Initial Results from the Royal College of Radiologists' UK National Audit of Anal Cancer Radiotherapy 2015

Clinical Outcomes, Patterns of Failure, and Salvage Therapies of a Large Modern Cohort of Patients With Anal Squamous Cell Carcinoma Treated With Definitive-Intent Intensity-Modulated Radiation Therapy

PURPOSE

Patterns of failure and salvage therapy options for patients with anal squamous cell carcinoma (ASCC) who recur after definitive-intent intensity-modulated radiation therapy (IMRT) with concurrent chemotherapy are not well described.

METHODS AND MATERIALS

We identified consecutive patients with ASCC treated with definitive-intent IMRT between July 2005 and December 2019. Relevant patient and tumor parameters, disease outcomes (locoregional failure [LRF], distant failure, progression-free survival, colostomy-free survival, and overall survival [OS]), patterns of failure, and salvage therapies were collected. Failures were analyzed using competing risk methods, whereas survival endpoints were estimated using the Kaplan-Meier method. Univariate and multivariate analyses were performed. Landmark analyses were conducted by considering whether patients had LRF within 12 months of completing IMRT.

RESULTS

A total of 375 patients were identified with a median follow-up of 6 years. Stage breakdown was 15%, 23%, and 62% for the American Joint Committee on Cancer stages 0 to I, II, and III, respectively. Six-year rates of LRF, distant failure, progression-free survival, colostomy-free survival, and OS were 12%, 13%, 73%, 76%, and 80%, respectively. Disease recurred in 74 patients. Among the 45 patients with LRF, 39 (87%) failed within the anorectum, with 25 anal canal, 6 anal margin, and 8 rectal recurrences. Only 4 (9%) patients had isolated nodal failure. Patients experiencing LRF had worse 6-year OS than patients without LRF (44% vs 86%, P < .0001). Approximately 30% of patients who underwent salvage therapy were alive to 10 years after recurrence, compared with none of the patients who were managed with chemotherapy alone or the best supportive care.

CONCLUSIONS

This large ASCC cohort managed with definitive-intent IMRT demonstrated excellent rates of locoregional control and survival. Isolated regional nodal failures were uncommon, whereas the majority of LRFs occurred within the anorectum, despite dose escalation by tumor stage. We observed poor outcomes for patients experiencing locoregional disease recurrence, even after aggressive salvage treatment.

Radiation Therapy for Anal Squamous Cell Carcinoma: An ASTRO Clinical Practice Guideline

PURPOSE

This guideline provides evidence-based recommendations addressing the indications for definitive treatment of primary squamous cell carcinoma of the anal canal and anal margin.

METHODS

The American Society for Radiation Oncology convened a task force to address 4 key questions focused on (1) indications for radiation therapy (RT), concurrent systemic therapy and local excision/surgery, (2) appropriate RT techniques, (3) appropriate RT dose-fractionation regimens, target volumes, and dose constraints, and (4) appropriate surveillance strategies after definitive treatment. Recommendations are based on a systematic literature review and created using a predefined consensus-based methodology and system for grading evidence quality and recommendation strength.

RESULTS

Multidisciplinary evaluation and decision-making are recommended for all patients. Definitive treatment with combined modality therapy is recommended for most patients using concurrent 5-fluorouracil or capecitabine plus mitomycin, with cisplatin as a conditional alternative to mitomycin with RT. Select patients with early-stage disease may be considered for local excision alone. RT target volumes should include the primary tumor/anal canal and rectum, and mesorectal, presacral, internal and external iliac, obturator, and inguinal lymph nodes. Intensity modulated RT-based treatment approaches are recommended. The primary tumor should receive doses of 4500 to 5940 cGy in 25 to 33 fractions, and clinically involved lymph nodes should receive 5040 to 5400 cGy in 28 to 30 fractions, depending on disease stage and RT approach. Elective nodal volumes should receive 3600 to 4500 cGy in 20 to 30 fractions, depending on disease stage and RT approach. Dose guidance for normal tissues and measures to minimize acute and chronic treatment-related toxicity are provided. Treatment breaks should be minimized. Posttreatment surveillance strategies, including timing of clinical/digital exam, anoscopy, computed tomography, magnetic resonance imaging, and positron emission tomography/computed tomography, are discussed.

CONCLUSIONS

These evidence-based recommendations guide clinical practice on the use of definitive therapy for localized anal squamous cell carcinoma. Future studies will further refine the optimal RT dose for early- and advanced-stage disease, use of alternative systemic agents, including immunotherapy, the role of adaptive RT, and other strategies to minimize long-term treatment-related toxicity.

Study of long-term effects of pelvic radiotherapy on the function of bone marrow in recurrent cervical cancer patients

Purpose: To study the effects of prior pelvic radiotherapy on bone marrow suppression in recurrent cervical cancer patients during chemotherapy. Methods and materials: The cases of 129 patients with recurrent cervical cancer were reviewed, of which 77 patients had pelvic radiotherapy history and another 52 patients with no pelvic radiotherapy history were used as control group. All patients received a chemotherapy regimen of paclitaxel combined with carboplatin (TC) per 21 days for 5-6 times. Hematologic toxicity, including count of red blood cell, white blood cell and neutrophil cell and platelet, was defined by using Common Terminology Criteria for Adverse Events (version 4.0). The relationship between age, body mass index, disease free survival, pathological types, FIGO stages, radiotherapy methods and the degree of bone marrow suppression during chemotherapy was statistically analyzed, respectively, for all recurrent cervical cancer patients. Results: Among 77 patients with previous radiotherapy history, 73 recurrent patients (94.8%) had bone marrow suppression followed by chemotherapy. Recurrent cervical cancer patients without prior radiotherapy (n=52) showed a lower risk of bone marrow suppression followed by chemotherapy (n=39, 75.0%, P < 0.05). The probability of severe bone marrow suppression (grade III-IV) after chemotherapy in recurrent cervical patients with or without history of radiotherapy was 41.6% and 13.5%, respectively (P < 0.05). In univariate analysis, radiotherapy methods were associated with the incidence of grade III-IV bone marrow suppression in recurrent cervical cancer patients (P=0.005). In multivariate analysis, radiotherapy methods and extended-field radiotherapy were the risk factor of grade III-IV bone marrow suppression (χ2=16.975, P=0.001). No significant differences in the counts of white blood cell, hemoglobin and platelet were observed before chemotherapy at relapse between patients with and without prior radiotherapy. Reduction of white blood cell counts, absolute value of neutrophil cell and platelet counts composited majority type of grade III and IV bone marrow suppression. Conclusions: The prior pelvic radiotherapy significantly increased the incidence of bone marrow suppression during chemotherapy in recurrent cervical cancer patients. When treating recurrent cervical cancer patients with chemotherapy who had prior radiotherapy, especially for those experienced external beam radiation therapy, essential attention and timely intervention are recommended to ensure completion of chemotherapy and clinical efficacy.

The Royal College of Radiologists National Vulvar Cancer Audit

AIMS

This audit examined UK vulvar cancer practice from March 2018 to January 2019 and compared it to standards from national and international recommendations. Follow-up data collection in 2020 examined patient outcomes and toxicity.

MATERIALS AND METHODS

Audit standards were based on Royal College of Radiologists (RCR) guidance and published literature. A web-based questionnaire was sent to the audit leads at all cancer centres in the UK. Prospective data collection included patient demographics, tumour characteristics, radiotherapy indications, dosimetry, timelines, and follow-up data. The audit targets were 95% compliance with the RCR dose/fractionation schemes in definitive and adjuvant patients, 40% use of intensity modulated radiotherapy (IMRT), 100% of radical patients treated as category 1, and 95% use of gap compensation for category 1 patients.

RESULTS

34/54 UK radiotherapy centres (63%) completed data entry for 152 patients. 23 out of 34 (68%) centres submitted follow-up data for 94 patients. One indicator exceeded the audit target: 98% of radical patients received IMRT. The indicators of RCR dose/fractionation compliance for adjuvant/definitive radiotherapy were achieved by 80%/43% for the primary, 80%/86% for elective lymph nodes, and 21%/21% for pathological lymph nodes. The use of concomitant chemotherapy with radical radiotherapy in suitable patients was achieved by 71%. Other indicators demonstrated that 78% were treated as category 1 and 27% used gap compensation. Acute toxicity was mostly related to skin, gastrointestinal, and genitourinary sites. Grade 3 and Grade 4 toxicities were seen at acceptable rates within the radical and adjuvant groups. Late toxicity was mostly grade 0.

CONCLUSION

This audit provides a comprehensive picture of UK practice. IMRT is widely used in the UK, and treatment-related toxicity is moderate. The dose fractionation was very heterogeneous. The designation of vulvar cancer as category 1 was not regularly followed for radical/adjuvant patients, and there was minimal gap compensation during treatment.

A five-year review of chemoradiotherapy practice in anal cancer: Radiotherapy audit results from a cancer centre in Wales, UK

AIM

To review a five-year clinical practice of radical chemoradiotherapy (CRT) for anal cancers at a cancer centre in Wales.

METHODS

A retrospective audit examined the quality of radical CRT for anal cancers treated between November 2016 and November 2021 by investigating seven critical indicators set by Radiation Therapy Oncology Group and ACT II trials, (1) 95% completion of computed tomography simulation within 14 days of consent, (2) 100% CRT delivery within 28 days of computed tomography simulation, (3) 100% CRT delivery within 28 days of consent, (4) overall treatment time of RT 38 days with > 2 days breaks <5%, (5) 75% completion of concurrent chemotherapy, (6) <2% CRT related colostomies, and (7) <2% the 30-days mortality rate.

RESULTS

A total of 80 anal cancers received CRT over five years. Around 95.0% underwent computed tomography simulation within 14 days of consent. The observed slight deviation was related to the Covid pandemic in 2020. About 96.3% started CRT within 28 days of computed tomography simulation. The mean duration of CRT was 37.9 days. Radiotherapy (RT) interruptions > 2 days were about 5%, and 67.5% started CRT within 28 days of consent. About 92.5% and 76.2% completed mitomycin and capecitabine without breaks, respectively. The colostomy rate was 1.2%, and the 30-day mortality was 1.2%.

CONCLUSION

Audit results matched with the standards in six domains. Overall treatment time of 37.9 days, colostomy rates of 1.2%, and the 30-day mortality rate of 1.2% were commendable. Overall time interval between consent and CRT delivery can be achieved by time-constrained measures.

Differential Response of Pelvic Bone Marrow Fluorodeoxyglucose Uptake in Patients Receiving Concurrent Chemoradiotherapy

AIMS

Irradiation of pelvic bone marrow (PBM) at the level of the typical low dose bath of intensity-modulated radiotherapy delivery (10-20 Gy) is associated with an increased risk of haematological toxicity, particularly when combined with concurrent chemotherapy. Although sparing of the whole of the PBM at a 10-20 Gy dose level is unachievable, it is known that PBM is divided into haematopoietically active and inactive regions that are identifiable based on the threshold uptake of [18F]-fluorodeoxyglucose (FDG) seen on positron emission tomography-computed tomography (PET-CT). In published studies to date, the definition of active PBM widely used is that of a standardised uptake value (SUV) greater than the mean SUV of the whole PBM prior to the start of chemoradiation. These studies include those looking at developing an atlas-based approach to contouring active PBM. Using baseline and mid-treatment FDG PET scans acquired as part of a prospective clinical trial we sought to determine the suitability of the current definition of active bone marrow as representative of differential underlying cell physiology.

MATERIALS AND METHODS

Active and inactive PBM were contoured on baseline PET-CT and using deformable registration mapped onto mid-treatment PET-CT. Volumes were cropped to exclude definitive bone, voxel SUV extracted and the change between scans calculated. Change was compared using Mann-Whitney U testing.

RESULTS

Active and inactive PBM were shown to respond differentially to concurrent chemoradiotherapy. The median absolute response of active PBM for all patients was -0.25 g/ml, whereas the median inactive PBM response was -0.02 g/ml. Significantly, the inactive PBM median absolute response was shown to be near zero with a relatively unskewed distribution (0.12).

CONCLUSIONS

These results would support the definition of active PBM as FDG uptake greater than the mean of the whole structure as being representative of underlying cell physiology. This work would support the development of atlas-based approaches published in the literature to contour active PBM based on the current definition as being suitable.

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.

Management of small (T1-T2) anal margin squamous cell carcinoma: clinical outcomes following local excision alone

AIM

Squamous cell carcinomas of the anus are normally treated with synchronous chemoradiotherapy (CRT). Small, localized anal margin tumours may be adequately treated by local excision (LE) alone. This study aims to investigate the outcomes of patients with anal margin tumours treated with LE alone, reserving the use of CRT for salvage on local recurrence (LR).

METHODS

Patients with small, localized (stage I/IIA) anal margin tumours treated by LE from October 1999 to September 2018 were identified. The effect of tumour size and resection margin on LR risk was analysed. Outcomes of overall survival and disease-free survival were measured.

RESULTS

Fifty-five patients with anal margin tumours were identified. Overall 5-year LR, overall survival and disease-free survival rates were 8%, 86% and 82% respectively. Of the seven LRs, five were successfully salvaged with CRT with no further recurrence and two were not fit for CRT. Resection margins in non-fragmented tumours and tumour size did not significantly influence LR risk.

CONCLUSIONS

Most small, localized anal margin tumours can be adequately treated by LE alone with low LR rates. Most patients who developed LR were salvaged using CRT, with no cancer-related deaths reported.

Volumetric modulated arc therapy (VMAT): a review of clinical outcomes—what is the clinical evidence for the most effective implementation?

Modern conformal radiation therapy using techniques such as modulation, image guidance and motion management have changed the face of radiotherapy today offering superior conformity, efficiency, and reproducibility to clinics worldwide. This review assesses the impact of these advanced radiotherapy techniques on patient toxicity and survival rates reported from January 2017 to September 2020. The main aims are to establish if dosimetric and efficiency gains correlate with improved survival and reduced toxicities and to answer the question ‘What is the clinical evidence for the most effective implementation of VMAT?’. Compared with 3DCRT, improvements have been reported with VMAT in prostate, locally advanced cervical carcinoma and various head and neck applications, leading to the shift in technology to VMAT. Other sites such as thoracic neoplasms and nasopharyngeal carcinomas have observed some improvement with VMAT although not in line with improved dosimetric measures, and the burden of toxicity and the incidence of cancer related deaths remain high, signaling the need to further mitigate toxicity and increase survival. As technological advancement continues, large randomised long-term clinical trials are required to determine the way-forward and offer site-specific recommendations. These studies are usually expensive and time consuming, therefore utilising pooled real-world data in a prospective nature can be an alternative solution to comprehensively assess the efficacy of modern radiotherapy techniques.

Is cancer a prognostic factor for severe COVID-19, especially for breast cancer patients?

The coronavirus disease 2019 (COVID-19) pandemic has caused a global upheaval in our health care system. Our hospital facilities have been subjected to a major influx of patients and the prevention of cross-contamination has been a key issue in the spread of the virus. New recommendations for good hygiene practice and new recommendations for disease management have emerged to limit the spread of the virus and reorganize the provision of care in key services. Many studies have attempted to identify factors that contribute to poor prognosis for COVID-19 infection. Among them, cancer patients, were considered more at risk of developing severe forms of COVID-19. In this article, we provide an overview of the current state of the pandemic as well as new recommendations for disease management that have emerged in oncology and radiation therapy in particular. In this article, we will try to provide some answers through a review of the literature to the question: is cancer a prognostic factor for severe COVID-19?

Quality of life in patients treated with radiochemotherapy for primary diagnosis of anal cancer

Anal cancer and the related treatment are generally known to affect patients’ quality of life. The aim of this study was to assess self-reported quality of life (QoL) of anal cancer patients after combined radiation and chemotherapy, and to identify patient-, disease-, and therapy-related factors associated with QoL. A total of 94 patients treated with definitive chemoradiation for anal cancer at our institution in the period from 2004 to 2018 were identified from our database. QoL was assessed in the remaining 52 patients using the EORTC QLQ-C30 questionnaire (cancer-specific QoL) and the newly developed anal cancer module QLQ-ANL27 (site-specific QoL). Differences in QoL between anal cancer patients and a German age and sex adjusted reference population were examined. The median follow-up was 71 months (range, 7–176). In the cancer-specific QoL module, the anal cancer cohort presented with significantly lower scores in role (− 12.2 points), emotional (− 6.6 points), and social functioning (− 6.8 points), but higher scores in diarrhea (+ 36.3 points) and constipation (+ 13.3 points) than the German reference population. There were no significant differences in disease- or therapy-related factors, but age greater than 70 years and a follow-up time greater than 71 months had a negative impact on global QoL. As for the site-specific QoL, patients with a tumor relapse showed significantly higher symptom scores than patients with a complete clinical remission in all scales except of micturition frequency. Compared to 3D conformal radiotherapy, IMRT treatment seemed to improve non-stoma bowel function (+ 23.3 points), female sexual functioning (+ 24.2 points), and came along with less scores in the symptom scales pain (− 35.9 points), toilet proximity (− 28.6 points), and cleanliness (− 26.2 points). Most of the functional scores of anal cancer patients were lower compared to the general German population, but did not seem to affect the general QoL. Fatigue, physical, and role functioning had the strongest impact on global QoL causing psychological symptoms as important as physical.

Current treatment and future directions in the management of anal cancer

Although rare, the rate of squamous cell carcinoma of the anus (SCCA) is rising globally. Most patients present with nonmetastatic disease and are curable with appropriate treatment, which has evolved significantly over the last several decades. Before the 1970s, SCCA was managed with radical surgery, resulting in a permanent colostomy. Researchers found that preoperative treatment with chemotherapy and concurrent radiation could achieve a pathologic complete response. After this observation, definitive therapy shifted from radical surgery to sphincter-preserving chemoradiation. Investigations into the necessity of chemotherapy and the optimal regimen found that chemotherapy with mitomycin-C and 5-fluorouracil is required for cure. Further studies evaluating the addition of induction or maintenance chemotherapy, monoclonal antibody therapy, or higher radiation doses have demonstrated no significant benefit to disease control. Advanced radiation delivery with intensity-modulated radiotherapy techniques is now considered the standard of care because of its prospectively determined, favorable acute toxicity profile compared with 3-dimensional conformal radiation. It is important to note that chemoradiation treatment response may be slow (up to 26 weeks) and should be assessed through serial clinical examinations. Today, surgical management of SCCA is reserved only for the lowest risk, early stage tumors or for recurrent/persistent disease. Current studies are evaluating radiation dose de-escalation in early stage disease and radiation dose escalation and the addition of immune checkpoint inhibitors in locally advanced cancers. In reviewing how and why modern-day treatment of SCCA was established, the objective of this report is to reenforce adherence to current treatment paradigms to assure the best possible outcomes for patients.

Multicentre Investigation of Prognostic Factors Incorporating p16 and Tumour Infiltrating Lymphocytes for Anal Cancer After Chemoradiotherapy

AIMS

Anal squamous cell carcinomas (ASCC) are strongly associated with human papillomaviruses. Standard of care is chemoradiotherapy at uniform doses with no treatment stratification. Immunohistochemical staining for p16INK4A (p16), a surrogate for human papillomaviruses, is prognostic for outcomes. We investigated this alongside clinical-pathological factors, including tumour infiltrating lymphocyte (TIL) scores.

MATERIALS AND METHODS

Using an independent, multicentre cohort of 257 ASCC treated with chemoradiotherapy, pretreatment biopsies were stained and scored for p16 and TIL. Kaplan-Meier curves were derived for outcomes (disease-free survival [DFS], overall survival and cancer-specific survival), by stage, p16 and TIL scores and Log-rank tests were carried out to investigate prognostic effect. A multivariate analysis was carried out using Cox regression.

RESULTS

Stage, sex, p16 and TILs were independently prognostic. Hazard ratios for death (overall survival) were 2.51 (95% confidence interval 1.36-4.63) for p16 negative versus p16 positive, 2.17 (1.34-3.5) for T3/4 versus T1/2, 2.42 (1.52-3.8) for males versus females and 3.30 (1.52-7.14) for TIL1 versus TIL3 (all P < 0.05).

CONCLUSIONS

We have refined prognostic factors in ASCC. p16 adds to stratification by stage with respect to DFS in early disease and overall survival/DFS in locally advanced cancers. Our data support the role of the host immune response in mediating outcomes. These factors will be prospectively evaluated in PLATO (ISRCTN88455282).

Intensity-modulated Radiotherapy for Rectal Cancer in the UK in 2020

AIMS

Preoperative (chemo)radiotherapy followed by total mesorectal excision is the current standard of care for patients with locally advanced rectal cancer. The use of intensity-modulated radiotherapy (IMRT) for rectal cancer is increasing in the UK. However, the extent of IMRT implementation and current practice was not previously known. A national survey was commissioned to investigate the landscape of IMRT use for rectal cancer and to inform the development of national rectal cancer IMRT guidance.

MATERIALS AND METHODS

A web-based survey was developed by the National Rectal Cancer IMRT Guidance working group in collaboration with the Royal College of Radiologists and disseminated to all UK radiotherapy centres. The survey enquired about the implementation of IMRT with a focus on the following aspects of the workflow: dose fractionation schedules and use of a boost; pre-treatment preparation and simulation; target volume/organ at risk definition; treatment planning and treatment verification. A descriptive statistical analysis was carried out.

RESULTS

In total, 44 of 63 centres (70%) responded to the survey; 30/44 (68%) and 36/44 (82%) centres currently use IMRT to treat all patients and selected patients with rectal cancer, respectively. There was general agreement concerning several aspects of the IMRT workflow, including patient positioning, use of intravenous contrast and bladder protocols. Greater variation in practice was identified regarding rectal protocols; use of a boost to primary/nodal disease; target volume delineation; organ at risk delineation and dose constraints and treatment verification. Delineation of individual small bowel loops and daily volumetric treatment verification were considered potentially feasible by most centres.

CONCLUSION

This survey identified that IMRT is already used to treat rectal cancer in many UK radiotherapy centres, but there is heterogeneity between centres in its implementation and practice. These results have been a valuable aid in framing the recommendations within the new National Rectal Cancer IMRT Guidance.

Impact of compliance to chemoradiation on long-term outcomes in squamous cell carcinoma of the anus: results of a post hoc analysis from the randomised phase III ACT II trial

BACKGROUND

Concurrent chemoradiation is standard-of-care for patients with squamous cell carcinoma of the anus. Poor compliance to chemotherapy, radiotherapy treatment interruptions and unplanned breaks may impact adversely on long-term outcomes.

METHODS

The ACT II trial recruited 940 patients with localised squamous cell carcinoma of the anus, and assigned patients to mitomycin (week 1) or cisplatin (weeks 1 and 5), with fluorouracil (weeks 1 and 5) and radiotherapy (50.4 Gy in 28 fractions over 38 days). This post hoc analysis examined the association between baseline factors (age, gender, site, T stage and N stage), and compliance to treatment (radiotherapy and chemotherapy), and their effects on locoregional failure-free survival, progression-free survival (PFS) and overall survival (OS). Compliance was categorised into groups. Radiotherapy: six groups according to total dose and overall treatment time (OTT). Chemotherapy: three groups (A = per-protocol; B = dose reduction or delay; C = omitted).

RESULTS

A total of 931/940 patients were assessable for radiotherapy and 936 for chemotherapy compliance. Baseline glomerular filtration rate <60 ml/min and cisplatin were significantly associated with poor week 5 compliance to chemotherapy (P = 0.003 and 0.02, respectively). Omission of week 5 chemotherapy was associated with significantly worse locoregional failure-free survival [hazard ratio (HR) 2.53 (1.33-4.82) P = 0.005]. Dose reductions/delays or omission of week 5 chemotherapy were associated with significantly worse PFS {HR: 1.56 [95% confidence interval (CI): 1.18-2.06], P = 0.002 and HR: 2.39 (95% CI: 1.44-3.98), P = 0.001, respectively} and OS [HR: 1.92 (95% CI: 1.41-2.63), P < 0.001 and HR: 2.88 (95% CI: 1.63-5.08), P < 0.001, respectively]. Receiving the target radiotherapy dose in >42 days is associated with worse PFS and OS [HR: 1.72 (95% CI: 1.17-2.54), P =0.006].

CONCLUSION

Poor compliance to chemotherapy and radiotherapy were associated with worse locoregional failure-free survival, PFS and OS. Treatment interruptions should be minimised, and OTT and total dose maintained.

CLINICAL TRIAL NUMBER

ISRCTN 26715889.

UK national cohort of anal cancer treated with intensity-modulated radiotherapy: One-year oncological and patient-reported outcomes

BACKGROUND

Concurrent chemoradiotherapy is the standard treatment for anal cancer. Following national UK implementation of intensity-modulated radiotherapy (IMRT), this prospective, national cohort evaluates the one-year oncological outcomes and patient-reported toxicity outcomes (PRO) after treatment.

MATERIALS AND METHODS

A national cohort of UK cancer centers implementing IMRT was carried out between February to July 2015. Cancer centers provided data on oncological outcomes, including survival, and disease and colostomy status at one-year. EORTC-QLQ core (C30) and colorectal (CR29) questionnaires were completed at baseline and one-year followup. The PRO scores at baseline and one year were compared.

RESULTS

40 UK Cancer Centers returned data with a total of 187 patients included in the analysis. 92% received mitomycin with 5-fluorouracil or capecitabine. One-year overall survival was 94%; 84% were disease-free and 86% colostomy-free at one-year followup. At one year, PRO results found significant improvements in buttock pain, blood and mucus in stools, pain, constipation, appetite loss, and health anxiety compared to baseline. No significant deteriorations were reported in diarrhea, bowel frequency, and flatulence. Urinary symptom scores were low at one year. Moderate impotence symptoms at baseline remained at one year, and a moderate deterioration in dyspareunia reported.

CONCLUSIONS

With national anal cancer IMRT implementation, at this early pre-defined time point, one-year oncological outcomes were reassuring and resulted in good disease-related symptom control. one-year symptomatic complications following CRT for anal cancer using IMRT techniques appear to be relatively mild. These PRO results provide a basis to benchmark future studies.

Patterns and Predictors of Relapse Following Radical Chemoradiation Therapy Delivered Using Intensity Modulated Radiation Therapy With a Simultaneous Integrated Boost in Anal Squamous Cell Carcinoma

PURPOSE

Our purpose was to describe the patterns and predictors of treatment failure in patients receiving definitive chemoradiation therapy (CRT) for anal squamous cell carcinoma (ASCC), delivered using intensity modulated radiation therapy (IMRT).

METHODS AND MATERIALS

Our study was a retrospective cohort analysis of consecutive patients treated with curative intent for ASCC using CRT delivered with a standardized IMRT technique in 5 UK cancer centers. Patients were included from the start of UK IMRT guidance from February 2013 to October 31, 2017. Collected data included baseline demographics, treatment details, tumor control, sites of relapse, and overall survival. Statistical analysis to calculate outcomes and predictive factors for outcome measures were performed using SPSS and R.

RESULTS

The medical records of 385 consecutive patients were analyzed. Median follow-up was 24.0 months. Within 6 months of completing CRT, 86.7% of patients achieved a complete response. Three-year disease-free survival and overall survival were 75.6% and 85.6%, respectively. Of all relapses, 83.4% occurred at the site of primary disease. There were 2 isolated relapses in regional nodes not involved at outset. Predictive factors for cancer recurrence included male sex, high N-stage, and failure to complete radiation therapy as planned.

CONCLUSIONS

The treatment results compare favorably to published outcomes from similar cohorts using 3-dimensional conformal CRT. The observed patterns of failure support the current UK IMRT voluming guidelines and dose levels, highlighting our prophylactic nodal dose as sufficient to prevent isolated regional relapse in uninvolved nodes. Further investigation of strategies to optimize CR should remain a priority in ASCC because the site of primary disease remains the overwhelming site of relapse.

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.

Response of FDG avid pelvic bone marrow to concurrent chemoradiation for anal cancer

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Chemoradiation suppression of active bone marrow shown in on-treatment FDG-PET.

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No suppression shown in un-irradiation bone marrow.

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Volumes of active bone marrow receiving 20 Gy are associated with blood count nadirs.

Background and purpose

To determine if suppression of active bone marrow, as defined on FDG PETCT, is seen in on-treatment imaging of anal cancer patients receiving concurrent chemoradiation.

Methods and materials

Scans from 26 patients participating in the ART trial (full title: Anal squamous cell carcinoma: Investigation of functional imaging during chemoRadioTherapy), a single center observational study with FDG PETCT prior to radiotherapy and at fraction 8–10 of concurrent chemoradiation were analysed. Active bone marrow was contoured in both the pelvis and un-irradiated thoracic spine. SUV and volume of active bone marrow after 8–10 fractions of treatment were compared to baseline. Dose metrics to pelvic active bone marrow were extracted and compared to reduction in SUV/active bone marrow volume and to blood count nadir using linear regression.

Results

Suppression of active bone marrow is seen in the pelvis by a reduction in mean SUV and volume of active bone marrow after 8–10 fractions of treatment. Suppression is not seen in un-irradiated thoracic spine. Dose metrics were associated with reduced SUV and reduced volume of active bone marrow. Volume of active bone marrow receiving <20 Gy was associated with WCC/ANC nadir. 20 Gy was identified as the most likely clinically meaningful dose threshold for toxicity. Volume of active bone marrow receiving <20 Gy correlated to WCC and ANC with an increase of 100 cc being associated with an increase of 0.4 and 0.3 respectively.

Conclusion

The effect of concurrent chemoradiation in suppression of active bone marrow is seen in on-treatment FDG PETCT scans. Chemotherapy appears well tolerated after 2 weeks of treatment.

Is There a Role for an 18F-fluorodeoxyglucose-derived Biological Boost in Squamous Cell Anal Cancer?

AIMS

To investigate the potential role for a biological boost in anal cancer by assessing whether subvolumes of high 18F-fluorodeoxyglucose (FDG) avidity, identified at outset, are spatially consistent during a course of chemoradiotherapy (CRT).

MATERIALS AND METHODS

FDG-positron emission tomography (FDG-PET) scans from 21 patients enrolled into the ART study (NCT02145416) were retrospectively analysed. In total, 29 volumes including both primary tumours and involved nodes >2 cm were identified. FDG-PET scans were carried out before treatment and on day 8 or 9 of CRT. FDG subvolumes were created using a percentage of maximum FDG avidity at thresholds of 34%, 40%, 50%, on the pre-treatment scans, and 70% and 80% on the subsequent scans. Both FDG-PET scans were deformably registered to the planning computed tomography scan. The overlap fraction and the vector distance were calculated to assess spatial consistency. FDG subvolumes for further investigation had an overlap fraction >0.7, as this has been defined in previous publications as a 'good' correlation.

RESULTS

The median overlap fractions between the diagnostic FDG-PET subvolumes 34%, 40% and 50% of maximum standardised uptake value (SUVmax) and subsequent FDG-PET subvolumes of 70% of SUVmax were 0.97, 0.92 and 0.81. The median overlap fraction between the diagnostic FDG-PET subvolumes 34%, 40% and 50% and subsequent FDG-PET subvolumes of 80% were 1.00, 1.00 and 0.92. The median (range) vector distance values between diagnostic FDG-PET subvolumes 34%, 40% and 50% and subsequent FDG-PET subvolumes of 80% were 0.74 mm (0.19-2.94) 0.74 mm (0.19-3.39) and 0.71 mm (0.2-3.29), respectively. Twenty of 29 volumes (69.0%) achieved a threshold > 0.7 between the FDG 50% subvolume on the diagnostic scan and the FDG 80% subvolume on the subsequent scan.

CONCLUSION

FDG-avid subvolumes identified at baseline were spatially consistent during a course of CRT treatment. The subvolume of 50% of SUVmax on the pre-treatment scan could be considered as a potential target for dose escalation.

Dosimetric comparison of helical tomotherapy and VMAT for anal cancer: A single institutional experience

To compare the dosimetric results of helical tomotherapy (HT) and volumetric arc therapy (VMAT) in the treatment of anal cancer. Plans were created for 20 (n = 20) patients treated for anal cancer using HT and 2 arc VMAT. Dosimetric comparison was assessed for doses to targets and organs at risk (small bowel, bladder, external genitalia, and femoral heads). Delivery time and dosimetric verification results were also compared. HT showed a higher V95% for both primary and nodal targets (V95% increase by 0.5% to 1.3%; p = ≤0.05). No differences were seen in V105%, V107%, or V110 % between techniques. HT provided better sparing of the small bowel for dose levels V30, V35, and V40 (p = 0.005, 0.001, and 0.030), but was similar at higher doses. Similarly HT provided better bladder dose at V35 only (p = 0.020). Doses to femoral heads and genitalia were similar. Delivery time was higher for the HT plans (4.58 ± 1.1 min) than VMAT (3.13 ± 0.2 minutes) (p = 0.011). Dose verification results were 99.5 ± 0.9% and 100 ± 0% (HT, n = 6) vs 95.0 ± 3.1% and 99.2 ± 0.8% (VMAT, n = 20) for global gamma criteria 3%/3 mm and 4%/4 mm, respectively. Both HT and VMAT produced high quality plans that frequently met most of the dose objectives apart from genitalia V20, V40, bladder V35, and V50. Although absolute dose differences were small, the PTV V95%, small bowel V30, V35, and V40 and bladder V35 were statistically better in the HT plans. VMAT provided a shorter delivery time by 1.45 minutes; however, our HT plans were more likely to pass tighter plan dose verification criteria than VMAT.

Toxicity, Tolerability, and Compliance of Concurrent Capecitabine or 5-Fluorouracil in Radical Management of Anal Cancer With Single-dose Mitomycin-C and Intensity Modulated Radiation Therapy: Evaluation of a National Cohort

PURPOSE

Chemoradiation therapy (CRT) with mitomycin C (MMC) and 5-fluorouracil (5-FU) is established as the standard of care for the radical treatment of patients with anal squamous cell carcinoma (ASCC). The use of the oral fluoropyrimidine-derivative capecitabine is emerging as an alternative to 5-FU despite limited evidence of its tolerability and toxicity.

METHODS AND MATERIALS

A national cohort evaluation of ASCC management within the United Kingdom National Health Service was undertaken from February to July 2015. The toxicity rates were prospectively recorded. For the present analysis, we report data from ASCC patients who underwent intensity modulated RT and a single dose of MMC with either 5-FU (5-FU/MMC) or capecitabine (capecitabine/MMC). All were treated with radical intent and intensity modulated radiation therapy (IMRT) was delivered in accordance with UK guidance.

RESULTS

Of the 242 patients received from 40 centers across the United Kingdom, 147 met the inclusion criteria; 52 of whom were treated with capecitabine/MMC and 95 with 5-FU/MMC. No treatment-related deaths and no overall difference were found in the proportion of patients experiencing any grade ≥3 toxicity between the capecitabine and 5-FU groups (45% vs 55%; P = .35). However, significantly fewer patients in the capecitabine/MMC group experienced grade 3 hematologic toxicity (4% vs 27%; P = .001). A lower proportion of patients completed their planned chemotherapy course in the capecitabine cohort, although this did not reach statistical significance (81% vs 90%; P = .21). The median RT duration was 38 days (interquartile range 38-39) for both groups. No difference was found in the 1-year oncologic outcomes.

CONCLUSIONS

Capecitabine/MMC resulted in similar levels of grade 3/4 toxicity overall compared with 5-FU/MMC as CRT for ASCC, although differences were found in the patterns of observed toxicities, with less hematologic toxicity with capecitabine. Further studies of capecitabine/MMC are required to understand the acute toxicity profile and long-term oncologic outcomes of this combination with intensity modulated RT for ASCC.

Target volume motion during anal cancer image guided radiotherapy using cone-beam computed tomography

OBJECTIVE

Literature regarding image-guidance and interfractional motion of the anal canal (AC) during anal cancer radiotherapy is sparse. This study investigates interfractional AC motion during anal cancer radiotherapy.

METHODS

Bone matched cone beam CT (CBCT) images were acquired for 20 patients receiving anal cancer radiotherapy allowing population systematic and random error calculations. 12 were selected to investigate interfractional AC motion. Primary anal gross tumour volume and clinical target volume (CTVa) were contoured on each CBCT. CBCT CTVa volumes were compared to planning CTVa. CBCT CTVa volumes were combined into a CBCT-CTVa envelope for each patient. Maximum distortion between each orthogonal border of the planning CTVa and CBCT-CTVa envelope was measured. Frequency, volume and location of CBCT-CTVa envelope beyond the planning target volume (PTVa) was analysed.

RESULTS

Population systematic and random errors were 1 and 3 mm respectively. 112 CBCTs were analysed in the interfractional motion study. CTVa varied between each imaging session particularly T location patients of anorectal origin. CTVa border expansions ≥ 1 cm were seen inferiorly, anteriorly, posteriorly and left direction. The CBCT-CTVa envelope fell beyond the PTVa ≥ 50% imaging sessions (n = 5). Of these CBCT CTVa distortions beyond PTVa, 44% and 32% were in the upper and lower thirds of PTVa respectively.

CONCLUSION

The AC is susceptible to volume changes and shape deformations. Care must be taken when calculating or considering reducing the PTV margin to the anus. Advances in knowledge: Within a limited field of research, this study provides further knowledge of how the AC deforms during anal cancer radiotherapy.

Management of early anal cancer: need for guidelines and standardisation

PURPOSE

The optimal management of early squamous cell carcinoma of the anal canal (AC) is yet to be determined. This study investigated current practice in the management of early AC.

METHODS

A patterns of care survey was completed by Australian surgeons and radiation oncologists. Specific topics addressed were as follows: geographical location of practice, staging of disease, treatment approaches to T1N0 tumours and grade 3 anal intra-epithelial neoplasia (AIN3) lesions, radiotherapy planning, toxicities, follow-up and clinical trial involvement.

RESULTS

Sixty-four responses were obtained. For the management of T1N0 disease, half the respondents recommended standard dose chemo-radiotherapy (CRT) and one third recommended wide local excision (WLE). For the management of AIN3, half recommended WLE while a quarter advocated observation.

CONCLUSIONS

This study reveals a significant variation in the management of early AC. The development of guidelines specific to the treatment of early AC could standardise treatment while further research is required to define the optimal management of T1N0 AC and AIN.

Feasibility of preference-driven radiotherapy dose treatment planning to support shared decision making in anal cancer

PURPOSE/OBJECTIVE

Chemo-radiotherapy is an established primary curative treatment for anal cancer, but clinically equal rationale for different target doses exists. If joint preferences (physician and patient) are used to determine acceptable tradeoffs in radiotherapy treatment planning, multiple dose plans must be simultaneously explored. We quantified the degree to which different toxicity priorities might be incorporated into treatment plan selection, to elucidate the feasible decision space for shared decision making in anal cancer radiotherapy.

MATERIAL AND METHODS

Retrospective plans were generated for 22 anal cancer patients. Multi-criteria optimization handles dynamically changing priorities between clinical objectives while meeting fixed clinical constraints. Four unique dose distributions were designed to represent a wide span of clinically relevant objectives: high-dose preference (60.2 Gy tumor boost and 50.4 Gy to elective nodes with physician-defined order of priorities), low-dose preference (53.75 Gy tumor boost, 45 Gy to elective nodes, physician-defined priorities), bowel sparing preference (lower dose levels and priority for bowel avoidance) and bladder sparing preference (lower dose levels and priority for bladder avoidance).

RESULTS

Plans satisfied constraints for target coverage. A senior oncologist approved a random subset of plans for quality assurance. Compared to a high-dose preference, bowel sparing was clinically meaningful at the lower prescribed dose [median change in V_45Gy: 234 cm³; inter-quartile range (66; 247); p < .01] and for a bowel sparing preference [median change in V_45Gy: 281 cm³; (73; 488); p < .01]. Compared to a high-dose preference, bladder sparing was clinically meaningful at the lower prescribed dose [median change in V_35Gy: 13.7%-points; (0.3; 30.6); p < .01] and for a bladder sparing preference [median change in V_35Gy: 30.3%-points; (12.4; 43.1); p < .01].

CONCLUSIONS

There is decision space available in anal cancer radiotherapy to incorporate preferences, although tradeoffs are highly patient-dependent. This study demonstrates that preference-informed dose planning is feasible for clinical studies utilizing shared decision making.