier analysis, mutational status did not significantly impact RFS or DSS for patients with either histologic sub-type. C-PTC therefore indicates higher-risk disease and predicts for significantly poorer long-term outcomes when compared to FV-PTC. The nature of this difference in outcome is not explained by traditional histopathologic findings or by the BRAF mutation.

Intensity Modulated Radiation Therapy and Image-Guided Adapted Brachytherapy for Cervix Cancer

PURPOSE

This study reported long-term outcomes of patients with cervical cancer who were treated with intensity modulated radiation therapy and 3-dimensional (3D) image-guided adapted brachytherapy (IMRT/3D-IGABT) compared with those treated with 2-dimensional (2D) external irradiation and 2D brachytherapy (2D EBRT/BT).

METHODS AND MATERIALS

This study included patients with newly diagnosed cervical cancer and pretreatment fluorodeoxyglucose positron emission tomography scans who were treated with curative-intent irradiation from 1997 to 2013. The treatment policy changed from using 2D EBRT/BT to IMRT/3D-IGABT in 2005. Patterns of recurrence, cancer-specific survival (CSS), and overall survival (OS) were evaluated. Late gastrointestinal and genitourinary toxicity were scored with National Cancer Institute Common Terminology Criteria for Adverse Events.

RESULTS

The median follow-up for patients alive at the time of last follow-up in the 2D EBRT/BT group (n = 300) was 15.3 years (range, 10.8-20.5 years). In the IMRT/3D-IGABT group (n = 300), it was 7 years (range, 5-12.4 years). According to the International Federation of Gynecology and Obstetrics, 33% of tumors were stage IB1 to IB2, 41% were stage IIA to IIB, and 26% were stage IIIA to IVA. The results after 5 years for patients treated with 2D EBRT/BT showed that freedom from relapse (FFR) was 57%, CSS was 62%, and OS was 57%. For the IMRT/3D-IGABT group, the 5-year results showed that FFR was 65% (P = .04), CSS was 69% (P = .01), and OS was 61% (P = .04). When stratified by lymph node status according to positron emission tomography scan results, disease control was most improved with IMRT/3D-IGABT versus 2D EBRT/BT in patients with positive pelvic lymph nodes only (P = .02). Cumulatively, 88 of 600 patients (15%) had grade ≥3 late bowel/bladder toxicity. The 2D EBRT/BT group had 55 patients (18%), and the IMRT/3D-IGABT group had 33 patients (11%; P = .02).

CONCLUSIONS

IMRT/3D-IGABT was associated with improved survival and decreased gastrointestinal and genitourinary toxicity in patients with cervical cancer compared with those who received 2D EBRT/BT.

Treatment Outcome Prediction for Cancer Patients based on Radiomics and Belief Function Theory

In this study, we proposed a new radiomics-based treatment outcome prediction model for cancer patients. The prediction model is developed based on belief function theory (BFT) and sparsity learning to address the challenges of redundancy, heterogeneity, and uncertainty of radiomic features, and relatively small-sized and unbalanced training samples. The model first selects the most predictive feature subsets from relatively large amounts of radiomic features extracted from pre- and/or in-treatment positron emission tomography (PET) images and available clinical and demographic features. Then an evidential k-nearest neighbor (EK-NN) classifier is proposed to utilize the selected features for treatment outcome prediction. Twenty-five stage II-III lung, 36 esophagus, 63 stage II-III cervix, and 45 lymphoma cancer patient cases were included in this retrospective study. Performance and robustness of the proposed model were assessed with measures of feature selection stability, outcome prediction accuracy, and receiver operating characteristics (ROC) analysis. Comparison with other methods were conducted to demonstrate the feasibility and superior performance of the proposed model.

Spatial relationship of 2-deoxy-2-[18F]-fluoro-D-glucose positron emission tomography and magnetic resonance diffusion imaging metrics in cervical cancer

Background

This study investigated the spatial relationship of 2-deoxy-2-[¹⁸F]-fluoro-D-glucose positron emission tomography ([¹⁸F]FDG-PET) standardized uptake values (SUVs) and apparent diffusion coefficients (ADCs) derived from magnetic resonance (MR) diffusion imaging on a voxel level using simultaneously acquired PET/MR data.

We performed an institutional retrospective analysis of patients with newly diagnosed cervical cancer who received a pre-treatment simultaneously acquired [¹⁸F]FDG-PET/MR. Voxel SUV and ADC values, and global tumor metrics including maximum SUV (SUV_max), mean ADC (ADC_mean), and mean tumor-to-muscle ADC ratio (ADC_T/M) were compared. The impacts of histology, grade, and tumor volume on the voxel SUV to ADC relationship were also evaluated. The potential prognostic value of the voxel SUV/ADC relationship was evaluated in an exploratory analysis using Kaplan-Meier/log-rank and univariate Cox analysis.

Results

Seventeen patients with PET/MR scans were identified. There was a significant inverse correlation between SUV_max and ADC_mean, and SUV_max and ADC_T/M. In the voxelwise analysis, squamous cell carcinomas (SCCAs) and poorly differentiated tumors showed a consistent significant inverse correlation between voxel SUV and ADC values; adenocarcinomas (AdenoCAs) and well/moderately differentiated tumors did not. The strength of the voxel SUV/ADC correlation varied with metabolic tumor volume (MTV). On log-rank analysis, the correlation between voxel SUV/ADC values was prognostic of disease-free survival (DFS).

Conclusions

In this hypothesis-generating study, a consistent inverse correlation between voxel SUV and ADC values was seen in SCCAs and poorly differentiated tumors. On univariate statistical analysis, correlation between voxel SUV and ADC values was prognostic for DFS.

Electronic supplementary material

The online version of this article (10.1186/s13550-018-0403-7) contains supplementary material, which is available to authorized users.

Serum squamous cell carcinoma antigen as an early indicator of response during therapy of cervical cancer

Background:

Pretreatment serum squamous cell carcinoma antigen (SCCA) is a prognostic biomarker in women with cervical cancer. SCCA has not been evaluated as an early indicator of response to chemoradiation therapy (CRT). The molecular role of the two SCCA isoforms, SCCA1 (SERPINB3) and SCCA2 (SERPINB4), in cervical cancer is unknown. We hypothesised that changes in serum SCCA during definitive CRT predicts treatment response, and that SCCA1 mediates radiation resistance.

Methods:

Patients treated with definitive CRT for cervical squamous carcinoma with serum SCCA measured were included. SCCA immunohistochemistry was performed on tumour biopsies. Post-treatment FDG-PET/CT, recurrence, and overall survival were recorded. Radiation response of cervical tumour cell lines after SCCA1 expression or CRISPR/Cas9 knockout was evaluated by clonogenic survival assay.

Results:

Persistently elevated serum SCCA during definitive CRT was an independent predictor of positive post-therapy FDG-PET/CT (P=0.043), recurrence (P=0.0046) and death (P=0.015). An SCCA1-expressing vector increased radioresistance, while SCCA knock out increased radiosensitivity of cervical tumour cell lines in vitro.

Conclusions:

Early response assessment with serum SCCA is a powerful prognostic tool. These findings suggest that escalation of therapy in patients with elevated or sustained serum SCCA and molecular targeting of SCCA1 should be considered.

MRI-based treatment planning and dose delivery verification for intraocular melanoma brachytherapy

PURPOSE

Episcleral plaque brachytherapy (EPB) planning is conventionally based on approximations of the implant geometry with no volumetric imaging following plaque implantation. We have developed an MRI-based technique for EPB treatment planning and dose delivery verification based on the actual patient-specific geometry.

METHODS AND MATERIALS

MR images of 6 patients, prescribed 85 Gy over 96 hours from Collaborative Ocular Melanoma Study-based EPB, were acquired before and after implantation. Preimplant and postimplant scans were used to generate "preplans" and "postplans", respectively. In the preplans, a digital plaque model was positioned relative to the tumor, sclera, and nerve. In the postplans, the same plaque model was positioned based on the imaged plaque. Plaque position, point doses, percentage of tumor volume receiving 85 Gy (V₁₀₀), and dose to 100% of tumor volume (D_min) were compared between preplans and postplans. All isodose plans were computed using TG-43 formalism with no heterogeneity corrections.

RESULTS

Shifts and tilts of the plaque ranged from 1.4 to 8.6 mm and 1.0 to 3.8 mm, respectively. V₁₀₀ was ≥97% for 4 patients. D_min for preplans and postplans ranged from 83 to 118 Gy and 45 to 110 Gy, respectively. Point doses for tumor apex and base were all found to decrease from the preimplant to the postimplant plan, with mean differences of 16.7 ± 8.6% and 30.5 ± 11.3%, respectively.

CONCLUSIONS

By implementing MRI for EPB, we eliminate reliance on approximations of the eye and tumor shape and the assumption of idealized plaque placement. With MRI, one can perform preimplant as well as postimplant imaging, facilitating EPB treatment planning based on the actual patient-specific geometry and dose-delivery verification based on the imaged plaque position.

Which patients with inoperable vulvar cancer may benefit from brachytherapy in addition to external beam radiation? A Surveillance, Epidemiology, and End Results analysis

PURPOSE

It is unknown whether brachytherapy after external beam radiation (EBRT + BT) results in improved outcomes compared with EBRT alone for patients with inoperable vulvar cancer. The purpose of this study was to compare survival outcomes for patients who received these treatment modalities.

METHODS AND MATERIALS

Data between 1973 and 2011 from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database were analyzed. Patients with Federation of International Gynecologists and Obstetricians stage I-IVA vulvar cancer treated with definitive EBRT + BT or EBRT alone were included. Patients with prior surgical resection were excluded. Disease-specific survival (DSS) and overall survival were compared using the Kaplan-Meier method and Cox proportional hazard models.

RESULTS

A total of 649 patients were analyzed, of which 617 received EBRT alone and 32 received EBRT + BT. Median follow-up was 33 months in surviving patients. The use of brachytherapy declined from 16% of cases treated in 1973-1980 to 4% in 2001-2011 (p = 0.04). EBRT + BT vs. EBRT alone was not significantly associated with improved DSS (45% vs. 33% at 5 years) or overall survival (34% vs. 24% at 5 years) on univariate or multivariate analyses. On post hoc subgroup analyses, brachytherapy consolidation was associated with higher 5-year DSS in a composite subgroup that included patients with stage IVA disease, tumor >4 cm, or node-positive disease (52% vs. 27%, p = 0.02).

CONCLUSIONS

Utilization of BT consolidation with EBRT for vulvar cancer is declining in the United States. EBRT + BT is not associated with improved survival compared with EBRT alone in the overall group of patients. Certain subgroups of patients might benefit from brachytherapy, but this hypothesis requires validation in future studies.

Survival of Cervical Cancer Patients Presenting with Occult Supraclavicular Metastases Detected by FDG-Positron Emission Tomography/CT: Impact of Disease Extent and Treatment

AIMS

The study aimed to do the following: (1) describe progression free survival (PFS) and overall survival (OS) of women with cervical cancer presenting with occult supraclavicular lymph node (SCLN) metastases, identified by positron emission tomography CT (PET-CT) and (2) compare OS of patients with isolated SCLN metastases to that of patients with SCLN and extranodal metastatic disease.

METHODS

Patients were identified retrospectively. Treatment intent was abstracted. PFS and OS in the high-dose chemo-radiotherapy (RT), palliative RT, and supportive treatment groups, as well as OS of patients with SCLN metastases only vs. SCLN and extranodal metastases were calculated.

RESULTS

Fourteen patients received high-dose chemo-RT, 32 received palliative RT, and 6 received supportive care (n = 52). Median PFS was 3 months in high-dose chemo-RT group and 1 month in palliative RT (p = ns). Median OS was 12 months in high-dose chemo-RT group, 7 months in palliative RT group, and 2 months in palliative care group (p = 0.05). OS was significantly different between patients with isolated SCLN disease vs. SCLN and extranodal disease, that is, 10.5 vs. 3 months (p = 0.009, χ2 = 6.9).

CONCLUSIONS

In this limited analysis, median OS of cervical cancer patients with PET/CT-positive SCLN metastases was the longest when treated with high-dose chemo-RT. Patients with SCLN and extranodal metastases experienced significantly shorter OS, as compared to patients with SCLN only disease.

Intensity modulated radiation therapy for squamous cell carcinoma of the vulva: Treatment technique and outcomes

OBJECTIVE

The objective of this study was to present the treatment technique and evaluate clinical outcomes after intensity modulated radiation therapy (IMRT) for vulvar cancer.

METHODS AND MATERIALS

This retrospective study included 39 patients with squamous cell carcinoma of the vulva treated with IMRT from 2005 to 2015. There were 21 patients treated with postoperative IMRT, 13 with definitive IMRT, and 5 with preoperative IMRT. Tumor staging was Federation of Gynecology and Obstetrics stage I in 6, stage II in 7, stage III in 19, and stage IV in 7 patients. Concurrent chemotherapy was administered to 14 patients. Brachytherapy was delivered in 8 patients.

RESULTS

The median follow-up was 34 months (range, 3.3-71). Median IMRT dose to patients receiving pre- or postoperative IMRT was 5040 cGy (range, 5040-6080). Median combined IMRT and brachytherapy dose to gross tumor was 7000 cGy (range, 5040-7520) in those treated with definitive RT. The 3-year locoregional control (LRC) and overall survival for those receiving postoperative RT were 89% and 67%, respectively. The 3-year LRC and overall survival for those receiving definitive IMRT were 42% and 49%, respectively. In patients receiving definitive or neoadjuvant IMRT, 69% had complete clinical response and 44% had complete pathologic response. The actuarial 3-year inguinal recurrence rate was 7%. There were no acute grade 3-4 hematological, gastrointestinal, or genitourinary toxicities. There were no late grade 3-4 gastrointestinal or genitourinary toxicities.

CONCLUSIONS

IMRT for vulvar cancer is associated with high rates of LRC in the postoperative setting and limited radiation-related toxicity. Durable LRC of disease after definitive IMRT remains challenging, and several refinements to our treatment technique are suggested.

Intensity modulated radiation therapy for squamous cell carcinoma of the vulva: Treatment technique and outcomes

Objective

The objective of this study was to present the treatment technique and evaluate clinical outcomes after intensity modulated radiation therapy (IMRT) for vulvar cancer.

Methods and materials

This retrospective study included 39 patients with squamous cell carcinoma of the vulva treated with IMRT from 2005 to 2015. There were 21 patients treated with postoperative IMRT, 13 with definitive IMRT, and 5 with preoperative IMRT. Tumor staging was Federation of Gynecology and Obstetrics stage I in 6, stage II in 7, stage III in 19, and stage IV in 7 patients. Concurrent chemotherapy was administered to 14 patients. Brachytherapy was delivered in 8 patients.

Results

The median follow-up was 34 months (range, 3.3-71). Median IMRT dose to patients receiving pre- or postoperative IMRT was 5040 cGy (range, 5040-6080). Median combined IMRT and brachytherapy dose to gross tumor was 7000 cGy (range, 5040-7520) in those treated with definitive RT. The 3-year locoregional control (LRC) and overall survival for those receiving postoperative RT were 89% and 67%, respectively. The 3-year LRC and overall survival for those receiving definitive IMRT were 42% and 49%, respectively. In patients receiving definitive or neoadjuvant IMRT, 69% had complete clinical response and 44% had complete pathologic response. The actuarial 3-year inguinal recurrence rate was 7%. There were no acute grade 3-4 hematological, gastrointestinal, or genitourinary toxicities. There were no late grade 3-4 gastrointestinal or genitourinary toxicities.

Conclusions

IMRT for vulvar cancer is associated with high rates of LRC in the postoperative setting and limited radiation-related toxicity. Durable LRC of disease after definitive IMRT remains challenging, and several refinements to our treatment technique are suggested.

PET/MRI Evaluation of Gynecologic Malignancies and Prostate Cancer

PET combined with cross-sectional anatomical imaging is an essential part of workup for most malignancies, in which CT or MRI provides anatomical context to the functional information from PET. Hybrid imaging with PET/CT has been extensively researched and implemented clinically in the evaluation and management of patients with gynecologic malignancies. Lately, integrated PET/MR scanners have become available. This new technology is fast gaining a role in clinical applications in the fields of oncology, neurology, and cardiology. MRI provides excellent soft tissue contrast especially in the pelvis and has been proven very useful for imaging prostate and female genital pathologies. The ability of PET to provide accurate functional imaging data with high sensitivity combined with the strength of MRI to provide accurate depiction of anatomy with high contrast and spatial resolution renders combined PET/MRI a desirable method for evaluation of gynecologic malignancies and other pelvic cancers such as prostate cancer. The goal of this article is to provide an overview of the published literature using PET/MRI in gynecologic and prostate cancers.

Intensity modulated radiation therapy for recurrent ovarian cancer refractory to chemotherapy

OBJECTIVE

To evaluate local control, survival outcomes, and toxicity after intensity modulated radiotherapy (IMRT) for recurrent chemorefractory ovarian cancer.

METHODS

Between 2006 and 2014, 33 patients were treated with IMRT for recurrent ovarian cancer. Patients received a median of 3 chemotherapy regimens prior to IMRT (range, 1-12) with 11 (33%) undergoing concurrent therapy. Local control (LC), recurrence free survival (RFS), and overall survival (OS) were calculated via Kaplan-Meier method. Toxicity was assessed using the Common Terminology Criteria for Adverse Events (CTCAE) v4.03. Impact of patient characteristics on outcomes was evaluated via Cox's proportional hazard model.

RESULTS

Median follow up was 23.7 months. Forty-nine sites were treated to a median dose of 5040cGy (range, 4500-7000). Nine (18%) of the 49 sites had in-field failures. Two year actuarial LC, RFS, and OS were 82%, 11%, and 63%, respectively. Seventeen patients had both a pre and post-treatment FDG-PET/CT; 6 (35%) had a complete metabolic response while 11 (65%) had a partial metabolic response. Acute ≥ grade 3 gastrointestinal (GI) toxicities occurred in 2 (6%) patients, late ≥ grade 3 GI toxicities occurred in 12 (36%), acute ≥ grade 3 hematological toxicities occurred in 5 (15%) and late ≥ grade 3 hematological toxicities occurred in 14 (42%).

CONCLUSIONS

IMRT for recurrent chemorefractory ovarian cancer is associated with excellent local control and limited radiation related toxicity. Future studies will be required to determine which subpopulation will benefit most from IMRT and whether alternative techniques such as stereotactic body radiotherapy may be feasible.

Clinical implementation of multisequence MRI-based adaptive intracavitary brachytherapy for cervix cancer

The purpose of this study was to describe the clinical implementation of a magnetic resonance image (MRI)-based approach for adaptive intracavitary brachytherapy (ICBT) of cervix cancer patients. Patients were implanted with titanium tandem and colpostats. MR imaging was performed on a 1.5-T Philips scanner using T2-weighted (T2W), proton-density weighted (PDW), and diffusion-weighted (DW) imaging sequences. Apparent diffusion coefficient (ADC) maps were generated from the DW images. All images were fused. T2W images were used for the definition of organs at risk (OARs) and dose points. ADC maps in conjunction with T2W images were used for target delineation. PDW images were used for applicator definition. Forward treatment planning was performed using standard source distribution rules normalized to Point A. Point doses and dose-volume parameters for the tumor and OARs were exported to an automated dose-tracking application. Brachytherapy doses were adapted for tumor shrinkage and OAR variations during the course of therapy. The MRI-based ICBT approach described here has been clinically implemented and is carried out for each brachytherapy fraction. Total procedure time from patient preparation to delivery of treatment is typically 2 hrs. Implementation of our tech-nique for structure delineation, applicator definition, dose tracking, and adaptation is demonstrated using treated patient examples. Based on published recommendations and our clinical experience in the radiation treatment of cervix cancer patients, we have refined our standard approach to ICBT by 1) incorporating a multisequence MRI technique for improved visualization of the target, OARs, and applicator, and by 2) implementing dose adaptation by use of automated dose tracking tools.

Three-dimensional dose accumulation in pseudo-split-field IMRT and brachytherapy for locally advanced cervical cancer

PURPOSE

Dose accumulation of split-field external beam radiotherapy (EBRT) and brachytherapy (BT) is challenging because of significant EBRT and BT dose gradients in the central pelvic region. We developed a method to determine biologically effective dose parameters for combined split-field intensity-modulated radiation therapy (IMRT) and image-guided BT in locally advanced cervical cancer.

METHODS AND MATERIALS

Thirty-three patients treated with split-field-IMRT to 45.0-51.2 Gy in 1.6-1.8 Gy per fraction to the elective pelvic lymph nodes and to 20 Gy to the central pelvis region were included in this study. Patients received six weekly fractions of high-dose rate BT to 6.5-7.3 Gy per fraction. A dose tracker software was developed to compute the equivalent dose in 2-Gy fractions (EQD2) to gross tumor volume (GTV), organs-at-risk and point A. Total dose-volume histogram parameters were computed on the 3D combined EQD2 dose based on rigid image registration. The dose accumulation uncertainty introduced by organ deformations between IMRT and BT was evaluated.

RESULTS

According to International Commission on Radiation Unit and Measurement and GEC European Society for Therapeutic Radiology and Oncology recommendations, D98, D90, D50, and D2cm3 EQD2 dose-volume histogram parameters were computed. GTV D98 was 84.0 ± 26.5 Gy and D2cc was 99.6 ± 13.9 Gy, 67.4 ± 12.2 Gy, 75.0 ± 10.1 Gy, for bladder, rectum, and sigmoid, respectively. The uncertainties induced by organ deformation were estimated to be -1 ± 4 Gy, -3 ± 5 Gy, 2 ± 3 Gy, and -3 ± 5 Gy for bladder, rectum, sigmoid, and GTV, respectively.

CONCLUSIONS

It is feasible to perform 3D EQD2 dose accumulation to assess high and intermediate dose regions for combined split-field IMRT and BT.

BRAF mutation is not predictive of long-term outcome in papillary thyroid carcinoma

The BRAF mutation occurs commonly in papillary thyroid carcinoma (PTC). Previous investigations of its utility to predict recurrence-free survival (RFS) and disease-specific survival (DSS) have reported conflicting results and its role remains unclear. The purpose of this retrospective study was to determine the incidence of the BRAF mutation and analyze its relationship to clinicopathologic risk factors and long-term outcomes in the largest, single-institution American cohort to date. BRAF mutational status was determined in 508 PTC patients using RFLP analysis. The relationships between BRAF mutation status, patient and tumor characteristics, RFS, and DSS were analyzed. The BRAF mutation was present in 67% of patients. On multivariate analysis, presence of the mutation predicted only for capsular invasion (HR, 1.7; 95% CI, 1.1–2.6), cervical lymph node involvement (HR, 1.7; 95% CI, 1.1–2.7), and classic papillary histology (HR, 1.8; 95% CI 1.1–2.9). There was no significant relationship between the BRAF mutation and RFS or DSS, an observation that was consistent across univariate, multivariate, and Kaplan–Meier analyses. This is the most extensive study to date in the United States to demonstrate that BRAF mutation is of no predictive value for recurrence or survival in PTC. We found correlations of BRAF status and several clinicopathologic characteristics of high-risk disease, but limited evidence that the mutation correlates with more extensive or aggressive disease. This analysis suggests that BRAF is minimally prognostic in PTC. However, prevalence of the BRAF mutation is 70% in the general population, providing the opportunity for targeted therapy.

Low-order non-spatial effects dominate second-order spatial effects in the texture quantifier analysis of 18F-FDG-PET images

BACKGROUND

There is increasing interest in applying image texture quantifiers to assess the intra-tumor heterogeneity observed in FDG-PET images of various cancers. Use of these quantifiers as prognostic indicators of disease outcome and/or treatment response has yielded inconsistent results. We study the general applicability of some well-established texture quantifiers to the image data unique to FDG-PET.

METHODS

We first created computer-simulated test images with statistical properties consistent with clinical image data for cancers of the uterine cervix. We specifically isolated second-order statistical effects from low-order effects and analyzed the resulting variation in common texture quantifiers in response to contrived image variations. We then analyzed the quantifiers computed for FIGOIIb cervical cancers via receiver operating characteristic (ROC) curves and via contingency table analysis of detrended quantifier values.

RESULTS

We found that image texture quantifiers depend strongly on low-effects such as tumor volume and SUV distribution. When low-order effects are controlled, the image texture quantifiers tested were not able to discern only the second-order effects. Furthermore, the results of clinical tumor heterogeneity studies might be tunable via choice of patient population analyzed.

CONCLUSION

Some image texture quantifiers are strongly affected by factors distinct from the second-order effects researchers ostensibly seek to assess via those quantifiers.

Treatment approach, surveillance, and outcome of well-differentiated thyroid cancer in childhood and adolescence

BACKGROUND

Well-differentiated thyroid carcinoma in children and adolescents is a rare disease with favorable prognosis despite regional and distant metastasis at presentation in many patients. Treatment recommendations are varied and there is little consensus on follow-up guidelines for these patients.

METHODS

Medical records of patients less than 22 years of age treated at our institution were reviewed. One hundred twelve patients treated between 1969 and 2009 were selected for further analysis. Effects of patient and tumor characteristics on progression-free survival (PFS) were evaluated along with the predictive value of whole-body (131)I scintigraphy in the follow-up setting.

RESULTS

Overall survival at 20 years and 30 years was 100% and 94.4%, respectively. PFS at 10, 20, and 30 years was 71%, 62%, and 55%, respectively. Although male patients and younger patients presented with more advanced disease, sex, and age at diagnosis had no effect on risk of PFS. Additionally, neither the presence of vascular invasion, capsular extension, positive margins, nor soft tissue invasion had an effect on PFS. Mean time to recurrence in patients who underwent immediate postoperative (131)I therapy was 3.8 years compared to 14.1 years in patients who either never received (131)I therapy or were treated in the salvage setting (p<0.0001). Negative posttreatment whole-body (131)I scintigraphy was strongly predictive for decreased risk of recurrence, especially in patients with three consecutive negative scans.

CONCLUSIONS

Pediatric patients are more likely to present with advanced disease and for this reason, the majority of patients treated at our institution receive postoperative (131)I. Long-term surveillance is required in this population because of the risk of late recurrences. Whole-body (131)I scintigraphy is useful for risk stratification; after three consecutive negative scans, the risk of recurrence is low.

BRAF V600E mutational status in pediatric thyroid cancer

BACKGROUND

Clinical outcome of papillary thyroid carcinoma (PTC) in children differs significantly from that of adults. There is no clear explanation of this difference although previous studies have demonstrated a lower prevalence of the BRAF(V600E) mutation in PTC of children. However, data are limited due to the rarity of this diagnosis. BRAF(V600E) mutation prevalence and its relationship with outcome in pediatric PTC remain unclear.

PROCEDURE

BRAF(V600E) mutational status was determined in 27 PTC patients less than 22 years of age using restriction fragment length polymorphism (RFLP) analysis. The relationship between BRAF(V600E) mutation status, patient and tumor characteristics as well as progression-free survival (PFS) were analyzed.

RESULTS

BRAF(V600E) was present in 63% of patients and occurred more often in male patients versus females (P = 0.033). Presence of the mutation did not correlate with any difference in extent of disease at diagnosis, tumor size, capsular invasion, vascular invasion, soft tissue invasion, or margin status. At 10 years, PFS for BRAF(V600E) positive versus negative patients was 55.5% versus 70.0%, respectively (P = 0.48). Overall survival was 100% and median follow-up was 13.9 years.

CONCLUSIONS

This study of pediatric PTC demonstrates that BRAF(V600E) mutations occur in children at a rate comparable to adults. We found a correlation of BRAF(V600E) with the male gender, but no evidence that the mutation correlates with more extensive or aggressive disease. This analysis suggests that differences in disease course of PTC in children versus adults are not strongly dependent upon the presence of the BRAF(V600E) mutation.