Treatment Of Anal Canal Cancer Research Articles

PD-L1 expression in keratinocyte and infiltration of CD4 + T lymphocyte can predict a severe type of erythema multiforme major induced by the anti-PD-1 antibody, pembrolizumab

AbstractSkin toxicity is the most common adverse event of treatment with immune check point inhibitors. Among them, erythema multiforme is a rare occurrence with a frequency of 4%, with most of the cases developing grade 1/2 disease. We experienced high grade erythema multiforme major developing with pembrolizumab treatment for anal canal cancer with extensive skin metastases. Steroid ointment was ineffective, and the skin lesions with blisters expanded to > 45% of the body surface area. The patient was at risk for symptom aggravation, and a pulse therapy with methylprednisolone and increasing the dose of oral prednisolone (1 mg/kg) were started. The skin lesions improved in 1.8 months. Unless urgent and appropriate treatments such as high dose steroid administration were conducted, the skin toxicities could not be controlled. The presence of CD4+ T cells and PD-L1+ keratinocytes in the skin biopsy might be a predictive marker of erythema multiforme major resistant to standard steroid treatment.

Revisiting the Radical Radiotherapy-Radiochemotherapy Results in Anal Canal Cancers: (TROD Gastrointestinal Group Study 02-005)

Background and AimThis study aimed to determine treatment outcomes and factors affecting prognosis in patients diagnosed with anal canal cancer who received radical radiotherapy (RT) or radiotherapy combined with chemotherapy (CT-RT) in radiation oncology centers in Turkey and compare the results with literature. Material and MethodThe study included 193 patients with anal canal cancer reported between 1995 and 2019, of which 162 had complete data. The study was conducted in 11 radiation oncology centers, and a joint database was shared among them. Patients received radiotherapy doses of 45 Gy to 60 Gy. Data analysis was done using SPSS for Windows version 20. ResultsMedian follow-up was 48.51 months (2-214). All patients received radiotherapy, and 140 (86.4%) received concurrent chemotherapy. Radiotherapy doses of 50.4 Gy to 60 Gy were administered to 74 patients (45.7%) using 2-dimensional-3-dimensional (2D-3D) conformal therapy and 70 patients (43.2%) using intensity modulated radiotherapy technique (IMRT). Acute phase hematologic toxicity was observed in 62 patients (38.3%), and nonhematologic toxicity in 123 patients (75.9%). The 5-year overall survival (OS) rate was 75.1% and disease-specific survival (DSS) rate was 76.4%. OS without colostomy was achieved in 79,8 % at 5 years, and complete response in 112 patients (69.1%). OS rate was significantly higher in 142 patients with positive response (P < .000) and 112 with complete response (P < .000). Anemia (P < .002), local progression, and systemic progression (P < .000) resulted in lower OS (P < .002). In univariate analysis, factors affecting OS rate were: gender, age, stage, lymph node status, T stage, RT treatment duration, and treatment planning with PET fusion, which were found to be statistically significant. Completing radiotherapy in less than 45 days, concurrent chemotherapy, and continued administration of mitomycin and 5 FU as chemotherapy had a significant positive effect on overall survival. OS rate was higher in patients receiving RT dose of 58 Gy or less and undergoing IMRT planning in radiotherapy. IMRT was associated with lower acute and late side effects. ConclusionRadiochemotherapy is the primary treatment for anal canal cancer and advanced radiotherapy techniques may increase survival by reducing side effects and improving treatment continuation. Higher treatment doses require further investigation. The efficacy of treatment can be improved by including patients treated with modern radiotherapy techniques in multicenter prospective studies using new and more effective chemotherapy and immunotherapy agents.

Prospective Evaluation of Interim FDG-PET Imaging during Chemoradiation for Anal SCC

<h3>Purpose/Objective(s)</h3> De-escalation of therapy for anal squamous cell carcinoma is under investigation in multiple prospective randomized trials. Imaging metrics from (F-18) fluorodeoxyglucose positron emission tomography (PET) before and during chemoradiation may serve as a biomarker to tailor treatment and aid in appropriate patient and dose selection. <h3>Materials/Methods</h3> From June 2012 to July 2021, 56 patients with anal canal cancer were enrolled in two prospective studies (30 and 26 patients, respectively) of PET prior to and during CRT after receiving ∼30 Gy. PET metrics of the primary site were calculated for the pre-treatment and interim images, including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) based on 40% SUVmax (MTV40, TLG40) or SUV 2.5 (MTV2.5, TLG2.5) thresholds. Associations between absolute pre-treatment and interim PET metrics and freedom from local/regional recurrence (FFLR) were investigated using the Cox proportional hazards method. Local/regional recurrence was defined as primary or nodal (in-field) recurrence. No adjustment was made for multiple comparisons. <h3>Results</h3> Forty-four patients were eligible for analysis. Patients with non-squamous cell histology (adenocarcinoma, melanoma) (3 patients), recurrent anal cancer (1 patient), metastatic disease (1 patient), and incomplete studies due to treatment toxicity or patient choice (7 patients) were excluded. Median follow-up was 2.4 years. Clinical stage was T3 or T4 in 43% of patients, and 52% were node positive. Seven patients have expired and disease recurrence patterns following treatment included local/regional (5 patients) and distant disease (7 patients). On univariate analysis, age, T and N stage, duration of treatment, and HIV status did not significantly correlate with FFLR. TLG2.5 (1.05 [0.99-1.11]) was marginally associated with FFLR. No pretreatment metrics or other interim metrics were significantly associated with FFLR. Multivariate analysis was not conducted given the small number of events (N=5). <h3>Conclusion</h3> In this expanded pilot study, characteristics of PET acquired during treatment of anal canal cancer were not significantly associated with FFLR. Given the limited number of FFLR events, definitive conclusions about the utility of interim PET cannot be drawn. The correlation of various PET metrics with FFLR warrants further investigation to determine if interim PET as an imaging biomarker can be used to personalize treatment, potentially in the setting of dose de-escalation.

Are two too many when it comes to the treatment of anal canal cancer with concurrent radiation and mitomycin C?

3 Background: Concurrent chemoradiation (CRT) with 2 doses of 5-fluorouracil (5-FU) and mitomycin C (MMC) is the standard of care for anal canal cancer (ACC) in North America while 1 dose of MMC is an acceptable practice. Given the lack of randomized data of 1 vs 2 doses of MMC on disease outcomes, we have conducted a population-based study to elucidate the impact of 1 vs. 2 doses of MMC on patterns of treatment failure (POF) and outcomes in ACC treatment. Zainab Al Habsi, Aswin Abraham, Mustafa Al Balushi, Gabriella Tankel, Karen Mulder, Heather Warkentin, Dan Schiller, Keith Tankel, Nawaid Usmani, Diane Severin, Kim Paulson, Hatim Karachiwala, Clarence Wong, Tirath Nijjar, Kurian Joseph. Methods: Data was collected from the provincial cancer registry of patients with stage I-III ACC who were treated with concurrent CRT from 2000 to 2018. Recurrence free survival (RFS), overall survival (OS), and ACC specific survival were calculated. Results: 428 patients with a median age of 58 years (29-88 years) were included in this analysis. 234 (54.7%) patients received 1 dose of MMC and 194 (45.3%) received 2 doses of MMC. At a median follow-up of 78.5 months (5-252 months), 89 (20.8%) patients developed disease recurrence: 44 (10.3%) loco-regionally, 39 (9.1%) distally and 6 (1.4%) had both local and distant recurrences. Cox Regression analysis showed that the dosage of MMC did not have an impact on overall recurrence (HR = 0.883, p = 0.561), whereas stage III was associated with increased risk for recurrence (HR = 5.238, p = 0.021). Subgroup analysis showed an association of stage IIIb and IIIc with recurrence (HR = 13.33, p = 0.008 and HR = 6.933, p = 0.011 respectively), but was not impacted by the use of 1 vs. 2 doses of MMC. The dosage of MMC did not show any association with local recurrence (HR = 1.136, p = 0.655) or distant recurrence (HR = 0.743, p = 0.267). However, in Stage IIIc patients, 2 doses of MMC showed a trend towards improved distant RFS (HR = 0.626,p = 0.084). Conclusions: Our analysis showed that the patterns of failure and the risk of loco-regional and distant failures were similar between patients who received 1 vs. 2 doses of MMC for stage groups I to IIIc. These finding support routine use of single dose of MMC along with 5FU and radiotherapy for definite chemoradiation. However, a trend towards better RFS was demonstrated with a second dose of MMC in patients with stage IIIc disease.

Long-Term Outcomes of NRG Oncology/RTOG 0529: A Phase 2 Evaluation of Dose-Painted Intensity Modulated Radiation Therapy in Combination With 5-Fluorouracil and Mitomycin-C for the Reduction of Acute Morbidity in Anal Canal Cancer

A multi-institutional phase 2 trial assessed long-term outcomes of dose-painted intensity modulated radiation therapy (IMRT) with 5-fluorouracil (5FU) and mitomycin-C (MMC) for anal canal cancer. T2-4N0-3M0 anal cancers received 5FU (1000 mg/m2/d, 96-hour infusion) and MMC (10 mg/m2 bolus) on days 1 and 29 of dose-painted IMRT prescribed as follows: T2N0=42 Gy elective nodal and 50.4 Gy anal tumor planning target volumes, 28 fractions; T3-4N0-3=45Gy elective nodal, 50.4 Gy ≤3 cm and 54 Gy >3cm metastatic nodal and 54 Gy anal tumor planning target volumes, 30 fractions. Local-regional failures, distant metastases, and colostomy failures were assessed using the cumulative incidence method, and disease-free survival, overall survival, and colostomy-free survival were assessed using the Kaplan-Meier method. Late effects were scored using National Cancer Institute-Common Terminology Criteria for Adverse Events v3. Of 52 patients, 54% were stage II, 25% were stage IIIA, and 21% were stage IIIB. Median follow-up was 7.9 years (min-max, 0.02-9.2 years). Local-regional failure, colostomy failures, distant metastases, overall survival, disease-free survival, and colostomy-free survival at 5 years are 16% (95% confidence interval [CI], 7%-27%), 10% (95% CI, 4%-20%), 16% (95% CI, 7%-27%), 76% (95% CI, 61%-86%), 70% (95% CI, 56%-81%), and 74% (95% CI, 59%-84%); and at 8 years they are 16% (95% CI, 7%-27%), 12% (95% CI, 5%-23%), 22% (95% CI, 12%-34%), 68% (95% CI, 53%-79%), 62% (95% CI, 47%-74%) and 66% (95% CI, 51%-77%), respectively. Eight patients experienced local-regional failure, with 5 patients having persistent disease at 12 weeks. No isolated nodal failures occurred in the microscopic elective nodal volumes. Six patients required colostomy-5 for local-regional salvage and 1 for a temporary ostomy for anorectal dysfunction. Rates of late adverse events included: 28 patients (55%) with grade 2, 8 patients (16%) with grade 3, 0 patients with grade 4, and 2 patients (4%) with grade 5 events (sinus bradycardia and myelodysplasia, possibly owing to chemotherapy). Only 11 patients reported grade 1 to 3 sexual dysfunction. Dose-painted IMRT with 5FU/MMC for the treatment of anal canal cancer yields comparable long-term efficacy as conventional radiation cohorts. Enhanced normal tissue protection lowered rates of grade 3 and higher late effects without compromising pelvic tumor control.

Pushing the limits for the treatment of anal canal cancer.

Pushing the limits for the treatment of anal canal cancer.

Long-term results of chemoradiation plus pulsed-dose-rate brachytherapy boost in anal canal carcinoma: A mono-institutional retrospective analysis.

PurposeConcurrent chemoradiation (CCRT) is the standard curative treatment of anal canal cancer (ACC). The role of a brachytherapy (BRT) boost in this setting is still debated. Therefore, the aim of this analysis was to retrospectively evaluate the clinical outcomes in a large cohort of ACC patients treated with CCRT plus BRT boost or external beam radiotherapy (EBRT) boost.Material and methodsPatients with non-metastatic ACC, treated in our department between January 2003 and December 2014 were included in this analysis. The initial treatment was based on EBRT to the pelvis (prescribed dose, 45 Gy/1.8 Gy) plus concurrent chemotherapy (5-fluorouracil and mitomycin-C). Patients received a pulsed-dose-rate BRT boost on the primary tumor (median dose, 20 Gy; range, 13-25 Gy) 2-3 weeks after the end of CCRT. In patients with contraindications to BRT, an EBRT boost (prescribed dose, 16 Gy, 2 Gy/fraction) was delivered immediately after CCRT.ResultsOne-hundred-twenty-three patients were included in this analysis (median age, 61 years; range, 36-93 years; squamous-cell carcinoma, 78%; HIV+, 6%; median follow-up, 71 months; range, 2-158 months). The actuarial 5-year local control (LC), distant metastasis-free survival, colostomy-free survival, and overall survival (OS) rates were 81.7%, 92.3%, 62.3%, and 74.0%, respectively. At univariate analysis, patients aged ≤ 65 years (p < 0.010), cT1-2 stage (p = 0.004), and receiving a BRT boost (p = 0.015) showed significantly improved OS. At multivariate analysis, advanced tumor stage cT3-cT4 (HR, 2.12; 95% CI: 1.09-4.14; p = 0.027), and age > 65 years (HR, 3.03; 95% CI: 1.54-5.95; p = 0.001) significantly predicted increased risk of mortality. The crude rate of toxicity-related colostomies was 4.9%.ConclusionsThe role of BRT boost in ACC remains unclear since the outcomes were not clearly different compared to CCRT alone. However, further improvement of clinical results in ACC treatment is needed, and therefore prospective trials based on advanced (image-guided/adapted) BRT techniques are warranted.

Definitive chemoradiotherapy for anal canal cancer: single-center experience.

Chemoradiotherapy (CRT) is a standard treatment for anal canal cancer although many patients with anal canal cancer undergo surgery in Japan. The efficacy of CRT for anal canal cancer was evaluated retrospectively. Medical charts of 13 patients with anal canal cancer treated by definitive CRT from October 2004 to May 2016 were reviewed. Twelve patients had squamous cell carcinoma and one had adeno-squamous carcinoma. PET/CT simulation was performed in nine patients. The median total dose was 59.4Gy (range 57.6-63.4Gy) with fractions of 1.8-2.0Gy. Ten patients received chemotherapy with mitomycin C (10mg/m2) and fluorouracil (5-FU) (800mg/m2 over 4 days) in weeks 1 and 5, while two patients were treated with cisplatin (40mg) and 5-FU (750mg over 5 days) in weeks 1 and 5. One elderly patient received radiotherapy (RT) alone. All 13 patients were alive after a median follow-up period of 102months (range 16-121months). Local failure only occurred in the patient with adeno-squamous cell carcinoma, while there was no loco-regional recurrence or distant metastasis in the other 12 patients. The 5-year loco-regional control rate (LRC) and 5-year overall survival rate (OS) were 92% and 100%, respectively. Acute toxicities of ≥ grade 3 were observed in six patients (46%), mainly being dermatitis around the anal verge, and late toxicity of ≥ grade 3 occurred in one patient. CRT for squamous cell carcinoma of the anal canal achieved good LRC and OS with acceptable toxicities.

Variation in the Use of Chemoradiotherapy for Stage II and III Anal Cancer: Analysis of the National Cancer Data Base.

Treatment for anal canal cancer has evolved from radical operations to definitive chemoradiotherapy (CRT), which allows for sphincter preservation in most patients. The aim of this study was to examine the use of CRT for patients with stage II and III anal cancer, among different patient demographics, geographic regions, and facility types. Utilizing the National Cancer Data Base, we examined patients with stage II and III anal canal squamous cell carcinoma from 2003 to 2010. Via univariate analysis, we examined patterns of treatment by patient demographics, tumor characteristics, geographic region, and facility type (academic vs. community). A multivariable logistic regression model was built to evaluate differences in treatment patterns when adjusting by age, sex, race, comorbidities, and stage. A total of 12,801 patients were analyzed, of which 11,312 (88%) received CRT. After adjusting for confounders, CRT was less likely to be administered to males [odds ratio (OR) 0.61, 95% confidence interval (CI) 0.54-0.69], Black patients (OR 0.70, 95% CI 0.59-0.83), and those with multiple comorbidities (OR 0.60, 95% CI 0.51-0.72). CRT was not as widely utilized in the West (OR 0.74, 95% CI 0.59-0.93), and patients treated in academic-based centers were less likely to receive CRT (OR 0.81, 95% CI 0.72-0.92). Improved median overall survival was observed when CRT was utilized (p=0.008). When controlling for age, sex, race, comorbidities, and stage, discrepancies in the use of CRT for anal cancer treatment exist between demographic subtypes, geographical regions, and facility types.

Safety and Efficacy of Image Guided Intensity Modulated Radiation Therapy in the Treatment of Anal Canal Cancer

Safety and Efficacy of Image Guided Intensity Modulated Radiation Therapy in the Treatment of Anal Canal Cancer

PO-0703: Safety and efficacy of image guided intensity-modulated radiation therapy in the treatment of anal canal cancer

PO-0703: Safety and efficacy of image guided intensity-modulated radiation therapy in the treatment of anal canal cancer

Helical Intensity Modulated Radiation Therapy With Daily Image Guidance in the Treatment of Anal Canal Cancer

Helical Intensity Modulated Radiation Therapy With Daily Image Guidance in the Treatment of Anal Canal Cancer

External Beam Radiotherapy ± Chemotherapy in the Treatment of Anal Canal Cancer: A Single-Institute Long-Term Experience on 100 Patients

One-hundred patients treated with curative radiotherapy (RT) ± chemotherapy (CT) for an anal canal carcinoma (T1–4N0–3M0) were retrospectively analyzed. Five- and 10-year local control (LC) rates were 73% and 67%, respectively. Acute and late G3–G4 toxicity rates were 32% and 12%, respectively. Two patients underwent a colostomy for a G4 anal toxicity. This study confirms the outcomes of RT ± CT in the treatment of anal canal cancer. Concomitant CT and LC statistically influenced Overall Survival and Colostomy-Free Survival. CT also statistically reduced the risk of nodal relapse. High rates of acute skin toxicity impose tailored volumes and techniques of irradiation.

Conservative treatment of anal canal cancer

Conservative treatment of anal canal cancer

PO-0698: Radiotherapy±chemotherapy in the treatment of anal canal cancer: A single-institute long-term experience

PO-0698: Radiotherapy±chemotherapy in the treatment of anal canal cancer: A single-institute long-term experience

Radiochemotherapy and brachytherapy could be the standard treatment for anal canal cancer in elderly patients? A retrospective single-centre analysis

Goal To retrospectively analyse all our elderly patients (>70 years old) treated with radiotherapy ± chemotherapy (RT ± CT) followed by brachytherapy (BRT) for anal canal cancer. Background Studies on clinical outcomes and toxicities of the standard treatments for anal canal cancers in elderly patients are rare and data are not homogeneous, so a standard of care cannot be defined for these patients. Study A retrospective analysis of efficacy and safety of RT ± CT followed by BRT has been performed. The impact of the modified Charlson Index and of other different clinical and therapeutic variables on these outcomes has been also studied. Results Seventy-six elderly patients with a histological diagnosis of anal canal cancer and with a median age of 76 years (range 70-88) were treated with a curative goal. Patients received radiotherapy alone (37/76, "RT group") or radiochemotherapy (39/76, "RT-CT group"). All patients underwent a BRT boost. Five-year local control, overall survival, disease-specific survival, nodal progression-free survival and metastasis-free survival rates were 75.8, 75.8, 82.8. 87.8 and 89.0 %, respectively. Globally, the incidence of acute and late Grade 3-4 toxicities was 14.5 and 6.6 %, respectively. Only 2 patients received surgery because of severe ano-rectal toxicities. Any relationship between the modified Charlson Index and all the considered clinical outcomes was found. Conclusions Curative RT ± CT + BRT showed an acceptable toxicity profile and a good efficacy also in elderly anal canal cancer patients and should be considered as an important therapeutic option also for these patients.

Definitive Organ-Sparing Treatment of Anal Canal Cancer: Can We Afford to Question It?

Definitive Organ-Sparing Treatment of Anal Canal Cancer: Can We Afford to Question It?

BENEFICIAL USE OF MAGNIFYING ENDOSCOPY WITH NARROW‐BAND IMAGING FOR DIAGNOSING A PATIENT WITH SQUAMOUS CELL CARCINOMA OF THE ANAL CANAL

The patient was a 74-year-old woman. She visited a dermatology clinic with a complaint of discomfort in the anal region. Erosion was observed in the anal region, and biopsies were performed. She was diagnosed with Bowen's disease and was referred to the dermatology department of our hospital for treatment. At our department, an endoscopic examination was performed for assessing the extent of Bowen's disease in the rectum. A retroflexed view of the anal canal revealed a slightly raised lesion with a faded color and an irregular surface. Narrow-band imaging (NBI) revealed a whitish lesion with a relatively clear margin and brown dots on the inside. Magnifying endoscopy with NBI revealed abnormal microvessels with dilatation, tortuosity, caliber change and various shapes, which were quite similar to the intrapapillary capillary loop patterns of superficial esophageal cancer. A complete transanal resection of the anal mucosa was performed thereafter. The patient was diagnosed with a well-differentiated squamous cell carcinoma on the basis of a pathological examination. An early diagnosis is critical for successful treatment of anal canal cancer. In this regard, magnifying endoscopy with NBI may be useful for determining the presence and extent of anal canal cancer.

Two-year outcomes of RTOG 0529: A phase II evaluation of dose-painted IMRT in combination with 5-fluorouracil and mitomycin-C for the reduction of acute morbidity in carcinoma of the anal canal.

368 Background: 5-Fluorouracil (5FU) and mitomycin-C (MMC) chemoradiation for anal cancer is associated with high rates of acute morbidity. We have previously shown that dose-painted IMRT (DP-IMRT) significantly reduces grade 3+ GI and dermatologic acute toxicity, as compared to the RTOG 9811 5FU/MMC arm, which used non-conformal radiation techniques. We now report on the two-year outcomes of this DP-IMRT approach. Methods: T2-4N0-3M0 anal canal cancers received 5FU (1,000 mg/m2/day 96 hour infusion) and MMC (10 mg/m2 bolus) days 1 and 29 of DP-IMRT prescribed as follows - T2N0: 42 Gy elective nodal and 50.4 Gy anal tumor planning target volumes (PTVs), 28 fractions; T3-4N0-3: 45 Gy elective nodal, 50.4 Gy ≤ 3 cm and 54 Gy &gt; 3 cm metastatic nodal and 54 Gy anal tumor PTVs, 30 fractions. The following two-year outcomes were assessed: local-regional (LRF) and colostomy failures (CF) using the cumulative incidence method, and disease-free (DFS), overall (OS) and colostomy-free survivals (CFS) using the Kaplan-Meier method. Results: Of 63 accrued patients, 52 were analyzable. Median age was 58 years; 81% female; 54% stage II; 25% IIIA; 21% IIIB. Median follow-up was 23.2 months (0.2-33). Two-year LRF, CF, DFS and 95% confidence intervals are 20% (9%, 31%), 8% (0.4%, 15%) and 77% (62%, 86%), respectively. The causes of death for the 7 patients that died are: anal cancer in 5, morbidity in one and second primary outside the radiation field in one. Two-year comparison data from the RTOG 9811 5FU/MMC arm are shown in the table below. Conclusions: DP-IMRT with 5FU/MMC for the treatment of anal canal cancer yields similar two-year outcomes as the RTOG 9811 conventional radiation, 5FU/MMC arm. Because of the associated acute toxicity sparing, DP-IMRT will be used as the platform, and may allow for radiation dose escalation, in future RTOG anal canal trials. Supported by RTOG U10 CA21661, CCOP U10 CA3742 and ATC U24 CA 81647 NCI grants. [Table: see text] No significant financial relationships to disclose.

Dose-Painted Intensity-Modulated Radiation Therapy for Anal Cancer: A Multi-Institutional Report of Acute Toxicity and Response to Therapy

Chemoradiation for anal cancer yields effective tumor control, but is associated with significant acute toxicity. We report our multi-institutional experience using dose-painted IMRT (DP-IMRT). Between August 2005 and May 2009, 43 patients were treated with DP-IMRT and concurrent chemotherapy for biopsy-proven, squamous cell carcinoma of the anal canal at two academic medical centers. DP-IMRT was prescribed as follows: T2N0: 42 Gy, 1.5 Gy/fraction (fx) to elective nodal planning target volume (PTV) and 50.4 Gy, 1.8 Gy/fx to anal tumor PTV; T3-4N0-3: 45 Gy, 1.5 Gy/fx to elective nodal PTV, and 54 Gy, 1.8 Gy/fx to the anal tumor and metastatic nodal PTV >3 cm with 50.4 Gy, 1.68 Gy/fx to nodal PTVs ≤ 3 cm in size. Acute and late toxicity was reported by the treating physician. Actuarial analysis was performed using the Kaplan-Meier method. Median age was 58 years; 67% female; 16% Stage I, 37% II; 42% III; 5% IV. Fourteen patients were immunocompromised: 21% HIV-positive and 12% on chronic immunosuppression. Median follow-up was 24 months (range, 0.6-43.5 months). Sixty percent completed chemoradiation without treatment interruption; median duration of treatment interruption was 2 days (range, 2-24 days). Acute Grade 3+ toxicity included: hematologic 51%, dermatologic 10%, gastrointestinal 7%, and genitourinary 7%. Two-year local control, overall survival, colostomy-free survival, and metastasis-free survival were 95%, 94%, 90%, and 92%, respectively. Dose-painted IMRT appears effective and well-tolerated as part of a chemoradiation therapy regimen for the treatment of anal canal cancer.