Emerging and Experimental Agents for Anal Cancer: What is New?

Medical treatment for ocular surface squamous neoplasia

Ocular surface squamous neoplasia (OSSN) is the most common non-melanocytic tumour of the ocular surface. Surgical excision with wide margins using the "no-touch" method was originally the most popular treatment for OSSN. However, in the past two decades, the use of topical medications for OSSN treatment has gained a reputation amongst ophthalmologists for being an effective alternative to surgical excision. Furthermore, technological advancements, such as those seen in high-resolution optical coherence tomography (HR-OCT) for the anterior segment, have facilitated the diagnosis and monitoring of OSSN. When selecting a topical agent, interferon alpha-2b (IFNα-2b) and 5-fluorouracil (5-FU) are two of the gentlest medications used for OSSN and are often considered first line therapies due to their high-resolution rates and mild side effect profiles. Mitomycin C (MMC), on the other hand, has a highly toxic profile; therefore, while effective, in our hands it is considered as a second-line treatment for OSSN if the other modalities fail. In addition, newer and less studied agents, such as immune checkpoint inhibitors, retinoic acid, aloe vera, and anti-vascular endothelial growth factor have anti-neoplastic properties and have shown potential for the treatment of OSSN. We enclose an updated literature review of medical treatments for OSSN.

Anal Cancer: The Past, Present and Future

Anal cancer is a rare cancer that accounts for about 2% of all gastrointestinal tract malignancies. Among anal cancer, squamous cell cancer is the most common malignancy. The incidence of all stages of anal squamous cell cancer has been increasing. Human papillomavirus infection and immunosuppression are major risk factors for anal cancer. The management of anal cancer has evolved over the past several decades and continues to do so. Chemoradiation therapy remains the mainstay for treatment for most patients with early-stage disease, whereas systemic therapy is the primary treatment for patients with metastatic disease. Patients with persistent disease or recurrence following chemoradiation therapy are treated with salvage surgery. Access to novel cytotoxic combinations and immunotherapy has improved the outcomes of patients with advanced disease. This review provides an overview of advances in the management of anal cancer over the past two decades. This paper reviews the epidemiology, risk factors, pathology, diagnosis, and management of localized and advanced anal squamous cell cancer, highlights current knowledge gaps in the management of anal cancer, and discusses future directions.

The Use of the Protease Inhibitor, Saquinavir, to Treat Anal Cancer Spheroids Derived From Human Papillomavirus Transgenic Mice

BACKGROUND

Anal cancer is associated with high-risk human papillomavirus infection and oncoprotein expression. We have identified several protease inhibitors, used to treat HIV, that decrease oncogene expression.

OBJECTIVE

The aim of this project is to determine whether saquinavir, a protease inhibitor, results in a treatment response in anal cancer spheroids.

DESIGN

K14E6/E7 transgenic mice (n = 5), which express human papillomavirus 16 oncoproteins E6 and E7 in their epithelium, were treated topically at the anus with a carcinogen, 7,12-dimethylbenz[a]anthracene, to promote anal tumor growth. Tumors were excised and digested, and cells were plated. The tumor cells form 3D multicellular aggregates known as spheroids.

SETTINGS

This study was performed in an American Association for Accreditation of Laboratory Animal Care-approved facility.

INTERVENTIONS

Spheroids were placed in treatment groups: no treatment, vehicle (dimethyl sulfoxide), and 15 μM saquinavir. Spheroids were imaged immediately pretreatment and 24 hours posttreatment.

MAIN OUTCOME MEASURES

Spheroid diameters were measured using ImageJ and mean percent reduction was calculated for each spheroid to determine treatment effect on spheroid growth. Analysis of variance using pairwise comparisons was performed with Fisher protected least significant difference tests.

RESULTS

The no-treatment (n = 119 spheroids) and vehicle (n = 126 spheroids) groups demonstrated an increase in spheroid diameter during the treatment period. In contrast, spheroids treated with saquinavir (n = 151 spheroids) demonstrated a statistically significant percent reduction compared to the no-treatment ( p < 0.0001) and vehicle ( p = 0.002) groups.

LIMITATIONS

A limitation of these data is that some human error is likely present given that images were analyzed by 3 different scientists.

CONCLUSIONS

Saquinavir leads to a statistically significant percent reduction in mice anal tumor spheroid growth ex vivo compared to control groups. Protease inhibitor therapy may be an effective treatment or adjuvant therapy to the Nigro protocol to promote anal cancer tumor regression. See Video Abstract at http://links.lww.com/DCR/C82 .

EL USO DEL INHIBIDOR DE LA PROTEASA, SAQUINAVIR, PARA TRATAR LOS ESFEROIDES DEL CNCER ANAL DERIVADOS DE RATONES TRANSGNICOS PARA EL VPH

ANTECEDENTES:El cáncer anal está asociado con la infección por el virus del papiloma humano de alto riesgo y la expresión de oncoproteínas. Hemos identificado varios inhibidores de la proteasa, utilizados para tratar el VIH, que disminuyen la expresión del oncogén.OBJETIVO:El objetivo de este proyecto es determinar si los esferoides de cáncer anal responden al tratamiento con inhibidor de la proteasa, Saquinavir.DISEÑO:Ratones transgénicos K14E6/E7 (n = 5), que expresan las oncoproteínas E6 y E7 del VPH16 en su epitelio, fueron tratados tópicamente en el ano con carcinógeno, 7,12 dimetilbenz[a]antraceno, para promover el crecimiento del tumor anal. Los tumores se extirparon y digirieron, y las células se sembraron en placas. Las células tumorales forman agregados multicelulares tridimensionales, conocidos como esferoides.ESCENARIO:Este estudio se realizó en un centro aprobado por la Asociación Estadounidense para la Acreditación de Cuidado de Animales de Laboratorio.INTERVENCIONES:Se colocaron esferoides en grupos de tratamiento: sin tratamiento, vehículo (sulfóxido de dimetilo) y saquinavir 15 μM. Se tomaron imágenes de los esferoides inmediatamente antes del tratamiento y 24 horas después del tratamiento.PRINCIPALES MEDIDAS DE RESULTADO:Los diámetros de los esferoides se midieron con ImageJ y se calculó el porcentaje medio de reducción de cada esferoide para determinar el efecto del tratamiento sobre el crecimiento de los esferoides. El análisis de varianza mediante comparaciones por pares se realizó con las pruebas de diferencia mínima significativa protegida de Fisher.RESULTADOS:Los grupos sin tratamiento (n =119 esferoides) y vehículo (n=126 esferoides) demostraron un aumento en el diámetro del esferoide durante el período de tratamiento. Por el contrario, los esferoides tratados con saquinavir (n =151 esferoides) demostraron una reducción porcentual estadísticamente significativa en comparación con los grupos sin tratamiento ( p < 0,0001) y con vehículo (p = 0,002).LIMITACIONES:una limitación de estos datos es que es probable que haya algún error humano dado que las imágenes fueron analizadas por tres científicos diferentes.CONCLUSIONES:Saquinavir conduce a una reducción porcentual estadísticamente significativa en el crecimiento de esferoides de tumores anales en ratones ex-vivo en comparación con los grupos de control. La terapia con inhibidores de la proteasa puede ser un tratamiento eficaz o una terapia adyuvante del protocolo Nigro para promover la regresión del tumor del cáncer anal. Consulte Video Resumen en http://links.lww.com/DCR/C82 . (Traducción-Dr. Felipe Bellolio ).

Prognostic role of HPV integration status and molecular profile in advanced anal carcinoma: An ancillary study to the epitopes-HPV02 trial

Squamous Cell Carcinoma of the Anal canal (SCCA) is a rare disease associated with a Human Papillomavirus (HPV) infection in most cases, predominantly the HPV16 genotype. About 15% of SCCA are diagnosed in metastatic stage and some will relapse after initial chemoradiotherapy (CRT). Treatment of patients by Docetaxel, Cisplatin and 5-fluorouracil (DCF) has been recently shown to improve their complete remission and progression-free survival. The aim of this retrospective study was to explore the impact of HPV infection, HPV DNA integration, TERT promoter mutational status and somatic mutations of oncogenes on both progression-free (PFS) and overall survivals (OS) of patients treated by DCF. Samples obtained from 49 patients included in the Epitopes-HPV02 clinical trial, diagnosed with metastatic or non-resectable local recurrent SCCA treated by DCF, were used for analyses. Median PFS and OS were not associated with HPV status. Patients with episomal HPV had an improved PFS compared with SCCA patients with integrated HPV genome (p=0.07). TERT promoter mutations were rarely observed and did not specifically distribute in a subset of SCCA and did not impact DCF efficacy. Among the 42 genes investigated, few gene alterations were observed, and were in majority amplifications (68.4%), but none were significantly correlated to PFS. As no biomarker is significantly associated with patients’ survival, it prompts us to include every patient failing CRT or with metastatic disease in DCF strategy.

Role of local therapy in the management of patients with metastatic anal squamous cell carcinoma: a National Cancer Database study

BACKGROUND

About 10-20% of patients with anal squamous cell carcinoma (SCCa) present with metastatic disease and are usually treated with systemic chemotherapy. However, primary tumor control is crucial as local failure is associated with significant morbidity. Using the largest cohort to date, we report the impact of local therapy on survival among patients with metastatic anal SCCa.

METHODS

Data were collected from US hospitals that contributed to the National Cancer Database (NCDB) between 2004 and 2015. Patients who did not receive palliative systemic chemotherapy were excluded from analysis. Univariate (UVA) and multivariable analyses (MVA) were performed to identify factors associated with patient outcome. Kaplan-Meier analysis and Cox proportional hazards models were used to evaluate the association between tumor/patient characteristics and overall survival (OS).

RESULTS

A total of 1,160 patients were identified over the 12 years of study. Median age was 57 years. Majority were female (64.9%), non-Hispanic Whites (79.1%) and had Charlson-Deyo Score of 0 (83.6%). Most common metastatic sites were liver (25.9%), lung (11.6%) and bone (8.5%). More than 79% of the patients had received radiation to the primary site, and 10.4% underwent surgical resection for local control. Use of local therapy correlated closely with OS on MVA (HR 0.66; 0.55-0.79; P<0.001), with a 12-month and 5-year OS rates of 72.8% and 25.7% respectively, compared with 61.1% and 14.6% for patients treated with chemotherapy only. Poor prognostic factors included male gender (HR 1.44; 1.24-1.67; P<0.001), age >70 years (HR 1.28; 1.02-1.62; P=0.034), lack of health insurance (HR 1.32; 1.02-1.71; P=0.034), and cloacogenic zone location (HR 4.02; 1.43-11.30; P=0.008). There was no benefit from abdominoperineal resection (mOS =19.7 months; HR 1.05; 0.48-2.29; P=0.909), but both local resection of the primary (mOS =24.8 months, HR 0.48; 0.29-0.80; P=0.005) and palliative radiation (mOS =22.6 months; HR 0.66; 0.55-0.79; P<0.001) were associated with improved OS.

CONCLUSIONS

In addition to systemic therapy, resection of the primary tumor or palliative radiation improved OS in patients with anal SCCa. Patients unlikely to benefit from local control were those >70 years of age, male, lack of health insurance and cloacogenic carcinoma.