Chemotherapy and low-dose radiotherapy in the treatment of HIV-infected patients with carcinoma of the anal canal

Biomarkers in Anal Cancer: Current Status in Diagnosis, Disease Progression and Therapeutic Strategies

Squamous cell carcinoma of the anal canal (SCCA) is a rare neoplasm, but with rising incidence rates in the past few decades; it is etiologically linked with the human papillomavirus (HPV) infection and is especially prevalent in immunocompromised patients, mainly those infected with HIV. Fluoropyrimidine-based chemoradiotherapy remains the cornerstone of the treatment of non-metastatic disease, but the locally advanced disease still presents high rates of disease recurrence and systemic therapy of SCCA is an unmet clinical need. Despite sharing common molecular aspects with other HPV-related malignancies, such as cervical and head and neck cancers, SCCA presents specific epigenomic, genomic, and transcriptomic abnormalities, which suggest that genome-guided personalized therapies should be specifically designed for this disease. Actionable mutations are rare in SCCA and immune checkpoint inhibition has not yet been proven useful in an unselected population of patients. Therefore, advances in systemic therapy of SCCA will only be possible with the identification of predictive biomarkers and the subsequent development of targeted therapies or immunotherapeutic approaches that consider the unique tumor microenvironment and the intra- and inter-tumoral heterogeneity. In the present review, we address the molecular characterization of SCCA and discuss potential diagnostic, predictive and prognostic biomarkers of this complex and challenging disease.

Anal Cancer: Emerging Standards in a Rare 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.

Case of Complete Remission After Volumetric Modulated Arc Therapy to Primary Tumor Alone in Locally Advanced Anal Canal Cancer With Active AIDS and Low CD4 Cell Count: Longest Survival in History?

The incidence of anal canal cancer (AC) is increased in HIV-positive individuals and is often associated with poor prognosis. High viral load and low CD4 cell count have long been considered relative contraindications for combined modality treatment (CMT) with concurrent chemotherapy and external beam radiation treatment (EBRT) for AC due to severe toxicities. EBRT alone is quite often considered as palliative treatment in nature. We report a case of complete remission (CR) of locally advanced anal canal squamous cell carcinoma (ACSCC) cured after volumetric modulated arc therapy (VMAT) to the primary tumor alone in a 62-year-old male with a 30-year history of AIDS, characterized by an HIV viral load over one million and low CD4 cell count around 100 mm^-3. VMAT achieved excellent long-term local control of AC and good quality of life (QoL) of the patient without severe toxicity that requires diverting colostomy.

Difference in toxicity between HIV-positive and HIV-negative patients with squamous-cell cancer of the anal canal treated with concomitant radio-chemotherapy

Background

The incidence of squamous cell carcinoma of the anal canal has been increasing over the last 30 years. HIV has been found to be a risk factor for the development of this disease; radio-chemotherapy (RTCT) may also be more toxic than in HIV-negative patients. The study aims at assessing whether there are any differences in terms of toxicity between HIV-positive and HIV-negative patients treated with concomitant RTCT.

Methods

Search in MEDLINE, EMBASE, CENTRAL (via Cochrane Library-Wiley), DARE, LILACS bibliographic databases. Experimental and analytical observational studies with at least two comparative arms were included: squamous-cell (SC) anal-canal cancer (ACC) treated with RTCT in HIV-positive vs. HIV-negative patients.

Results

Fifteen publications, 14 retrospective studies and 1 systematic review, were found. All radiotherapy (RT) techniques and all chemotherapeutic agents used to manage this disease were included. No differences were found in terms of duration (P=0.67) and dose (P=0.53) of RT, while CT results were contradictory. Acute and hematological toxicities were significantly higher in HIV-positive patients, while gastrointestinal, dermatological and chronic toxicities did not significantly differ between the two groups. Given the high heterogeneity of the studies, no objective comparison could be made between studies that included antiretrovirals and those that did not.

Conclusions

HIV-positive patients may be at higher risk for acute and hematological toxicity than HIV-negative patients. A precise conclusion cannot be drawn on the use of antiretrovirals, given the high heterogeneity of data.

HPV-Associated Anal Cancer in the HIV/AIDS Patient

The prevalence of anal human papillomavirus (HPV) infection and anal high-grade squamous intraepithelial lesion (HSIL) remain high among HIV-infected individuals on effective antiretroviral therapy (ART). The incidence of HPV-related anal cancers has continued to increase since the introduction of ART. Therefore, ART may confer only limited benefit with respect to reducing the risk of anal HSIL and cancer. Efforts are in progress to define the efficacy of secondary prevention programs for prevention of anal cancer. In the modern ART era, anal cancer recurrence and survival outcomes are similar in HIV-infected and HIV-uninfected patients, but HIV-infected patients may experience more toxicities. This article reviews the current literature on HPV-associated anal cancer in the HIV-infected population, including epidemiology, screening, clinical characteristics, and treatment outcomes.

Human Immunodeficiency Virus/AIDS, Human Papillomavirus, and Anal Cancer

Anal cancer is an increasingly common non-AIDS-defining cancer among individuals infected with the human immunodeficiency virus (HIV). It is associated with human papillomavirus (HPV). HPV16 is the most common genotype detected in anal cancers. The HPV types detected in anal cancer are included in the 9-valent vaccine. HPV vaccines have demonstrated efficacy in reducing anal precancerous lesions in HIV-infected individuals. Standard treatment has been fluorouracil and mitomycin (or cisplatin) plus radiation. Continued studies are needed to test new treatment strategies in HIV-infected patients with anal cancer to determine which treatment protocols provide the best therapeutic index.

Radiotherapy in patients with HIV: current issues and review of the literature

Although the introduction of highly active antiretroviral therapy has radically improved the life expectancy of patients with HIV, HIV positivity is still considered a major barrier to oncological treatment for patients with cancer because of their worse prognosis and increased susceptibility to toxic effects compared with patients who are immunocompetent. The use of radiotherapy with or without chemotherapy, immunotherapy, or molecular targeted therapy is the standard of care for several cancers. These new drugs and substantial improvements in radiotherapy techniques, including intensity-modulated radiotherapy, image-guided radiotherapy, and stereotactic ablative radiotherapy, are optimising the feasibility of such anticancer treatments and are providing new opportunities for patients with cancer and HIV. In this Review, we discuss the role of radiotherapy, with or without chemotherapy or new drugs, in the treatment of cancer in patients with HIV, with a focus on the efficacy and tolerability of this approach on the basis of available evidence. Moreover, we analyse and discuss the biological basis of interactions between HIV and radiotherapy, evidence from preclinical studies, and immunomodulation by radiotherapy in the HIV setting.

Cetuximab Plus Chemoradiotherapy for HIV-Associated Anal Carcinoma: A Phase II AIDS Malignancy Consortium Trial

Purpose Squamous cell carcinoma of the anal canal (SCCAC) is characterized by high locoregional failure (LRF) rates after definitive chemoradiation (CRT), associated with anogenital human papilloma virus, and often appears in HIV infection. Because cetuximab enhances the effect of radiation therapy in human papilloma virus-associated oropharyngeal SCC, we hypothesized that adding cetuximab to CRT would reduce LRF in SCCAC. Methods Forty-five patients with stage I to III SCCAC and HIV infection received CRT: 45 to 54 Gy radiation therapy to the primary tumor and regional lymph nodes plus eight once-weekly doses of concurrent cetuximab and two cycles of cisplatin and fluorouracil. The study was designed to detect at least a 50% reduction in 3-year LRF rate (one-sided α, 0.10; power, 90%), assuming a 35% LRF rate from historical data. Results The 3-year LRF rate was 42% (95% CI, 28% to 56%; one-sided P = .9) by binomial proportional estimate using the prespecified end point (LRF or alive without LRF and followed < 3 years), and 20% (95% CI, 10% to 37%) by Kaplan-Meier estimate in post hoc analysis using definitions and methods consistent with historical data. Three-year rates by Kaplan-Meier estimate were 72% (95% CI, 56% to 84%) for progression-free survival and 79% (95% CI, 63% to 89%) for overall survival. Grade 4 toxicity occurred in 26%, and 4% had treatment-associated deaths. Conclusion HIV-associated SCCAC is potentially curable with definitive CRT. Although addition of cetuximab may result in less LRF, the 20% recurrence and 26% grade 4 toxicity rates indicate the continued need for more-effective and less-toxic therapies.

Outcomes of abdominoperineal resection for management of anal cancer in HIV-positive patients: a national case review

BACKGROUND

The incidence of anal cancer in human immunodeficiency virus (HIV)-positive individuals is increasing, and how co-infection affects outcomes is not fully understood. This study sought to describe the current outcome disparities between anal cancer patients with and without HIV undergoing abdominoperineal resection (APR).

METHODS

A retrospective review of all US patients diagnosed with anal squamous cell carcinoma, undergoing an APR, was performed. Cases were identified using a weighted derivative of the Healthcare Utilization Project's National Inpatient Sample (2000-2011). Patients greater than 60 years old were excluded after finding a skewed population distribution between those with and without HIV infection. Multivariable logistic regression and generalized linear modeling analysis examined factors associated with postoperative outcomes and cost. Perioperative complications, in-hospital mortality, length of hospital stay, and hospital costs were compared for those undergoing APR with and without HIV infection.

RESULTS

A total of 1725 patients diagnosed with anal squamous cell cancer undergoing APR were identified, of whom 308 (17.9 %) were HIV-positive. HIV-positive patients were younger than HIV-negative patients undergoing APR for anal cancer (median age 47 years old versus 51 years old, p < 0.001) and were more likely to be male (95.1 versus 30.6 %, p < 0.001). Postoperative hemorrhage was more frequent in the HIV-positive group (5.1 versus 1.5 %, p = 0.05). Mortality was low in both groups (0 % in HIV-positive versus 1.49 % in HIV-negative, p = 0.355), and length of stay (LOS) (10+ days; 75th percentile of patient data) was similar (36.9 % with HIV versus 29.8 % without HIV, p = 0.262). Greater hospitalization costs were associated with patients who experienced a complication. However, there was no difference in hospitalization costs seen between HIV-positive and HIV-negative patients (p = 0.66).

CONCLUSIONS

HIV status is not associated with worse postoperative recovery after APR for anal cancer as measured by length of stay or hospitalization cost. Further study may support APRs to be used more aggressively in HIV-positive patients with anal cancer.

HIV Infection Is Associated With Poor Outcomes for Patients With Anal Cancer in the Highly Active Antiretroviral Therapy Era

BACKGROUND

HIV status may affect outcomes after definitive chemoradiotherapy for anal cancer.

OBJECTIVE

Here, we report a large series in the highly active antiretroviral therapy era comparing outcomes between HIV-positive and HIV-negative patients with anal cancer.

DESIGN

This was a retrospective chart review.

SETTINGS

The study was conducted at an outpatient oncology clinic at large academic center.

PATIENTS

A total of 107 patients were reviewed, 39 HIV positive and 68 HIV negative. All of the patients underwent definitive chemoradiation for anal cancer.

MAIN OUTCOME MEASURES

Data on patient characteristics, treatment, toxicity, and outcomes were collected. Overall survival, colostomy-free survival, local recurrence-free survival, and distant metastasis-free survival were analyzed.

RESULTS

Median follow-up was 15 months. HIV-positive patients were younger (median, 52 vs 64 years; p < 0.001) and predominantly men (82% men vs 49% men; p = 0.001). There were no significant differences in T, N, or stage groups. HIV-positive patients had a significantly longer duration from biopsy to start of chemoradiation (mean number of days, 82 vs 54; p = 0.042). There were no differences in rates of acute toxicities including diarrhea, fatigue, or dermatitis. HIV-positive patients had significantly higher rates of hospitalization (33% vs 15%; p = 0.024). The 3-year overall survival rate was 42% in HIV-positive and 76% in HIV-negative patients (p = 0.037; HR, 2.335 (95% CI, 1.032-5.283)). Three-year colostomy-free survival was 67% in HIV-positive and 88% in HIV-negative patients (p = 0.036; HR, 3.231 (95% CI, 1.014-10.299)). Differences in overall survival rates were not significant on multivariate analysis.

LIMITATIONS

This study was limited by its retrospective design and small patient numbers.

CONCLUSIONS

In this cohort, HIV-positive patients had significantly worse overall and colostomy-free survival rates than HIV-negative patients. However, differences in survival were not significant on multivariate analysis. Additional studies are necessary to establish the etiology of this difference.

Chemoradiotherapy for squamous cell carcinoma of the anal canal: Comparison of one versus two cycles mitomycin-C

BACKGROUND AND PURPOSE

Concurrent chemoradiotherapy with 5-fluorouracil (5-FU) and mitomycin-C (MMC) is standard treatment for anal cancer. Randomized clinical trials in Europe have used 1 cycle MMC, while North American studies use 2 cycles. We compared treatment outcomes between patients treated with either 1 or 2 cycles of concurrent MMC.

MATERIAL AND METHODS

217 consecutive patients were treated definitively with chemoradiation from 2004 to 2012 in an integrated health system. Concurrent chemotherapy regimen depended on individual practice, and consisted of 2 cycles 5-FU (1000 mg/m(2)/day on days 1-4 and 29-32), along with MMC (10-15 mg/m(2)), given on either day 1 alone (n = 154), or days 1 and 29 (n = 63). Outcomes included progression-free (PFS), cancer-specific (CSS), overall (OS), and colostomy-free survival (CFS), as well as toxicity criteria.

RESULTS

Median age 60 years, 70% female, 52% T3-T4, and 40% node-positive. Median follow-up 26 months. At 2 years, outcomes were: PFS 80%, CSS 89%, OS 86%, and CFS 88%. There was no difference in PFS (HR 0.85, 95% CI 0.37-1.92), CSS (HR 0.32, 95% CI 0.07-1.42), OS (HR 0.67, 95% CI 0.25-1.83), or CFS (HR 0.91, 95% CI 0.31-2.67) between the MMC1 and MMC2 groups. Stage and male gender were predictive of worse outcomes. Acute grade ⩾ 2 toxicities were worse in the MMC2 group. There were 3 treatment-related deaths, all in the MMC2 group.

CONCLUSIONS

This study suggests that MMC1 is efficacious and may be an alternative to MMC2 in patients with anal cancer treated with definitive chemoradiation, with the potential for less acute treatment-related toxicity. Randomized trials comparing these two regimens could be considered.

Optimal treatment strategies for anal cancer

OPINION STATEMENT

Squamous cell carcinoma (SCCA) of the anal canal is an underrecognized malignancy that is growing in annual incidence. Over the years, combined chemoradiation has been the mainstay of treatment for locally advanced SCCA of the anal canal. Currently, the human papilloma virus (HPV) vaccine is recommended to prevent the development of HPV and its associated precancerous lesion(s). Patients diagnosed with the human immunodeficiency virus (HIV+) are prone to develop anal cancer due to their high risk of contracting HPV infection. We will focus on the development and management of SCCA of the anal canal (both localized and metastatic), including special details on HIV-positive patients. Highlights will include the role of targeted therapy based on available literature. Our objective is to aid practicing physicians in formulating a treatment plan for both locally advanced and metastatic patients.

The changing pattern of ano-rectal cancer, squamous cell carcinoma of the eye, and Hodgkin's lymphoma as non-AIDS-defining cancers, by HIV status, in Tanzania over 11 years (2002-2012): a retrospective case-report study

BACKGROUND

In Tanzania, 5.1% of adults aged 15-49 are infected with HIV. While rates of HIV-related malignancies have declined globally with antiretroviral therapy (ART), including Tanzania, rates of non-AIDS-defining cancers (NADCs) are believed to have increased. Therefore, we determined trends of three NADCs in Tanzania: ano-rectal cancer, squamous cell carcinoma of the eye, and Hodgkin's lymphoma.

METHODS

This study was conducted at the Ocean Road Cancer Institute (ORCI) in Dar es Salaam. All medical records of patients diagnosed with ano-rectal cancer, squamous cell carcinoma of the eye, and Hodgkin's lymphoma between 2002 and 2012 were reviewed regarding HIV status, cancer clinical characteristics and management. Analysis was conducted to determine trends and proportions in these three NADCs and patient characteristics.

RESULTS

We identified 980 NADCs. The relative proportion of these three NADCs at ORCI out of all cancers treated increased from 2.37% in 2002 to a peak of 4.34% in 2009. The prevalence of HIV in patients diagnosed with these NADCs also increased-from 6.67% in 2002 to 20.87% in 2010-and 85% of squamous cell carcinoma of the eye cancer patients with a reported HIV status were HIV-positive.

CONCLUSIONS

The frequency and proportions of these three NADCs in Tanzania have increased over the past 11 years, as has the prevalence of HIV positivity amongst these NADC patients. The current and possibly increasing burden of NADCs in Tanzania and other low- and middle-income countries with high HIV rates should be a focus for future cancer prevention and control and HIV therapy programs.

HIV positivity but not HPV/p16 status is associated with higher recurrence rate in anal cancer

AIM

Human papillomavirus (HPV) is a pathogenic factor of squamous cell carcinoma in various mucosal locations, including anal carcinoma (ACA). It is also known that patients positive for HIV are at high risk of ACA. The goal of this study was to examine clinical outcome in ACA in relation to HPV/p16 positivity, histologic tumor differentiation, and HIV status. Patients with oropharyngeal cancers that are positive for HPV and show overexpression of p16 as well as having non-keratinizing/basaloid histology have been reported to have better outcomes following chemoradiation (CRT). However, such relationships in ACA remain unknown.

METHODS

Forty-two patients with SCC of the anus treated with CRT between 1997 and 2009 were identified. The tumors were subclassified as either non-keratinizing (including basaloid) or keratinizing categories. HPV testing was performed using SPF10-PCR, and all cases were immunostained for p16.

RESULTS

There were 23 men and 19 women; 43% of men and 11% of women were HIV-positive (p = 0.04). Fifty-five percent of patients had local disease (stages I and II) and 41% were stages III and IV, with 4% stage unknown. All tumors were positive for high-oncogenic risk HPVs, and all were positive with p16 immunostain. Sixty-four percent of tumors were non-keratinizing/basaloid and 36 % were keratinizing. The keratinizing tumors were more common in HIV-positive patients (67%), whereas non-keratinizing/basaloid tumors were more common in HIV-negative patients (77%) (p = 0.008). Thirty-one percent of patients had recurrence of disease, including 50% HIV-positive patients and 23% HIV-negative patients (p = 0.09). There was no difference in the recurrence rate between non-keratinizing and keratinizing tumor subtypes (p = 0.80). The 24-month recurrence-free survival for the cohort was 66% (95% CI = 46%, 81%), with HIV-positive patients having worse recurrence-free survival compared to HIV-negative patients (HR = 2.85, 95% CI = 0.95, 8.53; p = 0.06).

CONCLUSION

The regional and distant failure rate was not related to HPV/p16 positivity or histologic differentiation of ACA; however, HIV positivity appeared to be associated with a higher recurrence rate and worse recurrence-free survival.

Long-term effects of chemoradiotherapy for anal cancer in patients with HIV infection: oncological outcomes, immunological status, and the clinical course of the HIV disease

BACKGROUND

Despite the increasing evidence for chemoradiotherapy as standard treatment for anal cancer in patients with HIV infection, there is still some uncertainty regarding increased toxicity and adverse effects on the immune status.

OBJECTIVE

We report the clinical outcome of 5-fluorouracil/mitomycin C-based concurrent chemoradiotherapy for anal carcinoma in patients with HIV infection with an emphasis on the long-term course of CD4 counts and the HIV-related morbidity during follow-up.

DESIGN AND SETTINGS

A retrospective single-institution chart review was performed.

PATIENTS

Between 1997 and 2012, 36 HIV-positive patients were treated with standard chemoradiotherapy (median tumor dose, 54 (range, 50.4-60.4) Gy at 1.8 Gy/fraction; 5-fluorouracil, 800-1000 mg/m(2), days 1-4 or 1-5; mitomycin C, 10 mg/m(2), day 1, in the first and fifth week).

MAIN OUTCOME MEASURES

A retrospective analysis was performed with respect to tumor response, local control, cancer and overall survival, and toxicity. Immunological parameters, including pre- and posttreatment CD4 counts, viral load, and HIV-specific morbidity were recorded during follow-up.

RESULTS

Chemoradiotherapy could be completed in all patients. Acute grade 3 toxicities occurred in 17/36 patients (47%). Complete response was achieved in 31 patients (86%). Five-year local control, colostomy-free, cancer-specific, and overall survival were 72%, 87%, 77%, and 74%. The median pretreatment CD4 count significantly decreased from 367 cells/μL to 139 cells/μL, 3 to 7 weeks after completion of chemoradiotherapy (p < 0.001). Four patients (11%) experienced opportunistic illnesses during the follow-up (median, 66; range, 10-164 months).

LIMITATIONS

This study is limited by its retrospective design and its small sample size.

CONCLUSIONS

Our data confirm again that, in the highly active antiretroviral therapy era, anal cancer can be treated in HIV-positive patients with standard chemoradiotherapy, with a clinical outcome similar to their HIV-negative counterparts. The chemoradiotherapy-related decline of the CD4 counts, which remain decreased up to 6 years after chemoradiotherapy, was not associated with increased HIV-related clinical morbidity.

Chemoradiotherapy for anal cancer in HIV patients causes prolonged CD4 cell count suppression

BACKGROUND

Despite the advent of highly active antiretroviral therapy, anal cancer remains a significant health problem in human immunodeficiency virus (HIV) patients. We present the clinical features and treatment outcomes of anal cancer in 60 HIV-positive patients over a 20-year period.

PATIENTS AND METHODS

A prospective database of all HIV-positive individuals managed in a specialist unit since 1986 includes 11 112 patients (71 687 person-years of follow-up). Sixty patients with anal cancer were identified. Their clinicopathological and treatment details were analysed.

RESULTS

At anal cancer diagnosis, the mean age was 44 years (range: 28-75 years) and the median CD4 cell count was 305 mm(-3) (range: 16-1252 mm(-3)). Fifty (83%) had chemoradiotherapy (CRT). Forty-six (92%) responded, of whom 10 (22%) subsequently relapsed with locoregional (70%), metastatic disease (10%) or both (20%). The overall 5-year survival is 65% (95% confidence interval 51% to 78%). The median CD4 count fell from 289 mm(-3) before CRT to 132 mm(-3) after 3 months and to 189 mm(-3) after 1 year (P<0.05). Six patients in remission of anal cancer died of acquired immunodeficiency syndrome defining illnesses.

CONCLUSIONS

The management of anal cancer with CRT achieves similar outcomes as the general population. CRT is associated with significant prolonged CD4 suppression that may contribute to late deaths of patients in remission.

The cost-effectiveness of screening for anal cancer in men who have sex with men: a systematic review

Anal cancer is a relatively rare neoplasm, related to human papillomavirus (HPV), with an incidence that does not warrant general screening. However, as many cases occur in identifiable high-risk populations, targeting these groups may be cost-effective. Screening for anal cancer in men who have sex with men (MSM) may be appropriate, given their elevated risk of anal cancer. Examining existing cost-effectiveness analyses can help inform the design and conduct of future clinical and economic studies. A review of the literature was performed using three databases to identify studies that assessed the cost-effectiveness of anal cancer screening in MSM. Five analyses were identified: four modelled the cost-effectiveness of cytological screening over a patient’s lifetime, and estimated final health outcomes as survival or quality adjusted survival. The fifth presented a decision analysis with intermediate health outcomes only and did not extrapolate to longer-term health outcomes. Several factors influenced the incremental cost-effectiveness ratios. These factors were related to a paucity of primary data and included: availability of longer-term epidemiological and natural history data; availability of utility-based quality of life data from an appropriate respondent population; appropriate resource use information; and availability of information on screening adherence. There is considerable uncertainty in model results: analyses from the United States suggest screening is almost always cost-effective; analyses from the United Kingdom suggest that screening is unlikely to be cost-effective. Uncertainty is primarily driven by data paucity; by summarising key uncertainties in existing models, this review can inform the design and conduct of future studies.

Squamous cell carcinoma of the anus-an opportunistic cancer in HIV-positive male homosexuals

Squamous cell carcinoma of the anus (SCCA) is a common cancer in the human immunodeficiency virus (HIV)-infected population, and its incidence continues to increase in male homosexuals. Combined chemoradiation with mitomycin C and 5-fluorouracil was poorly tolerated by severely immunocompromised patients in the early 1990s. In the era of highly active antiretroviral therapy (HAART), however, recent data indicate that: (1) most HIV patients with anal cancer can tolerate standard chemotherapy regimens; and (2) this approach is associated with survival rates similar to those of HIV-negative patients. However, HIV-positive patients with SCCA are much younger, more likely to develop local tumor recurrence, and ultimately die from anal cancer than immune competent patients. Taken together, these findings suggest that anal cancer is an often fatal neoplasia in middle-aged HIV-positive male homosexuals. In this population, SCCA is an opportunistic disease resulting in patients with suboptimal immune function from persistent infection and prolonged exposition to oncogenic human papillomaviruses (HPVs). Large-scale cancer-prevention strategies (routine anuscopy and anal papanicolaou testing) should be implemented in this population. In addition, definitive eradication of oncogenic HPVs within the anogenital mucosa of high-risk individuals might require a proactive approach with repeated vaccination.

Concurrent chemoradiotherapy with 5-fluorouracil and mitomycin C for anal carcinoma: are there differences between HIV-positive and HIV-negative patients in the era of highly active antiretroviral therapy?

PURPOSE

To report treatment compliance, toxicity and clinical outcome of chemoradiotherapy (CRT) for anal carcinoma in HIV-negative vs. HIV-positive patients treated with highly active antiretroviral therapy.

MATERIAL AND METHODS

Between 1997 and 2008, 25 HIV-positive and 45 HIV-negative patients received CRT (50.4 Gy at 1.8 Gy/fraction plus 5.4-10.8 Gy boost; 5-fluorouracil, 1000 mg/m(2), Days 1-4 and 29-32, mitomycin C, 10 mg/m(2), Days 1 and 29). Median follow-up was 51 (range, 3-235) months.

RESULTS

HIV-positive patients were significantly younger (mean age, 47 vs. 57 years, p<0.001) and predominantly male (92% vs. 29%, p<0.001). CRT could be completed in all patients with a reduction of chemotherapy and/or RT-interruption in 28% and 8%, respectively, in HIV-positive patients, and in 9% and 11%, respectively, in HIV-negative patients. Acute Grade 3/4-toxicity occurred in 44% vs. 49% (p=0.79). Initial complete response (84% vs. 93%, p=0.41), 5-year rates of local control (65% vs. 78%, p=0.44), cancer-specific (78% vs. 90%, p=0.17) and overall survival (71% vs. 77%, p=0.76) were not significantly different.

CONCLUSION

HIV-positive patients with anal cancer can be treated with standard CRT, with the same tolerability and toxicity as HIV-negative patients. Long-term local control and survival rates are not significantly different between these groups.

HIV- positive anal cancer: an update for the clinician

Anal cancer used to be a rare cancer traditionally associated with elderly women. There are approximately 5260 cases per year in the U.S. (1). The onslaught of the Human Immunodeficiency Virus (HIV) virus has led to a change in anal cancer demographics. Anal cancer is on the rise in the U.S and the number of anal cases documented has quadrupled in the past 20 yrs correlating with the rise of the HIV epidemic. The incidence of anal cancer is 40 to 80 fold higher in the HIV positive (HIV+) population when compared to the general population (2). With the advent of highly active antiretroviral therapy (HAART), HIV+ patients are living longer as less are progressing to AIDS. As a consequence non AIDS defining cancers such as anal cancer are on the rise. Factors implicated in the etiology of anal cancer in HIV+ patients include (Human papillomavirus) HPV virus status, sexual habits, and a history of smoking. HPV 16 and receptive anal intercourse (RAI) increase the risk of anal cancer by 33% over the general population. In the general population, the rate of anal cancer is approximately 0.9 cases per 100,000. In patients with a history of RAI, the rate approaches 35 cases per 100,000 which is equivalent to the prevalence of cervical cancer (3). Smokers are eight times more likely to develop anal cancer. There has been much discussion about tailoring treatment decisions in HIV+ patients with anal cancer. This review focuses on squamous cell carcinomas of the anal canal which comprise 80 to 90% of all anal cancers diagnosed and highlight key issues in the management of HIV+ anal cancer patients including recent clinical trials.

Epidermoid carcinoma of the anal canal

Anal cancers are rare tumors with only an expected 4000 new diagnoses in 2005. The majority of these are epidermoid or squamous cell cancers. Despite the rarity of this disease, great advances have been made in its understanding and treatment. The human papillomavirus (HPV), immunosuppression for solid organ transplantation, the human immunodeficiency virus (HIV), and sexual practices are changing the demographics of the disease from elderly women to young men who have sex with men and young women infected with HPV and HIV. The treatment of these malignancies was radically changed with Dr. Nigro's description in 1974 of the use of a nonoperative treatment strategy. Today, radiochemotherapy represents first-line therapy and the role of surgery has been largely relegated to that of salvage therapy for treatment failures of nonoperative management.

Azidothymidine enhances fluorodeoxyuridine-mediated radiosensitization

PURPOSE

To examine the role of DNA repair and altered thymidine analogues in altering the response to radiation during thymidine deprivation.

METHODS AND MATERIALS

Mismatch repair-deficient and -proficient cell lines HEC59 and HC-2.4 were treated with fluorodeoxyuridine (FUdR), azidothymidine (AZT), and irradiation either alone or in combination, and outcomes of clonogenic survival and cell-cycle distributions were determined.

RESULTS

Survival outcomes for all treatments were similar for both cell lines, suggesting that hMSH2 does not significantly influence thymidine deprivation toxicity or radiosensitization. The chain-terminating thymidine analogue AZT increased the toxicity of FUdR and increased DNA fragmentation. The combination of FUdR and AZT afforded greater radiosensitization than either drug alone. Drug enhancement ratios, the degree of excess radiation-induced cell death in drug-treated cultures compared with radiation alone for HEC59, were 1.2, 1.4, and 1.8 for AZT, FUdR, and the combination, respectively. Enhancement ratios for HC-2.4 were 1.3, 1.5, and 1.8 for AZT, FUdR, and the combination, respectively.

CONCLUSION

Azidothymidine, a chain-terminating thymidine analogue, can enhance the radiosensitizing affects of thymidine deprivation. Deoxyribonucleic acid strand breaks may play an important role in the mechanism of thymidine deprivation-induced radiosensitization.

Toxicity of head-and-neck radiation therapy in human immunodeficiency virus-positive patients

PURPOSE

To examine the acute morbidity of high dose head and neck RT and CRT in patients with infected with HIV.

METHODS AND MATERIALS

All HIV-positive patients who underwent radiation therapy for head and neck cancer in our department between 2004 and 2008 were reviewed. Treatment related data were examined. All treatments were delivered with megavoltage photon beams or electron beams. Patients were evaluated by an attending radiation oncologist for toxicity and response on a weekly basis during therapy and monthly after treatment in a multidisciplinary clinic. Acute toxicities were recorded using the Radiation Therapy and Oncology Group (RTOG) common toxicity criteria. Response to treatment was based on both physical exam as well as post-treatment imaging as indicated.

RESULTS

Thirteen patients who underwent RT with a diagnosis of HIV were identified. Median age was 53 years and median follow-up was 22 months. Twelve had squamous cell carcinoma and one had lymphoproliferative parotiditis. Median radiation dose was 66.4 Gy and median duration of treatment was 51 days. The median number of scheduled radiotherapy days missed was zero (range 0 to 7). One patient (8%) developed Grade 4 confluent moist desquamation. Eight patients (61%) developed Grade 3 toxicity.

CONCLUSION

Based on our results, HIV-positive individuals appear to tolerate treatment for head and neck cancer, with toxicity similar to that in HIV-negative individuals.

Radiotherapy for patients with the human immunodeficiency virus: are special precautions necessary?

Shortly after the onset of the acquired immunodeficiency syndrome (AIDS) epidemic in the 1980s, reports of radiation-associated toxicity in patients with the human immunodeficiency virus (HIV) and AIDS began to appear in the medical literature. Although the majority of reports have focused on AIDS-defining malignancies such as Kaposi sarcoma, greater-than-expected toxicity after a course of radiotherapy or chemoradiotherapy has also been documented in cancers not generally classified as being related to HIV. With improved antiretroviral therapies, HIV patients are living longer and have the potential to develop a variety of HIV-associated and nonassociated malignancies that require treatment, including radiotherapy. This review reports the published data regarding the interactions of HIV, AIDS, and antiretroviral therapy with radiotherapy and implications for the management of malignancies in patients with HIV.

Treatment of anal carcinoma in immune-compromised patients

BACKGROUND

Immune-compromised populations show an increased incidence of anogenital tract neoplasms. This study was undertaken to evaluate local control (LC), overall survival (OS) and toxicity in immune-compromised patients with anal carcinoma treated with radiotherapy with or without chemotherapy.

METHODS

We identified 25 patients with anal carcinoma and human immunodeficiency virus (HIV) infection or history of solid-organ transplant on chronic medical immune-suppression. Median age and follow-up were 44 years and 26 months respectively. AJCC T-stages were Tis (4%), T1 (8%), T2 (58%) and T3 (29%). N-stages were N0 (79%), N1 (4%), N2 (13%) and N3 (4%). One patient had metastatic disease at diagnosis. Seventy-five percent received concurrent chemoradiotherapy. Median radiation dose to the primary tumour was 50 Gy.

RESULTS

One-, 3- and 5-year LC without salvage therapy was 87%, 87% and 70% respectively. One-, 3- and 5-year actuarial OS was 96%, 73% and 61% respectively. One-, 3- and 5-year OS was 100% for treatment time (TT) <50 days and 57%, 38% and 0% for TT > or =50 days (p=0.0009). All patients had acute grade 2-3 skin toxicity. Acute grade 3-4 gastrointestinal (GI), genitourinary (GU) and haematological toxicity occurred in 8%, 0% and 38%. Late grade 3-4 skin, GI and GU toxicity occurred in 8%, 4% and 0%.

CONCLUSIONS

Most HIV-positive and organ transplant patients receiving radiotherapy with or without chemotherapy experience acute toxicity but few have chronic complications. T-stage and CD4 level in HIV-positive patients predict for LC. T-stage and TT predict for OS.

Concurrent chemoradiotherapy with 5-fluorouracil and mitomycin C for invasive anal carcinoma in human immunodeficiency virus-positive patients receiving highly active antiretroviral therapy

PURPOSE

To report the clinical outcomes of chemoradiotherapy (CRT) for anal carcinoma in human immunodeficiency virus (HIV)-infected patients receiving highly active antiretroviral therapy.

PATIENTS AND METHODS

Between 1997 and 2008, 21 HIV-positive patients who were receiving highly active antiretroviral therapy were treated with CRT (50.4 Gy at 1.8 Gy/fraction plus a 5.4-10.8-Gy external boost; 5-fluorouracil, 1,000 mg/m(2), Days 1-4 and 29-32; and mitomycin C, 10 mg/m(2), Days 1 and 29). A retrospective analysis was performed with respect to the tumor response, local control, cancer-specific and overall survival, and toxicity. The immunologic parameters, including pre- and post-treatment CD4 count, viral load, and acquired immunodeficiency syndrome-specific morbidity was recorded during follow-up (median, 53 months; range, 10-99).

RESULTS

CRT could be completed in all 21 patients with a reduction in the chemotherapy dose and/or interruption of radiotherapy in 5 and 5 cases, respectively. Acute Grade 3 toxicity occurred in 8 (38%) of the 21 patients. A complete response was achieved in 17 patients (81%), and tumor persistence or early progression was noted in 4 (19%). Six patients (29%) died, 5 of cancer progression and 1 of treatment-related toxicity. The 5-year local control, cancer-specific, and overall survival rate was 59%, 75%, and 67%, respectively. The median CD4 count significantly decreased from 347.5 cells/microL before CRT to 125 cells/microL 3-7 weeks after CRT completion (p <.001). In 6 (32%) of 19 patients, an increase of the HIV viral load was noted. Both parameters returned to the pretreatment values with additional follow-up.

CONCLUSION

Our data have confirmed that in the highly active antiretroviral therapy era, HIV-related anal cancer can be treated with standard CRT without dose reductions. Close surveillance of the immunologic parameters is necessary.

HIV and anal cancer outcomes: a single institution's experience

PURPOSE

The purpose of this study is to identify the effect of HIV status on outcome of treatment for squamous-cell carcinoma of the anal canal.

METHODS

A retrospective review was performed on all patients with squamous-cell carcinoma of the anal canal treated at a single academic institution between January 1996 and December 2006.

RESULTS

Our search identified 87 (21 HIV-positive) patients who had invasive squamous-cell cancer. The median follow-up was 38 months. Eighty-five percent of HIV-negative patients and 81 percent of HIV-positive were identified as complete responders at 6 weeks after completion of combined modality therapy. Eight percent of HIV-negative and 29 percent of HIV-positive patients developed recurrent disease after 6 months (P = 0.0009). Overall survival for HIV-negative and HIV-positive patients was 71 percent and 73 percent, respectively.

CONCLUSIONS

HIV-positive patients respond equally to combined modality therapy but have recurrences more frequently than patients who are HIV negative. Overall survival in these two groups is equivalent.

Anal cancer: an overview

Anal cancer is a rare tumor with an incidence that has been rising over the last 25 years. The disease was once thought to develop as a result of chronic irritation, but it is now known that this is not the case. Multiple risk factors, including human papillomavirus (HPV) infection, anoreceptive intercourse, cigarette smoking, and immunosuppression, have been identified. HIV infection is also associated with anal cancer; there is a higher incidence in HIV-positive patients but the direct relationship between HIV and anal cancer has been difficult to separate from the prevalence of HPV in this population. HIV infection is also associated with anal cancer; there are increasing numbers of HIV-positive patients being diagnosed with the disease. Treatment of anal cancer prior to the 1970s involved abdominoperineal resection, but the standard of care is now concurrent chemoradiation therapy, with surgery reserved for those patients with residual disease. We present a case of anal cancer followed by a general discussion of both risk factors and treatment.

Involved-field, low-dose chemoradiotherapy for early-stage anal carcinoma

PURPOSE

To report the results of patients with early-stage anal cancer treated using a low-dose, reduced-volume, involved-field chemoradiotherapy protocol.

METHODS AND MATERIALS

Between June 2000 and June 2006, 21 patients were treated with external beam radiotherapy (30 Gy in 15 fractions within 3 weeks) and concurrent chemotherapy (bolus mitomycin-C 12 mg/m(2) on Day 1 to a maximum of 20 mg followed by infusion 5-fluorouracil 1,000 mg/m(2)/24 h on Days 1-4). Of the 21 patients, 18 underwent small-volume, involved-field radiotherapy and 3 were treated with anteroposterior-posteroanterior parallel-opposed pelvic fields. Of the 21 patients, 17 had had lesions that were excised with close (<1 mm) or involved margins, 1 had had microinvasive disease on biopsy, and 3 had had macroscopic tumor <2 cm in diameter (T1). All were considered to have Stage N0 disease radiologically.

RESULTS

After a median follow-up of 42 months, only 1 patient (4.7%) had experienced local recurrence and has remained disease free after local excision. No distant recurrences or deaths occurred. Only 1 patient could not complete treatment (because of Grade 3 gastrointestinal toxicity). Grade 3-4 hematologic toxicity occurred in only 2 patients (9.5%). No significant late toxicity was identified.

CONCLUSION

The results of our study have shown that for patients with anal carcinoma who have residual microscopic or very-small-volume disease, a policy of low-dose, reduced-volume, involved-field chemoradiotherapy produces excellent local control and disease-free survival, with low rates of acute and late toxicity.

AIDS malignancies

Among individuals with HIV-infection, coinfection with oncogenic viruses including EBV, HHV-8, and HPV cause significant cancer-related morbidity and mortality. It is clear that these viruses interact with HIV in unique ways that predispose HIV-infected individuals to malignant diseases. In general, treatment directed specifically against these viruses does not appear to change the natural history of the malignant disease, and once the malignancy develops, if their health permits, HIV-infected patients should be treated using similar treatment protocols to HIV-negative patients. However, for the less frequent HIV-related malignancies, such as PEL, or MCD, optimal treatments are still emerging. For certain AIDS-defining malignancies, it is clear that the widespread access to HAART has significantly decreased the incidence, and improved outcomes. However, for other cancers, such as the HPV-related tumors, the role of HAART is much less clear. Further research into prevention and treatment of these oncogenic virally mediated AIDS-related malignancies is necessary.

Oncologic Complications of Human Immunodeficiency Virus Infection: Changing Epidemiology, Treatments, and Special Considerations in the Era of Highly Active Antiretroviral Therapy

Although highly active antiretroviral therapy (HAART) has revolutionized the treatment of human immunodeficiency virus (HIV)-positive patients, malignancies in the setting of HIV infection remain an appreciable problem. We evaluated the changing epidemiology of HIV-related malignancies, optimal neoplastics and their effect on viral dynamics, and evidence regarding drug interactions between chemotherapy and antiretrovirals. A MEDLINE search (January 1966-June 2006) was performed to identify clinical trials, review articles, and meta-analyses; abstracts from HIV conferences were also searched. Survival of patients with HIV-related malignancies has substantially improved since the advent of HAART. Chemotherapy for malignancies in the HIV-positive population generally resembles that for the HIV-negative population, with trials revealing an elevated frequency of toxicities in HIV-positive patients. Studies of antineoplastics have shown no long-term adverse effects on viral dynamics in terms of immunologic or virologic HIV markers. Limited pharmacokinetic data with antineoplastics and antiretrovirals suggest possible changes in some pharmacokinetic parameters, but these results should be interpreted cautiously because of the small numbers of patients enrolled in the trials. Researchers also report an increased frequency of chemotherapy-related toxicities when HAART was coadministered with antineoplastics. This increase was likely due to impairment of cytochrome P450 metabolism of antineoplastics by protease inhibitors. Because of the survival benefits of HAART, the integration of antiretrovirals with chemotherapy is now preferred for patients with HIV-related malignancies. However, because the metabolic pathways of many of these agents are similar, the effectiveness of antineoplastic therapy and its related toxicities should be vigilantly monitored in this patient population.

Combined modality therapy for HIV-infected patients with squamous cell carcinoma of the anus: outcomes and toxicities

PURPOSE

We report toxicity and survival data of human immunodeficiency virus (HIV)-infected men with anal carcinoma treated with combined modality therapy (CMT) of radiotherapy and concurrent chemotherapy.

METHODS AND MATERIALS

A retrospective review was performed on the records of 17 HIV-positive patients with anal squamous cell carcinoma treated with CMT at our institution between 1991 and 2004. Radiotherapy consisted of 30.6 to 45 Gy to the pelvis, total dose of 50.4 to 59.4 Gy to initial gross disease, at 1.8 Gy/fraction. Chemotherapy consisted of 5-fluorouracil and either mitomycin C or cisplatin. The mean follow-up was 25.6 months (median, 15.6 months; range, 4.6-106 months).

RESULTS

Significant acute skin and hematologic toxicity developed in 8 of 17 and 9 of 17 patients, respectively. One patient died 12 days after treatment of progressive disease and sepsis. Significant late toxic sequelae developed in 3 patients: 1 anorectal ulcer, 2 dermatologic (perianal ulceration, hemorrhagic perineal sores and suspected fissure). Fourteen of 15 patients with Stage I-III disease had a complete response; 2 complete responders subsequently had a relapse in the anorectum. For all patients, actuarial 18-month survival was 67%. For patients with Stage I-III disease, survival at last follow-up by low CD4 count (<200) vs. high count (>200) was 4 of 7 vs. 7 of 8, respectively; significant acute toxicities developed in 4 of 8 vs. 6 of 9, respectively.

CONCLUSION

For HIV patients with anal carcinoma, CMT yields reasonable local control with significant acute complications. Survival is lower than in the general population, attributable more to the underlying infection than to the malignancy.

Local tumor control and toxicity in HIV-associated anal carcinoma treated with radiotherapy in the era of antiretroviral therapy

PURPOSE

To investigate the outcome of HIV-seropositive patients under highly active antiretroviral treatment (HAART) with anal cancer treated with radiotherapy (RT) alone or in combination with standard chemotherapy (CT).

PATIENTS AND METHODS

Clinical outcome of 81 HIV-seronegative patients (1988-2003) and 10 consecutive HIV-seropositive patients under HAART (1997-2003) that were treated with 3-D conformal RT of 59.4 Gy and standard 5-fluorouracil and mitomycin-C were retrospectively analysed. 10 TNM-stage and age matched HIV-seronegative patients (1992-2003) were compared with the 10 HIV-seropositive patients. Pattern of care, local disease control (LC), overall survival (OS), cancer-specific survival (CSS), and toxicity were assessed.

RESULTS

RT with or without CT resulted in complete response in 100% of HIV-seropositive patients. LC was impaired compared to matched HIV-seronegative patients after a median follow-up of 44 months (p = 0.03). OS at 5 years was 70% in HIV-seropositive patients receiving HAART and 69% in the matched controls. Colostomy-free survival was 70% (HIV+) and 100% (matched HIV-) and 78% (all HIV-). No HIV-seropositive patient received an interstitial brachytherapy boost compared to 42% of all HIV-seronegative patients and adherence to chemotherapy seemed to be difficult in HIV-seropositive patients. Acute hematological toxicity reaching 50% was high in HIV-seropositive patients receiving MMC compared with 0% in matched HIV-seronegative patients (p = 0.05) or 12% in all HIV-seronegative patients. The rate of long-term side effects was low in HIV-seropositive patients.

CONCLUSION

Despite high response rates to organ preserving treatment with RT with or without CT, local tumor failure seems to be high in HIV-positive patients receiving HAART. HIV-seropositive patients are subject to treatment bias, being less likely treated with interstitial brachytherapy boost probably due to HIV-infection, and they are at risk to receive less chemotherapy.

Screening HIV-infected individuals for anal cancer precursor lesions: a systematic review

Individuals with human immunodeficiency virus (HIV) infection are at increased risk for human papillomavirus-related squamous cell cancer of the anus. Screening HIV-infected patients for squamous cell cancer of the anus and human papillomavirus-related anal dysplasia may prevent excess morbidity and mortality. We have conducted a systematic review of the indirect evidence in the literature regarding the utility of anal Papanicolau (Pap) smear screening of HIV-infected individuals in the highly active antiretroviral therapy era. Although there are no published studies evaluating the efficacy of anal Pap smear screening for preventing squamous cell cancer of the anus or anal intraepithelial neoplasia, we reviewed data regarding the burden of disease, anal Pap smear sensitivity and specificity, the prevalence of anal dysplasia, and 1 cost effectiveness study. The available evidence demonstrates that HIV-infected individuals have an increased risk for squamous cell cancer of the anus and anal intraepithelial neoplasia. This review identifies important areas for further study before routine anal Pap smear screening can be recommended.

Non-AIDS-defining cancers and HIV infection

With fewer patients now succumbing to infectious complications of AIDS, other HIV-related morbidities, such as malignancies, have become increasingly important. Apart from Kaposi's sarcoma, non-Hodgkin's lymphoma, and cervical cancer, which are considered as AIDS-defining, several additional cancers, referred to as non-AIDS-defining cancers, are also statistically increased in HIV-infected persons. These include Hodgkin's disease, anal carcinoma, lung cancer, nonmelanomatous skin cancer, and testicular germ cell tumors, among others. However, the types of cancer observed at an increased frequency and the relative risks reported vary widely among studies. Although immunosuppression is consistently associated with an increased risk of AIDS-related malignancies, the role of immunosuppression in the pathogenesis of non-AIDS- defining cancers is controversial. Although data regarding the optimal management of these cancers are lacking, current studies suggest that patients with HIV-associated malignancies should be treated with similar approaches to those of their counterparts in the general population.

Non—AIDS–Defining cancers and HIV infection

With fewer patients now succumbing to infectious complications of AIDS, other HIV-related morbidities such as malignancies have become increasingly important. Apart from Kaposi's sarcoma, non-Hodgkin's lymphoma, and cervical cancer, which are considered as AIDS-defining, several additional cancers, referred to as non-AIDS-defining cancers, are also statistically increased in HIV-infected persons. These include Hodgkin's disease, anal carcinoma, lung cancer, nonmelanomatous skin cancer, and testicular germ cell tumors, among others. However, the types of cancer observed at an increased frequency and the relative risks reported vary widely among studies. Although immunosuppression is consistently associated with an increased risk of AIDS-related malignancies, the role of immunosuppression in the pathogenesis of non-AIDS- defining cancers is controversial. Although data regarding the optimal management of these cancers are lacking, current studies suggest that patients with HIV-associated malignancies should be treated with similar approaches to those of their counterparts in the general population.

Anal carcinomas in HIV-positive patients: high-dose chemoradiotherapy is feasible in the era of highly active antiretroviral therapy

BACKGROUND

Anal carcinoma, a common disease in HIV-positive patients, is usually treated with chemoradiotherapy. Generally tolerance was poor before the availability of highly active antiretroviral therapies. We report our experience of treating anal carcinoma in the era of new antiviral drugs.

PATIENTS AND METHODS

Between 1997 and 2001, nine men on highly active antiretroviral therapies with good immune status before chemoradiotherapy received concomitant chemoradiotherapy consisting of 5-fluorouracil and cisplatinum, and high-dose radiotherapy (60-70 Gy) for anal carcinoma. Six cancers were Stage I, two were Stage II, and one was Stage III. CD4+ cell counts were <200/ml for four patients, between 200/ml and 500/ml for four, and >500/ml for one.

RESULTS

All patients received the planned dose of radiation (> or = 60 Gy). The chemotherapy dose was reduced 25 percent in six patients. Overall treatment time was 58 days. Grade 3 hematologic or skin toxicity occurred in four patients. No association was observed between high-grade toxicity and CD4+ cell count. None of the patients developed opportunistic infections during follow-up. Eight patients were disease-free after a median follow-up of 33 months. Among them, four had no or minor anal function impairment at the last follow-up visit. One patient with T4N2 disease relapsed locally one year after treatment and underwent salvage abdominoperineal excision.

CONCLUSION

High-dose chemoradiotherapy for anal carcinomas is feasible with low toxicity in HIV-positive patients treated with highly active antiretroviral therapies. Local control is similar to that obtained for HIV-negative patients.

Effective treatment of anal cancer in the elderly with low-dose chemoradiotherapy

Chemoradiotherapy (CRT) is accepted as the standard initial treatment for squamous cell anal cancer. However, frail elderly patients cannot always tolerate full-dose CRT. This paper reports the results of a modified regimen for this group of patients. In all, 16 patients with biopsy-proven squamous cell carcinoma of the anal canal or margin and performance status or co-morbidity precluding the use of full-dose CRT were included in this protocol. The median age was 81 (range 77-91). Patients received a dose of 30 Gy to the gross tumour volume plus 3 cm margin in all directions. Concurrent chemotherapy comprised 5-fluorouracil 600 mg m(-2) given over 24 h on days 1-4 of radiotherapy. The treatment was well tolerated. All 16 patients completed treatment as planned. Only one patient experienced any grade 3 toxicity (skin). The local control at a median follow-up of 16 months was 73% (13 out of 16). The overall survival was 69% and disease-specific survival 86%. This is a well-tolerated regimen for elderly/poor performance patients with anal cancer, which can achieve high rates of local control and survival. Longer follow-up will determine whether these encouraging results are maintained.

Overview of anal cancer for the surgeon

Cancers of the anal canal represent a diverse group of pathology and require a multidisciplinary approach for treatment. For the most common anal canal cancer, anal SCC, the primary therapy is CMT with systemic chemotherapy and radiation. The surgeon plays a key role in the diagnosis and follow-up after treatment, with surgical intervention reserved for residual or recurrent disease. The overall prognosis for this disease is favorable. For anal adenocarcinoma, aggressive surgical resection remains the mainstay of therapy, with radiation therapy and chemotherapy used to aid in local disease control and for treatment of metastatic disease. A high rate of distant failure in this disease is responsible for the poor long-term prognosis. Anorectal melanoma has a high rate of distant failure and a poor overall survival rate. Surgical intervention is focused on local disease control with preservation of sphincter function. The biggest improvements in survival for this disease will come with more effective systemic therapy.

Anal cancer and its precursors in HIV-positive patients: perspectives and management

Anal cancer is an increasing problem among HIV-infected persons. Although patients are living longer and with better quality of life because of treatment with HAART, they remain at risk for invasive anal cancer and its precursor, anal HSIL. Given the substantial numbers of patients with anal HSIL, further studies need to be done to determine the efficacy and optimal mode of treatment of HSIL, to define the optimal method for screening patients at risk, to define the best way to follow up patients with documented HSIL to ensure early detection, to define prognostic factors for progression to invasive cancer, and to determine the progression rate of HSIL to invasive cancer. Although patients with good functional status and immunologic function seem to do relatively well with standard CMT for anal cancer, there are less fortunate patients who experience substantial morbidity from therapy and have a poorer outcome. It is difficult to draw definitive conclusions about the therapy of HIV-positive patients with anal cancer based on the available literature because of the retrospective nature of the analyses, the small number of patients, and the heterogeneity of the patients reported with regard to tumor size, pretreatment immunologic status, and the variety of treatments received by patients in some series. Identifying patients who develop invasive anal cancer as early as possible will improve results to some degree, but prospective, controlled, multi-institutional trials evaluating the treatment of anal cancer in HIV-infected persons are required to accurately define ways to improve outcome with less morbidity. The results of ongoing therapeutic HPV vaccine trials are eagerly awaited. Improvement may come by the following, determining ways to more accurately stage patients, such as endoanal ultrasound, sentinel lymph node sampling, or positron emission tomography scans; defining the role of cisplatin and whether it is indeed less toxic and equally or more effective; consideration of continuous protracted infusion of low-dose 5-FU; the optimum use of growth factors; and an evaluation of the role of conformal radiotherapy or the use of radio-protectants, such as amifostine. Meanwhile, the best way to treat anal cancer in HIV-infected persons may be to prevent it from occurring by screening persons at risk and treating HSIL, or at a minimum, following up patients carefully and detecting cancers, if they occur, at the earliest possible time.

Cancer of the anal canal

Anal cancer is an uncommon tumour that represents 4% of all cancers of the lower gastrointestinal tract. Its pathogenesis and treatment have undergone substantial reassessment over the past two decades, and this is likely to continue. Anal cancer can be cured by synchronous chemoradiotherapy, a treatment that both enables anal continence to be retained and reserves abdominoperineal resection of the rectum and anal canal (with formation of a permanent colostomy) for recurrent or residual disease after primary chemoradiotherapy. Overall, survival from anal cancer is now around 70-80% at 5 years. Future challenges will be influenced by an increasing incidence due to human papillomavirus and HIV infection, more accurate characterisation and treatment of early (in situ) disease, and optimisation of chemoradiation regimens.

Therapeutic approaches to AIDS-related malignancies

The introduction of highly active antiretroviral therapy (HAART) has changed dramatically the landscape of HIV disease. Deaths from AIDS-related diseases have been reduced by 75% since protease inhibitor therapy and combination antiretroviral therapy came into use in late 1995. While KS is declining, the situation for non-Hodgkin's lymphoma is more complex with a reduced incidence of primary central nervous system lymphoma, but a relatively stability in the number of patients developing systemic NHL. AIDS related NHL appears not to be markedly decreased by the introduction of HAART and it is the greatest therapeutic challenge in the area of AIDS oncology. The emphasis has now shifted to cure while maintaining vigilance regarding the unique vulnerability of HIV-infected hosts. Furthermore, also for the prolongation of the survival expectancy of these patients, other non AIDS-defining tumors, such as Hodgkin's disease, anal and head and neck, lung and testicular cancer, and melanoma have been recently reported with increased frequency in patients with HIV infection.