Risk factors for nodal failure after radiochemotherapy and image guided brachytherapy in locally advanced cervical cancer: An EMBRACE analysis

OBJECTIVE

To assess risk factors for nodal failure (NF) after definitive (chemo)radiotherapy and image-guided brachytherapy for locally advanced cervical cancer (LACC) for patients treated in the EMBRACE I study.

MATERIALS AND METHODS

Data for pelvic NF and para-aortic (PAO) NF (NF_PAO) were analysed. After multiple imputation, univariable and multivariable Cox-regression was performed for clinical and treatment-related variables. For patients with affected pelvic nodes but no PAO nodes at diagnosis, additional analyses were performed for two subgroups: 1. 'small pelvis' nodes in internal and external iliac, obturator, parametrial, presacral and/or common iliac (CI) region and 2. any CI nodes (subgroup of 1).

RESULTS

1338 patients with 152 NF and 104 NF_PAO events were analysed with a median follow-up of 34.2 months (IQR 16.4-52.7). For the entire group, larger tumour width, nodal risk groups (in particular any CI nodes without PAO nodes), local failure, and lower Hb-nadir increased the risk of NF. Elective PAO-irradiation was independently associated with a decreased risk of NF_PAO (HR 0.53, 95%-CI 0.28-1.00, p = 0.05). For subgroup 1, having 'any CI nodes without PAO nodes' and local failure significantly increased NF risk. Additionally, elective PAO-irradiation was associated with less risk of NF_PAO (HR 0.38, 95%-CI 0.17-0.86, p = 0.02). For subgroup 2 only local failure was associated with higher risk of NF.

CONCLUSION

In this patient cohort, nodal disease and tumour width at diagnosis, as well as local failure, are risk factors for NF after definitive treatment. Having either 'any PAO nodes' (with or without pelvic nodes) or 'any CI nodes' (without PAO nodes) are stronger risk factors than involvement of nodes in the small pelvis alone. Elective PAO-irradiation was associated with significantly less NF_PAO, particularly in patients with nodal disease in the 'small pelvis' and/or CI region at time of diagnosis.

Impact of Vaginal Symptoms and Hormonal Replacement Therapy on Sexual Outcomes After Definitive Chemoradiotherapy in Patients With Locally Advanced Cervical Cancer: Results from the EMBRACE-I Study

PURPOSE

To evaluate patient-reported sexual outcomes after chemoradiation therapy and image-guided adaptive brachytherapy for locally advanced cervical cancer in the observational, prospective, multicenter EMBRACE-I study.

METHODS AND MATERIALS

Sexual outcomes were assessed prospectively with the European Organization for Research and Treatment of Cancer Qualify of Life Questionnaire (EORTC-QLQ-CX24) at baseline and follow-up. Crude incidence and prevalence rates of sexual activity, vaginal functioning problems (dryness, shortening, tightening, pain during intercourse), and sexual enjoyment were evaluated. Associations between pain during intercourse and vaginal functioning problems or sexual enjoyment were calculated, pooling observations over all follow-ups (Spearman correlation coefficient). In patients who were frequently sexually active (≥50% of follow-ups), the effects of regular hormonal replacement therapy (HRT) on vaginal functioning problems were evaluated (Pearson χ²).

RESULTS

The analysis involved 1045 patients with a median follow-up of 50 months. Sexual activity was reported by 22% of patients at baseline and by 40% to 47% of patients during follow-up (prevalence rates). Vaginal functioning problems in follow-up were dryness (18%-21%), shortening (15%-22%), tightening (16%-22%), pain during intercourse (9%-21%), and compromised enjoyment (37%-47%). Pain during intercourse was significantly associated with vaginal tightening (r = 0.544), shortening (r = 0.532), and dryness (r = 0.408) and negatively correlated with sexual enjoyment (r = -0.407). Regular HRT was associated with significantly less vaginal dryness (P = .015), shortening (P = .024), pain during intercourse (P = .003), and borderline higher sexual enjoyment (P = .062).

CONCLUSIONS

Vaginal functioning problems are associated with pain and compromised sexual enjoyment. Further effort is required for the primary prevention of vaginal morbidity with dose optimization and adaptation. Secondary prevention strategies, including HRT for vaginal and sexual health after radiation therapy in locally advanced cervical cancer, should be considered and sexual rehabilitation programs should be developed further.

Side Effects 15 Years after Lymph Node Irradiation in Breast Cancer: Randomized EORTC Trial 22922/10925

BACKGROUND

Uncertainty about the benefit/risk ratio of regional lymph node irradiation led to varying clinical protocols. We investigated long-term late side effects after internal mammary and medial supraclavicular (IM-MS) lymph node irradiation to improve shared decision-making.

METHODS

The multicentre EORTC trial (ClinicalTrials.gov, NCT00002851) randomized stage I-III breast cancer patients with involved axillary nodes and/or a medially located primary tumor. We analyzed late side effects, both longitudinally at every follow-up and cross-sectionally at 5-year intervals. All statistical tests were 2-sided.

RESULTS

Between 1996 and 2004, 46 departments from 13 countries accrued 4004 patients. Median follow-up was 15.7 years. Longitudinal follow-up data showed cumulative incidence rates at 15 years of 2.9% (95% confidence interval [CI] = 2.2%-3.8%) vs. 5.7% (95% CI = 4.7%-6.9%) (P<.001) for lung fibrosis, of 1.1% (95% CI = 0.7%-1.7%) vs. 1.9% (95% CI = 1.3%-2.6%) (P=.07) for cardiac fibrosis, and of 9.4% (95% CI = 8.0%-10.8%) vs. 11.1% (95% CI = 9.6%-12.7%) (P=.04) for any cardiac disease, when treated without or with IM-MS lymph node irradiation. There was no evidence for differences between left- and right-sided breast cancer (Wald chi-square test of treatment by breast side interaction, P=.33 and P=.35, for cardiac fibrosis and for any cardiac disease, respectively). The cumulative incidence probabilities of cross-sectionally reported side effects with a score of 2 or greater at 15 years were 0.1% (95% CI = 0.0%-0.5%) vs. 0.8% (95% CI = 0.4%-1.4%) for pulmonary (P=.02), 1.8% (95% CI = 1.1%-2.8%) vs. 2.6% (95% CI = 1.8%-3.7%) for cardiac (P=.15), and 0.0% (95% CI not evaluated) vs. 0.1% (95% CI = 0.0%-0.4%) for oesophageal (P=.16), respectively. No difference was observed in the incidence of second malignancies, contralateral breast cancer or cardiovascular deaths.

CONCLUSIONS

The incidence of late pulmonary side effects was statistically significantly higher after IM-MS lymph node irradiation, as were some of the cardiac events, without a difference between left- and right-sided treatments. Absolute rates and differences were very low, without increased non-breast cancer related mortality, even before introducing heart-sparing techniques.

Nomogram Predicting Overall Survival in Patients With Locally Advanced Cervical Cancer Treated With Radiochemotherapy Including Image-Guided Brachytherapy: A Retro-EMBRACE Study

PURPOSE

To present a nomogram for prediction of overall survival (OS) in patients with locally advanced cervical cancer (LACC) undergoing definitive radiochemotherapy including image-guided adaptive brachytherapy (IGABT).

METHODS AND MATERIALS

Seven hundred twenty patients with LACC treated with radiochemotherapy including IGABT in 12 institutions (median follow-up 56 months) were analyzed; 248 deaths occurred. Thirteen candidate predictors for OS were a priori chosen on the basis of the literature and expert knowledge. Missing data (7.2%) were imputed using multiple imputation and predictive mean matching. Univariate analysis with a multivariable Cox regression model for OS stratified by center was performed. Stepwise selection of predictive factors with the Akaike Information Criterion was used to obtain a predictive model and construct a nomogram for OS predictions 60 months from diagnosis; this was internally validated by concordance probability as a measure of discrimination and a calibration plot.

RESULTS

Thirteen potential predictive factors were evaluated; 10 factors reached statistical significance in univariate analysis (age, Hemoglobin, FIGO Stage₂₀₀₉, tumor width, corpus involvement, lymph node involvement, concurrent chemotherapy, dose to 90% of the high-risk clinical target volume_, volume of CTV at the first brachytherapy [CTV_HRVolumeBT], overall treatment time [OTT]). Four factors were confirmed significant within the multivariable Cox regression model (FIGO Stage₂₀₀₉, lymph node involvement, concurrent chemotherapy, CTV_HRVolumeBT). The predictive model and corresponding nomogram were based on 7 Akaike Information Criterion-selected factors (age, corpus involvement, FIGO Stage₂₀₀₉, lymph node involvement, concurrent chemotherapy, CTV_HRVolumeBT, OTT) and showed promising calibration and discrimination (cross-validated concordance probability c = 0.73).

CONCLUSIONS

This is the first nomogram to predict OS in patients with LACC treated with IGABT. In addition to previously reported factors (age, FIGO₂₀₀₉ stage, corpus involvement, chemotherapy delivery, OTT, lymph node involvement), status of primary tumor at the time of brachytherapy seems to be an essential outcome predictor. These results can facilitate individualized tailoring of treatment and patient counseling during the treatment.

Effect of tumor dose, volume and overall treatment time on local control after radiochemotherapy including MRI guided brachytherapy of locally advanced cervical cancer

BACKGROUND AND PURPOSE

Currently, there is no consensus on dose prescription in image guided adaptive brachytherapy (IGABT) in locally advanced cervical cancer. The purpose of this study was to provide evidence based recommendations for tumor dose prescription based on results from a multi-center patient series (retroEMBRACE).

MATERIALS AND METHODS

This study analyzed 488 locally advanced cervical cancer patients treated with external beam radiotherapy±chemotherapy combined with IGABT. Brachytherapy contouring and reporting was according to ICRU/GEC-ESTRO recommendations. The Cox Proportional Hazards model was applied to analyze the effect on local control of dose-volume metrics as well as overall treatment time (OTT), dose rate, chemotherapy, and tumor histology.

RESULTS

With a median follow up of 46months, 43 local failures were observed. Dose (D90) to the High Risk Clinical Target Volume (CTV_HR) (p=0.022, HR=0.967 per Gy) was significant for local control, whereas increasing CTV_HR volume (p=0.004, HR=1.017 per cm³), and longer OTT (p=0.004, HR=1.023 per day) were associated with worse local control. Histology (p=0.084), chemotherapy (p=0.49) and dose rate (p=1.00) did not have significant impact on local control. Separate analyses according to stage of disease showed that dose to CTV_HR, residual gross tumor volume (GTV_res), and Intermediate Risk CTV (CTV_IR) has significant impact on local control.

CONCLUSION

CTV_HR dose of ⩾85Gy (D90) delivered in 7weeks provides 3-year local control rates of >94% in limited size CTV_HR (20cm³), >93% in intermediate size (30cm³) and >86% in large size (70cm³) CTV_HR. CTV_IR and GTV_res dose of ⩾60Gy and ⩾95Gy (D98) leads to similar local control. A dose of 5Gy (CTV_HR) is required to compensate an increase of OTT by one week. Increased CTV_HR volume by 10cm³ requires additional 5Gy for equivalent local control.

Recommendations from GEC ESTRO Breast Cancer Working Group (II): Target definition and target delineation for accelerated or boost partial breast irradiation using multicatheter interstitial brachytherapy after breast conserving open cavity surgery

OBJECTIVE

To prepare guidelines for target definition and delineations after open cavity breast conserving surgery in accelerated partial breast irradiations or boost treatments using multicatheter interstitial brachytherapy based on the consensus of the Breast Working Group of GEC-ESTRO.

METHOD

Following a study on interobserver variations of target volume delineation in multicatheter breast brachytherapy after open cavity surgery and a number of discussions in consensus meetings these guidelines were worked out by experts on the field.

PROPOSED RECOMMENDATIONS

(1) Consistent windowing has to be used for proper cavity visualization. (2) The cavity visualization score has to be at least 3 in order to minimize the interobserver variations of target definition. (3) At delineation of surgical cavity only the homogeneous part of the postoperative seroma has to be included in the contours and protrusions or sharp irregularities have to be excluded. When surgical clips are present, they have to be surrounded by the contour with close contact. (4) CTV is created from the outlined surgical cavity with a nonisotropic geometrical extension. In each direction the safety margin is calculated by taking into account the size of the free resection margin. The total size of safety margin is always 20mm which is the sum of the surgical and added safety margins. CTV is limited to chest wall/pectoral muscles and 5mm below the skin surface.

CONCLUSION

Following these guidelines the target volume definition in breast brachytherapy after open cavity surgery is expected to be accomplished in more consistent way with low interobserver variations.

Prediction of breast cancer risk based on profiling with common genetic variants

BACKGROUND

Data for multiple common susceptibility alleles for breast cancer may be combined to identify women at different levels of breast cancer risk. Such stratification could guide preventive and screening strategies. However, empirical evidence for genetic risk stratification is lacking.

METHODS

We investigated the value of using 77 breast cancer-associated single nucleotide polymorphisms (SNPs) for risk stratification, in a study of 33 673 breast cancer cases and 33 381 control women of European origin. We tested all possible pair-wise multiplicative interactions and constructed a 77-SNP polygenic risk score (PRS) for breast cancer overall and by estrogen receptor (ER) status. Absolute risks of breast cancer by PRS were derived from relative risk estimates and UK incidence and mortality rates.

RESULTS

There was no strong evidence for departure from a multiplicative model for any SNP pair. Women in the highest 1% of the PRS had a three-fold increased risk of developing breast cancer compared with women in the middle quintile (odds ratio [OR] = 3.36, 95% confidence interval [CI] = 2.95 to 3.83). The ORs for ER-positive and ER-negative disease were 3.73 (95% CI = 3.24 to 4.30) and 2.80 (95% CI = 2.26 to 3.46), respectively. Lifetime risk of breast cancer for women in the lowest and highest quintiles of the PRS were 5.2% and 16.6% for a woman without family history, and 8.6% and 24.4% for a woman with a first-degree family history of breast cancer.

CONCLUSIONS

The PRS stratifies breast cancer risk in women both with and without a family history of breast cancer. The observed level of risk discrimination could inform targeted screening and prevention strategies. Further discrimination may be achievable through combining the PRS with lifestyle/environmental factors, although these were not considered in this report.

Genome-wide association analysis of more than 120,000 individuals identifies 15 new susceptibility loci for breast cancer

Genome-wide association studies (GWAS) and large-scale replication studies have identified common variants in 79 loci associated with breast cancer, explaining ∼14% of the familial risk of the disease. To identify new susceptibility loci, we performed a meta-analysis of 11 GWAS, comprising 15,748 breast cancer cases and 18,084 controls together with 46,785 cases and 42,892 controls from 41 studies genotyped on a 211,155-marker custom array (iCOGS). Analyses were restricted to women of European ancestry. We generated genotypes for more than 11 million SNPs by imputation using the 1000 Genomes Project reference panel, and we identified 15 new loci associated with breast cancer at P < 5 × 10(-8). Combining association analysis with ChIP-seq chromatin binding data in mammary cell lines and ChIA-PET chromatin interaction data from ENCODE, we identified likely target genes in two regions: SETBP1 at 18q12.3 and RNF115 and PDZK1 at 1q21.1. One association appears to be driven by an amino acid substitution encoded in EXO1.

Fine-scale mapping of the 5q11.2 breast cancer locus reveals at least three independent risk variants regulating MAP3K1

Genome-wide association studies (GWASs) have revealed SNP rs889312 on 5q11.2 to be associated with breast cancer risk in women of European ancestry. In an attempt to identify the biologically relevant variants, we analyzed 909 genetic variants across 5q11.2 in 103,991 breast cancer individuals and control individuals from 52 studies in the Breast Cancer Association Consortium. Multiple logistic regression analyses identified three independent risk signals: the strongest associations were with 15 correlated variants (iCHAV1), where the minor allele of the best candidate, rs62355902, associated with significantly increased risks of both estrogen-receptor-positive (ER(+): odds ratio [OR] = 1.24, 95% confidence interval [CI] = 1.21-1.27, ptrend = 5.7 × 10(-44)) and estrogen-receptor-negative (ER(-): OR = 1.10, 95% CI = 1.05-1.15, ptrend = 3.0 × 10(-4)) tumors. After adjustment for rs62355902, we found evidence of association of a further 173 variants (iCHAV2) containing three subsets with a range of effects (the strongest was rs113317823 [pcond = 1.61 × 10(-5)]) and five variants composing iCHAV3 (lead rs11949391; ER(+): OR = 0.90, 95% CI = 0.87-0.93, pcond = 1.4 × 10(-4)). Twenty-six percent of the prioritized candidate variants coincided with four putative regulatory elements that interact with the MAP3K1 promoter through chromatin looping and affect MAP3K1 promoter activity. Functional analysis indicated that the cancer risk alleles of four candidates (rs74345699 and rs62355900 [iCHAV1], rs16886397 [iCHAV2a], and rs17432750 [iCHAV3]) increased MAP3K1 transcriptional activity. Chromatin immunoprecipitation analysis revealed diminished GATA3 binding to the minor (cancer-protective) allele of rs17432750, indicating a mechanism for its action. We propose that the cancer risk alleles act to increase MAP3K1 expression in vivo and might promote breast cancer cell survival.

The role of genetic breast cancer susceptibility variants as prognostic factors

Recent genome-wide association studies identified 11 single nucleotide polymorphisms (SNPs) associated with breast cancer (BC) risk. We investigated these and 62 other SNPs for their prognostic relevance. Confirmed BC risk SNPs rs17468277 (CASP8), rs1982073 (TGFB1), rs2981582 (FGFR2), rs13281615 (8q24), rs3817198 (LSP1), rs889312 (MAP3K1), rs3803662 (TOX3), rs13387042 (2q35), rs4973768 (SLC4A7), rs6504950 (COX11) and rs10941679 (5p12) were genotyped for 25 853 BC patients with the available follow-up; 62 other SNPs, which have been suggested as BC risk SNPs by a GWAS or as candidate SNPs from individual studies, were genotyped for replication purposes in subsets of these patients. Cox proportional hazard models were used to test the association of these SNPs with overall survival (OS) and BC-specific survival (BCS). For the confirmed loci, we performed an accessory analysis of publicly available gene expression data and the prognosis in a different patient group. One of the 11 SNPs, rs3803662 (TOX3) and none of the 62 candidate/GWAS SNPs were associated with OS and/or BCS at P<0.01. The genotypic-specific survival for rs3803662 suggested a recessive mode of action [hazard ratio (HR) of rare homozygous carriers=1.21; 95% CI: 1.09-1.35, P=0.0002 and HR=1.29; 95% CI: 1.12-1.47, P=0.0003 for OS and BCS, respectively]. This association was seen similarly in all analyzed tumor subgroups defined by nodal status, tumor size, grade and estrogen receptor. Breast tumor expression of these genes was not associated with prognosis. With the exception of rs3803662 (TOX3), there was no evidence that any of the SNPs associated with BC susceptibility were associated with the BC survival. Survival may be influenced by a distinct set of germline variants from those influencing susceptibility.

Recommendations from Gynaecological (GYN) GEC-ESTRO Working Group (IV): Basic principles and parameters for MR imaging within the frame of image based adaptive cervix cancer brachytherapy

The GYN GEC-ESTRO working group issued three parts of recommendations and highlighted the pivotal role of MRI for the successful implementation of 3D image-based cervical cancer brachytherapy (BT). The main advantage of MRI as an imaging modality is its superior soft tissue depiction quality. To exploit the full potential of MRI for the better ability of the radiation oncologist to make the appropriate choice for the BT application technique and to accurately define the target volumes and the organs at risk, certain MR imaging criteria have to be fulfilled. Technical requirements, patient preparation, as well as image acquisition protocols have to be tailored to the needs of 3D image-based BT. The present recommendation is focused on the general principles of MR imaging for 3D image-based BT.

Methods and parameters have been developed and progressively validated from clinical experience from different institutions (IGR, Universities of Vienna, Leuven, Aarhus and Ljubljana) and successfully applied during expert meetings, contouring workshops, as well as within clinical and interobserver studies.

It is useful to perform pelvic MRI scanning prior to radiotherapy (“Pre-RT-MRI examination”) and at the time of BT (“BT MRI examination”) with one MR imager. Both low and high-field imagers, as well as both open and close magnet configurations conform to the requirements of 3D image-based cervical cancer BT. Multiplanar (transversal, sagittal, coronal and oblique image orientation) T2-weighted images obtained with pelvic surface coils are considered as the golden standard for visualisation of the tumour and the critical organs. The use of complementary MRI sequences (e.g. contrast-enhanced T1-weighted or 3D isotropic MRI sequences) is optional. Patient preparation has to be adapted to the needs of BT intervention and MR imaging. It is recommended to visualise and interpret the MR images on dedicated DICOM-viewer workstations, which should also assist the contouring procedure. Choice of imaging parameters and BT equipment is made after taking into account aspects of interaction between imaging and applicator reconstruction, as well as those between imaging, geometry and dose calculation.

In a prospective clinical context, to implement 3D image-based cervical cancer brachytherapy and to take advantage of its full potential, it is essential to successfully meet the MR imaging criteria described in the present recommendations of the GYN GEC-ESTRO working group.