Rising Incidence and Improved Survival of Anal Squamous Cell Carcinoma in Norway, 1987-2016

Accuracy and Clinical Impact of Persistent Disease Diagnosed on Diffusion-Weighted Imaging and Accuracy of Pelvic Nodal Assessment on Magnetic Resonance Imaging for Squamous Cell Carcinoma of the Anus in the 6-Month Interval Post Chemoradiotherapy

PURPOSE

To evaluate the diagnostic performance of diffusion-weighted imaging (DWI) in the 6-month interval post chemoradiation therapy (CRT) in determining persistent disease and whether persistent diffusion restriction on DWI at 6 months is associated with overall survival; and secondarily, to investigate the accuracy of pelvic lymph node assessment on T2-weighted imaging and DWI in the 6-month interval post CRT, in patients with squamous cell carcinoma of the anus.

METHODS AND MATERIALS

This retrospective study included patients with squamous cell carcinoma of the anus who underwent CRT followed by restaging rectal MRI from January 2010 to April 2020, with ≥1 year of follow-up after CRT. DW images were qualitatively evaluated by 2 junior and 2 senior abdominal radiologists to determine anal persistent disease. The reference standard for anal persistent disease was digital rectal examination/endoscopy and histopathology. Diagnostic performance was estimated using sensitivity, specificity, negative predictive value, and positive predictive value. Survival outcomes were evaluated via Kaplan-Meier analysis, and associations between survival outcomes and DWI status were tested for significance using the log-rank test. Additionally, DW and T2-weighted images were evaluated to determine lymph node status.

RESULTS

Among 84 patients (mean age, 63 ± 10.2 years; 64/84 [76%] female), 14 of 84 (17%) had confirmed persistent disease. Interreader agreement on DWI between all 4 radiologists was moderate (Light's κ = 0.553). Overall, DWI had a sensitivity of 71.4%, specificity of 72.1%, positive predictive value of 34.5%, and negative predictive value of 92.5%. Patients with a negative DWI showed better survival than patients with a positive DWI (3-year overall survival of 92% vs 79% and 5-year overall survival of 87% vs 74%), although the difference did not reach statistical significance (P = .063). All patients with suspicious lymph nodes (14/14, 100%) showed negative pathology or decreased size during follow-up.

CONCLUSIONS

At 6 months post CRT, DWI showed value in excluding anal persistent disease. Persistent diffusion restriction on DWI was not significantly associated with overall survival. Pelvic nodal assessment on DWI and T2-weighted imaging was limited in predicting persistent nodal metastases.

A study of microRNAs as new prognostic biomarkers in anal cancer patients

BACKGROUND

MicroRNA (MiR) influences the growth of cancer by regulation of mRNA for 50-60% of all genes. We present as per our knowledge the first global analysis of microRNA expression in anal cancer patients and their prognostic impact.

METHODS

Twenty-nine patients with T1-4 N0-3 M0 anal cancer treated with curative intent from September 2003 to April 2011 were included in the study. RNA was extracted from fresh frozen tissue and sequenced using NGS. Differentially expressed microRNAs were identified using the R-package DEseq2 and the endpoints were time to progression (TTP) and cancer specific survival (CSS).

RESULTS

Five microRNAs were significantly associated with 5-year progression free survival (PFS): Low expression of two microRNAs was associated with higher PFS, miR-1246 (100% vs. 55.6%, p = 0.008), and miR-135b-5p (92.9% vs. 59.3%, p = 0.041). On the other hand, high expressions of three microRNAs were associated with higher PFS, miR-148a-3p (93.3% vs. 53.6%, p = 0.025), miR-99a-5p (92.9% vs. 57.1%, p = 0.016), and let-7c-3p (92.9% vs. 57.1%, p = 0.016). Corresponding findings were documented for CSS.

INTERPRETATION

Our study identified five microRNAs as prognostic markers in anal cancer. MiR-1246 and microRNA-135b-5p were oncoMiRs (miRs with oncogene effects), while miR-148a-3p, miR- 99a-5p, and let-7c-3p acted as tumour suppressors in anal cancer patients.

Trends in epidemiology and primary treatment of anal squamous cell carcinoma in the Netherlands (1990-2021)

A rapid increase in the incidence of anal squamous cell carcinoma (SCC) was reported in several countries over the past decades. This study assessed trends in epidemiology and primary treatment over a 32-year period (1990-2021) using the Netherlands Cancer Registry. The study population included 4273 patients, 44.2% male and 55.8% female (median age 63 years). The age-standardised incidence rate (European Standardised Rate, ESR) increased from 0.5 to 1.6 per 100,000, which entailed an average annual percentage change (AAPC) of 5.0% (95% confidence interval [CI]: 4.5%-5.8%). While incidence among females increased continuously over the total period (AAPC 4.9%; 95%CI: 4.4%-5.6%), to 1.8 per 100,000 ESR in 2021, incidence among males increased until 2016 (annual percentage change [APC] of 6.3%; 95%CI: 5.6%-10.7%), after which it seemed to stabilise (APC -2.1%; 95%CI: -16.8%-4.5%). Significant trends were also observed in distribution of age, tumour stage and primary treatment modalities. Five-year relative survival (RS) was estimated using the Pohar-Perme estimator, and this improved from 56.1% in 1990-1997 (95%CI: 49.3%-62.4%) to 67.9% in 2014-2021 (95%CI: 64.7%-70.9%), but remained poor for stage IV disease. Evaluation through a multivariable Poisson regression model demonstrated diagnosis in the most recent period to be independently associated with better RS, in addition to female sex, younger age, early disease stage and any treatment. In conclusion, the rising incidence of anal SCC seems to decline in males, but not in females, and advances in diagnostics and therapeutic management have likely contributed to improved prognosis.

Pelvic Exenteration for Squamous Cell Carcinoma of the Anus: Oncological, Morbidity, and Quality-of-Life Outcomes

BACKGROUND

Salvage surgery is the only potentially curative treatment option for recurrent squamous cell carcinoma of the anus. Where adjacent pelvic viscera, soft tissues, and bone are involved, pelvic exenteration with a wide perineal excision may be required to ensure clear surgical margins and increase the likelihood of long-term survival.

OBJECTIVE

To report oncological, morbidity, and quality-of-life outcomes of pelvic exenteration for anal squamous cell carcinoma.

DESIGN

Cohort study with retrospective analysis of prospectively collected data.

SETTINGS

This study was conducted at a high-volume pelvic exenteration center.

PATIENTS

Those who underwent pelvic exenteration for anal squamous cell carcinoma between 1994 and 2022.

MAIN OUTCOME MEASURES

Local recurrence-free and overall survival, intraoperative and postoperative complication rates, R0 resection rate, and long-term quality-of-life outcomes.

RESULTS

Of 958 patients who underwent pelvic exenteration, 66 (6.9%) had anal squamous cell carcinoma. Thirty-two patients (48.5%) were male and the median age was 57 years (range, 31-79). Ten patients (15%) had primary anal squamous cell carcinoma, 49 (74%) had a recurrent tumor, and 7 (11%) had a re-recurrent tumor. Twenty-two patients (33%) and 16 patients (24%) had a major complication and unplanned return to the operating theater, respectively. Of the 62 patients who underwent pelvic exenteration with curative intent, 50 (81%) had R0 resection, and the 5-year overall and local recurrence-free survival rates were 41% and 37%, respectively. R0 resection was associated with a higher 5-year overall survival (50% vs 8%, p < 0.001). The mental health component scores and several individual quality-of-life domains presented improved trajectories postoperatively (all p values <0.05).

LIMITATIONS

The generalizability of the findings outside specialist pelvic exenteration centers may be limited.

CONCLUSIONS

Morbidity, long-term survival, and quality-of-life outcomes after pelvic exenteration for anal squamous cell carcinoma are comparable to published outcomes of pelvic exenteration for other tumor types.

EXENTERACIN PLVICA POR CARCINOMA EPIDERMOIDE DE ANO RESULTADOS ONCOLGICOS, DE MORBILIDAD Y DE CALIDAD DE VIDA

ANTECEDENTES:La cirugía de rescate es la única opción de tratamiento potencialmente curativa para el carcinoma de células escamosas del ano recurrente. Cuando están involucradas vísceras pélvicas, tejidos blandos y huesos adyacentes, puede ser necesaria una exenteración pélvica con una escisión perineal amplia para asegurar márgenes quirúrgicos claros y aumentar la probabilidad de supervivencia a largo plazo.OBJETIVO:Informar sobre los resultados oncológicos, de morbilidad y de calidad de vida de la exenteración pélvica por carcinoma anal de células escamosas.DISEÑO:Estudio de cohortes con análisis retrospectivo de datos recogidos prospectivamente.ENTORNO CLINICO:Este estudio se realizó en un centro de exenteración pélvica de alto volumen.PACIENTES:Aquellos que se sometieron a exenteración pélvica por carcinoma anal de células escamosas entre 1994 y 2022.PRINCIPALES MEDIDAS DE VALORACIÓN:Supervivencia global y libre de recidiva local, tasas de complicaciones intraoperatorias y posoperatorias, tasa de resección R0 y resultados de calidad de vida a largo plazo.RESULTADOS:De 958 pacientes que se sometieron a exenteración pélvica, 66 (6,9%) tenían carcinoma anal de células escamosas. 32 pacientes (48,5%) eran varones y la mediana de edad fue de 57 años (rango 31-79). 10 pacientes (15%) tenían carcinoma anal primario de células escamosas, 49 (74%) tenían un tumor recurrente y 7 (11%) tenían una segunda recurrencia. 22 (33%) y 16 pacientes (24%) tuvieron una complicación mayor y regreso no planificado al quirófano, respectivamente. De los 62 pacientes que se sometieron a una exenteración pélvica con intención curativa, 50 (81%) tuvieron una resección R0, las tasas de supervivencia global y libre de recidiva local a los 5 años fueron del 41% y el 37%, respectivamente. La resección R0 se asoció con una mayor supervivencia general a los 5 años (50% frente a 8%, p < 0,001). Las puntuaciones del componente de salud mental y varios dominios de calidad de vida individuales presentaron trayectorias mejoradas después de la operación (todos los valores de p < 0,05).LIMITACIONES:La generalización de los hallazgos fuera de los centros especializados en exenteración pélvica puede ser limitada.CONCLUSIONES:Los resultados de morbilidad, supervivencia a largo plazo y calidad de vida después de la EP para el carcinoma anal de células escamosas son comparables a los resultados publicados de la exenteración pélvica para otros tipos de tumores. (Traducción-Dr. Ingrid Melo ).

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.

Epidemiology of human papillomavirus-associated anogenital cancers in Granada: a three-decade population-based study

Introduction

HPV infection is a common risk factor for all anogenital cancers. However, there are important differences in the epidemiology of anogenital cancers and these have not been compared considering diverse epidemiological indicators over a long period of time. To fill this gap, we investigated incidence, mortality, and survival trends of anogenital cancers over a period of three decades.

Methods

We conducted an observational registry-based study using data from the population-based cancer registry of Granada in southern Spain. We collected data on all incident cases of anogenital cancer (cervical, anal, penile, vulvar, and vaginal cancer) diagnosed between 1985 and 2017. We calculated crude and age-standardized incidence and mortality rates, and 1, 3, and 5-year overall and net survival. We further conducted time-trend analysis calculating annual percent changes (APC) for each cancer site.

Results

The incidence of anogenital cancers decreased slightly during the past 30 years, with the exception of vulvar cancer, where a slight increase was observed. Mortality decreased significantly for cervical cancer over the study period but increased non-significantly for the remaining cancer sites. Survival rates were similar to those reported in comparable countries and increased for cervical and vulvar cancer.

Discussion

Cervical cancer was the greatest contributor to the burden of anogenital cancers and showed a marked improvement in all indicators in comparison to the remaining cancer sites.

Anal cancer in Sweden 2015-2019. Implementation of guidelines, structural changes, national registry and early results

BACKGROUND

Squamous cell cancer of the anus is an uncommon malignancy, usually caused by human papilloma virus (HPV). Chemoradiotherapy (CRT) is the recommended treatment in localized disease with cure rates of 60-80%. Local failures should be considered for salvage surgery. With the purpose of improving and equalizing the anal cancer care in Sweden, a number of actions were taken between 2015 and 2017. The aim of this study was to describe the implementation of guidelines and organizational changes and to present early results from the first 5 years of the Swedish anal cancer registry (SACR).

METHODS

The following were implemented: (1) the first national care program with treatment guidelines, (2) standardized care process, (3) centralization of CRT to four centers and salvage surgery to two centers, (4) weekly national multidisciplinary team meetings where all new cases are discussed, (5) the Swedish anal cancer registry (SACR) was started in 2015.

RESULTS

The SACR included 912 patients with a diagnosis of anal cancer from 2015 to 2019, reaching a national coverage of 95%. We could show that guidelines issued in 2017 regarding staging procedures and radiotherapy dose modifications were rapidly implemented. At baseline 52% of patients had lymph node metastases and 9% had distant metastases. Out of all patients in the SACR 89% were treated with curative intent, most of them with CRT, after which 92% achieved a local complete remission and the estimated overall 3-year survival was 85%.

CONCLUSIONS

This is the first report from the SACR, demonstrating rapid nation-wide implementation of guidelines and apparently good treatment outcome in patients with anal cancer in Sweden. The SACR will hopefully be a valuable source for future research.

Long-term survival after treatment for primary anal cancer- results from the Swedish national ANCA cohort study

BACKGROUND

Squamous cell carcinoma of the anus is increasing in incidence but remains a rare disease with good 3- and 5-year recurrence free and overall survival rates of 63%-86%. The treatment includes chemoradiotherapy, mainly with 5-fluoruracil (5FU) and mitomycin. The aim of this study was to describe long-term (up to 9 years after treatment) oncological outcome and the types of treatments given, in a Swedish national cohort of patients diagnosed with anal cancer between 2011 and 2013.

METHOD

Patients were identified in the Swedish Cancer Registry. Patients still alive were contacted and asked for consent. Clinical data were retrieved from National Patient Register at the Swedish National Board of Health and Welfare and from medical records. Unadjusted and adjusted analyses were performed for overall survival.

RESULTS

Three hundred and eighty-eight patients were included in the study of which 338 patients (87%) received treatment with a curative intent. Follow up was 85 months (0-113 months) for patients treated with curative intent (information missing in one patient) 7.5 months (0-55) for patients with treated with a palliative intent. Curative treatment varied and consisted of both chemoradiotherapy and radiotherapy (46-64 Gy) alone. 5-FU, mitomycin and cisplatin were the most used chemotherapy agents. Five-year overall survival for patients treated with curative intent was 73%. In an adjusted analysis 5-FU and mitomycin is associated with a lower mortality than 5-FU and cisplatin but the association was weaker (HR 1.61 (95% CI: 0.904; 2.85) than in the unadjusted analysis.

CONCLUSIONS

In this national cohort overall five-year survival was 73% for patients treated with curative intent. As reported by others our results indicate that 5-FU and mitomycin C should be the preferred chemotherapy in treatment for cure.

Incidence, Persistence, and Clearance of Anal Human Papillomavirus among Men Who Have Sex with Men in China: An Observational Cohort Study

(1) Background: We conducted a prospective observational cohort study to measure incidence, persistence, and clearance of anal human papillomavirus (HPV) among men who have sex with men (MSM) in China. (2) Methods: MSM were recruited in Guangzhou, Shenzhen and Wuxi, China in 2017. A tablet-based questionnaire was used to collect sociodemographic and behavioral characteristics. An anal brush sample was collected for HPV testing and genotyping. Participants were followed up 12 months after enrolment. (3) Results: A total of 196 participants completed two HPV tests with a median age of 27.3 (interquartile range (IQR) 24.0–32.8) years. Rate of incidence, persistence, and clearance for HPV among MSM were 31.3 (95% confidence interval (CI) 24.7–39.2), 47.9 (36.8–61.3), and 122.5 (104.3–143.0) per 1000 person months (pm), respectively. HPV 16 (4.1/1000 pm) had the highest incidence rate, and HPV 6 (47.4/1000 pm) had the highest persistence rate. Having lower education and engaging in receptive anal intercourse were potential risk factors of HPV incidence. A higher incidence rate was observed among younger MSM. (4) Conclusions: The high incidence and low clearance of anal HPV highlight the necessity of HPV vaccination among MSM. Further studies are needed to clarify the HPV dynamics at multiple anatomical sites and the burden of HPV-related diseases among MSM.

Outcomes of anus squamous cell carcinoma. Management of anus squamous cell carcinoma and recurrences

BACKGROUND

Little is known about the management of squamous cell carcinoma of the anal canal and its recurrence at a population level. The aim of this study was to draw a picture of management, recurrence and survival in squamous cell carcinoma of the anal canal.

MATERIAL AND METHODS

The 5-year probability of recurrences was estimated using the cumulative incidence function to consider competing risks of death. Net survival was estimated and a multivariate survival analysis was performed. The study was conducted using data of the Burgundy Digestive Cancer Registry. Overall, 273 squamous cell carcinomas of the anal canal registered between 1998 and 2014 were considered.

RESULTS

Overall, 80% of patients were treated with curative intent. Of these, 61% received chemoradiotherapy, 35% received radiotherapy and 4% received abdominoperineal resection alone. After these treatments, for cure the 5-year cumulative recurrence rate was 27% overall; it was 20% after chemoradiotherapy and 38% after radiotherapy. Five-year net survival was 71% overall; it was 81% after chemoradiotherapy and 55% after radiotherapy.

CONCLUSIONS AND RELEVANCE

Chemoradiotherapy was highly effective in routine practice. We confirm that it is difficult to distinguish between persistent active disease and local inflammation due to radiotherapy. Squamous cell carcinoma of the anal canal recurrences remains a substantial problem, highlighting the interest of prolonged surveillance. Aggressive management of recurrences may be beneficial.

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%.

Predicting outcomes in anal cancer patients using multi-centre data and distributed learning - A proof-of-concept study

BACKGROUND AND PURPOSE

Predicting outcomes is challenging in rare cancers. Single-institutional datasets are often small and multi-institutional data sharing is complex. Distributed learning allows machine learning models to use data from multiple institutions without exchanging individual patient-level data. We demonstrate this technique in a proof-of-concept study of anal cancer patients treated with chemoradiotherapy across multiple European countries.

MATERIALS AND METHODS

atomCAT is a three-centre collaboration between Leeds Cancer Centre (UK), MAASTRO Clinic (The Netherlands) and Oslo University Hospital (Norway). We trained and validated a Cox proportional hazards regression model in a distributed fashion using data from 281 patients treated with radical, conformal chemoradiotherapy for anal cancer in three institutions. Our primary endpoint was overall survival. We selected disease stage, sex, age, primary tumour size, and planned radiotherapy dose (in EQD2) a priori as predictor variables.

RESULTS

The Cox regression model trained across all three centres found worse overall survival for high risk disease stage (HR = 2.02), male sex (HR = 3.06), older age (HR = 1.33 per 10 years), larger primary tumour volume (HR = 1.05 per 10 cm3) and lower radiotherapy dose (HR = 1.20 per 5 Gy). A mean concordance index of 0.72 was achieved during validation, with limited variation between centres (Leeds = 0.72, MAASTRO = 0.74, Oslo = 0.70). The global model performed well for risk stratification for two out of three centres.

CONCLUSIONS

Using distributed learning, we accessed and analysed one of the largest available multi-institutional cohorts of anal cancer patients treated with modern radiotherapy techniques. This demonstrates the value of distributed learning in outcome modelling for rare cancers.

The Clinical Value of Measuring Circulating HPV DNA during Chemo-Radiotherapy in Squamous Cell Carcinoma of the Anus

BACKGROUND AND PURPOSE

Circulating tumor DNA (ctDNA) is investigated in various cancers. In squamous cell carcinoma of the anus (SCCA) infection with human papilloma virus (HPV) is found in around 90% of cases and here, plasma HPV (pHPV) can be used as ctDNA. Preliminary data have proved the ability to detect pHPV16 and -18 in SCCA. We have developed a highly sensitive method for measurement of six relevant pHPV subtypes, to investigate the elimination pattern of pHPV during chemo-radiotherapy (CRT) for SCCA and its clinical value.

MATERIAL AND METHODS

Patients treated at Aarhus University Hospital from 2016-2020 were included. P16 status in the primary biopsy was measured and 82% of patients had P16 positive tumor. Blood samples were collected prior to treatment (PT), mid treatment (MT), end of therapy (EOT), and during follow-up (FU). An in-house multiplex digital droplet PCR method measured pHPV subtypes 16, 18, 31, 33, 51, 58.

RESULTS

Samples from 88 patients were drawn PT (n = 73), MT (n = 72), EOT (n = 64) and during FU (n = 41). Plasma HPV was detectable in 52 patients and PT pHPV levels correlated to tumor stages. Three elimination patterns were observed during CRT with correlation to outcome: fast responders with no local or distant failures (0/12); slow responders with high risk of local failures (4/20), no distant failures; persistent molecular responders with high risk of distant failures (4/13), but no local failures, p < 0.01.

CONCLUSION

During CRT, pHPV can divide patients with SCCA into three groups with significantly different risk of failure. The use of pHPV can potentially assist in clinical treatment decision.

Patterns of pathologic lymph nodes in anal cancer: a PET-CT-based analysis with implications for radiotherapy treatment volumes

Background

This study investigates the patterns of PET-positive lymph nodes (LNs) in anal cancer. The aim was to provide information that could inform future anal cancer radiotherapy contouring guidelines.

Methods

The baseline [18F]-FDG PET-CTs of 190 consecutive anal cancer patients were retrospectively assessed. LNs with a Deauville score (DS) of ≥3 were defined as PET-positive. Each PET-positive LN was allocated to a LN region and a LN sub-region; they were then mapped on a standard anatomy reference CT. The association between primary tumor localization and PET-positive LNs in different regions were analyzed.

Results

PET-positive LNs (n = 412) were identified in 103 of 190 patients (54%). Compared to anal canal tumors with extension into the rectum, anal canal tumors with perianal extension more often had inguinal (P < 0.001) and less often perirectal (P < 0.001) and internal iliac (P < 0.001) PET-positive LNs. Forty-two patients had PET-positive LNs confined to a solitary region, corresponding to first echelon nodes. The most common solitary LN region was inguinal (25 of 42; 60%) followed by perirectal (26%), internal iliac (10%), and external iliac (2%). No PET-positive LNs were identified in the ischiorectal fossa or in the inguinal area located posterolateral to deep vessels. Skip metastases above the bottom of the sacroiliac joint were quite rare. Most external iliac PET-positive LNs were located posterior to the external iliac vein; only one was located in the lateral external iliac sub-region.

Conclusions

The results support some specific modifications to the elective clinical target volume (CTV) in anal cancer. These changes would lead to reduced volumes of normal tissue being irradiated, which could contribute to a reduction in radiation side-effects.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08187-8.

Feasibility and safety study of a high resolution wide field-of-view scanning endoscope for circumferential intraluminal intestinal imaging

Global anal cancer incidence is increasing. High resolution anoscopy (HRA) currently screens for anal cancer, although the definitive test remains unknown. To improve on intraluminal imaging of the anal canal, we conducted a first-in-human study to determine feasibility and safety of a high-resolution, wide field-of-view scanning endoscope. Fourteen patients, under an IRB-approved clinical study, underwent exam under anesthesia, HRA, and imaging with the experimental device. HRA findings were photographed using an in-line camera attached to the colposcope and compared with the scanning endoscope images. Patients were followed up within 2 weeks of the procedure. The imaging device is inserted into the anal canal and the intraluminal surface is digitally photographed in 10 s and uploaded to a computer monitor for review. Ten patients completed imaging with the device. Three patients were not imaged due to severe anal stenosis. One patient was not imaged due to technical device malfunction. The device images were compared to the HRA images. No adverse event attributable to the device was reported. The intraluminal scanning endoscope can be used for circumferential anal canal imaging and is safe for clinical use. Future clinical studies are needed to evaluate the performance of this device.

Evaluation of the stage classification of anal cancer by the TNM 8th version versus the TNM 7th version

Background: The UICC TNM 7th edition introduced stage groups for anal cancer which in 2019 has not yet come into general use. The new TNM 8th edition from 2016 defines 7 sub-stages. Background data for these changes are lacking. We aimed to investigate whether the new classification for anal cancer reliably predict the prognosis in the different stages.Patients and methods: The Nordic Anal Cancer Group (NOAC) conducted a large retrospective study of all anal cancers in Norway, Sweden and most of Denmark in 2000-2007. From the Nordic cohort 1151 anal cancer patients with follow-up data were classified by the TNM 4th edition which has identical T, N and M definitions as the TNM 7th edition, and therefore also can be classified by the TNM 7th stage groups. We used the Nordic cohort to translate the T, N and M stages into the TNM 8th stages and sub-stages. Overall survival for each stage was assessed.Results: Although the summary stage groups for TNM 8th edition discriminates patients with different prognosis reasonably well, the analyses of the seven sub-stages show overlapping overall survival: HR for stage IIA 1.30 (95%CI 0.80-2.12) is not significantly different from stage I (p = .30) and HR for stage IIB 2.35 (95%CI 1.40-3.95) and IIIA 2.48 (95%CI 1.43-4.31) are also similar as were HRs for stage IIIB 3.41 (95%CI 1.99-5.85) and IIIC 3.22 (95%CI 1.99-5.20). Similar overlapping was shown for local recurrence and distant spread.Conclusion: The results for the sub-stages calls for a revision of the staging system. We propose a modification of the TNM 8th edition for staging of anal cancer into four stages based on the T, N and M definitions of the TNM 8th classification.

Measurement of circulating free DNA in squamous cell carcinoma of the anus and relation to risk factors and recurrence

BACKGROUND

Measuring circulating-free-deoxyribonucleic-acid (cfDNA) has created a new framework for personalized treatment in oncology. The aim of this study was to analyze the relation between cfDNA and risk factors and outcome in squamous cell carcinoma of the anus (SCCA).

METHODS

Patients treated with radiotherapy for localized SCCA were included in Aarhus, Denmark from 2016 to 2019. Serum samples from baseline, during and after therapy, were measured for the level of cfDNA in copies per mL by a direct fluorescent assay.

RESULTS

Eighty patients were included. Samples were available at baseline (n = 73) mid-therapy (n = 74), end-therapy (n = 67) and one-year follow-up (1Y) (n = 29). P16-positivity was found in 89% (n = 55). The median level of cfDNA was higher for P16 negative tumors (1.48) compared with the P16 positive tumors (0.90, P = 0.04). Data showed a correlation between baseline cfDNA levels and Gross Tumor Volume (R² = 0.13, P < 0.01), and increasing levels with increasing T-stage (T1 = 0.80, T2 = 0.94, T3 = 1.11, T4 = 1.3). Higher cfDNA levels were observed in patients with poor performance status (P < 0.01). The cfDNA level decreased from baseline to mid-therapy (0.92-0.78, P < 0.01) and from baseline to 1Y (0.92-0.71, P < 0.01). Baseline levels for patients with treatment failure (n = 8) were above the 25th percentile (p = 0.05) which translates into difference in disease free survival.

CONCLUSION

Results indicate an association between baseline cfDNA levels and risk factors in SCCA and a low baseline level correlates to lower risk of treatment failure. Findings contribute with new knowledge of the biological role of cfDNA in SCCA and holds potential knowledge for personalized treatment of SCCA.

Investigating epidemiologic trends and the geographic distribution of patients with anal squamous cell carcinoma throughout Canada

Background

Anal cancer is a rare disease, constituting 0.5% of new cancer cases in the United States. The most common subtype is squamous cell carcinoma (scc). Studies in several developed nations have reported on an increasing incidence of anal cancer in recent decades, and various risk factors pertaining to the pathogenesis of the disease have been identified, including infection with the human papillomavirus, tobacco use, and immunosuppression. The epidemiology and distribution of anal scc throughout Canada remain poorly understood, however.

Methods

Using 3 population-based cancer registries, a retrospective analysis of demographic data across Canada for 1992-2010 was performed. The incidence and mortality for anal scc was examined at the levels of provinces, cities, and the forward sortation area (FSA) component (first 3 characters) of postal codes.

Results

During 1992-2010, 3720 individuals were diagnosed with anal scc in Canada; 64% were women. The overall national incidence rate was 6.3 cases per million population per year, with an average age at diagnosis of 60.4 years. The incidence increased over time, with significantly higher incidence rates documented in British Columbia and Nova Scotia (9.3 cases per million population each). Closer examination revealed clustering of cases in various urban centres and self-identified lgbtq communities in Toronto, Montreal, and Vancouver.

Discussion

This study provides, for the first time, a comprehensive analysis of the burden of anal scc in Canada, identifying susceptible populations and shedding light onto novel avenues of research to lower the incidence of anal cancer throughout the country.

Temporal improvements in loco-regional failure and survival in patients with anal cancer treated with chemo-radiotherapy: treatment cohort study (1990-2014)

Background

We evaluated oncological changes in patients with squamous cell carcinoma of the anus (SCCA) treated by chemoradiotherapy (CRT) from a large UK institute, to derive estimates of contemporary outcomes.

Methods

We performed a treatment-cohort analysis in 560 patients with non-metastatic SCCA treated with CRT over 25 years. The primary outcomes were 3-year loco-regional failure (LRF), 5-year overall survival (OS), and 5-year cancer-specific survival (CSS). We developed prediction models; and overlaid estimates on published results from historic trials.

Results

Age distributions, proportions by gender and cT stage remained stable over time. The median follow-up was 61 (IQR: 36–79) months. Comparing the first period (1990–1994) with the last period (2010–2014), 3-year LRF declined from 33 to 16% (P_trends < 0.001); 5-year OS increased from 60% to 76% (P_trends = 0.001); and 5-year CCS increased from 62% in to 80% (P_trends = 0.001). For 2020, the models predicted a 3-year LRF of 14.7% (95% CIs: 0–31.3); 5-year OS of 74.7% (95% CIs: 54.6–94.9); and 5-year CSS of 85.7% (95% CIs: 75.3–96.0). Reported oncological outcomes from historic trials generally underestimated contemporary outcomes.

Conclusions

Current and predicted rates for 3-year LRF and 5-year survivals are considerably improved compared with those in historic trials.

C-Reactive Protein-to-Albumin Ratio as Prognostic Marker for Anal Squamous Cell Carcinoma Treated With Chemoradiotherapy

Background: Definitive chemoradiotherapy (CRT) is the primary treatment for non-metastatic anal squamous cell carcinoma (ASCC). Despite favorable treatment outcomes in general, failure rates up to 40% occur in locally advanced disease. For treatment escalation or de-escalation strategies easily assessable and valid biomarkers are needed. Methods: We identified 125 patients with ASCC treated with standard CRT at our department. C-reactive protein (CRP) to albumin ratio (CAR) was calculated dividing baseline CRP by baseline albumin levels. We used maximally selected rank statistics to dichotomize patients to high and low risk groups. Associations of CAR with clinicopathologic parameters were evaluated and the prognostic impact was tested using univariate and multivariate cox regression analysis. In a subset of 78 patients, pretreatment tumor tissue was available and CD8+ tumor infiltrating lymphocytes (TILs) and p16^INK4a status were scored by immunohistochemistry and correlated with CAR. Results: Advanced T-stage and male gender were significantly associated with higher baseline CAR. Using the calculated cutoff of 0.117, a high baseline CAR was also associated with worse locoregional control (p = 0.002), distant metastasis-free survival (p = 0.01), disease-free survival (DFS, p = 0.002) and overall survival (OS, p < 0.001). A combined risk score incorporating N-stage and CAR, termed N-CAR score, was associated with worse outcome across all endpoints and in multivariate analysis independent of T-stage and Gender (HR 4.27, p = 0.003). In the subset of 78 patients, a strong infiltration with intratumoral CD8+ TIL was associated with a significantly lower CAR (p = 0.007). CAR is an easily accessible biomarker that is associated with DFS. Our study revealed a possible link between chronic systemic inflammation and an impaired intratumoral immune response.

Anal cancer chemoradiotherapy outcome prediction using 18F-fluorodeoxyglucose positron emission tomography and clinicopathological factors

OBJECTIVE

To assess the role of [¹⁸F]fluorodeoxyglucose (FDG) positron emission tomography (PET), obtained before and during chemoradiotherapy, in predicting locoregional failure relative to clinicopathological factors for patients with anal cancer.

METHODS

93 patients with anal squamous cell carcinoma treated with chemoradiotherapy were included in a prospective observational study (NCT01937780). FDG-PET/CT was performed for all patients before treatment, and for a subgroup (n = 39) also 2 weeks into treatment. FDG-PET was evaluated with standardized uptake values (SUV_{max/peak/mean}), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and a proposed Z-normalized combination of MTV and SUV_peak (ZMP). The objective was to predict locoregional failure using FDG-PET, tumor and lymph node stage, gross tumor volume (GTV) and human papilloma virus (HPV) status in univariate and bivariate Cox regression analysis.

RESULTS

N3 lymph node stage, HPV negative tumor, GTV, MTV, TLG and ZMP were in univariate analysis significant predictors of locoregional failure (p < 0.01), while SUV_{max/peak/mean} were not (p > 0.2). In bivariate analysis HPV status was the most independent predictor in combinations with N3 stage, ZMP, TLG, and MTV (p < 0.02). The FDG-PET parameters at 2 weeks into radiotherapy decreased by 30-40 % of the initial values, but neither absolute nor relative decrease improved the prediction models.

CONCLUSION

Pre-treatment PET parameters are predictive of chemoradiotherapy outcome in anal cancer, although HPV negativity and N3 stage are the strongest single predictors. Predictions can be improved by combining HPV with PET parameters such as MTV, TLG or ZMP. PET 2 weeks into treatment does not provide added predictive value.

ADVANCES IN KNOWLEDGE

Pre-treatment PET parameters of anal cancer showed a predictive role independent of clinicopathological factors. Although the PET parameters show substantial reduction from pre- to mid-treatment, the changes were not predictive of chemoradiotherapy outcome.