Treatment outcomes and HPV characteristics for an institutional cohort of patients with anal cancer receiving concurrent chemotherapy and intensity-modulated radiation therapy

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

PURPOSE

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

METHODS AND MATERIALS

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

RESULTS

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

CONCLUSIONS

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

HPV status and immunohistochemical analysis of p16, p53 and PD‑L1 expression as prognostic biomarkers in patients with squamous cell anal cancer receiving definitive radiotherapy/chemoradiotherapy

Anal squamous cell carcinoma (SCC) treated with definitive radiotherapy (RT)/chemoradiotherapy (CRT) has shown high success rates, yet challenges such as treatment resistance and recurrence persist. The present study aimed to investigate the associations between immunohistochemical (IHC) evaluation, treatment response and prognosis in anal SCC. A retrospective cohort analysis included 42 patients with anal SCC treated at a single institution between 2006 and 2022. Human papillomavirus (HPV) status was determined, and the IHC analysis of p16, p53 and PD-L1 expression was conducted using formalin-fixed, paraffin-embedded biopsies. A complete response to RT/CRT was observed in 71.4% of patients. Recurrence occurred in 38.1% of cases, of which 7.1% had local-regional recurrence (LRR), 14.3% had distant recurrence (DR), and 16.7% had both LRR and DR. HPV positivity (71.4%) was significantly associated with p16 positivity. Lack of complete response was associated with HPV-negative status, p16-negative status, increased recurrence and DR. In addition, recurrence was significantly associated with p53-positive status, and p53 positivity was significantly associated with increased LRR. PD-L1 positivity, defined as a combined positive score (CPS) ≥1% was found in 73.8% of the patients, and exhibited significant associations with HPV positivity and p16 positivity. PD-L1 CPS ≥ 1% was also associated with an increased LRR. Univariate analysis revealed that age <65 years, a complete response and HPV positivity were associated with increased 5-year overall survival (OS), while a complete response, HPV positivity and p53-negative status were associated with increased 5-year disease-free survival (DFS). Multivariate analysis identified that age <65 years and HPV positivity are independent prognostic factors for 5-year OS, and a complete response and p53-negative status are independent prognostic factors for 5-year DFS. In conclusion, these findings suggust that the identification of HPV status and poor prognostic biomarkers at diagnosis may be used to guide personalized treatment strategies, with the combination of immunotherapy with standard CRT potentially providing improved outcomes.

Circulating tumor-tissue modified HPV DNA analysis for molecular disease monitoring after chemoradiation for anal squamous cell carcinoma: a case report

Squamous cell carcinoma (SCC) of the anus typically arises after human papillomavirus (HPV) infection. We report on the use of molecular disease monitoring using a novel blood test measuring circulating tumor-tissue -modified HPV DNA in two patients with anal cancer. Two patients with anal SCC received concurrent chemotherapy and radiation therapy (chemoRT) with curative intent, one with a T2N0 anal margin squamous cell carcinoma with a history of AIDS, and one with a T3N0 anal squamous cell carcinoma and a history of concurrent prostate cancer. HPV genotyping at diagnosis confirmed the presence of HPV16 DNA in both cases. Circulating, tumor-tissue-modified HPV DNA (TTMV-HPV DNA) was measured in the peripheral blood utilizing digital PCR at baseline and in follow-up. Disease burden was assessed post-treatment with standard anoscopy, biopsy, and PET/CT. Plasma TTMV-HPV DNA levels were elevated at diagnosis, and decreased during and after chemoRT completion in both cases. During post treatment surveillance, TTMV-HPV DNA levels correlated with disease status including one case with progressive local recurrence within 2 months, and one case with 12 months of local control both confirmed by biopsy. These case studies present the first use of circulating tumor-tissue-modified HPV DNA as a biomarker for anal cancer. Further study of this blood test an adjunct to standard treatment and monitoring is warranted in HPV-positive anal cancer.

Intensity modulated radiotherapy for anal canal squamous cell carcinoma: A 16-year single institution experience

Introduction

To report long-term efficacy and adverse events (AEs) associated with intensity modulated radiotherapy (IMRT) for patients with anal canal squamous cell carcinoma (ASCC).

Materials and methods

This was a retrospective review of patients with ASCC who received curative-intent IMRT and concurrent chemotherapy (98%) between 2003 and 2019. Overall survival (OS), colostomy-free survival (CFS), and progression-free survival (PFS) were estimated using the Kaplan-Meier method. The cumulative incidence of local recurrence (LR), locoregional recurrence (LRR), and distant metastasis (DM) were reported. Acute and late AEs were recorded per National Cancer Institute Common Terminology Criteria for AEs.

Results

127 patients were included. The median patient age was 63 years (interquartile range [IQR] 55-69) and 79% of patients were female. 33% of patients had T3-4 disease and 68% had clinically involved pelvic or inguinal lymph nodes (LNs).The median patient follow-up was 47 months (IQR: 28-89 months). The estimated 4-year OS, CFS, and PFS were 81% (95% confidence interval [CI]: 73%-89%), 77% (95% CI: 68%-86%), and 78% (95% CI: 70%-86%), respectively. The 4-year cumulative incidences of LR, LRR, and DM were 3% (95% CI: 1%-9%), 9% (95% CI: 5%-17%), and 10% (95% CI: 6%-18%), respectively. Overall treatment duration greater than 39 days was associated with an increased risk of LRR (Hazard Ratio [HR]: 5.2, 95% CI: 1.4-19.5, p = 0.015). The most common grade 3+ acute AEs included hematologic (31%), gastrointestinal (GI) (17%), dermatologic (16%), and pain (15%). Grade 3+ late AEs included: GI (3%), genitourinary (GU) (2%), and pain (1%). Current smokers were more likely to experience grade 3+ acute dermatologic toxicity compared to former or never smokers (34% vs. 7%, p < 0.001).

Conclusions

IMRT was associated with favorable toxicity rates and long-term efficacy. These data support the continued utilization of IMRT as the preferred treatment technique for patients with ASCC.

Prognostic Significance of HPV DNA and p16INK4a in Anal Cancer: A Systematic Review and Meta-Analysis

We conducted a systematic review and meta-analysis of observational studies evaluating survival in patients with anal cancer, according to human papillomavirus (HPV) DNA, p16^INK4a, and combined HPV DNA/p16^INK4a status. We systematically searched PubMed, EMBASE, and Cochrane Library databases to identify studies published in English until July 25, 2018, directly providing or allowing estimation of survival of patients with anal cancer according to the presence of HPV DNA and/or overexpression of p16^INK4a We estimated pooled HRs and 95% confidence intervals (CI) for overall survival (OS) using a random-effects model. We included 16 studies, comprising 1,724 patients with anal cancer tested for HPV DNA (65% positive), and 567 patients tested for p16^INK4a (87% positive). The pooled HR for OS was 0.54 (95% CI, 0.33-0.89) for HPV DNA positive versus negative, 0.37 (95% CI, 0.24-0.57) for p16^INK4a positive versus negative, and 0.36 (95% CI, 0.22-0.58) for HPV DNA positive/p16^INK4a positive versus HPV DNA positive/p16^INK4a negative patients with anal cancer. Patients with HPV DNA or p16^INK4a positive anal cancer have significantly better OS compared with HPV DNA or p16^INK4a negative. This points to the possible value of HPV DNA and/or p16^INK4a testing when planning the management and follow-up strategy for patients diagnosed with anal cancer.

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

PURPOSE

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

METHODS AND MATERIALS

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

RESULTS

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

CONCLUSIONS

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

Correction: Treatment outcomes and HPV characteristics for an institutional cohort of patients with anal cancer receiving concurrent chemotherapy and intensity-modulated radiation therapy

[This corrects the article DOI: 10.1371/journal.pone.0194234.].