Clinical characteristics and prognosis of anal squamous cell carcinoma: a retrospective audit of 144 patients from 11 cancer hospitals in southern China

Background

The incidence of anal squamous cell carcinoma (SCC) has been steadily growing globally in the past decade. Clinical data on anal SCC from China are rare. We conducted this study to describe the clinical and epidemiological characteristics of anal SCC in China and explore prognostic factors of outcomes among patients with anal SCC.

Methods

We audited demographic characteristics, relevant symptoms, risk factors, treatment modalities and outcomes for patients diagnosed with anal SCC at 11 medical institutions in China between January 2007 and July 2018.

Results

A total of 144 patients (109 females) were diagnosed with SCC during this period. Median age at initial diagnosis was 52.0 (interquartile range: 46.0–61.8) years. The most common symptoms were bleeding (n = 93, 64.6%), noticing a lump (n = 49, 34.0%), and pain (n = 47, 32.6%). The proportion of patients at the American Joint Committee on Cancer (AJCC) stages I-IV were 10 (6.9%), 22 (15.3%), 61 (42.4%) and 8 (5.6%), respectively, and AJCC stages in 43 (29.9%) patients were unknown. Thirty-six patients (25.0%) underwent abdominoperineal resection initially. Univariable analysis showed that T stage predicted recurrence-free survival (RFS) (Hazard ratio [HR] = 3.03, 95% Confidence interval [CI]: 1.10–8.37, p = 0.032), and age group (HR = 2.90, 95% CI: 1.12–7.49, p = 0.028), AJCC stage (HR = 4.56, 95% CI: 1.02–20.35, p = 0.046), and N stage (HR = 3.05, 95% CI: 1.07–8.74, p = 0.038) predicted overall survival (OS).

Conclusions

T stage was identified as prognostic factor of RFS, and age, AJCC stage, and N stage were identified as prognostic factors of OS. Improving symptom awareness and earlier presentation among patients potentially at risk for anal SCC should be encouraged. Familiarity with the standard treatment among health care providers in China should be further improved.

Systematic review of outcome measures following chemoradiotherapy for the treatment of anal cancer (CORMAC)

AIM

Six Phase III randomized trials have determined the effectiveness of chemoradiotherapy as primary treatment for anal squamous cell carcinoma (ASCC), but outcomes reported in these trials varied widely, hindering evidence synthesis. To improve reporting in all future trials, we aim to develop a core outcomes set (COS). As the first stage of COS development, we undertook a systematic review to summarize the outcomes reported in studies evaluating chemoradiotherapy for ASCC.

METHOD

Systematic literature searches identified studies evaluating radiotherapy or chemoradiotherapy for ASCC. Outcomes and accompanying definitions were extracted verbatim and categorized into domains.

RESULTS

From 5170 abstracts, we identified 95 eligible studies, reporting 1192 outcomes and 533 unique terms. We collapsed these terms into 86 standardized outcomes and five domains: survival; disease activity; life impact [including quality of life (QoL)]; delivery of care; and toxicity. The most commonly reported domains were survival and disease activity, reported in 74 (86%) and 54 (62%) studies, respectively. No outcome was reported in every publication. Over half (43/86) of the standardized outcome terms were reported in fewer than five studies, and 21 (25%) were reported in a single study only. There was wide variation in definitions of disease-free survival, colostomy-free survival and progression-free survival (PFS). Anal continence was reported in only 35 (41%) studies.

CONCLUSION

Outcomes reported in studies evaluating chemoradiotherapy for ASCC were heterogenous and definitions varied widely. Outcomes likely to be important to patients, such as ano-rectal function, toxicity and QoL, have been neglected. A COS for future trials will address these issues.

Anal canal squamous cell cancer: are surgical alternatives to chemoradiation just as effective?

PURPOSE

The purpose of this paper is to study long-term oncologic outcomes after different treatment strategies for anal canal cancer (SCAC).

METHODS

Patients with SCAC (2004-2013) were identified from Surveillance, Epidemiology, and End Results (SEER) database. Patients undergoing radiation (RT) were compared to those undergoing local excision (LE), abdominoperineal resection (APR), and abdominoperineal resection after radiation (RT + APR). Overall survival (OS) and cancer-specific survival (CSS) data were evaluated using Kaplan-Meier and Cox regression.

RESULTS

Two thousand seven hundred and seventy-two (83.8%) patients underwent RT, 382 (11.6%) LE, 77 (2.3%) APR, 76 (2.3%) RT + APR. Median age for the four groups was 60, 57, 64, and 56 years and 32, 49.7, 53.2, and 39.5% were male, respectively, while median tumor size was 4.4, 2.6, 5.3, and 5.5 cm, respectively. Five-year OS of RT, LE, APR, and RT + APR groups was 63.7, 79.6, 25.8, and 41.8% while CSS was 79.6, 92.5, 75.6, and 58.8%, respectively, (p < 0.001). Adjusted hazard ratios for OS for LE, APR, and RT + APR with RT as reference were 1.007 (0.702-1.444), 2.311 (1.367-3.906), and 2.072 (1.016-4.228), respectively.

CONCLUSION

These data suggest that APR does not provide better outcomes in treatment of SCAC. Chemoradiation remains the gold standard treatment for majority of patients. Local excision is associated with favorable outcomes in some circumstances.

A qualitative investigation among men who have sex with men on the acceptability of performing a self- or partner anal exam to screen for anal cancer

PURPOSE

Persistent infection with oncogenic human papillomavirus (HPV) is the primary cause of anal cancer, a disease that disproportionately affects men who have sex with men (MSM); however, there is no uniform screening protocol to detect anal cancer. This qualitative study explores whether a self-anal exam (SAE) or partner anal exam (PAE), that includes self-palpation or palpation of a partner's anal canal, is an acceptable and self-efficacious screening test, which will cue appropriate follow-up care in MSM.

METHODS

Twenty-four MSM living in Houston took part in four focus group sessions eliciting their responses to a study teaching them to perform an SAE or PAE (SAE/PAE). Participants were asked about the acceptability and feasibility of executing an SAE/PAE routinely. Thematic analysis of session transcripts was used to identify common patterns in participant responses.

RESULTS

Overall, participants expressed self-efficacy for performing an SAE/PAE and voiced a preference for being taught the procedure by a clinician. Participants agreed that they would consult with a clinician if they ever discovered an abnormality while performing an SAE/PAE. A lack of knowledge about anal cancer among MSM may present a barrier to adopting SAE/PAE. In discussing their experience of the exams, some participants suggested that it could become a routine practice for them.

CONCLUSIONS

Our findings suggest that SAE and PAE, as a screen for anal cancer, are acceptable and feasible to MSM. Future research should explore attitudes and beliefs of MSM, with the aim of improving anal cancer education and understanding of pathologic findings.

Front-to-back & dabbing wiping behaviour post-toilet associated with anal neoplasia & HR-HPV carriage in women with previous HPV-mediated gynaecological neoplasia

BACKGROUND

Anal cancer is a human papillomavirus (HPV)-mediated neoplasia of the anal squamous epithelium. Anal cancer is much more common among women, particularly those with a previous high-grade gynaecological neoplasia.

METHODS

Cross-sectional study of women with a previous HPV-mediated gynaecological neoplasia in Tasmania, Australia. Women presenting for follow-up gynaecological care had anal swab samples taken for anal cytology by Hologic Liquid ThinPrep, followed by HPV genotyping. Women with abnormal anal cytology were invited for high-resolution anoscopy. Potential risk factors, including post-toilet wiping behaviours, were queried by questionnaire while clinical covariates were extracted from medical records. Covariates of anal outcomes evaluated by log-binomial and log-multinomial regression.

RESULTS

From 163 women enrolled in the study, 65 (39.9%) had abnormal cytology, with 46 (28.2%) being high-grade. Of the 50 women with abnormal anal cytology having high-resolution anoscopy, 32 (64.0%) had abnormal histology with 13 (26.0%) being high-grade. Of the 123 women tested for HR-HPV DNA, 48 (39.0%) had HR-HPV detected, the most common genotypes being 16 and 51 (14/123, 11.4% for both). In addition to some known anal cancer risk factors, we found front-to-back wiping was associated with significantly increased (Prevalence ratio (PR) range: 1.99-3.60) prevalence of cytological and histological abnormality and HR-HPV carriage/co-carriage, while dabbing post-toilet was significantly associated with decreased prevalences (PR range: 0.50-0.62).

CONCLUSIONS

Post-toilet wiping behaviours were significantly associated with the prevalence of anal cytological, histological and HR-HPV carriage outcomes. This suggests a biologically plausible mechanism for HR-HPV introduction and the higher frequencies of anal neoplasia in women.

Trends in incidence and survival for anal cancer in New South Wales, Australia, 1972-2009

INTRODUCTION

Little is known about the incidence and survival of anal cancer in New South Wales (NSW), Australia, as anal cancer cases are often grouped together with other colorectal cancers in descriptive epidemiological analyses.

METHODS

We studied patterns and trends in the incidence and survival of people diagnosed with anal cancer in NSW, Australia, 1972-2009 (n=2724). We also predicted anal cancer incidence in NSW during 2010-2032. Given the human papilloma virus-associated aetiology for most anal cancers, we quantified these changes over time in incidence and survival by histological subtype: anal squamous cell carcinoma (ASCC); and anal adenocarcinoma (AAC).

RESULTS

There was a linear increase in incident anal cancer cases in NSW with an average annual percentage change (AAPC) of 1.6 (95% CI 1.1-2.0) such that, in combination with age-period-cohort modelling, we predict there will be 198 cases of anal cancer in the 2032 calendar year (95% CI 169-236). Almost all of these anal cancer cases are projected to be ASCC (94%). Survival improved over time regardless of histological subtype. However, five-year relative survival was substantially higher for people with ASCC (70% (95% CI 66-74%)) compared to AAC (51% (95% CI 43-59%)), a 37% difference. Survival was also greater for women (69% (95% CI 64-73%)) with ASCC compared to men (55% (95% CI 50-60%)). It was not possible to estimate survival by stage at diagnosis particularly given that 8% of all cases were recorded as having distant stage and 22% had missing stage data.

INTERPRETATION

Aetiological explanations, namely exposure to oncogenic types of human papillomavirus, along with demographic changes most likely explain the actual and projected increase in ASCC case numbers. Survival differences by gender and histological subtype point to areas where further research is warranted to improve treatment and outcomes for all anal cancer patients.

Anal intraepithelial neoplasia and squamous cell carcinoma in HIV-infected adults

Anal cancer is one of the most common non-AIDS-defining malignancies in the era of combination antiretroviral therapy. Its precursor lesion, anal intraepithelial neoplasia (AIN), is highly prevalent in HIV-infected populations. More than 90% of anal squamous cell cancers are attributable to human papillomavirus (HPV). While the biology of HPV-related intraepithelial neoplasia is consistent across lower anogenital sites, the natural history of AIN is not well established and cannot be assumed to be identical to that of cervical intraepithelial neoplasia. Screening strategies to prevent anal cancer should be developed based on robust natural history data in HIV-infected and uninfected populations. Likewise, treatments need to be tested in randomized clinical trials, and reserved for those at significant risk of progression to cancer. This review covers the epidemiology, pathogenesis and immunology of HPV infection, AIN and anal cancer, and summarizes the current diagnosis, screening and treatment strategies in HIV-infected adults.