Phase I study of cetuximab in combination with 5-fluorouracil, mitomycin C and radiotherapy in patients with locally advanced anal cancer

Stability of metabolic tumor volume may enable radiotherapy dose painting in anal cancer

PURPOSE

To evaluate the variability of the 18F-FDG-PET/CT-based metabolic tumor volume (MTV) in anal cancers during fractionated chemoradiotherapy (CRT), and assess the impact of this variability on dosimetric accuracy in MTV-targeted dose painting.

METHODS

Eleven patients with anal squamous cell carcinoma who received fractionated chemoradiotherapy with curative intent were included. 18F-FDG PET/CT images were acquired at pre- and mid-treatment. Target volumes and organs at risk (OARs) were contoured manually on both image series. The MTV was generated from the PET images by thresholding. Treatment plans were retrospectively optimized for both image series using volumetric modulated arc therapy (VMAT). Standard plans prescribed 48.6 Gy, 54 Gy and 57.5 Gy in 27 fractions to elective regions, lymph node metastases and primary tumor, respectively. Dose painting plans included an extra dose level of 65 Gy to the MTV. Pre-treatment plans were transferred and re-calculated at mid-treatment basis.

RESULTS

MTV decreased from pre- to mid-treatment in 10 of the 11 patients. On average, 71 % of MTVmid overlapped with MTVpre. The median and mean doses to the MTV were robust against anatomical changes, but the transferred dose painting plans had lower D98% values than the original and re-optimized plans. No major differences were found between standard and dose painting plans for OARs.

CONCLUSIONS

Despite volumetric changes in the MTV, adequate dose coverage was observed in most dose painting plans. The findings indicate little or no need for adaptive dose painting at mid-treatment. Dose painting appears to be a safe treatment alternative with similar dose sparing of OARs.

Panitumumab in combination with chemoradiotherapy for the treatment of locally-advanced anal canal carcinoma: Results of the FFCD 0904 phase II trial

BACKGROUND AND PURPOSE

Standard treatment of squamous cell carcinoma of the anus (SCCA)is 5-fluorouracil (5FU) and mitomycin C (MMC) based chemoradiotherapy (CRT). This phase II study (EudraCT: 2011-005436-26) assessed the tolerance and complete response (CR) rate at 8 weeks of panitumumab (Pmab) combined with MMC-5FU-based CRT.

METHODS

Patients with locally advanced tumors without metastases (T2 > 3 cm, T3-T4, or N + whatever T stage) were treated with IMRT up to 65 Gy and concomitant CT according to the doses defined by a previous phase I study (MMC: 10 mg/m2; 5FU: 400 mg/m2; Pmab: 3 mg/kg). The expected CR rate was 80%.

RESULTS

Forty-five patients (male: 9, female: 36; median age: 60.1 [41.5-81]) were enrolled in 15 French centers. The most common related grade 3-4 toxicities observed were digestive (51.1%), hematologic (lymphopenia: 73.4%; neutropenia: 11.1%), radiation dermatitis (13.3%), and asthenia (11.1%) with RT interruption in 14 patients. One patient died because of mesenteric ischemia during the CRT, possibly related to treatment. In ITT analysis, the CR rate at 8 weeks after CRT was 66.7% [90%CI: 53.4-78.2]. Median follow-up was 43.6 months [IC 95%: 38.61-47.01]. Overall survival, recurrence-free and colostomy-free survival at 3 years were 80% [95%CI: 65.1-89], 62.2% [IC95%: 46.5-74.6] and 68.8 % [IC95%: 53.1-80.2] respectively.

CONCLUSION

Panitumumab in combination with CRT for locally advanced SCCA failed to meet the expected CR rate and exhibited a poor tolerance. Furthermore, late RFS, CFS, and OS did not suggest any outcome improvement to justify further clinical trials.

CLINICALTRIALS

gov identifier: NCT01581840.

Nordic anal cancer (NOAC) group consensus guidelines for risk-adapted delineation of the elective clinical target volume in anal cancer

Background: To date, anal cancer patients are treated with radiotherapy to similar volumes despite a marked difference in risk profile based on tumor location and stage. A more individualized approach to delineation of the elective clinical target volume (CTVe) could potentially provide better oncological outcomes as well as improved quality of life. The aim of the present work was to establish Nordic Anal Cancer (NOAC) group guidelines for delineation of the CTVe in anal cancer.Methods: First, 12 radiation oncologists reviewed the literature in one of the following four areas: (1) previous delineation guidelines; (2) patterns of recurrence; (3) anatomical studies; (4) common iliac and para-aortic recurrences and delineation guidelines. Second, areas of controversy were identified and discussed with the aim of reaching consensus.Results: We present consensus-based recommendations for CTVe delineation in anal cancer regarding (a) which regions to include, and (b) how the regions should be delineated. Some of our recommendations deviate from current international guidelines. For instance, the posterolateral part of the inguinal region is excluded, decreasing the volume of irradiated normal tissue. For the external iliac region and the cranial border of the CTVe, we agreed on specifying two different recommendations, both considered acceptable. One of these recommendations is novel and risk-adapted; the external iliac region is omitted for low-risk patients, and several different cranial borders are used depending on the individual level of risk.Conclusion: We present NOAC consensus guidelines for delineation of the CTVe in anal cancer, including a risk-adapted strategy.

The Role of Immunotherapy in the Treatment of Anal Cancer and Future Strategies

OPINION STATEMENT

Despite being markedly sensitive to chemoradiotherapy, patients with locally advanced (T3-4 and/or node-positive) squamous cell carcinoma of the anal canal (SCCA) still present high rates of disease recurrence, which is characterized by meaningful morbidity and mortality. Abdominoperineal resection as salvage surgery may be considered for patients with local recurrence, but with an important negative impact in the quality of life. Systemic therapy of advanced SCCA is an unmet clinical need. Palliative chemotherapy for the management of unresectable or metastatic disease yields approximately 60% of objective response rate; however, it still portends a grim prognosis. Based on the recently published InterAACT trial, carboplatin plus paclitaxel has become the standard of care of advanced disease; modified DCF (docetaxel, cisplatin, and 5-fluorouracil) may also be considered for fit patients amenable to intensive therapy. There are no FDA-approved therapies for the treatment of chemorefractory patients. Nevertheless, both nivolumab and pembrolizumab may be considered for these patients with promising results, regardless of PD-L1 expression or other predictive biomarkers. It is estimated that approximately 1 out of 5 patients with SCCA will derive large benefit from PD-1 inhibitors, which may produce considerable durations of response. Ongoing clinical trials exploring the combination of chemotherapy plus immune checkpoint inhibitors in the first-line therapy, combination of anti-PD-1/PD-L1 plus anti-CTLA-4, and emerging immunotherapeutic approaches, such as adoptive T cell therapies, are eagerly awaited and may bring practice-changing results in the next few years for the treatment of this challenging disease.

Dosimetric and Clinical Predictors for Acute and Late Gastrointestinal Toxicity Following Chemoradiotherapy of Locally Advanced Anal Cancer

AIMS

To analyse dosimetric and clinical predictors for acute and late gastrointestinal toxicity following chemoradiotherapy of anal cancer.

MATERIALS AND METHODS

Consecutive patients with locally advanced (T2 ≥4 cm - T4 or N+) anal cancer were selected from an institutional database (n = 114). All received intensity-modulated radiotherapy with concomitant 5-fluorouracil and mitomycin C. Gastrointestinal toxicity was retrospectively graded according to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 and bowel cavity, small bowel and large bowel were contoured. Dosimetric and clinical variables were tested for associations with acute grade ≥3 gastrointestinal toxicity and late grade ≥2 gastrointestinal toxicity using the Mann-Whitney test, area under receiver operating characteristic curve (AUC) and logistic regression.

RESULTS

The median follow-up was 40 months. Acute grade ≥3 gastrointestinal toxicity was seen in 51 (44.7%) of the patients; late grade ≥2 gastrointestinal toxicity was seen in 36 of the patients (39.6% of 91 patients with >1 year recurrence-free follow-up). Bowel cavity V30Gy was the best dosimetric predictor for acute gastrointestinal toxicity (AUC 0.633; P = 0.02). Large bowel V20Gy was the best dosimetric predictor for late gastrointestinal toxicity (AUC 0.698; P = 0.001) but showed no association with acute gastrointestinal toxicity. In multivariate logistic regression, increasing age was significantly associated with acute gastrointestinal toxicity; smoking and large bowel V20Gy were significantly associated with late gastrointestinal toxicity. Patients who experienced acute grade ≥3 gastrointestinal toxicity were not at an increased risk of late grade ≥2 gastrointestinal toxicity (odds ratio 1.3; P = 0.55).

CONCLUSIONS

Factors of importance for acute and late gastrointestinal toxicity were not the same. Bowel cavity V30Gy is a good metric to use for the prediction of acute gastrointestinal toxicity, but the results of our study indicate that individual large and small bowel loops need to be contoured for better prediction of late gastrointestinal toxicity. The role of the large bowel as an important organ at risk for late gastrointestinal toxicity merits further research.

Treatment of Squamous Cell Carcinoma of the Anus, Unresolved Areas and Future Perspectives for Research: Perspectives of Research Needs in Anal Cancer

Anal cancer is a relatively rare, mostly HPV-related cancer. The curative treatment consists of concurrent chemoradiation delivered with modern radiotherapy techniques. The prognosis for most patients with early localized disease is very favourable; however patients with locally advanced disease and/or HPV negative tumours are at higher risk of locoregional and distant treatment failure. Tailored approaches are presently being investigated to determine the most suitable regimen in terms of radiotherapy dose prescription, target volume selection, normal tissue avoidance, and combination therapy. Metastatic anal cancer is treated with chemotherapy aiming at prolonged survival. The role of immune therapy in the clinical setting is being investigated. There is little knowledge on the biology of anal cancer, and an urgent need for more clinical and translational research dedicated to this disease. In this article, the evidence-base for the current treatment is briefly reviewed, and perspectives on future research needs are high-lighted.

Treatment outcomes and prognostic factors after chemoradiotherapy for anal cancer

BACKGROUND

Squamous cell carcinoma of the anus (SCCA) is a rare malignancy with rising incidence, associated with human papilloma virus (HPV). Chemoradiotherapy (CRT) is the preferred treatment. The purpose was to investigate treatment failure, survival and prognostic factors after CRT.

MATERIAL AND METHODS

In this prospective observational study from a large regional centre, 141 patients were included from 2013 to 2017, and 132 were eligible for analysis. The main inclusion criteria were SCCA, planned radiotherapy, and performance status (ECOG) ≤2. Patient characteristics, disease stage, treatment, and treatment response were prospectively registered. Disease-free survival (DFS), overall survival (OS), and locoregional treatment failure after CRT were analysed. Hazard ratios (HRs) were estimated with Cox`s proportional hazards model.

RESULTS

Median follow-up was 54 (range 6-71) months. Eighteen patients (14%) had treatment failures after CRT; of these 10 (8%) had residual tumour, and 8 (6%) relapse as first failure. The first treatment failure was locoregional (11 patients), distant (5 patients), and both (2 patients). Salvage abdomino-perineal resection was performed in 10 patients, 2 had resections of metastases, and 3 both. DFS was 85% at 3 years and 78% at 5 years. OS was 93% at 3 years and 86% at 5 years. In analyses adjusted for age and gender, HPV negative tumours (HR 2.5, p = 0.024), N3 disease (HR 2.6, p = 0.024), and tumour size ≥4 cm (HR 2.4, p = 0.038) were negative prognostic factors for DFS.

CONCLUSION

State-of-the-art chemoradiotherapy for SCCA resulted in excellent outcomes, and improved survival compared with previous national data, with <15% treatment failures and a 3-year DFS of >80%.

Improved treatment outcome and lower skin toxicity with intensity-modulated radiotherapy vs. 3D conventional radiotherapy in anal cancer

PURPOSE

Radiochemotherapy is the standard treatment for anal carcinoma (ACa). Intensity-modulated radiotherapy (IMRT) has been introduced, allowing focused irradiation of the tumor area. Whether physical benefits of IMRT translate to clinical benefits has not been sufficiently demonstrated.

METHODS

We retrospectively reviewed data from 82 patients with newly diagnosed ACa. Patients treated with IMRT were compared with previous patients treated with conventional three-dimensional computational radiotherapy (3D-CRT). The influence of IMRT on complete remission and acute and chronic side effects was analyzed in univariate and multivariate analyses.

RESULTS

39/40 patients treated with IMRT were in complete remission after 1 year compared to 31/39 patients treated with 3D-CRT (p = 0.014). Multivariate analysis confirmed tumor T stage as well as lack of IMRT treatment as risk factors for persistent tumor at 6 months. No significant benefits of IMRT were apparent at later timepoints (median follow up 52 months, IQR: 31.5-71.8 months). Patients treated with IMRT had a significantly lower degree of skin toxicity (median 2 vs. 3 in a scale ranging from 0 to 3, p = 0.00092). Rates of hematological toxicity/proctitis were not reduced and rates of acute diarrhea increased (p = 0.034). Median length of hospitalization tended to be shorter in patients treated with IMRT (n. s.).

CONCLUSION

We present a real-world experience of shifting radiation technique from conventional 3D-CRT to IMRT. IMRT patients had better tumor control at 1 year and lower degrees of skin toxicity. Our data indicate that IMRT can enable therapies with lower side effects with equal or better oncological results for patients with ACa.

VITAL phase 2 study: Upfront 5-fluorouracil, mitomycin-C, panitumumab and radiotherapy treatment in nonmetastatic squamous cell carcinomas of the anal canal (GEMCAD 09-02)

Aim

VITAL, a phase II single‐arm study, aimed to evaluate efficacy and safety of panitumumab addition to 5‐fluorouracil (5‐FU), mitomycin‐C (MMC) and radiotherapy (RT) in patients with localized squamous cell carcinoma of the anal canal (SCCAC).

Methods

Adult, treatment‐naïve SCCAC patients (Stage T2‐T4, any N, M0) and ECOG‐PS ≤2, received panitumumab (6 mg/kg, day 1 and Q2W; 8 weeks), 5‐FU (1000 mg/m²/d, days 1‐4 and 29‐32), MMC (10 mg/m², days 1 and 29) and RT 45 Gy (1.8 Gy/fraction) to the primary tumor and mesorectal, iliac and inguinal lymph nodes, plus 10‐15 Gy boost dose to the primary tumor and affected lymph nodes. The primary objective was disease free survival rate (DFS) at 3‐years (expected 3‐year DFS rate: 73.7 ± 12%).

Results

Fifty‐eight patients (31 women; median age: 59 years; ECOG‐PS 0‐1:98%; TNM II [29%] (T2 or T3/N0/M0)/IIIA (T1‐T3/N1/M0 or T4/N0/M0) [21%]/IIIB (T4/N1/M0 or any T/N2 or N3/M0) [47%]/nonevaluable [4%]) were included. The median follow‐up was 45 months. The 3‐year DFS rate was 61.1% (95% CI: 47.1, 72.4). The 3‐year overall survival rate was 78.4% (95% CI: 65.1, 87.1). Eighteen patients (31.0%) required a colostomy within 2 years posttreatment. Grade 3‐4 toxicities were experienced by 53 (91%) patients. Most common grade 3‐4 treatment‐related events were radiation skin injury (40%) and neutropenia (24%). No toxic deaths occurred. Improved efficacy in colostomy‐free survival and complete response rate was observed in human papilloma virus positive patients.

Conclusions

Panitumumab addition to MMC‐5FU regimen in SCCAC patients increases toxicity and does not improve patients’ outcomes. RT plus MMC‐5FU remains the standard of care for localized SCCAC patients.

Relapsed refractory metastatic squamous cell cancer of anal canal in a patient with retroviral infection responding to cetuximab

INTRODUCTION

Conventional first-line therapy for squamous cell carcinoma of anal canal is definitive chemoradiotherapy with a curative intent. Due to the efficacy of treatment for locoregional disease and rarity of metastatic anal carcinoma, clinical trial data for treatment of metastatic disease is lacking.

CASE REPORT

Herein, we describe a patient with relapsed, metastatic squamous cell carcinoma of the anal canal treated with cetuximab as the third-line therapy. Management and outcome: The patient responded to this pharmacological agent, meeting the definition of a partial response per response evaluation criteria in solid tumors (RECIST).

DISCUSSION

EGFR inhibitors are potential avenues for the subsequent lines of therapy in metastatic or relapsed/refractory anal cancer. Prospective clinical trials of cetuximab alone or in combination with other agents are warranted in this setting in the future.

[Anal channel cancer: customization of dose, volume and breaching]

The conservative treatment of squamous cell carcinoma of anal canal by irradiation is recommended as first indication. Despite its rarity, significant improvements were obtained by retrospective or prospective clinical studies these 20 past years, evaluating concomitant chemotherapy and IMRT. Nevertheless, the individualisation of the treatment, over dose distribution, has poor data available. Fractionation remains classic (1.8-2.0Gy/Fr), but the optimal dose level remains under discussion. The strategy concerning the volumes and doses for the prophylactic volumes remains under discussion. This paper will describe the data published, and the recommendations of working Groups, and the main options under evaluation. To conclude, today only the absence of gap is recommended, the benefit of a one-step schedule reducing the treatment time, then increasing local control and survival, but personalised schedules remain under investigation.

Anti-epidermal growth factor receptor therapy in combination with chemoradiotherapy for the treatment of locally advanced anal canal carcinoma: Results of a phase I dose-escalation study with panitumumab (FFCD 0904)

BACKGROUND AND PURPOSE

Standard treatment of epidermoid anal cancer is 5-fluorouracil (5FU) and mitomycin C (MMC) based chemoradiotherapy (CRT). This phase I study aims to evaluate the addition of panitumumab (Pmab) to CRT and to determine the maximum tolerated dose (MTD) of Pmab and 5-FU in combination with CRT.

MATERIALS AND METHODS

Immunocompetent patients with locally advanced tumour without metastases (Stage T2, T3 or T4, whatever N stage; Stage N1-N3 whatever T stage) followed two RT periods (45 Gy in 5 weeks and 20 Gy in 2 weeks, separated by a 2-week break) with concomitant CT sessions of 5FU/MMC at RT weeks 1, 5 and 8. Pmab was administered on RT weeks 1, 3, 5, 8 and 10 according to a predefined dose escalation schedule.

RESULTS

Ten patients were enroled. One was excluded due to unmet dose constraints respect. Three patients received dose level (DL) 0 (Pmab 3 mg/kg + 5FU 600 mg/m²/day) and six received DL-1 (Pmab 3 mg/kg + 5FU 400 mg/m²/day). Dose-limiting toxicities occurred in all patients at DL 0 and 2 at DL-1. Most common grade 3-4 toxicities observed at DL 0 were haematologic (100%), dermatitis (67%), and anaemia (67%). No death occurred. Four months after ending CRT, five and two patients had a local complete response and a partial response, respectively. One patient had a colostomy with abdomino-perineal amputation due to a tumour recurrence.

CONCLUSIONS

The MTD is 5FU at 400 mg/m²/day, MMC at 10 mg/m² and Pmab at 3 mg/kg. The effect of the MTD on tumour response is evaluated in the phase 2 study.

The Management and Prevention of Anal Squamous Cell Carcinoma

Our aim is to discuss the current established management of care and associated prevention strategies of anal squamous cell carcinoma (SCCA). In general, the development of SCCA is commonly linked to a prior history of HPV. Unfortunately, HPV vaccination continues to be underutilized in the United States versus other countries. Increased acknowledgment of the importance of HPV vaccination as an anticancer vaccine should be encouraged. The present standard of care is primary chemoradiotherapy (CRT), which results in a high level of disease control for small, early-stage SCCA. More advanced cancers still fare poorly with this treatment, and the disease relapses locoregionally in the majority of cases (30%-50% of patients), resulting in an abdominoperineal resection. Current treatment recommendations are associated with substantial morbidity; alternative radiation doses and/or novel combinations of agents with CRT are needed to improve quality of life and oncologic outcomes. Cytotoxic chemotherapy remains the standard of care for treatment-naïve patients with metastatic disease, with a possible new treatment paradigm of carboplatin/weekly paclitaxel. In addition, immune checkpoint inhibition appears to have a promising role in the setting of patients with refractory disease. Several clinical trials with immunotherapeutic and vaccine approaches for locally advanced and metastatic anal cancer are ongoing, as are HPV-agnostic umbrella trials. Whenever possible, clinical trial enrollment is always encouraged for further therapeutic development in the setting of a rare cancer, given the potentially substantial global impact for other HPV-associated malignancies.

Experimental and investigational drugs for the treatment of anal cancer

INTRODUCTION

Squamous cell carcinoma of the anal canal (SCCA) is a rare malignancy, but its incidence rates have been increasing in the last decade. Studies have demonstrated that up to 47% of patients with locally advanced disease have high-risk features for treatment failure. The potential high rates of recurrence after standard chemoradiotherapy for locally advanced disease and the lack of established care for metastatic disease have created an urgent need for the evaluation of new drugs that will ultimately improve the efficacy of treatment.

AREAS COVERED

This review presents results of recent phase-I and -II clinical trials which evaluate novel therapeutic modalities. The review also describes the findings of comprehensive genomic profiling studies which provide insights for promising therapeutics.

EXPERT OPINION

HPV vaccination is underutilized in the United States and as a result, HPV-associated malignancies are likely to continue for several decades; however, pivotal breakthroughs may create a foundation for distinctive treatment approaches for other HPV-associated malignancies for which no other standard of care exists.

Systematic review of outcome measures following chemoradiotherapy for the treatment of anal cancer (CORMAC)

AIM

Six Phase III randomized trials have determined the effectiveness of chemoradiotherapy as primary treatment for anal squamous cell carcinoma (ASCC), but outcomes reported in these trials varied widely, hindering evidence synthesis. To improve reporting in all future trials, we aim to develop a core outcomes set (COS). As the first stage of COS development, we undertook a systematic review to summarize the outcomes reported in studies evaluating chemoradiotherapy for ASCC.

METHOD

Systematic literature searches identified studies evaluating radiotherapy or chemoradiotherapy for ASCC. Outcomes and accompanying definitions were extracted verbatim and categorized into domains.

RESULTS

From 5170 abstracts, we identified 95 eligible studies, reporting 1192 outcomes and 533 unique terms. We collapsed these terms into 86 standardized outcomes and five domains: survival; disease activity; life impact [including quality of life (QoL)]; delivery of care; and toxicity. The most commonly reported domains were survival and disease activity, reported in 74 (86%) and 54 (62%) studies, respectively. No outcome was reported in every publication. Over half (43/86) of the standardized outcome terms were reported in fewer than five studies, and 21 (25%) were reported in a single study only. There was wide variation in definitions of disease-free survival, colostomy-free survival and progression-free survival (PFS). Anal continence was reported in only 35 (41%) studies.

CONCLUSION

Outcomes reported in studies evaluating chemoradiotherapy for ASCC were heterogenous and definitions varied widely. Outcomes likely to be important to patients, such as ano-rectal function, toxicity and QoL, have been neglected. A COS for future trials will address these issues.

Evolution and Management of Treatment-Related Toxicity in Anal Cancer

Over the past several decades, clinical trials have demonstrated improved disease-related outcomes in the definitive treatment of anal cancer. Although treatment with radiation and concurrent chemotherapy results in high rates of cure, significant acute and late toxicities are seen. This review focuses on the evolution of treatment-related toxicity for anal cancer. Management of these adverse effects is reviewed, as are future directions in anal cancer treatment and their impact on toxicity.

Treatment of squamous cell carcinoma of the anal canal: A new strategies with anti-EGFR therapy and immunotherapy

The incidence of squamous cell carcinoma of the anal canal (SCAC) is increasing in both sexes but the standard treatment remains that of 20 years ago. However, interesting data have recently emerged on the use of anti-epidermal growth factor receptor (EGFR) agents and immunotherapy in advanced disease. Thus, new avenues of research are opening up that will hopefully lead to more effective therapeutic strategies. We provide an overview of the latest studies published on this tumor and discuss the possible future therapeutic options for combination therapy, anti-EGFR treatment and radiotherapy.

Target volume delineation of anal cancer based on magnetic resonance imaging or positron emission tomography

Purpose

To compare target volume delineation of anal cancer using positron emission tomography (PET) and magnetic resonance imaging (MRI) with respect to inter-observer and inter-modality variability.

Methods

Nineteen patients with anal cancer undergoing chemoradiotherapy were prospectively included. Planning computed tomography (CT) images were co-registered with 18F–fluorodexocyglucose (FDG) PET/CT images and T2 and diffusion weighted (DW) MR images. Three oncologists delineated the Gross Tumor Volume (GTV) according to national guidelines and the visible tumor tissue (GTV_T). MRI and PET based delineations were evaluated by absolute volumes and Dice similarity coefficients.

Results

The median volume of the GTVs was 27 and 31 cm³ for PET and MRI, respectively, while it was 6 and 11 cm³ for GTV_T. Both GTV and GTV_T volumes were highly correlated between delineators (r = 0.90 and r = 0.96, respectively). The median Dice similarity coefficient was 0.75 when comparing the GTVs based on PET/CT (GTV_PET) with the GTVs based on MRI and CT (GTV_MRI). The median Dice coefficient was 0.56 when comparing the visible tumor volume evaluated by PET (GTV_{T_PET}) with the same volume evaluated by MRI (GTV_{T_MRI}). Margins of 1–2 mm in the axial plane and 7–8 mm in superoinferior direction were required for coverage of the individual observer’s GTVs.

Conclusions

The rather good agreement between PET- and MRI-based GTVs indicates that either modality may be used for standard target delineation of anal cancer. However, larger deviations were found for GTV_T, which may impact future tumor boost strategies.

Volumetric modulated arc therapy for treatment of solid tumors: current insights

Aim

This article discusses the current use of volumetric modulated arc therapy (VMAT) techniques in clinical practice and reviews the available data from clinical outcome studies in different clinical settings. An overview of available literature about clinical outcomes with VMAT stereotactic/radiosurgical treatment is also reported.

Materials and methods

All published manuscripts reporting the use of VMAT in a clinical setting from 2009 to November 2016 were identified. The search was carried out in December 2016 using the National Library of Medicine (PubMed/Medline). The following words were searched: “volumetric arc therapy”[All Fields] OR “vmat”[All Fields] OR “rapidarc”[All Fields], AND “radiotherapy”[All Fields] AND “Clinical Trial”[All Fields].

Results

Overall, 37 studies (21 prospective and 16 retrospective) fulfilling inclusion criteria and thus included in the review evaluated 2,029 patients treated with VMAT; of these patients, ~30.8% had genitourinary (GU) tumors (81% prostate, 19% endometrial), 26.2% head-and-neck cancer (H&NC), 13.9% oligometastases, 11.2% had anorectal cancer, 10.6% thoracic neoplasms (81% breast, 19% lung), and 7.0% brain metastases (BMs). Six different clinical scenarios for VMAT use were identified: 1) BMs, 2) H&NC, 3) thoracic neoplasms, 4) GU cancer, 5) anorectal tumor, and 6) stereotactic body radiation therapy (SBRT) performed by VMAT technique in the oligometastatic patient setting.

Conclusion

The literature addressing the clinical appropriateness of VMAT is scarce. Current literature suggests that VMAT, especially when used as simultaneous integrated boost or SBRT strategy, is an effective safe modality for all cancer types.

Therapeutic options for treatment of human papillomavirus-associated cancers - novel immunologic vaccines: ADXS11-001

Survival of patients with advanced, recurrent, or metastatic human papillomavirus (HPV)-associated cancer is suboptimal despite the availability of various treatment modalities. The recently developed bacterial vector Listeria monocytogenes (Lm) activates innate and adaptive immune responses and is expected to offer immunologic advantages. Axalimogene filolisbac (AXAL or ADXS11-001) is a novel immunotherapeutic based on the live, irreversibly attenuated Lm fused to the nonhemolytic fragment of listeriolysin O (Lm-LLO) and secretes the Lm-LLO-HPV E7 fusion protein targeting HPV-positive tumors. Herein are reported the development and recent results of various clinical trials in patients with HPV-associated cervical, head and neck, and anal cancers.

Significance of Co-expression of Epidermal Growth Factor Receptor and Ki67 on Clinical Outcome in Patients With Anal Cancer Treated With Chemoradiotherapy: An Analysis of NRG Oncology RTOG 9811

PURPOSE

To measure co-expression of EGFR and Ki67 proteins in pretreatment tumor biopsies of anal cancer patients enrolled on NRG Oncology RTOG 9811, a phase III trial comparing 5-fluorouracil/mitomycin-C/radiation therapy (Arm A) versus 5-fluorouracil/cisplatin/radiation therapy (Arm B), and to correlate expression with clinical outcome.

METHODS AND MATERIALS

EGFR and Ki67 co-expression was measured after constructing a tissue microarray using fluorescence immunohistochemistry and automated quantitative image analysis. The Ki67 score within EGFR high versus low areas (Ki67ratio in EGFRhigh:low) in each tumor core was analyzed at the median, quartiles, and as a continuous variable. Associations between the tumor markers and clinical endpoints (overall and disease-free survival, locoregional and colostomy failure, and distant metastases) were explored.

RESULTS

A total of 282 pretreatment tumors were analyzed from NRG Oncology RTOG 9811. Of evaluated specimens, 183 (65%, n=89, Arm A; n=94, Arm B) were eligible and analyzable. There were no significant differences in baseline characteristics or outcomes between analyzable and unanalyzable patient cases. Median follow-up was 6.0 years. On multivariate analysis, after adjusting for gender, patients with Ki67ratio in EGFRhigh:low ≥median had worse overall survival (hazard ratio 2.41, 95% confidence interval 1.38-4.19, P=.0019). After adjusting for N stage and largest tumor dimension, patients with Ki67ratio in EGFRhigh:low ≥ median had a higher risk of a disease-free failure (hazard ratio 1.85, 95% confidence interval 1.18-2.92, P=.0078). Technical validation with an independent anal cancer patient cohort was performed and shows a very similar biomarker score distribution.

CONCLUSIONS

High Ki67ratio in EGFRhigh:low is associated with worse clinical outcome in this subset of patients with anal cancer treated with chemoradiation on NRG Oncology RTOG 9811. Evaluation within a clinical trial will be required to determine whether patients with these tumor characteristics may specifically benefit from an EGFR-targeted therapeutic agent.

Cetuximab Plus Chemoradiotherapy in Immunocompetent Patients With Anal Carcinoma: A Phase II Eastern Cooperative Oncology Group-American College of Radiology Imaging Network Cancer Research Group Trial (E3205)

Purpose Squamous cell carcinoma of the anal canal (SCCAC) is characterized by high locoregional failure (LRF) rates after sphincter-preserving definitive chemoradiation (CRT) and is typically associated with anogenital human papilloma virus infection. Because cetuximab enhances the effect of radiation therapy in human papilloma virus-associated oropharyngeal squamous cell carcinoma, we hypothesized that adding cetuximab to CRT would reduce LRF in SCCAC. Methods Sixty-one patients with stage I to III SCCAC received CRT including cisplatin, fluorouracil, and radiation therapy to the primary tumor and regional lymph nodes (45 to 54 Gy) plus eight once-weekly doses of concurrent cetuximab. The study was designed to detect at least a 50% reduction in 3-year LRF rate (one-sided α, 0.10; power 90%), assuming a 35% LRF rate from historical data. Results Poor risk features included stage III disease in 64% and male sex in 20%. The 3-year LRF rate was 23% (95% CI, 13% to 36%; one-sided P = .03) by binomial proportional estimate using the prespecified end point and 21% (95% CI, 7% to 26%) by Kaplan-Meier estimate in a post hoc analysis using methods consistent with historical data. Three-year rates were 68% (95% CI, 55% to 79%) for progression-free survival and 83% (95% CI, 71% to 91%) for overall survival. Grade 4 toxicity occurred in 32%, and 5% had treatment-associated deaths. Conclusion Although the addition of cetuximab to chemoradiation for SCCAC was associated with lower LRF rates than historical data with CRT alone, toxicity was substantial, and LRF still occurs in approximately 20%, indicating the continued need for more effective and less toxic therapies.

No evidence of NRAS mutation in squamous cell anal carcinoma (SCAC)

Epidermal growth factor receptor (EGFR) is usually expressed in squamous cell anal carcinoma (SCAC) and anti-EGFR agents could represent a valid treatment strategy, also considering that KRAS and BRAF mutations are rare events in this type of cancer. However, no data are available on NRAS status in SCAC. In this study we analyzed NRAS status (exons 2–4) by Pyrosequencing in a case series of 50 SCAC patients previously characterized in our laboratory for KRAS, BRAF, PIK3CA mutations and HPV and HIV infections. We found no mutation in NRAS gene. These results confirm that since the principal anti-EGFR resistance mechanisms are almost absent in SCAC, anti-EGFR agents should be considered for the treatment of this type of cancer.

Background and Current Treatment of Squamous Cell Carcinoma of the Anus

In this review, a summary of our current understanding of squamous cell carcinoma of the anus (SCCA) and the advances in our knowledge of SCCA regarding screening, prevention, the role of the immune system, current treatment and the potential for novel targets are discussed. The present standard of care in terms of treatment is 5-fluorouracil (5-FU) and mitomycin C (MMC) concurrently with radiation, which results in a high level of disease control for small early cancers. Preservation of the anal sphincter is achieved in the majority, although anorectal function is often impaired. Although evidence from prospective studies to support a change in the treatment strategy is lacking, patients with HPV-negative SCCA appear to be less responsive to chemoradiation (CRT) and relapse more frequently. In contrast, HPV-positive tumours usually fare better, but oncological outcomes are modified by smoking and immune incompetence. There is current interest in escalating the radiotherapy dose for larger, more advanced tumours, and de-escalating treatment for HPV-positive tumours. The use of novel immunological treatments to target the underlying different molecular pathways of HPV-positive cancers is exciting.

Anal cancer - What is the optimum chemoradiotherapy?

Radical concurrent chemoradiotherapy with 5FU and Mitomycin C is the standard-of-care for squamous-cell carcinoma of the anus (SCCA). Phase III trials combined radiation doses of 50-60 Gy with concurrent Fluoropyrimidines, Mitomycin C and Cisplatin in various doses and schedules. CRT is highly successful for early T1/T2 cancers, but results in appreciable late morbidities and still fails to control larger and node-positive tumours. Compliance to chemotherapy is important for local control. Modern radiotherapy techniques such as intensity-modulated radiotherapy (IMRT), rotational IMRT, image-guided radiotherapy (IGRT) have enabled smaller margins and highly conformal plans, resulting in decreased radiation doses to the organs at risk and ensuring a shorter overall treatment time. These advances offer the potential for integrating higher doses of radiation, escalation of the currently used drugs and the safe use of other more novel agents with acceptable toxicity. In this chapter potential novel approaches are discussed in the context of SCCA.