Prognostic factors derived from a prospective database dictate clinical biology of anal cancer: the intergroup trial (RTOG 98-11)

Efficacy and Toxicity of (Chemo)Radiation Therapy in HIV+ Patients with Squamous Cell Anal Cancer, a Subgroup Analysis of the National Multicenter Cohort FFCD-ANABASE

PURPOSE

The influence of human immunodeficiency virus (HIV) infection on clinical outcomes in patients receiving (chemo)radiation therapy (RT) for squamous cell carcinoma of the anus (SCCA) is debated. The objective of this study was to compare efficacy and safety according to HIV status in patients with SCCA treated with C/RT.

METHODS AND MATERIALS

Between January 2015 and April 2020, 488 patients with a known HIV status (17.6% HIV+) were treated with radiation therapy for SCCA and included in the FFCD-ANABASE multicentric prospective cohort. Clinical outcomes including overall survival (OS), locoregional recurrence-free survival, colostomy-free survival, response rate at 4 to 6 months, cancer-specific survival, relapse-free survival, and severe acute and late toxicity were compared between HIV+ and HIV- patients.

RESULTS

The median follow-up was 35.8 months. HIV+ patients were younger (P < .01) and predominantly male (P < .01). Intensity modulated radiation therapy was performed in 80.7% of patients, and 80.9% received concurrent chemotherapy. A higher proportion of HIV+ patients received induction chemotherapy compared with HIV- patients. No statistically significant difference in overall treatment time or severe acute and late toxicities was found between HIV+ and HIV- patients. In univariate analyses, OS (HR = 2.1 [CI 95% 1.2;3.5], P = .007), locoregional recurrence-free survival (HR = 1.7 [1.1;2.7], P = .02), and colostomy-free survival (HR = 1.7 [1.1;2.6], P = .01) were significantly shorter in HIV+ patients than in HIV- patients. Response rate, cancer-specific survival, and relapse-free survival were not significantly different. The recurrence site was significantly different according to HIV status. In the multivariate analysis, prognostic factors for OS were a World Health Organization performance status of ≥1 for the whole population, as well as HIV+ status for the subgroup of women.

CONCLUSIONS

HIV+ patients treated with chemo-RT for SCCA have poorer clinical outcomes, especially women. No difference was found in toxicity according to HIV status with intensity modulated radiation therapy technique.

Pre-treatment magnetic resonance imaging in anal cancer: large-scale evaluation of mrT, mrN and novel staging parameters

BACKGROUND

In patients with squamous cell carcinoma of the anus (SCCA), magnetic resonance (MR) imaging is recommended for pre-treatment staging prior to chemo-radiotherapy (CRT), but large-scale evaluation of its staging performance is lacking.

METHODS

We re-characterised pre-treatment MRs from 228 patients with non-metastatic SCCA treated consecutively by CRT (2006-2015) at one UK cancer centre. We derived TN staging from tumour size (mrTr) and nodal involvement (mrN), and additionally characterised novel beyond TN features such as extramural vascular invasion (mrEMVI) and tumour signal heterogeneity (mrTSH). Primary outcomes were 5-year overall survival (OS) and 3-year loco-regional failure (LRF). Time-to-event analyses used Kaplan-Meier estimates; Hazard Ratios (HRs) with confidence intervals (CIs) were derived from Cox models.

RESULTS

With a median follow up of 60.9 months, 5-year OS was 74%. Poor OS was associated with increasing mrT (HR: 1.12 per cm [95% CI: 1.07-1.33]), nodal positivity (HR 2.08 [95% CI 1.23-3.52]) and mrEMVI (HR 3.66 [95% CI: 1.88-7.41]). 3-year LRF rate was 16.5%. Increased LRF was associated with increasing mrT (HR: 1.43 per cm [95% CI: 1.26-1.63]), nodal positivity (HR 2.70 [95% CI 1.39-5.24]) and mrTSH (HR 2.66 [95% CI 1.29-5.48]).

CONCLUSIONS

In SCCA, the study demonstrates that mrT and mrN stages are prognostic, while mrEMVI and mrTSH may be novel prognostic factors.

A Population-Level Validation of the New 9th Edition of the American Joint Commission on Cancer Staging System for Anal Squamous Cell Carcinoma

BACKGROUND AND OBJECTIVES

The staging system for anal squamous cell carcinoma (ASCC) was recently revised, downstaging selected node-positive patients and upstaging some with larger tumors. We aimed to validate this staging system using a population-based cohort.

METHODS

The Surveillance, Epidemiology, and End Results database was analyzed to identify adult ASCC patients. Patients were staged according to the American Joint Committee on Cancer (AJCC) 8th and 9th edition systems. Survival probabilities were estimated using Kaplan-Meier curves. Cox regression models were utilized to estimate the effect of stage on overall (OS) and cancer-specific survival (CSS).

RESULTS

A total of 2117 patients were identified and staged based on the two AJCC classifications. At 24 months when comparing stage IIB versus stage IIIA, the 8th edition revealed an improved OS (79% vs. 88%) and CSS (84% vs. 91%) for stage IIIA disease, while the 9th edition restored the hierarchical OS (IIB 88% vs. IIIA 78%) and CSS (91% vs. 82%) order.

CONCLUSIONS

The hierarchical increase of the OS HRs, and nearly all CSS HRs, across disease stages validated the updated edition of the AJCC classification. Although this change may not have significant implication on the management of ASCC, it does provide better prognostication.

Clinical outcomes and prognostic factors of concurrent chemoradiotherapy for anal squamous cell carcinoma in Japan

BACKGROUND

Concurrent chemoradiotherapy (CCRT) is the standard treatment for locoregional anal squamous cell carcinoma (ASCC) in western countries. However, there have been few reports on the clinical outcomes of CCRT in Japan. This study aimed to evaluate the clinical outcomes of CCRT, prognostic factors, and the clinical impact of programmed cell death-ligand 1 (PD-L1) expression of ASCC in Japan.

METHODS

Patients with locoregional ASCC were enrolled between 2007 and 2017. All patients received CCRT consisting of ≥ 45 Gy of radiation, 5-fluorouracil, and mitomycin C. Disease-free survival (DFS), overall survival (OS), and adverse events (AEs) were estimated. Expression of p16 and PD-L1 were assessed by immunohistochemical staining (IHC).

RESULTS

This study included 36 patients, of whom 30 (83.3%) were female. Among the participants, 32 (88.9%) achieved complete clinical remission, while six (16.7%) experienced recurrence. The five-year DFS and five-year OS were 72.2% and 84.7%, respectively. Grades ≥ 3 serious AEs included neutropenia in 10 (27.7%) and perianal dermatitis in eight (22.2%). In a univariate analysis, male sex, lymph node metastasis, and large tumor size were significantly associated with worse outcome. In a multivariate analysis, tumor size was an independent factor associated with short DFS. Of the 30 patients whose biopsy specimens were available for IHC, 29 (96.7%) were positive for p16, and 13 (43.3%) were positive for PD-L1. However, PD-L1 expression did not show any clinical impact.

CONCLUSIONS

The comparative etiology, clinical outcomes, and prognostic factors of CCRT observed in Japanese patients with locoregional ASCC were consistent with western data.

A population-based analysis of the impact of 1 vs. 2 doses of mitomycin on patterns of failure of anal cancer patients treated with concurrent chemoradiotherapy

PURPOSE

We report the impact of 1 vs. 2 doses of mitomycin-C (MMC) based chemoradiation (CRT) on patterns of treatment failure and long-term patient outcomes in anal squamous cell carcinoma (ASCC) and the predictors for locoregional failure (LRF) and distant metastasis (DM).

METHODS

In this population-based study, we identified all patients with anal cancer in our province treated radically with radiation and concurrent 5-Fluorouracil (5FU) and 1 vs. 2 doses of MMC between the years 2000-2019. The primary outcomes analyzed were locoregional recurrence (LRR), disease free survival (DFS), ASCC cancer-specific survival (ASCC-CSS) and overall survival (OS).

RESULTS

451 patients were identified. 272 (60%) patients received 1 cycle of MMC (MMC1) and 179 (40%) received 2 cycles (MMC2) as part of the CRT regimen. The median follow-up was 57 (36-252) and 97 (38-239) months for MMC1 and MMC2, respectively. Cox Regression analysis showed stage IIIb and IIIc were associated with worse locoregional recurrence free survival (RFS) (HR=2.851, p=<0.001) and distant RFS (HR=3.391, p=<0.001). Similarly, stage IIIb and IIIc patients had poorer DFS (HR 3.439, p=<0.001), ASCC-SS (HR 3.729, p=<0.001) and OS (2.230, p=<0.001). The use of MMC2 showed a positive impact on improved ASCC-SS (HR 0.569, p=0.029) and distant RFS (HR 0.555, p=0.040) in patients with stage IIIb and IIIc.

CONCLUSIONS

Our analysis showed that 1 vs. 2 cycles of MMC along with 5FU and radiation is associated with comparable treatment outcomes in general. However, in patients with stage IIIb and IIIc cancer, 2 doses of MMC were associated with improved ASCC-SS and distant DFS.

Inflammatory pathways confer resistance to chemoradiotherapy in anal squamous cell carcinoma

Anal squamous cell carcinoma (ASCC) is associated with immunosuppression and infection with human papillomavirus (HPV). Response to standard chemoradiotherapy (CRT) varies considerably. A comprehensive molecular characterization of CRT resistance is lacking, and little is known about the interplay between tumor immune contexture, host immunity, and immunosuppressive and/or immune activating effects of CRT. Patients with localized ASCC, treated with CRT at three different sites of the German Cancer Consortium (DKTK) were included. Patient cohorts for molecular analysis included baseline formalin fixed paraffin embedded biopsies for immunohistochemistry (n = 130), baseline RNA sequencing (n = 98), peripheral blood immune profiling (n = 47), and serum cytokine measurement (n = 35). Gene set enrichment analysis showed that pathways for IFNγ, IFNα, inflammatory response, TNFα signaling via NF-κB, and EMT were significantly enriched in poor responders (all p < 0.001). Expression of interferon-induced transmembrane protein 1 (IFITM1), both on mRNA and protein levels, was associated with reduced Freedom from locoregional failure (FFLF, p = 0.037) and freedom from distant metastasis (FFDM, p = 0.014). An increase of PD-L1 expression on CD4+ T-cells (p < 0.001) and an increase in HLA-DR expression on T-cells (p < 0.001) was observed in the peripheral blood after CRT. Elevated levels of regulatory T-cells and CXCL2 were associated with reduced FFLF (p = 0.0044 and p = 0.004, respectively). Inflammatory pathways in tissue in line with elevated levels of regulatory T-cells and CXCL2 in peripheral blood are associated with resistance to CRT. To counteract this resistance mechanism, the RADIANCE randomized phase-2 trial currently tests the addition of the immune checkpoint inhibitor durvalumab to standard CRT in locally advanced ASCC.

MRI morphological characteristics of lymph nodes in anal squamous cell carcinoma

OBJECTIVES

Pre-treatment staging of anal squamous cell carcinoma (ASCC) includes pelvic MRI and [18F]-fluorodeoxyglucose positron emission tomography with computed tomography (PET-CT). MRI criteria to define lymph node metastases (LNMs) in ASCC are currently lacking. The aim of this study was to describe the morphological characteristics of lymph nodes (LNs) on MRI in ASCC patients with PET-CT-positive LNs.

METHODS

ASCC patients treated at Skåne University Hospital between 2009 and 2017 were eligible for inclusion if at least one positive LN according to PET-CT and a pre-treatment MRI were present. All PET-CT-positive LNs and PET-CT-negative LNs were retrospectively identified on baseline MRI. Each LN was independently classified according to pre-determined morphological characteristics by two radiologists blinded to clinical patient information.

RESULTS

Sixty-seven ASCC patients were included, with a total of 181 PET-CT-positive LNs identified on baseline MRI with a median short-axis diameter of 9.0 mm (range 7.5-12 mm). MRI morphological characteristics of PET-CT-positive LNs included regular contour (87%), round shape (89%), and homogeneous signal intensity on T2-weighed images (67%). An additional 78 PET-CT-negative LNs were identified on MRI. These 78 LNs had a median size of 6.8 mm (range 5.5-8.0 mm). The majority of PET-CT-negative LNs had a regular contour, round shape, and a homogeneous signal that was congruent to the primary tumor.

CONCLUSIONS

There are MRI-specific morphological characteristics for pelvic LNs in ASCC. PET-CT-positive and negative LNs share similar morphological features apart from size, with PET-CT-positive LNs being significantly larger. Further studies are needed to determine discrimination criteria for LNM in ASCC.

Unraveling Emerging Anal Cancer Clinical Biomarkers from Current Immuno-Oncogenomics Advances

Anal squamous cell carcinoma (ASCC) is a rare gastrointestinal malignancy associated with high-risk human papillomavirus (HPV) and is currently one of the fastest-growing causes of cancer incidence and mortality in developed countries. Although next-generation sequencing technologies (NGS) have revolutionized cancer and immuno-genomic research in various tumor types, a limited amount of clinical research has been developed to investigate the expression and the functional characterization of genomic data in ASCC. Herein, we comprehensively assess recent advancements in "omics" research, including a systematic analysis of genome-based studies, aiming to identify the most relevant ASCC cancer driver gene expressions and their associated signaling pathways. We also highlight the most significant biomarkers associated with anal cancer progression, gene expression of potential diagnostic biomarkers, expression of therapeutic drug targets, and emerging treatment opportunities. This review stresses the urgent need for developing target-specific therapies in ASCC. By illuminating the molecular characteristics and drug-target expression in ASCC, this study aims to provide insights for the development of precision medicine in anal cancer.

IAP inhibitor plus chemoradiotherapy for the treatment of bulky anal canal carcinoma

The aim of this editorial is to focus on the urgent need to improve clinical outcomes in patients with bulky primary anal canal carcinoma.

Utility of CYP2D6 copy number variants as prognostic biomarker in localized anal squamous cell carcinoma

BACKGROUND

Anal squamous cell carcinoma (ASCC) is an infrequent tumor whose treatment has not changed since the 1970s. The aim of this study is the identification of biomarkers allowing personalized treatments and improvement of therapeutic outcomes.

METHODS

Forty-six paraffin tumor samples from ASCC patients were analyzed by whole-exome sequencing. Copy number variants (CNVs) were identified and their relation to disease-free survival (DFS) was studied and validated in an independent retrospective cohort of 101 ASCC patients from the Multidisciplinary Spanish Digestive Cancer Group (GEMCAD). GEMCAD cohort proteomics allowed assessing the biological features of these tumors.

RESULTS

On the discovery cohort, the median age was 61 years old, 50% were males, stages I/II/III: 3 (7%)/16 (35%)/27 (58%), respectively, median DFS was 33 months, and overall survival was 45 months. Twenty-nine genes whose duplication was related to DFS were identified. The most representative was duplications of the CYP2D locus, including CYP2D6, CYP2D7P, and CYP2D8P genes. Patients with CYP2D6 CNV had worse DFS at 5 years than those with two CYP2D6 copies (21% vs. 84%; p < .0002, hazard ratio [HR], 5.8; 95% confidence interval [CI], 2.7-24.9). In the GEMCAD validation cohort, patients with CYP2D6 CNV also had worse DFS at 5 years (56% vs. 87%; p = .02, HR = 3.6; 95% CI, 1.1-5.7). Mitochondria and mitochondrial cell-cycle proteins were overexpressed in patients with CYP2D6 CNV.

CONCLUSIONS

Tumor CYP2D6 CNV identified patients with a significantly worse DFS at 5 years among localized ASCC patients treated with 5-fluorouracil, mitomycin C, and radiotherapy. Proteomics pointed out mitochondria and mitochondrial cell-cycle genes as possible therapeutic targets for these high-risk patients.

PLAIN LANGUAGE SUMMARY

Anal squamous cell carcinoma is an infrequent tumor whose treatment has not been changed since the 1970s. However, disease-free survival in late staged tumors is between 40% and 70%. The presence of an alteration in the number of copies of CYP2D6 gene is a biomarker of worse disease-free survival. The analysis of the proteins in these high-risk patients pointed out mitochondria and mitochondrial cell-cycle genes as possible therapeutic targets. Therefore, the determination of the number of copies of CYP2D6 allows the identification of anal squamous carcinoma patients with a high-risk of relapse that could be redirected to a clinical trial. Additionally, this study may be useful to suggest new treatment strategies to increase current therapy efficacy.

Prognostic Factors of Long-Term Outcomes after Primary Chemo-Radiotherapy in Non-Metastatic Anal Squamous Cell Carcinoma: An International Bicentric Cohort

Anal squamous cell carcinoma (ASCC) is a rare malignancy with a rising incidence associated with human papillomavirus (HPV) infection. The locally advanced disease is associated with a 30% rate of treatment failure after standard chemoradiotherapy (CRT). We aimed to elucidate the prognostic factors for ASCC after curative CRT. A retrospective multicenter study of 176 consecutive patients with ASCC having completed CRT treated between 2010 and 2017 at two centers was performed. Complete response (CR), disease-free survival (DFS), and overall survival (OS) were analyzed by Kaplan–Meier estimates with log-rank tests. The hierarchical clustering on principal components (HCPC) method was employed in an unsupervised and multivariate approach. The CR rate was 70% and was predictive of DFS (p < 0.0001) and OS (p < 0.0001), where non-CR cases were associated with shorter DFS (HR = 16.5, 95% CI 8.19–33.21) and OS (HR = 8.42, 95% CI 3.77–18.81) in a univariate analysis. The median follow-up was 38 months, with a 3-year DFS of 71%. The prognostic factors for DFS were cT1-T2 (p = 0.0002), N0 (p = 0.035), HIV-positive (p = 0.047), HIV-HPV coinfection (p = 0.018), and well-differentiated tumors (p = 0.037). The three-year OS was 81.6%. Female sex (p = 0.05), cT1-T2 (p = 0.02) and well-differentiated tumors (p = 0.003) were associated with better OS. The unsupervised analysis demonstrated a clear segregation of patients in three clusters, identifying that poor prognosis clusters associated with shorter DFS (HR = 1.74 95% CI = 1.25–2.42, p = 0.0008) were enriched with the locally advanced disease, anal canal location, HIV-HPV coinfection, and non-CR. In conclusion, our results reinforce the prognostic value of T stage, N stage, sex, differentiation status, tumor location, and HIV-HPV coinfection in ASCC after CRT.

Circulating HPV16 DNA in Blood Plasma as Prognosticator and Early Indicator of Cancer Recurrence in Radio-Chemotherapy for Anal Cancer

BACKGROUND

Implementation of anal squamous cell carcinoma (ASCC) treatment modifications requires reliable patient risk stratification. The circulating tumor-related human papillomavirus type 16 (ctHPV16) may play a role in predicting survival or assessing treatment response.

METHODS

The study included 62 ASCC patients treated with chemoradiotherapy. A threshold of 2.5 was used to determine the maximum standardized uptake value (SUVmax). The ctHPV16 viral load (VL) was quantified by qPCR.

RESULTS

In the multivariate Cox analysis, lower SUVmax (p = 0.047) and ctHPV16-positive (p = 0.054) proved to be independent prognostic factors for favorable overall survival (OS). In the subgroup with the higher SUVmax, ctHPV16 and nodal (N) status were independent prognostic factors with p = 0.022 for ctHPV16 and p = 0.053 for N. The best survival rate (95%) presented ctHPV16-positive/N-negative patients. High ctHPV16 VL tended to be slightly specific for patients younger than 63 years (p = 0.152). The decrease in ctHPV16 VL to undetectable level after the end of treatment correlated with the overall clinical response.

CONCLUSIONS

A prognostic stratification by SUVmax, ctHPV16 and N-positive status allows consideration of more aggressive treatment in high-risk patients (those with high SUVmax, ctHPV16-negative, and N-positive) or de-intensification of therapy in low-risk patients (those with low SUVmax, ctHPV16-positive and N-negative). However, prospective clinical trials on a large group are needed.

External validation of a composite bio-humoral index in anal cancer patients undergoing concurrent chemoradiation

BACKGROUND AND PURPOSE

A prognostic scoring system based on laboratory inflammation parameters, [Hemo-Eosinophils-Inflammation (HEI) index], including baseline hemoglobin level, the systemic inflammatory index and eosinophil count was recently proposed in patients with squamous cell carcinoma of the anus (ASCC). HEI was shown to discriminate disease-free (DFS) and overall (OS) survival in ASCC patients treated with concurrent chemoradiation (CRT). We tested the accuracy of the model on a multicentric cohort for external validation.

MATERIALS AND METHODS

Patients treated with CRT were enrolled. The Kaplan-Meier curves for DFS and OS based on HEI risk group were calculated and the log-rank test was used. Cox proportional hazards models were used to assess the prognostic factors for DFS and OS. The exponential of the regression coefficients provided an estimate of the hazard ratio (HR). For model discrimination, we determined Harrell's C-index, Gönen & Heller K Index and the explained variation on the log relative hazard scale.

RESULTS

A total of 877 patients was available. Proportional hazards were adjusted for age, gender, tumor-stage, and chemotherapy. Two-year DFS was 77 %(95 %CI:72.0-82.4) and 88.3 %(95 %CI:84.8-92.0 %) in the HEI high- and low- risk groups. Two-year OS was 87.8 %(95 %CI:83.7-92.0) and 94.2 %(95 %CI:91.5-97). Multivariate Cox proportional hazards model showed a HR = 2.02(95 %CI:1.25-3.26; p = 0.004) for the HEI high-risk group with respect to OS and a HR = 1.53(95 %CI:1.04-2.24; p = 0.029) for DFS. Harrel C-indexes were 0.68 and 0.66 in the validation dataset, for OS and DFS. Gonen-Heller K indexes were 0.67 and 0.71, respectively.

CONCLUSION

The HEI index proved to be a prognosticator in ASCC patients treated with CRT. Model discrimination in the external validation cohort was acceptable.

Influence of radiation treatment technique (IMRT vs. 3D-RT) on acute toxicity and prognostic factors for survival for anal cancer

We compared our institutional experience with intensity-modulated radiotherapy (IMRT) and 3D-conformal radiotherapy (3D-RT) for definitive treatment of primary anal cancer. We performed a single-institution retrospective review of all patients with anal squamous cell carcinoma treated with definitive (chemo) radiotherapy with curative intent from 2004 through 2018. We assessed several prognostic factors in respect to relevant survival endpoints. In addition, acute toxicities were determined and compared between IMRT and 3D-RT patients. This study included 94 patients (58 IMRT, 36 3D-RT). Mean follow up for all patients, for IMRT and 3D-RT patients was 61 months (range 6-176), 46 months (range 6-118), and 85 months (range 6-176), respectively. 5-year overall survival (OS) was 86%, disease-free survival (DFS) was 72%, and colostomy-free survival (CFS) was 75% in the IMRT cohort. In the 3D-RT cohort, OS was 87%, DFS was 71%, and CFS was 81% (all p > 0.05). Male gender and Karnofsky Index (KI) were revealed as independent prognostic factors for 5-year OS (p = 0.017; p = 0.023). UICC stage was an independent prognostic factor for DFS and CFS (p = 0.023; p = 0.042). In addition, the pre-treatment leukocyte count was an independent prognostic factor for CFS (p = 0.042). Acute grade ≥ 3 toxicity was not significantly different between IMRT and 3D-RT patients, but the IMRT cohort had favorable outcomes. This study confirmed IMRT as the primary definitive treatment of anal cancer. With similar survival rates, IMRT had the potential to reduce acute toxicity by sparing organs at risk. Promising prognostic factors such as BMI, KI, and leucocyte and hemoglobin levels should be further investigated.

Phase II INTERACT-ION study: ezabenlimab (BI 754091) and mDCF (docetaxel, cisplatin, and 5-fluorouracil) followed by chemoradiotherapy in patients with Stage III squamous cell anal carcinoma

Background

Chemoradiotherapy alone is the standard treatment for locally advanced squamous cell anal carcinoma (SCAC). However, up to 50% of patients will experience recurrence; thus, there is a need for new treatments to improve outcomes. Modified docetaxel, cisplatin and 5-fluorouracil (mDCF) is a treatment option for first-line metastatic SCAC, having shown efficacy in the Epitopes-HPV01 and -02 trials (NCT01845779 and NCT02402842). mDCF treatment also plays a role in the modulation of anti-tumor immunity, suggesting it may be a good combination partner for immunotherapy in patients with SCAC. Anti-programmed death protein-1 (PD-1) immunotherapy has been shown to be effective in metastatic SCAC. We therefore designed the INTERACT-ION study to assess the combination of mDCF with ezabenlimab (BI 754091), an anti-PD-1 antibody, followed by chemoradiotherapy, in patients with Stage III SCAC.

Methods

INTERACT-ION is a pivotal, open-label, single-arm phase II study in patients with treatment-naïve Stage III SCAC. Patients will receive induction treatment with mDCF (docetaxel 40 mg/m² and cisplatin 40 mg/m² on Day 1, 5-fluorouracil 1200 mg/m²/day for 2 days) every 2 weeks for 4 cycles and ezabenlimab (240 mg given intravenously) every 3 weeks for 3 cycles. In the absence of disease progression at 2 months, two additional cycles of mDCF and one additional cycle of ezabenlimab will be administered. Patients with radiological objective response, pathological complete/near-complete response and biological complete response will then receive an involved-node radiotherapy with intensity-modulated radiation therapy and concurrent chemotherapy, followed by ezabenlimab alone for seven cycles. All other patients will receive standard chemoradiotherapy. The primary endpoint is the clinical complete response rate 10 months after the first cycle of mDCF plus ezabenlimab. Major secondary endpoints are major pathological response and biological complete response after induction treatment. An extensive ancillary biomarker study in tumor tissue and peripheral blood will also be conducted.

Discussion

The addition of immunotherapy to chemotherapy is an area of active interest in metastatic anal cancer. This pivotal study will evaluate this combination in the locally advanced setting. Ancillary biomarker studies will contribute to the understanding of predictors of response or resistance to treatment.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT04719988, identifier NCT04719988.

Prognostic factors for patients with anal cancer treated with conformal radiotherapy-a systematic review

AIMS

Anal cancer is primarily treated using concurrent chemoradiotherapy (CRT), with conformal techniques such as intensity modulated radiotherapy (IMRT) and volumetric arc therapy (VMAT) now being the standard techniques utilised across the world. Despite this, there is still very limited consensus on prognostic factors for outcome following conformal CRT. This systematic review aims to evaluate the existing literature to identify prognostic factors for a variety of oncological outcomes in anal cancer, focusing on patients treated with curative intent using contemporary conformal radiotherapy techniques.

MATERIALS AND METHODS

A literature search was conducted using Medline and Embase to identify studies reporting on prognostic factors for survival and cancer-related outcomes after conformal CRT for anal cancer. The prognostic factors which were identified as significant in univariable and multivariable analysis, along with their respective factor effects (where available) were extracted. Only factors reported as prognostic in more than one study were included in the final results.

RESULTS

The results from 19 studies were analysed. In both univariable and multivariable analysis, N stage, T stage, and sex were found to be the most prevalent and reliable clinical prognostic factors for the majority of outcomes explored. Only a few biomarkers have been identified as prognostic by more than one study - pre-treatment biopsy HPV load, as well as the presence of leukocytosis, neutrophilia and anaemia at baseline measurement. The results also highlight the lack of studies with large cohorts exploring the prognostic significance of imaging factors.

CONCLUSION

Establishing a set of prognostic and potentially predictive factors for anal cancer outcomes can guide the risk stratification of patients, aiding the design of future clinical trials. Such trials will in turn provide us with greater insight into how to effectively treat this disease using a more personalised approach.

Pretreatment colostomy in patients with anal squamous cell carcinoma: Risk factors for a permanent stoma

BACKGROUND

The current standard of care for anal squamous cell carcinoma (SCC) is concurrent chemoradiation (CRT), which enables tumor eradication while preserving the anal sphincter. Patients with locally advanced tumors, however, may experience complications that preclude treatment before stoma creation.

OBJECTIVE

To evaluate the reversal rate of pretreatment stomas and the risk factors associated with nonreversal.

METHODS

This single-institution retrospective cohort study using a prospective database included patients diagnosed with anal SCC from January 2008 to December 2020 who required a stoma before curative CRT.

RESULTS

In total, 651 patients were identified; 65 required a stoma before chemoradiation due to obstruction (43.1%), rectovaginal fistula (20%), and perianal sepsis (36.9%). The stoma was reversed in nine patients after a mean follow-up of 35.8 months. Risk factors associated with a permanent stoma were perianal sepsis (p = 0.010), interruptions during radiotherapy for more than 7 days (p = 0.010), male sex (p = 0.013), poor performance status (Eastern Cooperative Oncology Group [ECOG] ≥ 2) (p = 0.023), large tumors (p = 0.045), and cisplatin-based chemotherapy (p = 0.047).

CONCLUSIONS

Pretreatment stomas are unlikely to be reversed, and risk factors for a permanent stoma are perianal sepsis, interruptions during radiotherapy for more than 7 days, male sex, poor performance status (ECOG ≥ 2), large tumors, and cisplatin-based chemotherapy.

Evaluation of prognostic factors after primary chemoradiotherapy of anal cancer: A multicenter study of the German Cancer Consortium-Radiation Oncology Group (DKTK-ROG)

BACKGROUND AND PURPOSE

Prognosis after chemoradiotherapy (CRT) for anal squamous cell carcinoma (ASCC) shows marked differences among patients according to TNM subgroups, however individualized risk assessment tools to better stratify patients for treatment (de-) escalation or intensified follow-up are lacking in ASCC.

MATERIALS AND METHODS

Patients' data from eight sites of the German Cancer Consortium - Radiation Oncology Group (DKTK-ROG), comprising a total of 605 patients with ASCC, treated with standard definitive CRT with 5-FU/Mitomycin C or Capecitabine/Mitomycin C between 2004-2018, were used to evaluate prognostic factors based on Cox regression models for disease-free survival (DFS). Evaluated variables included age, gender, Karnofsky performance score (KPS), HIV-status, T-category, lymph node status and laboratory parameters. Multivariate cox models were separately constructed for the whole cohort and the subset of patients with early-stage (cT1-2 N0M0) tumors.

RESULTS

After a median follow-up of 46 months, 3-year DFS for patients with early-stage ASCC was 84.9%, and 67.1% for patients with locally-advanced disease (HR 2.4, p < 0.001). T-category (HR vs. T1: T2 2.02; T3 2.11; T4 3.03), N-category (HR versus N0: 1.8 for N1-3), age (HR 1.02 per year), and KPS (HR 0.8 per step) were significant predictors for DFS in multivariate analysis in the entire cohort. The model performed with a C-index of 0.68. In cT1-2N0 patients, T-category (HR 2.14), HIV status (HR 2.57), age (1.026 per year), KPS (HR 0.7 per step) and elevated platelets (HR 1.3 per 100/nl) were associated with worse DFS (C-index of 0.7).

CONCLUSION

Classical clinicopathologic parameters like T-category, N-category, age and KPS remain to be significant prognostic factors for DFS in patients treated with contemporary CRT for ASCC. HIV and platelets were significantly associated with worse DFS in patients with early stage ASCC.

Prognostic impact of neutrophilia and lymphopenia on survival in anal cancer treated with definitive concurrent chemoradiotherapy: a retrospective multicenter study

PURPOSE

This study evaluated the prognostic value of leukocyte, lymphocyte, and neutrophil counts in anal cancer patients undergoing concurrent chemoradiotherapy (CCRT).

METHODS

Multi-institutional retrospective data review included 148 non-metastatic anal cancer patients treated with definitive CCRT with 5-fluorouracil plus mitomycin C between the year 2001 and 2019. The median radiation dose to the primary tumor was 54 Gy with a median pelvic dose of 45 Gy. Median follow-up duration was 56 months, and complete blood cell counts were analyzed from baseline to 1 year after the completion of radiotherapy.

RESULTS

Although most patients showed a normal number of blood cells before treatment, 6.1% and 4.1% of patients showed leukocytosis (> 10,000/μl) and neutrophilia (> 7500/μl), respectively. After the initiation of treatment, seven patients (4.7%) displayed grade 4 lymphopenia (< 200/μl) at 1 month. Patients with initial leukocytosis showed inferior progression- and locoregional progression-free survival, and neutrophilia was a prognostic factor in all survival outcomes. Grade 4 lymphopenia at 1 month was also significantly associated with overall, progression-, and distant metastasis-free survival. On multivariate analyses, baseline neutrophilia was associated with 56.8-, 22.6-, 10.7-, and 23.0-fold increased risks of death, disease relapse, locoregional progression, and distant metastasis, respectively. Furthermore, lymphocytes < 200/μl at 1 month was linked to 6.8-, 5.4-, and 6.3-fold increased risks for death, disease relapse, and distant metastasis, respectively.

CONCLUSION

The number of leukocytes, lymphocytes, and neutrophils readily acquired from routine blood tests before and during treatment could be an independent prognostic factor of survival in patients with anal cancer.

Definitive Radiotherapy for Patients With Anal Squamous Cell Carcinoma: A Retrospective Cohort Study

Background

Anal squamous cell carcinoma accounts for less than 2-3% of all digestive system carcinomas. The present study aimed to determine the clinical characteristics, treatment patterns, and treatment outcomes of patients at our institution.

Methodology

We reviewed the clinical data of all consecutive patients with anal squamous cell carcinoma who were treated with definitive radiotherapy in our department between July 2009 and July 2020. Radiotherapy was delivered in 1.8-2 Gy daily fractions to a whole pelvic dose ranging from 45 to 50 Gy, followed by boost radiotherapy of 10-15 Gy, resulting in a total dose of approximately 60 Gy. Concurrent chemotherapy with radiotherapy included 5-fluorouracil/mitomycin C or 5-fluorouracil/cisplatin.

Results

A total of 14 patients with a median age of 61.5 years (range: 45-85 years) were analyzed. There were nine women and five men. The clinical T stage was T1 in two patients, T2 in six patients, T3 in two patients, and T4 in four patients. The clinical N stage was N0 in four patients and N1 in 10 patients. Patients with clinical stage III disease comprised 79% of the entire study population. For the entire cohort, the five-year overall survival rate was 83.3% and the five-year progression-free survival rate was 48.5%. One patient experienced grade 3 fecal incontinence, and the others experienced no radiation-induced severe delayed adverse events.

Conclusions

The results of our study demonstrated that definitive radiotherapy with or without chemotherapy for patients with anal squamous cell carcinoma is an effective and feasible treatment.

The impact of gender and HPV status on anal squamous cell carcinoma survival

BACKGROUND

Anal cancer is a rare entity and the effect of gender and HPV status on survival is controversial. We aimed to evaluate the difference in overall survival (OS) according to gender and analyzed the effect of HPV status on OS.

PATIENTS AND METHODS

The National Cancer Database (NCDB) was queried for patients with anal squamous cell carcinoma between 2004 and 2016. We evaluated the OS based on gender and HPV status using Kaplan-Meier estimates and we used multivariate Cox regression analyses to evaluate factors associated with overall survival.

RESULTS

A total of 6133 patients with known HPV status were included for analysis. In the non-metastatic group, male gender was associated with worse OS (HR 1.50, 95% CI 1.32-1.70; P<0.001) whereas HPV status did not affect the OS (HR 1.08, 95% CI 0.96-1.22; P=0.213). In the metastatic group, there was no difference in OS based on gender (HR 1.29, 95% CI 0.91-1.82; P=0.148), whereas HPV-negative status was associated with worse OS (HR 1.52, 95% CI 1.09-2.12; P=0.014).

CONCLUSION

Females had better OS only in non-metastatic anal squamous cell carcinoma (ASCC). HPV-negative status was associated with worse OS only in metastatic ASCC.

Prognostic and Predictive Clinical and Biological Factors in HPV Malignancies

Human papillomavirus (HPV) causes the majority of oropharyngeal, cervical, and anal cancers, among others. These HPV-associated cancers cause substantial morbidity and mortality despite ongoing vaccination efforts. Aside from the earliest stage tumors, chemoradiation is used to treat most HPV-associated cancers across disease sites. Response rates are variable, and opportunities to improve oncologic control and reduce toxicity remain. HPV malignancies share multiple commonalities in oncogenesis and tumor biology that may inform personalized methods of screening, diagnosis, treatment and surveillance. In this review we discuss the current literature and identify promising molecular targets, prognostic and predictive clinical factors and biomarkers in HPV-associated oropharyngeal, cervical and anal cancer.

Present and Future Research on Anal Squamous Cell Carcinoma

Squamous cell carcinoma of the anus is an orphan disease, and after more than three decades of no substantial advances in disease knowledge and treatment, it is finally gaining momentum with the arrival of a taxane-based chemotherapy and immunotherapy. Currently, about 20 combination clinical trials with an anti-PD1/L1 are ongoing in localized and advanced stages, in association with radiotherapy, chemotherapy, tumor vaccines, anti-CTLA4, anti-EGFR, or antiangiogenic molecules. Moreover, a new biomarker with high sensitivity and specificity such as HPV circulating tumor DNA (HPV ctDNA) by liquid biopsy, is improving not only the prognostic measurement but also the treatment strategy guidance for this disease. Finally, better understanding of potential targets is reshaping the present and future clinical research in this unique, HPV genotype-16-related disease in the great majority of patients.

Role of 18F-FDG PET-derived parameters for predicting complete response to chemoradiotherapy in squamous cell anal carcinoma

PURPOSE

We aimed to evaluate the accuracy of metabolic parameters, calculated on pretreatment positron emission computed tomography (PET/CT) with fluorodeoxyglucose (F-FDG), for predicting complete response to chemoradiotherapy (CRT) of patients affected by squamous cell anal carcinoma (SCAC).

PATIENTS AND METHODS

Clinical records of 20 patients affected by SCAC and treated with CRT were retrospectively evaluated. F-FDG PET/CT was performed at time 0 (baseline) and time 1 (12 weeks after CRT). The following parameters were extracted from PET at time 0: standardized uptake values (SUVmax and SUVmean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG). Response was assessed according to PET response criteria in solid tumors and classified as complete metabolic response (CMR), partial metabolic response (PMR) and progressive metabolic disease (PMD). Receiver operating characteristic analysis was performed to analyze the predictive value of each PET-derived parameter on CMR.

RESULTS

Sixteen patients were finally enrolled. All presented increased F-FDG uptake in the primary tumor and 11 (68.7%) also showed metastatic lymph nodes. At PET/CT performed at time 1, 11 subjects (68.7%) presented CMR, three (18.7%) had PMR and the remaining two (12.5%) showed PMD (i.e. hepatic metastases). Among baseline PET-derived parameters, both MTV and TLG efficiently predicted response to CRT with an area under the curve of 0.9 (cutoff 62.3 cm, sensitivity 80%, specificity 100%, P = <0.0001) and 0.87 (cutoff 654.1 g, sensitivity 80%, specificity 100%, P = 0.004), respectively.

CONCLUSION

Among PET-derived parameters, both MTV and TLG presented a high predictive value on subjects' outcome after CRT.

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%.

Intensified Induction Chemotherapy in Locally Advanced Squamous Cell Carcinoma of the Anus-A Population-Based Experience from the Danish Anal Cancer Group

Simple Summary

The primary treatment modality for anal cancer is chemoradiotherapy, but patients with locally advanced disease (i.e., large tumors and/or involvement of regional lymph nodes) have a high risk of treatment failure. The use of chemotherapy prior to radiotherapy (induction chemotherapy) can potentially shrink the tumor and/or eradicate small cancer cells with metastatic potential, with a chance of a better outcome. With this paper, the authors present 20 years of nationwide experience with intensified induction chemotherapy in the treatment of locally advanced anal cancer, which indicates a role for further investigation in the most advanced cases.

Abstract

Locally advanced squamous cell carcinoma of the anus (LASCCA) has a poor prognosis with a high risk of treatment failure calling for intensified therapy. We present the long-term follow-up of a nationwide cohort of LASCCA treated with intensified induction chemotherapy (ICT). The study included patients with LASCCA (T3-4N0 or T1-4N+) treated with at least one cycle of ICT (cisplatin, ifosfamide, leucoverin, and 5-flourouracil) between 1998–2018. Data were retrospectively collected from medical records, and statistics were performed in STATA 16.1. In total, 166 patients with LASCCA were identified. Following ICT, 157 patients (95%) received primary curative treatment with either radiotherapy (70%), chemoradiotherapy (27%), or abdominal perineal resection (3%). The overall local tumor response rate after ICT was 76% with 20 (13%) achieving complete local tumor response. After the primary treatment, 123 patients (79%) obtained complete response, and 27 underwent salvage surgery due to persistent disease. The median follow-up time was 6 years, local and distant failure rates 22% and 13%, respectively. The 3- and 5-year disease-free survival rates were 70% and 67%, and the 3- and 5-year overall survival rates were 76% and 70%, respectively. Intensified ICT regimen could be a supplementary treatment option in the most advanced cases of LASCCA. Prospective randomized trials are needed to investigate this approach further.

A population-based analysis of chemoradiation versus radiation alone in the definitive treatment of patients with stage I-II squamous cell carcinoma of the anus

BACKGROUND

The optimal management of patients with stage I-II squamous cell carcinoma (SCC) of the anus is controversial. The current study evaluates the efficacy of combined chemotherapy and radiation therapy (CRT) versus radiation therapy (RT) alone in the treatment of these patients using the Surveillance, Epidemiology, and End Results (SEER) registries.

METHODS

SEER 18 Custom Data registries were queried for patients with stage I-II SCC of the anus. Univariate analysis (UVA) and multivariable analysis (MVA) using Kaplan-Meier and Cox proportional hazards regression modeling were performed. Propensity-score matched analysis with inverse probability of treatment weighting (IPTW) was used to account for indication bias.

RESULTS

A total of 4,288 patients with stage I-II disease were identified, of whom 3,982 (93%) underwent CRT and 306 (7%) underwent RT. Median follow-up was 42 months. Approximately 30.8% had T1 disease and 69.2% had T2-T3 disease. The IPTW-adjusted 5-year overall survival (OS) was 76.7%, with no significant differences between the CRT and RT groups (77% vs. 73.5%, P=0.33). On multivariate IPTW-adjusted analysis, the lack of association between CRT use and OS was upheld (HR, 0.84, 95% CI, 0.65-1.08, P=0.2). On subgroup analyses, 5-year OS was 86% with CRT (n=1,216) and 84.2% with RT (n=103) (P=0.74) in stage I (T1N0) patients, while 5-year OS was 72.8% with CRT (n=2,766) and 66.4% with RT (n=203) (P=0.13) in stage II (T2-3N0) patients. CRT was associated with improved median OS in stage II patients (119 months vs. not reached, P=0.04).

CONCLUSIONS

The current study suggests that omission of concurrent chemotherapy is not associated with inferior OS in patients with stage I SCC of the anus. However, combined chemoradiation was superior to radiation alone in patients with stage II disease. Prospective evidence is needed to optimize clinical decision-making in this patient population.

Evolution of the Role of Radiotherapy for Anal Cancer

Prior to the 1980s, the primary management of localized anal cancer was surgical resection. Dr. Norman Nigro and colleagues introduced neoadjuvant chemoradiotherapy prior to abdominoperineal resection. Chemoradiotherapy 5-fluorouracil and mitomycin C afforded patients complete pathologic response and obviated the need for upfront surgery. More recent studies have attempted to alter or exclude chemotherapy used in the Nigro regimen to mitigate toxicity, often with worse outcomes. Reductions in acute adverse effects have been associated with marked advancements in radiotherapy delivery using intensity-modulated radiation therapy (IMRT) and image-guidance radiation delivery, resulting in increased tolerance to greater radiation doses. Ongoing trials are attempting to improve IMRT-based treatment of locally advanced disease with efforts to increase personalized treatment. Studies are also examining the role of newer treatment modalities such as proton therapy in treating anal cancer. Here we review the evolution of radiotherapy for anal cancer and describe recent advances. We also elaborate on radiotherapy's role in locally persistent or recurrent anal cancer.

Cancer of the anal canal, a reality in the Colombian coffee region. Clinical-epidemiological review 2000-2019

INTRODUCTION

Anal cancer is a rare pathology which has increased over the last few decades, and, therefore, gained importance for the quality of life of affected individuals. Thus, a review has been conducted in the Colombian coffee region (Departments of Caldas, Quindío y Risaralda) describing its behaviour and clinical-epidemiological profile.

MATERIALS AND METHODS

Descriptive review of 437 patients of Western SAS Oncologists between January 2000 and December 2019 with a diagnosis of anal cancer.

RESULTS

62% of cases presented in women with a median age of 62 years, 30% in the sixth decade; centred at 65% in three main cities designated as capitals (Manizales, Pereira and Armenia); 62% as localised disease, with 40% stage II-A and 6% as initial metastasis; 29% presented positive ganglia, particularly N1a; squamous cell or epidermoid histology in 90%; 16% poorly differentiated; 5% related to Human Immunodeficiency Virus infection; localisation in the medial area of the anal canal in 63% of cases; 83% completed treatment, and 92% of them received chemotherapy/radiation therapy with 87% based on the Nigro protocol; finally, 11% presented with relapse in the liver in 10% of cases and 55% local.

CONCLUSION

Four hundred and thirty-seven patients evaluated over 20 years with follow up at median 34.13 months (standard deviation 41.75) with median survival at later ages decreasing to 62% in patients older than 80 years, and differences in survival in localised disease at 78% in comparison to 46% in advanced metastasis. Finally, the overall 5-year survival rate is 69% with a median survival of 191 months in the study.

The Prognostic Value of the New Combined Hemo-Eosinophil Inflammation Index (HEI Index): A Multicenter Analysis of Anal Cancer Patients Treated with Concurrent Chemo-Radiation

Anal squamous cell carcinoma (SCC) is a rare tumor, and bio-humoral predictors of response to chemo-radiation (CT-RT) are lacking. We developed a prognostic score system based on laboratory inflammation parameters. We investigated the correlation between baseline clinical and laboratory variables and disease-free (DFS) and overall (OS) survival in anal SCC patients treated with CT-RT in five institutions. The bio-humoral parameters of significance were included in a new scoring system, which was tested with other significant variables in a Cox's proportional hazard model. A total of 308 patients was included. We devised a prognostic model by combining baseline hemoglobin level, SII, and eosinophil count: the Hemo-Eosinophils Inflammation (HEI) Index. We stratified patients according to the HEI index into low- and high-risk groups. Median DFS for low-risk patients was not reached, and it was found to be 79.5 months for high-risk cases (Hazard Ratio 3.22; 95% CI: 2.04-5.10; p < 0.0001). Following adjustment for clinical covariates found significant at univariate analysis, multivariate analysis confirmed the HEI index as an independent prognostic factor for DFS and OS. The HEI index was shown to be a prognostic parameter for DFS and OS in anal cancer patients treated with CT-RT. An external validation of the HEI index is mandatory for its use in clinical practice.

[Squamous cell anal carcinoma. What's next ?]

Despite its status as a rare disease, the incidence of the squamous cell carcinoma of the anus (SCCA) is surging, especially in its metastatic form. In addition, the prognosis of initially localized diseases has not substantially changed since the 1970s with a recurrence rate of between 25-40 % after the chemoradiotherapy. The updated data from 115 patients included in the Epitopes-HPV01 and Epitopes-HPV02 trials, confirm the modified regimen of DCF (mDCF) as the treatment of choice for patients with advanced SCCA given the rate of sustained remissions and complete molecular responses observed. The carboplatin-paclitaxel regimen may be considered as an option for patients with contraindication to cisplatin or 5-FU. In chemo-refractory patients, the efficacy of anti-PD-1/PD-L1 in monotherapy is limited and only brings benefit to 10-20 % of patients, and its use cannot be generalized in the absence of an association potentiating its effectiveness. In order to better understand the immunological parameters associated with advanced SCCA, an analysis of peripheral immune responses was carried out in the Epitopes-HPV01 and 02 trials. It demonstrated the key role of CD4 Th1 specific responses of telomerase and M-MDSC as main prognostic factors for the therapeutic efficacy of DCF. Numerous combination trials are currently underway or will soon begin in localized SCCA, as well as in the first and second-line in the advanced stage. Finally, the detection of circulating tumor DNA of HPV oncoprotein E6 and E7 (HPVtc), especially by the "digital droplet PCR" technique, is highly sensitive and specific, and can be used in daily practice.

Feasibility and Outcome of Routine Use of Concurrent Chemoradiation in HIV-positive Patients With Squamous Cell Anal Cancer

OBJECTIVES

Clinical concerns about hematologic toxicities in human immunodeficiency virus (HIV)+ patients with squamous cell anal cancer (SCAC) may lead to de-escalation of treatment intensity. The objective of this study is to evaluate clinical outcomes including toxicity following standard concurrent curative-intent chemoradiation for HIV+ and HIV- patients with SCAC.

MATERIALS AND METHODS

Among 97 evaluable patients treated between 2009 and 2016 (median age 52.2 y), 43 (44.3%) were HIV+ and 54 (55.7%) HIV-. The majority of the radiation was delivered using intensity-modulated radiation therapy and chemotherapy consisting primarily (93%) of 5-fluorouracil and mitomycin C. Clinical outcomes assessed included toxicity, locoregional control (LRC), distant metastasis (DM), progression-free survival (PFS), colostomy-free survival (CFS), overall survival (OS), and cause-specific survival (CSS).

RESULTS

With a median follow-up of 45 months, HIV+ patients exhibited a trend toward reduced OS compared with HIV- patients (4 y OS 61.2% vs. 78.3%; HR 2.09; 95% CI, 0.97-4.52; P=0.055) on univariable analysis, but HIV status was not significant after adjusting for additional parameters on multivariable analysis. Toxicity rates, LRC, CFS, PFS, freedom from DM, and CSS were similar between the 2 cohorts. On multivariable analysis, tumor size >5 cm impacted all clinical outcomes (trend for LRC) except CFS. Radiation treatment extension beyond 7 days was found to negatively impact LRC and CSS. Male sex was associated with worse CFS.

CONCLUSIONS

Radiation therapy with concurrent 5-fluorouracil and mitomycin C chemotherapy is reasonably well-tolerated as curative treatment for HIV+ patients with SCAC, and no significant difference in outcomes was noted relative to HIV- patients.

Prognostic implications of advancing nodal stage in anal cancer: evaluating AJCC 8 staging changes through an NCDB analysis

PURPOSE

In the AJCC8, nodal staging for squamous cell carcinoma of the anus (SCCA) has been changed to a binary format (N0 or N+), and overall stage groups have been redefined. We evaluated the effect of AJCC8 nodal stage by T stage and hypothesized similar survival regardless of the extent of AJCC7-defined nodal involvement.

METHODS

The National Cancer Database (NCDB) was used to identify patients' SCCA. Overall survival (OS) for each T stage within the AJCC7 was compared with increasing nodal stage, as well as for the new AJCC8 overall stage groups and subsets.

RESULTS

There were 6738 patients analyzed. The 5-year OS by AJCC8 stage was I = 81%, IIA = 78%, IIB = 64%, IIIA = 69%, IIIB = 59%, IIIC = 57% (p < 0.0001). In AJCC8 IIIA (T1-2, N+), there was no difference in 5-year OS between T1N+ or T2N+ patients (70.3% vs 68.6%, p = 0.09). A significant survival difference was demonstrated between AJCC7 N1, N2, and N3 for patients with either T1 (p = 0.0047) or T2 (p = 0.0389) disease. In the AJCC 8 IIIC (T3-4, N+) group, there was no difference in 5-year OS between T3N+ and T4N+ (58% vs 55%, p = 0.81). There was no OS difference between AJCC7 N1-3 for either T3 (p = 0.19) or T4 (0.35) disease.

CONCLUSION

For earlier T stages, advancing nodal stage per AJCC7 retains prognostic implications for OS. Survival in AJCC8 stage IIIA is heterogeneous and is largely driven by burden of nodal disease in patients with T1-2 disease.

Tailoring the radiotherapy approach in patients with anal squamous cell carcinoma based on inguinal sentinel lymph node biopsy

BACKGROUND AND OBJECTIVES

The aim of our study was to analyze the results of selective inguinal node irradiation in patients with anal cancer, based on the biopsy of the inguinal sentinel lymph node (SLN), in terms of local control and prognosis.

METHODS

Records of patients with anal squamous cell carcinoma from January 2001 to December 2016 were retrospectively reviewed. Tc99 lymphoscintigraphy was performed in all the clinically inguinal negative patients, followed by radio-guided surgical removal of the inguinal SLN. All patients were treated with combined radiochemotherapy. In patients with negative sentinel nodes, the inguinal area was excluded in the radiotherapy field.

RESULTS

A total of 123 patients, 76 females (61.8%), mean age 60.1 ± 12.19 years old, underwent intraoperative lymph node retrieval. The histological analysis showed metastasis in the SLN in 28 patients (22.8%). The mean follow-up was 43.44 ± 31.86 months. No inguinal recurrence was observed in patients with negative inguinal sentinel node(s). A statistically significant difference was observed for overall and disease-free survivals in a patient with positive and negative inguinal sentinel nodes.

CONCLUSIONS

In patients with anal canal cancer, the exclusion of the inguinal regions from the radiotherapy field, in patients with negative SLN, does not compromise locoregional control nor prognosis.

Sarcopenia Is Associated With Hematologic Toxicity During Chemoradiotherapy in Patients With Anal Carcinoma

Purpose

Sarcopenia, defined as a loss of muscle mass and quality, has been associated with impaired oncological outcome and treatment toxicities in several malignancies. However, its role in anal squamous cell carcinoma (ASCC) remains less well explored.

Methods/Materials

Planning CT scans were used to measure cross-sectional skeletal muscle area (SMA) to calculate the skeletal muscle index (SMI). The association of sarcopenia with clinical and treatment-related parameters, and toxicity was assessed in 114 patients with ASCC that underwent standard 5-Fluorouracil/Mitomycin C chemoradiotherapy (CRT). The prognostic impact of sarcopenia on local relapse-free survival (LRFS), disease-free survival (DFS), and overall survival was examined using a Cox regression analysis.

Results

29 (25.4%) patients had sarcopenia. Patients with sarcopenia had lower baseline hemoglobin levels (p = 0.002), worse Karnofsky Performance Status (p = 0.001) lower BMI (p < 0.001), and a significantly lower body surface area (p = 0.03), and lower incidence of involved lymph nodes (p = 0.03). Regarding acute toxicity, sarcopenia was associated with a significantly higher incidence of ≥grade 3leukopenia (OR: 3.5; 95% CI: 1.6-7.5, p = 0.007) and ≥grade 3 thrombopenia (OR: 5.1; 95% CI: 1.3-21, p = 0.018) after CRT. Despite higher hematologic toxicity in sarcopenic patients, total treatment time was similar between patients with and without sarcopenia (median 44 vs 45 days, p = 0.95). There was no significant prognostic impact of sarcopenia on either LRFS, DFS, or OS.

Conclusion

This is the largest study to assess the impact of sarcopenia on toxicity and oncological outcome in patients with ASCC. Increased clinician awareness of higher hematological toxicity risk is needed for sarcopenic patients with ASCC undergoing CRT to facilitate closer monitoring of side effects and earlier introduction of supportive measures. Further prospective studies are needed to elucidate the prognostic role and impact of sarcopenia on CRT-related toxicity in ASCC.

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.

Squamous cell anal cancer: Management and therapeutic options

The incidence of anal cancer has increased during the second half of the 20th century, with an incidence rate over 2.9% greater than in the decade of 1992-2001. Yet, it still constitutes a small percentage, about 4%, of all anorectal tumours. Its risk factors are human papillomavirus infection, a history of sexually transmitted diseases, a history of vulvar or cervical carcinoma, immunosuppression related to human immunodeficiency virus infection or after organ transplantation, haematological or immunological disorders, and smoking. The most frequent symptom is rectal bleeding (45%), followed by anal pain, and sensation of a rectal mass. The diagnosis requires clinical examination, palpation of the inguinal lymph nodes, high resolution anoscopy followed by fine-needle aspiration biopsy or core biopsy. Subsequent histologic diagnosis is necessary, as well as computed tomography or magnetic resonance imaging evaluation of the pelvic lymph nodes. Since 1980, patients with a diagnosis of anal cancer have shown a significant improvement in survival. In Europe during the years 1983-1994, 1-year survival increased from 78% to 81%, and the improvement over 5 years was between 48% and 54%. Prior to 1974, patients with invasive cancer were routinely scheduled for abdominoperineal amputation, after which it was demonstrated that treatment with 5-fluorouracil and radiotherapy associated with mitomycin or capecitabine could be adequate to treat the tumour without surgery. Today, numerous studies have confirmed that combined multimodal treatment is effective and sufficient.

Prognostic Impact of Pretherapeutic FDG-PET in Localized Anal Cancer

Due to the heterogeneity of tumour mass segmentation methods and lack of consensus, our study evaluated the prognostic value of pretherapeutic positron emission tomography with fluorodeoxyglucose (FDG-PET) metabolic parameters using different segmentation methods in patients with localized anal squamous cell carcinoma (SCC). Eighty-one patients with FDG-PET before radiochemotherapy were retrospectively analyzed. Semiquantitative data were measured with three fixed thresholds (35%, 41% and 50% of Maximum Standardized Uptake Value (SUVmax)) and four segmentation methods based on iterative approaches (Black, Adaptive, Nestle and Fitting). Metabolic volumes of primary anal tumour (P-MTV) and total tumour load (T-MTV: P-MTV+ lymph node MTV) were calculated. The primary endpoint was event-free survival (EFS). Seven multivariate models were created to compare FDG-PET tumour volumes prognostic impact. For all segmentation thresholds, PET metabolic volume parameters were independent prognostic factor and T-MTV variable was consistently better associated with EFS than P-MTV. Patient's sex was an independent variable and significantly correlated with EFS. With fixed threshold segmentation methods, 35% of SUVmax threshold seemed better correlated with EFS and the best cut-off for discrimination between a low and high risk of event occurrence was 40 cm3. Determination of T-MTV by FDG-PET using fixed threshold segmentation is useful for predicting EFS for primary anal SCC. If these data are confirmed in larger studies, FDG-PET could contribute to individualized patient therapies.

Comprehensive Characterization of the Mutational Landscape in Localized Anal Squamous Cell Carcinoma

Anal squamous cell carcinoma (ASCC) is a rare neoplasm. Chemoradiotherapy is the standard of care, with no therapeutic advances achieved over the past three decades. Thus, a deeper molecular characterization of this disease is still necessary. We analyzed 46 paraffin-embedded tumor samples from patients diagnosed with primary ASCC by exome sequencing. A bioinformatics approach focused in the identification of high-impact genetic variants, which may act as drivers of oncogenesis, was performed. The relation between genetics variants and prognosis was also studied. The list of high-impact genetic variants was unique for each patient. However, the pathways in which these genes are involved are well-known hallmarks of cancer, such as angiogenesis or immune pathways. Additionally, we determined that genetic variants in BRCA2, ZNF750, FAM208B, ZNF599, and ZC3H13 genes are related with poor disease-free survival in ASCC. This may help to stratify the patient's prognosis and open new avenues for potential therapeutic intervention. In conclusion, sequencing of ASCC clinical samples appears an encouraging tool for the molecular portrait of this disease.

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

Aim

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

Methods

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

Results

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

Conclusions

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

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 Squamous Cell Carcinoma: Radiation Therapy Alone Must Be Avoided

BACKGROUND

Anal squamous cell carcinoma (ASCC) is the most common histological subtype of anal cancer. Rates have been observed to increase in recent years. Combined chemoradiotherapy (CCRT) is currently the gold standard of treatment. The aim of this study is to assess ASCC prevalence, treatment trends, and overall survival (OS) in the United States.

METHODS

Patients diagnosed with stage I-IV ASCC were identified from the National Cancer Database from 2004 to 2015. The primary outcome was 5-year OS, which was analyzed using Kaplan-Meier survival curves, log-rank test, and Cox proportional hazards models.

RESULTS

34,613 cases were included (stage I: 21.45%; II: 41.00%; III: 31.62%; IV: 5.94%), with an increasing trend in prevalence. CCRT was the most used treatment. Multimodal treatment, combining surgery with CCRT, offered the best OS rates for stage I, II, and IV cancers (I: 84.87%; II: 75.12%; IV: 33.08%), comparable with survival of stage III patients treated with CCRT (III: 61.14%). Radiation alone had the worse OS rates, and on adjusted analysis, radiation treatment alone had the greatest risk of mortality (I: hazard ratio, 2.01; 95% confidence interval, 1.14-3.54; P = 0.016; II: 2.05, 1.44-2.93, P < 0.001; IV: 1.99, 0.99-4.02, P = 0.054).

CONCLUSIONS

ASCC has increased in prevalence, notably in stage III and IV disease. Although CCRT is the most commonly used treatment type for all stages of ASCC, multimodal treatment offers better OS in stages I, II, and IV. Treatment with radiation alone offers the worst OS no matter the stage and should no longer be used as a solitary treatment modality.

Have we achieved adequate recommendations for target volume definitions in anal cancer? A PET imaging based patterns of failure analysis in the context of established contouring guidelines

Background

There are different contouring guidelines for the clinical target volume (CTV) in anal cancer (AC) which vary concerning recommendations for radiation margins in different anatomical regions, especially on inguinal site. PET imaging has become more important in primary staging of AC as a very sensitive method to detect lymph node (LN) metastases. Using PET imaging, we evaluated patterns of LN spread, and examined the differences of the respective contouring guidelines on the basis of our results.

Methods

We carried out a retrospective study of thirty-seven AC patients treated with chemoradiation (CRT) who underwent FDG-PET imaging for primary staging in our department between 2011 and 2018. Patients showing PET positive LN were included in this analysis. Using a color code, LN metastases of all patients were delineated on a template with “standard anatomy” and were divided indicating whether their location was in- or out-field of the standard CTV as recommended by the Radiation Therapy Oncology Group (RTOG), the Australasian Gastrointestinal Trials Group (AGITG) or the British National Guidance (BNG). Furthermore, a detailed analysis of the location of LN of the inguinal region was performed.

Results

Twenty-two out of thirty-seven AC patients with pre-treatment PET imaging had PET positive LN metastases, accumulating to a total of 154 LN. The most commonly affected anatomical region was inguinal (49 LN, 32%). All para-rectal, external/internal iliac, and pre-sacral LN were covered by the recommended CTVs of the three different guidelines. Of forty-nine involved inguinal LN, fourteen (29%), seven (14%) and five (10%) were situated outside of the recommended CTVs by RTOG, AGITG and BNG. Inguinal LN could be located up to 5.7 cm inferiorly to the femoral saphenous junction and 2.8 cm medial or laterally to the big femoral vessels.

Conclusion

Pelvis-related, various recommendations are largely consistent, and all LN are covered by the recommended CTVs. LN “misses” appear generally cranially (common iliac or para-aortic) or caudally (inguinal) to the recommended CTVs. The established guidelines differ significantly, particular regarding the inguinal region. Based on our results, we presented our suggestions for CTV definition of the inguinal region. LN involvement of a larger number of patients should be investigated to enable final recommendations.

Introducing the eighth edition of the tumor-node-metastasis classification as relevant to colorectal cancer, anal cancer and appendiceal cancer: a comparison study with the seventh edition of the tumor-node-metastasis and the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma

BACKGROUND

The eighth edition of the tumor-node-metastasis classification of malignant tumors updates cancer staging according to the evidence accumulated in the last 8 years since the release of the tumor-node-metastasis seventh edition. This review focuses on the new staging system.

METHODS

The eight edition was compared with the seventh edition as well as the Japanese Classification of Colorcetal, Appendiceal, and Anal carcinoma ninth edition.

RESULTS

Of colon and rectum, the tumor-node-metastasis eighth edition expands the M category. Specifically, colorectal cancer with peritoneal metastasis is newly categorized as M1c, distinguishing it from M1a (metastasis to one organ) and M1b (metastasis to more than one organ). In the ninth edition of Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma, M1c is further subdivided into M1c1 (metastasis to the peritoneum without other organ involvement) and M1c2 (metastasis to the peritoneum with other organ involvement). In the T category, the tumor-node-metastasis eighth edition excludes high-grade dysplasia (intraepithelial carcinoma) from Tis; this differs from both the tumor-node-metastasis seventh edition and the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma ninth edition. In the N category, the tumor-node-metastasis eighth edition does not add the number of tumor deposits to the number of positive regional lymph nodes, whereas this number is added in the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma ninth edition. The definition of anal cancer is also modified considerably in the tumor-node-metastasis eighth edition; specifically, tumors of perianal skin defined as within 5 cm of the anal margin are also classified as anal canal carcinoma, external iliac lymph nodes become regional lymph nodes, and both N2 and N3 are abolished in the N category. With regard to appendix, Tis (low-grade appendiceal mucinous neoplasma) and tumor deposit(s) are newly introduced. Finally, the tumor-node-metastasis eighth edition offers a new structure, labeled a 'prognostic factors grid', which consists of prognostic factors for survival in both colorectal and anal cancer.

CONCLUSIONS

Staging classification is updated regularly, which clinicians should always catch up with.

MRI heterogeneity analysis for prediction of recurrence and disease free survival in anal cancer

BACKGROUND

The aim of this study was to evaluate the role of image heterogeneity analysis of standard care magnetic resonance imaging (MRI) in patients with anal squamous cell carcinoma (ASCC) to predict chemoradiotherapy (CRT) outcome. The ability to predict disease recurrence following CRT has the potential to inform personalized radiotherapy approaches currently being explored in novel clinical trials.

METHODS

An IRB waiver was obtained for retrospective analysis of standard care MRIs from ASCC patients presenting between 2010 and 2014. Whole tumor 3D volume-of-interest (VOI) was outlined on T2-weighted (T2w) and diffusion weighted imaging (DWI) of the pre- and post-treatment scans. Independent imaging features most predictive of disease recurrence were added to the baseline clinico-pathological model and the predictive value of respective extended models was calculated using net reclassification improvement (NRI) algorithm. Cross-validation analysis was carried out to determine percentage error reduction with inclusion of imaging features to the baseline model for both endpoints.

RESULTS

Forty patients who underwent 1.5 T pelvic MRI at baseline and following completion of CRT were included. A combination of two baseline MR heterogeneity features (baseline T2w energy and DWI coefficient of variation) was most predictive of disease recurrence resulting in significant NRI (p = 0 < 0.001). This was confirmed in cross-validation analysis with 34.8% percentage error reduction for the primary endpoint and 18.1% reduction for the secondary endpoint with addition of imaging variables to baseline model.

CONCLUSION

MRI heterogeneity analysis offers complementary information, in addition to clinical staging, in predicting outcome of CRT in anal SCC, warranting validation in larger datasets.