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

Prognostic Value of External Iliac Lymph Node (N1b) Metastasis in Anal Carcinoma and Validation of a New Stage Grouping System

OBJECTIVE

To assess the impact of external iliac lymph node (N1b) metastasis on anal carcinoma (AC) staging and refine the Tumor-Node-Metastasis (TNM) system without modifying existing criteria.

METHODS

This retrospective study was performed utilizing the data of 3,815 patients with AC included in the Surveillance, Epidemiology, and End Results (SEER) registry from 2018 to 2021. We compared the TNM8th and 9th editions with our proposed system, focusing on overall survival (OS) and cancer-specific survival (CSS). The Kaplan-Meier survival analysis and time-dependent C-index measures were employed to evaluate the 3 staging systems.

RESULTS

The SEER registry identified only 42 patients with solitary N1b metastasis, with lymph node (LN) metastasis rates rising with higher T stages. No significant survival differences were found among N1a to N1c subgroups, yet N1a showed better OS and CSS than N1b+c (hazard ratio [HR] = 1.306, 95% confidence interval (CI): 1.011-1.687, P = .041 for OS; HR = 1.432, 95% CI: 1.088-1.886, P = .011 for CSS). The proposed TNM system, reclassifying T 1N1M0 as stage I and defining T3-T4 with LN status as stages IIIA and IIIB, showed marginally improved predictive accuracy (C-index: 0.684 vs. 0.683 for OS; 0.635 vs. 0.634 for CSS).

CONCLUSIONS

N1b metastasis minimally affects AC staging. We introduce a simplified TNM system for clinical use: M Staging: Distant metastasis presence as M1. T Staging: T1 as stage I, T2 as stage II, T3-T4 as stage III. N Staging: N status noncontributory for stage I; N negative as stage A (IIA or IIIA), N positive as stage B (IIB or IIIB).

Surgery, chemoradiotherapy, or chemoradiation plus immunotherapy: Treatment strategies for nonmetastatic anal squamous cell carcinoma

The current standard of care for anal squamous cell carcinoma (ASCC) is definitive concurrent chemoradiotherapy (CRT). However, about a third of patients may experience treatment failure. Recently, immunotherapy has emerged as a novel strategy for metastatic ASCC patients. We evaluated the efficacy and safety of surgery, CRT alone, and CRT with immunotherapy (CRT-I) in 100 nonmetastatic ASCC patients, treated from April 2012 through May 2023, by determining survival outcomes and acute adverse events. The median (range) follow-up was 30.7 (7.6 to 134.9) months. The study cohort 3-year overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and locoregional recurrence-free survival (LRFS) rates were 80.7 %, 62.2 %, 71.1 %, and 67.6 %, respectively. The Surgery group had significantly lower rates than the CRT and CRT-I groups for 3-year PFS (33.1% vs. 65.2% vs. 92.9 %, P < 0.001), DMFS (46.7% vs. 74.6% vs. 92.9 %, P = 0.002) and LRFS (37.0% vs. 73.3% vs. 92.9 %, P < 0.001), respectively. All patients receiving CRT-I were alive at last follow-up. Of 100 patients, 26 (26.0 %) experienced severe (≥ grade 3) acute toxicity. Of 24 patients receiving CRT-I, 8 (33.3 %) had severe acute toxicity. Using immunohistochemistry, peritumoural stromal infiltration by CD8+ T cells was significantly higher after CRT-I compared to before CRT-I and to after CRT alone. The addition of immunotherapy to CRT may be an effective first-line treatment option with favourable survival outcomes and acceptable toxicity for patients with ASCC. A prospective, randomized trial assessing the efficacy of CRT combined with a PD-1 inhibitor in patients with locally advanced ASCC is in progress.

International consensus to define outcomes for trials of chemoradiotherapy for anal cancer (CORMAC-2): defining the outcomes from the CORMAC core outcome set

Variation in outcomes definitions and reporting limit the utility of clinical trial results. The Core Outcome Research Measures in Anal Cancer (CORMAC) project developed a core outcome set (COS) for chemoradiotherapy trials for anal squamous cell carcinoma (ASCC) through an international healthcare professional and patient consensus process. The CORMAC-COS comprises 19 outcomes across 4 domains (disease activity, survival, toxicity, life impact). In CORMAC-2 we have established standardised definitions for the 11 disease activity and survival outcomes in the CORMAC COS. Definitions were agreed through a 3 step process, initially identifying existing definitions through systematic review (registered with PROSPERO, CRD42016036540), using these to populate a two-round Delphi questionnaire completed by 51 experts from 13 countries, and finally ratification through an online consensus meeting. Standardising the definitions for these core outcomes facilitates real world utilisation of the CORMAC-COS, thereby increasing the quality of data available for clinical decision-making and ultimately enhancing patient care.

Prognostic implications of HIF-1α expression in anal squamous cell carcinoma treated with intensity-modulated radiotherapy (IMRT)

Background

Hypoxia-inducible factor-1α (HIF-1α) is a crucial transcription factor activated under hypoxic conditions, known to regulate genes associated with tumor survival, progression, and response to therapy. This study aimed to evaluate the prognostic significance of HIF-1α expression in patients with anal squamous cell carcinoma (ASCC) undergoing chemoradiation therapy.

Methods

We conducted a retrospective analysis of 28 ASCC patients treated with intensity-modulated radiotherapy (IMRT) at our center from 2009 to 2022. HIF-1α expression was assessed via immunohistochemistry on formalin-fixed paraffin-embedded tissue specimens. Quantitative analysis of HIF-1α expression was performed, and its relationship with clinical outcomes, including disease-free survival (DFS), locoregional relapse-free survival (LRRFS), and overall survival (OS), was examined using Cox regression models. Furthermore, ASCC tissue specimens from 17 patients were analyzed for potential PIK3CA mutations using Sanger sequencing.

Results

High HIF-1α expression was significantly associated with poorer DFS (p = 0.005), LRRFS (p = 0.012), and OS (p = 0.009). HIF1α expression was marginally significantly higher in males compared to females (p = 0.056) while there was no significant difference found based on tumor stage or p16 status. However, a positive correlation was identified between BMI and HIF-1α levels (Pearson correlation r = 0.5, p = 0.0084), suggesting a link between metabolic status and tumor hypoxia. Only one patient exhibited a PIK3CA mutation, preventing a reliable assessment of its correlation with HIF-1α expression.

Conclusion

Our findings underscore the importance of HIF-1α as a potential biomarker for predicting survival outcomes in ASCC patients treated with chemoradiation. The association between higher BMI and increased HIF-1α expression may provide insights into the interplay between metabolic health and tumor biology in ASCC. Further studies with larger cohorts are needed to validate these findings and explore targeted therapies focusing on HIF-1α modulation.

Prognostic Significance of Bulky Nodal Disease in Anal Cancer Management: A Multi-institutional Study

PURPOSE

This study aimed to assess the prognostic significance of bulky nodal involvement in patients with anal squamous cell carcinoma treated with definitive chemoradiotherapy.

MATERIALS AND METHODS

We retrospectively analyzed medical records of patients diagnosed with anal squamous cell carcinoma who underwent definitive chemoradiotherapy at three medical centers between 2004 and 2021. Exclusion criteria included distant metastasis at diagnosis, 2D radiotherapy, and salvage treatment for local relapse. Bulky N+ was defined as nodes with a long diameter of 2 cm or greater.

RESULTS

A total of 104 patients were included, comprising 51 with N0, 46 with non-bulky N+, and seven with bulky N+. The median follow-up duration was 54.0 months (range, 6.4 to 162.2 months). Estimated 5-year progression-free survival (PFS), loco-regional recurrence-free survival (LRRFS), and overall survival (OS) rates for patients with bulky N+ were 42.9%, 42.9%, and 47.6%, respectively. Bulky N+ was significantly associated with inferior PFS, LRRFS, and OS compared to patients without or with non-bulky N+, even after multivariate analysis. We proposed a new staging system incorporating bulky N+ as N2 category, with estimated 5-year LRRFS, PFS, and OS rates of 81.1%, 80.6%, and 86.2% for stage I, 67.7%, 60.9%, and 93.3% for stage II, and 42.9%, 42.9%, and 47.6% for stage III disease, enhancing the predictability of prognosis.

CONCLUSION

Patients with bulky nodal disease treated with standard chemoradiotherapy experienced poor survival outcomes, indicating the potential necessity for further treatment intensification.

Factors Influencing Outcomes and Survival in Anal Cancer

BACKGROUND

We aim to ascertain prognostic factors in the current management of anal cancer within this study.

METHODS

We reviewed the management and outcomes of anal cancer cases over a seven-year period, inclusive (2016-2023). The primary objectives were to assess the demographic characteristics, clinical presentation, and outcomes of all anal cancer patients within our institution. Kaplan-Meier survival analysis was used to estimate survival differences between cohorts, with statistical significance determined using log-rank testing. Cox proportional hazards regression was utilised to identify prognostic factors. Cox regression hazard ratios were reported along with confidence intervals and p-values.

RESULTS

The median follow-up time for the study was 29.8 months. Seventy-five patients with anal cancer were included in this study, with 88% (66/75) being squamous cell carcinoma (SCC) and the majority having regional disease (82.7% (62/75)). The median age at diagnosis was 63.4 years (36-94). There was a female preponderance (57.3% (43/75)). In total, 84% (63/75) underwent definitive chemoradiation (dCRT), with 7/63 (11.1%) requiring a salvage abdomino-perineal resection (APR) for residual or recurrent disease. Adverse prognostic indicators include those with T4 disease hazard ratio = 3.81, (95% CI 1.13-12.83, * p = 0.04), poorly differentiated tumour disease HR = 3.37, (95% CI 1.13-10.02, * p = 0.04), having N2 nodal status HR = 5.03, (95% CI 1.11-22.8, * p = 0.04), and having metastatic disease at diagnosis HR = 5.8, (95% CI 1.28-26.42, * p = 0.02).

CONCLUSION

Presenting characteristics including stage, nodal, and differentiation status remain key prognostic indicators in those diagnosed with anal malignancy.

Sexually Transmitted Human Papillomavirus: Update in Epidemiology, Prevention, and Management

This review presents the epidemiology, pathophysiology, prevention, and management of sexually transmitted human papillomavirus (HPV) and its associated diseases. HPV is the most common sexually transmitted infection worldwide. Prevalence varies regionally. Low-risk strains cause anogenital warts, which can be managed with patient- or provider-applied therapies. High-risk strains cause lower anogenital cancers. Primary and secondary prevention strategies include vaccination and screening for precancerous lesions, respectively. Management of abnormal screening results vary by test result, anatomic site, and individual cancer risk. Approaches include close rescreening, high-resolution visualization with biopsy, and-when biopsy-proven precancer is identified-removal or destruction of the lesion.

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.

Body Composition as a Predictor of the Survival in Anal Cancer

Background and aim: Sarcopenia and body composition parameters such as visceral and subcutaneous adipose tissue and visceral-to-subcutaneous adipose tissue ratio have been shown to be relevant biomarkers for prognosis in patients with different types of cancer. However, these findings have not been well studied in anal cancer to date. Therefore, the aim of this study was to evaluate the prognostic value of different body composition parameters in patients undergoing radiation therapy for the treatment of anal cancer with curative intent. Material and Methods: After approval by the institutional ethical committee, we retrospectively identified 81 patients in our local registry, who received radical intensity-modulated radiotherapy for the management of anal squamous cell cancer (ASCC). Clinical information, including body mass index (BMI), survival, and toxicities outcome, were retrieved from the local hospital registry. Based on the pre-therapeutic computer tomography (CT), we measured the total psoas muscle area, visceral adipose tissue area (VAT), subcutaneous adipose tissue area (SAT), and visceral-to-subcutaneous adipose tissue area ratio (VSR). In addition to the classical prognostic factors as T-stage, N-stage, gender, and treatment duration, we analyzed the impact of body composition on the prognosis in univariate and multivariate analyses. Results: Sarcopenia was not associated with increased mortality in anal cancer patients, whereas increased BMI (≥27 kg/m2) and VSR (≥0.45) were significantly associated with worsened overall survival and cancer-specific survival in both univariate and multivariate analyses. VSR-not BMI-was statistically higher in males. Sarcopenia and VSR ≥ 0.45 were associated with advanced T-stages. None of the body composition parameters resulted in a significant increase in treatment-related toxicities. Conclusion: BMI and visceral adiposity are independent prognostic factors for the survival of patients with anal cancer. Measurements to treat adiposity at the time of diagnosis may be needed to improve the survival outcomes for the affected patients.

Development and validation of prognostic models for anal cancer outcomes using distributed learning: protocol for the international multi-centre atomCAT2 study

BACKGROUND

Anal cancer is a rare cancer with rising incidence. Despite the relatively good outcomes conferred by state-of-the-art chemoradiotherapy, further improving disease control and reducing toxicity has proven challenging. Developing and validating prognostic models using routinely collected data may provide new insights for treatment development and selection. However, due to the rarity of the cancer, it can be difficult to obtain sufficient data, especially from single centres, to develop and validate robust models. Moreover, multi-centre model development is hampered by ethical barriers and data protection regulations that often limit accessibility to patient data. Distributed (or federated) learning allows models to be developed using data from multiple centres without any individual-level patient data leaving the originating centre, therefore preserving patient data privacy. This work builds on the proof-of-concept three-centre atomCAT1 study and describes the protocol for the multi-centre atomCAT2 study, which aims to develop and validate robust prognostic models for three clinically important outcomes in anal cancer following chemoradiotherapy.

METHODS

This is a retrospective multi-centre cohort study, investigating overall survival, locoregional control and freedom from distant metastasis after primary chemoradiotherapy for anal squamous cell carcinoma. Patient data will be extracted and organised at each participating radiotherapy centre (n = 18). Candidate prognostic factors have been identified through literature review and expert opinion. Summary statistics will be calculated and exchanged between centres prior to modelling. The primary analysis will involve developing and validating Cox proportional hazards models across centres for each outcome through distributed learning. Outcomes at specific timepoints of interest and factor effect estimates will be reported, allowing for outcome prediction for future patients.

DISCUSSION

The atomCAT2 study will analyse one of the largest available cross-institutional cohorts of patients with anal cancer treated with chemoradiotherapy. The analysis aims to provide information on current international clinical practice outcomes and may aid the personalisation and design of future anal cancer clinical trials through contributing to a better understanding of patient risk stratification.