Anal Cancer: Emerging Standards in a Rare Disease.

The social stigma surrounding an anal cancer diagnosis has traditionally prevented open discussions about this disease. However, as recent treatment options and an increasing rate of diagnoses are made worldwide, awareness is growing. In the United States alone, 9,090 individuals were expected to be diagnosed with anal cancer in 2021. The US annual incidence of squamous cell carcinoma of the anus continues to increase by 2.7% yearly, whereas the mortality rate increases by 3.1%. The main risk factor for anal cancer is a human papillomavirus infection; those with chronic immunosuppression are also at risk. Patients with HIV are 19 times more likely to develop anal cancer compared with the general population. In this review, we have provided an overview of the carcinoma of the anal canal, the role of screening, advancements in radiation therapy, and current trials investigating acute and chronic treatment-related toxicities. This article is a comprehensive approach to presenting the existing data in an effort to encourage continuous international interest in anal cancer.

Comparing outcomes following total neoadjuvant therapy and following neoadjuvant chemoradiation therapy in patients with locally advanced rectal cancer.

BACKGROUND: There is recent interest in treating locally advanced rectal cancer (LARC) patients with total neoadjuvant therapy (TNT). However, whether TNT is associated with improved overall survival (OS) remains unknown. This study compares outcomes following TNT and following neoadjuvant chemoradiation therapy (nCRT) in patients with LARC, clinically defined cT3/4 or node positive disease, using the National Cancer Database. METHODS: LARC patients diagnosed between 2004-2015 were included. TNT was defined as multi-agent chemotherapy given at least 2 months before RT followed by pre-operative chemoradiation therapy and definitive surgery without adjuvant chemotherapy. nCRT was defined as pre-operative RT and chemotherapy started within 2 weeks from each other followed by definitive surgery with or without adjuvant chemotherapy. Kaplan-Meier curve with logrank test and multivariable Cox proportional hazards regression modelling were used to analyse the primary endpoint of overall survival (OS). Multivariable logistic regression modelling was used for secondary outcomes to determine if TNT is associated with pathological complete response (pCR), defined as ypT0N0, and negative circumferential resection margin (CRM). FINDINGS: Data from 372 TNT patients and 707 nCRT patients were analysed after a 2:1 propensity matching with replacement. Kaplan-Meier curve showed that OS with TNT was comparable to that with nCRT (p = 0•16). The 5-year OS rates for TNT and nCRT were 73•6% vs. 78•5% (p = 0•20). Multivariable Cox proportional hazards regression modelling confirmed no difference in OS between TNT and nCRT (HR = 1•21, p = 0•25). With TNT, 16•9% patients achieved pCR, whereas 13•1% patients achieved pCR with nCRT (p = 0•12). TNT was not found to be significantly associated with pCR (OR = 1•36, p = 0•13) or negative CRM (OR = 1•77, p = 0•19) in multivariable logistic regression modelling. INTERPRETATION: With results from current clinical trials pending, our data suggested that TNT and nCRT resulted in similar survival, while TNT led to higher pCR and CRM negative rate, albeit not statistically significant.

Human papillomavirus, radiation dose and survival of patients with anal cancer.

Purpose: To determine if anal cancer patients with HPV positive disease have different overall survival (OS) compared to those with HPV negative disease, and to elucidate differences in the association between radiation dose and OS.Patients and methods: We utilized the National Cancer Database (NCDB) registry to identify a cohort of non-metastatic anal cancer patients treated with curative intent between 2008 and 2014. Propensity score matching was used to account for potential selection bias between patients with HPV positive and negative disease. Multivariable Cox regression was used to determine the association between HPV status and OS. Kaplan-Meier methods were used to compare actuarial survival estimates.Results: We identified 5927 patients with tumor HPV status for this analysis, 3523 (59.4%) had HPV positive disease and 2404 (40.6%) had HPV negative disease. Propensity-matched analysis demonstrated that patients with HPV positive locally advanced (T3-4 or node positive) anal cancer had better OS (HR = 0.81 (95%CI: 0.68-0.96), p=.018). For patients with early stage disease (T1-2 and node negative) there was no difference in OS (HR = 1.11 (95%CI: 0.86-1.43), p=.43). In the unmatched cohort, we found a significant improvement in OS with increasing radiation dose only for patients with locally advanced, HPV negative disease (p<.001). In those patients, significant improvement in OS compared to the group receiving 30-45 Gy was seen for increasing doses up to 55-60 Gy, but not beyond 60 Gy.Conclusion: We found HPV to be a significant prognostic marker in anal tumors, especially for locally advanced disease. We further found that higher radiation dose up to 55-60 Gy was associated with better OS, but only for patients with locally advanced, HPV negative disease.