Radiation dose associated with local control in advanced anal cancer: retrospective analysis of 129 patients. Radiother Oncol. 2008;87:367-375. [PMID: 18501453 DOI: 10.1016/j.radonc.2008.05.001]

Impact of dose escalation on colostomy-free survival and treatment outcome in squamous cell anal carcinoma

PURPOSE

Primary radiochemotherapy (RCT) constitutes the standard of care for early- and advanced-stage anal carcinoma. This retrospective study investigates the impact of dose escalation on colostomy-free survival (CFS), overall survival (OS), locoregional control (LRC), progression-free survival (PFS), and acute and late toxicities in patients with squamous cell anal cancer.

METHODS

Considered were the outcomes of 87 patients with anal cancer treated with radiation/RCT between May 2004 and January 2020 at our institution. Toxicities were evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE version 5.0).

RESULTS

The 87 patients received treatment with a median boost of 63 Gy to the primary tumor. With a median follow-up of 32 months, the 3‑year CFS, OS, LRC, and PFS were 79.5%, 71.4%, 83.9%, and 78.5%, respectively. Tumor relapse occurred in 13 patients (14.9%). Dose escalation to > 63 Gy (maximum 66.6 Gy) to the primary tumor in 38/87 patients revealed a nonsignificant trend for improved 3‑year CFS (82.4% vs. 97%, P = 0.092), a significantly improved CFS for T2/T3 tumors (72.6% vs. 100%, P = 0.008), and a significantly improved 3‑year PFS for T1/T2 tumors (76.7% vs. 100%, P = 0.035). While acute toxicities did not differ, dose escalation > 63 Gy led to a higher rate of chronic skin toxicities (43.8% vs. 69%, P = 0.042). Treatment with intensity-modulated radiotherapy (IMRT) showed a significant improvement in 3‑year OS (75.4% vs. 53.8%, P = 0.048). In multivariate analysis, significant improvements for T1/T2 tumors (CFS, OS, LRC, PFS), G1/2 tumors (PFS), and IMRT (OS) were shown. The nonsignificant trend for CFS improvement with dose escalation > 63 Gy was also apparent in multivariate analysis (P = 0.067).

CONCLUSION

Dose escalation > 63 Gy (maximum 66.6 Gy) may improve CFS and PFS for certain subgroups, with a concomitant increase in chronic skin toxicities. Modern IMRT seems to be associated with an improvement in OS.

Proton beam radiotherapy for anal and rectal cancers

Gastrointestinal cancers are bordered by radiosensitive visceral organs, resulting in a narrow therapeutic window. The search for more efficacious and tolerable therapies raises the possibility that proton beam therapy's (PBT) physical and dosimetric differences from conventional therapy may be better suited to treat both primary and recurrent disease, which carries its own unique challenges. Currently, the maximal efficacy of radiation plans for primary and recurrent anorectal cancer is constrained by delivery techniques and modalities which must consider feasibility challenges and toxicity secondary to exposure of organs at risk (OARs). Studies using volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT) demonstrate that more precise dose delivery to target volumes improves local control rates and reduces complications. By reducing the low-to-moderate radiation dose-bath to bone marrow, small and large bowel, and skin, PBT may offer an improved side-effect profile. The potential to reduce toxicity, increase patient compliance, minimize treatment breaks, and enable dose escalation or hypofractionation is appealing. In cases where prognosis is favorable, PBT may mitigate long-term morbidity such as secondary malignancies, femoral fractures, and small bowel obstruction.

Long-term follow-up experience in anal canal cancer treated with Intensity-Modulated Radiation Therapy: Clinical outcomes, patterns of relapse and predictors of failure

BACKGROUND AND PURPOSE

To assess the long-term outcomes of patients with squamous cell carcinoma of the anal canal (SCCAC) treated with Intensity-Modulated Radiation Therapy (IMRT).

MATERIAL AND METHODS

From 2007 to 2015, 193 patients were treated by IMRT for SCCAC. Radiotherapy delivered 45 Gy in 1.8 Gy daily-fractions to the primary tumor and elective nodal areas, immediately followed by a boost of 14.4-20 Gy to the primary tumor and involved nodes. Concurrent chemotherapy with 5-FU-mitomycin (MMC) or cisplatin was added for locally advanced tumors. Survivals were estimated by Kaplan-Meier method. Locoregional (LR) relapses were precisely assessed. Prognostic factors were evaluated by uni- and multivariate analyses. Late toxicity was scored according to the Common Toxicity Criteria for Adverse Events v4.0.

RESULTS

Median follow-up was 70 months (range, 1-131). Forty-nine men (25%) and 144 women (75%) were analyzed. Median age was 62 years. Tumor stages were I, II, III and IV in 7%, 24%, 63% and 6% of cases, respectively. Chemotherapy was delivered in 167 patients (87%), mainly MMC (80%). Five-year OS, DFS, CFS and LR control rates were 74%, 68%, 66% and 85%, respectively. Forty-one patients (21%) had a relapse: 22 were LR, mostly in-field (68%). Predictors for LR failure were exclusive radiotherapy, chemotherapy lacking MMC and treatment breaks >3 days. Overall late toxicity ≥grade 2 occurred in 43% of patients, with 24% grade 3 and one case of grade 4 (hematuria).

CONCLUSION

CRT with IMRT assures excellent local control in locally advanced SCCAC with manageable long-term toxicity. Multicentric prospective trials are required to reinforce those results.

Late gastrointestinal toxicity after radiotherapy for anal cancer: a systematic literature review

INTRODUCTION

There is a paucity of data on incidence and mechanisms of long-term gastrointestinal consequences after chemoradiotherapy for anal cancer. Most of the adverse effects reported were based on traditional external beam radiotherapy whilst only short-term follow-ups have been available for intensity-modulated radiotherapy, and there is lack of knowledge about consequences of dose-escalation radiotherapy.

METHOD

A systematic literature review.

RESULTS

Two thousand nine hundred and eighty-five titles (excluding duplicates) were identified through the search; 130 articles were included in this review. The overall incidence of late gastrointestinal toxicity was reported to be 7-64.5%, with Grade 3 and above (classified as severe) up to 33.3%. The most commonly reported late toxicities were fecal incontinence (up to 44%), diarrhea (up to 26.7%), and ulceration (up to 22.6%). Diarrhea, fecal incontinence and buttock pain were associated with lower scores in radiotherapy specific quality of life scales (QLQ-CR29, QLQ-C30, and QLQ-CR38) compared to healthy controls. Intensity-modulated radiation therapy appears to reduce late toxicity.

CONCLUSION

Late gastrointestinal toxicities are common with severe toxicity seen in one-third of the patients. These symptoms significantly impact on patients' quality of life. Prospective studies with control groups are needed to elucidate long-term toxicity.

Brachytherapy boost after chemoradiation in anal cancer: a systematic review

Radio-chemotherapy (RCT) is the primary treatment of anal cancer (AC). However, the role and the optimal total dose of a radiation boost is still unclear. No randomized controlled trials nor systematic reviews have been performed to analyze the efficacy of brachytherapy (BRT) as boost in AC. Therefore, we performed this systematic review based on PRISMA methodology to establish the role of BRT boost in AC.

A systematic search of the bibliographic databases: PubMed, Scopus, and Cochrane library from the earliest possible date through January 31, 2018 was performed. At least one of the following outcomes: local control (LC), loco-regional control (LRC), overall survival (OS), disease-free survival (DFS), or colostomy-free survival (CFS) had to be present for inclusion in this systematic review in patients receiving a BRT boost. Data about toxicity and sphincter function were also included.

Ten articles fulfilled the inclusion criteria. All the studies had retrospective study design. All studies were classified to provide a level of evidence graded as 3 according to SIGN classification. Median 5-year LC/LRC, CFS, DFS, and OS were: 78.6% (range, 70.7-92.0%), 76.1% (range, 61.4-86.4%), 75.8% (range, 65.9-85.7%), and 69.4% (63.4-82.0%), respectively. The reported toxicities were acceptable.

RCT is the treatment cornerstone in AC. High-level evidences from studies on BRT boost in AC are lacking. Further studies should investigate: efficacy of BRT boost in comparison to no boost and to external beam boost, patients who can benefit from this treatment intensification, and optimal radiation dose.

Nodal stage migration and prognosis in anal cancer: a systematic review, meta-regression, and simulation study

BACKGROUND

In patients with squamous cell carcinoma of the anus (SCCA), lymph node positivity (LNP) indicates poor prognosis for survival and is central to radiotherapy planning. Over the past three decades, LNP proportion has increased, mainly reflecting enhanced detection with newer imaging modalities; a process known as nodal stage migration. If accompanied by constant T stage distributions, prognosis for both lymph node-positive and lymph node-negative groups may improve without any increase in overall survival for individual patients; a paradox termed the Will Rogers phenomenon. Here, we aim to systematically evaluate the impact of nodal stage migration on survival in SCCA and address a novel hypothesis that this phenomenon results in reduced prognostic discrimination.

METHODS

We did a systematic review and meta-regression to quantify changes in LNP over time and the impact of this change on survival and prognostic discrimination. We searched MEDLINE, Embase, and the Cochrane Library to identify randomised trials and observational studies in patients with SCCA published between Jan 1, 1970, and Oct 11, 2016. Studies were eligible if patients received chemoradiotherapy or radiotherapy as the main treatment, reported LNP proportions (all studies), and reported overall survival (not necessarily present in all studies). We excluded studies with fewer than 50 patients. We extracted study-level data with a standardised, piloted form. The primary outcome measure was 5-year overall survival. To investigate scenarios in which reduced prognostic discrimination might occur, we simulated varying true LNP proportions and true overall survival, and compared these with expected observed outcomes for varying levels of misclassification of true nodal state.

FINDINGS

We identified 62 studies reporting LNP proportions, which included 10 569 patients. From these, we included 45 studies (6302 patients) with whole cohort 5-year overall survival, 11 studies with 5-year survival stratified by nodal status, and 20 studies with hazard ratios in our analyses of temporal changes. In 62 studies, the LNP proportions increased from a mean estimate of 15·3% (95% CI 10·5-20·1) in 1980 to 37·1% (34·0-41·3) in 2012 (p<0·0001). In 11 studies with prognostic data, increasing LNP was associated with improved overall survival in both lymph node-positive and lymph node-negative categories, whereas the proportions with combined tumour stage T3 and T4 remained constant. In 20 studies, across a range of LNP proportions from 15% to 40%, the hazard ratios for overall survival of lymph node-positive versus lymph node-negative patients decreased significantly from 2·5 (95% CI 1·8-3·3) at 15% LNP to 1·3 (1·2-1·9; p=0·014) at 40% LNP. The simulated scenarios reproduced this effect if the true LNP proportions were 20% or 25%, but not if the true LNP proportions were 30% or greater.

INTERPRETATION

We describe a consequence of staging misclassification in anal cancer that we have termed reduced prognostic discrimination. We used this new observation to infer that the LNP proportions of more than 30% seen in modern clinical series (11 out of 15 studies with a median year since 2007) are higher than the true LNP proportion. The introduction of new staging technologies in oncology might misclassify true disease stage, spuriously informing disease management and ultimately increasing the risk of overtreatment.

FUNDING

Bowel Disease Research Foundation.

Chemoradiotherapy with Brachytherapy or Electron Therapy Boost for Locally Advanced Squamous Cell Carcinoma of the Anus-Reducing the Colostomy Rate

Purpose

The aim of this study is to determine overall survival, disease-specific survival and stoma-free survival after treatment of squamous cell carcinoma of the anus with chemoradiotherapy followed by brachytherapy or electron boost in a recent cohort of patients.

Methods

Fifty-two patients (median age 62 years) were treated with radical chemoradiotherapy (mitomycin C, infusional 5-fluorouracil concurrently with conformal radical radiotherapy 45 Gy in 25 fractions over 5 weeks) followed by a radiotherapy boost between 1 December 2000 and 30 April 2011. Follow-up was to 30 November 2014. Thirty-six patients received a boost (15–20 Gy) over 2 days with ¹⁹²Ir needle brachytherapy for anal canal tumours, and 16 patients received electron beam therapy (20 Gy in 10 fractions in 2 weeks) for anal margin tumours. A defunctioning stoma was only created prior to chemoradiotherapy for fistula or severe anal pain.

Results

The overall survival for the 36 patients treated with chemoradiotherapy followed by brachytherapy was 75 % (95 % CI, 61–89) at 5 years, the disease-specific survival was 91 % (95 % CI, 81–101 %), and the stoma-free survival was 97 % (95 % CI, 91–103 %) all at 5 years. For the 16 patients treated with an electron boost for anal margin tumours, the 5-year overall survival, disease-specific survival and stoma-free survival were 68 % (95 % CI, 44–92 %), 78 % (95 % CI, 56–100 %) and 80 % (95 % CI, 60–100 %), respectively.

Conclusions

A very low stoma formation rate can be obtained with radical chemoradiotherapy followed by a brachytherapy boost for squamous cell carcinoma of the anal canal but not with an electron boost for anal margin tumours.

A tumor control probability model for anal squamous cell carcinoma

BACKGROUND AND PURPOSE

A recent update of the RTOG 9811, reported differing relapse rates for early and late anal squamous cell carcinoma following chemoradiotherapy (CRT). There may be a role for dose-individualization, however the dose-response relationship for anal cancer is not currently known. Intensity-modulated radiotherapy (IMRT) has been widely adopted with multiple series published. The aim is to fit a tumor control probability (TCP) model to the published IMRT data.

MATERIALS AND METHODS

We performed a systematic review of PubMed and Embase databases to identify thirteen appropriate papers, including 625 patients. Predefined data fields were collected. A standard linear quadratic TCP model, which included repopulation, was fit by least squares minimization.

RESULTS

The fitted TCP curve demonstrated a dose-response relationship with α=0.196 Gy(-1). The curve suggests: in early stage tumours, a dose reduction from 50 Gy to 45 Gy reduces 2 year local control from 98% to 95%; in late stage tumours, a dose escalation from 50 Gy to 55 Gy improves the 2 year local control rate from approximately 50% to 80%.

CONCLUSIONS

The published data are broadly consistent with a linear quadratic dose-response model. Dose-individualization in anal cancer should be further investigated in the context of clinical trials.

Anal cancer: current standards in care and recent changes in practice

Answer questions and earn CME/CNE The management of squamous cell carcinomas of the anal canal has evolved from surgery as first-line treatment to curative chemoradiation, with surgery reserved for salvage. Significant progress has been made in understanding how to most effectively deliver chemotherapy and reduce toxicity through advancements in radiation delivery. The purpose of this article is to review the multimodality approach to the diagnosis and management of anal cancer based on a review of the published data and in light of available guidelines.

Anal squamous cell carcinoma: An evolution in disease and management

Anal cancer represents less than 1% of all new cancers diagnosed annually in the United States. Yet, despite the relative paucity of cases, the incidence of anal cancer has seen a steady about 2% rise each year over the last decade. As such, all healthcare providers need to be cognizant of the evaluation and treatment of anal squamous cell carcinoma. While chemoradiation remains the mainstay of therapy for most patients with anal cancer, surgery may still be required in recurrent, recalcitrant and palliative disease. In this manuscript, we will explore the diagnosis and management of squamous cell carcinoma of the anus.

Inguinal lymph node recurrence in the untreated groin of patients with anal carcinoma

BACKGROUND

Inguinal lymph node metastasis is predictive of locoregional recurrence and poor overall survival in anal carcinoma. Metachronous lymph node metastasis occurs in 10% of all anal cancer patients, but multiple studies have shown that the benefit of elective irradiation of the groin depends on T-stage, and the toxicity of groin irradiation must not be underestimated.

OBJECTIVE

To analyze the inguinal recurrence rates among patients with anal carcinoma (T1-4, N0-1) who did not receive elective irradiation therapy to the groin and to determine predictors of inguinal recurrence.

DESIGN

Data on 119 patients treated between 1987 and 2005 were retrospectively analyzed. Patients were treated with 3-dimensional radiotherapy. The median dose was 60 Gy. During radiotherapy, 108 patients also received chemotherapy (5-fluorouracil and mitomycin-C).

RESULTS

AJCC staging showed a distribution of 21 T1 (18%), 58 T2 (49%), 27 T3 (23%), 13 T4 (11%), 101 N0 (85%) and 18 N1 (15%) tumors. The median follow up was 65 months (range, 1-240 months). The 5-year inguinal recurrence rate was 0% for T1, 10% for T2, 21% for T3 and 19% for T4 tumors (p = 0.034). T2 tumors of the perianal skin and the anal canal had 5-year inguinal recurrence rates of 12% and 8%, respectively. The 5-year inguinal recurrence rate was 21% for tumors ≥4 cm vs. 2% for tumors <4 cm in size (p = 0.003).

LIMITATIONS

Eleven patients did not receive chemotherapy.

CONCLUSIONS

Elective irradiation of the groin should be considered for local control in patients (N0-N1) with T2 tumors ≥4 cm in size and/or located in the perianal skin, and in all patients with T3 and T4 tumors.

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.

[Positron emission tomography for volume delineation of pelvic nodal involvement]

Radiotherapy planification has recently known important developments, with the rise of new technologies, such as conformational radiation therapy, intensity-modulated radiation therapy (IMRT) or stereotaxic radiation therapy. Delineation of target volumes has become primordial. Hybrid imaging by positron emission tomography associated to computed tomography scanner (PET-CT) gives an access to functional and morphological information. Radiotherapist and nuclear physicians working closely have the potential to allow a more optimal delineation, and a better preservation of organs at risk. During the past few years, this has been explored by many articles, and we propose a literature review organized by localization, about the use of PET-CT for pelvic nodes delineation.

[Curative radiotherapy in patients with anal cancer: clinical outcomes and prognostic factors in a single-institution experience]

PURPOSE

Our aim was to retrospectively analyse a series of patients with anal cancer treated with curative intent at a single institute in terms of survival and local disease control.

MATERIALS AND METHODS

Forty-two patients with anal cancer were treated with primary radiotherapy with or without concurrent chemotherapy. The influence of the prognostic factors on overall (OS), disease-free (DFS), disease-specific (DSS), colostomy-free (CFS) and metastasis-free (MFS) survival was evaluated.

RESULTS

Nine patients had stage I, 15 stage II, four stage IIIA and 14 stage IIIB disease. Tumour progression/ persistence occurred in five patients (12%). The 5-year OS, DSS, DFS, CFS and MFS were 72.7%, 84.2%, 85.7%, 81.1% and 87.1%, respectively. On univariate analysis, T stage emerged as highly significant for OS, DSS, CFS and DFS, whereas N status was a significant prognostic factor for DSS. On multivariate analysis, T stage was a significant prognostic factor for OS and CFS.

CONCLUSIONS

Our data support the view that combined chemoradiation treatment of anal cancer is feasible and may provide survival benefits with an acceptable rate of adverse effects. We should consider T and N stages as important prognostic factors for survival.

Twenty-year experience in the management of squamous cell anal canal carcinoma with interstitial brachytherapy

OBJECTIVES

The aim of this study was to retrospectively evaluate clinical characteristics, local control, acute and late toxicity, and prognostic factors of patients with anal canal carcinoma treated with brachytherapy.

METHODS

From 1989 to 2009, 38 patients were treated with iridium 192 low-dose-rate (N = 26) or pulsed-dose-rate (N = 12) interstitial brachytherapy at a single institution. The median age was 62 years (range, 38-86 years). The TNM classification was as follows: 10 T1, 22 T2, 5 T3 and 1 T4; 32 N0, 3 N1 and 3 N2. Most patients (32/38) received either a first course of radiochemotherapy (N = 22) or radiotherapy alone (N=10) consisting of a total delivered dose of 45 Gy to the pelvis (range, 32-50) followed by a boost a median of 18 days later of 15-35 Gy (median 20 Gy) to the anal canal. The remaining 6 cases were treated with brachytherapy alone (dose range, 60-65 Gy).

RESULTS

With a median follow-up of 30 months (range, 4-200), 2- and 5-year local control rates were 91% and 87%, respectively. Preservation of the anal sphincter was achieved in 32 patients (84%). Three patients experienced incontinence after brachytherapy. Only 2 patients showed chronic mucositis grade 3/4. Age proved to be a statistically significant prognostic factor for overall survival in the univariate (p = 0.033) and multivariate analyses (p = 0.018). Concurrent chemotherapy with external beam radiotherapy was a statistically significant prognostic factor for disease-free survival in the univariate and multivariate analyses (p = 0.007 and p = 0.044, respectively).

CONCLUSIONS

Interstitial brachytherapy appears to be an effective and well tolerated treatment for anal carcinoma offering both high local tumour control and anal sphincter preservation.

Intensity-modulated radiotherapy for squamous cell carcinoma of the anal canal: efficacy of a low daily dose to clinically negative regions

BACKGROUND

We aimed to assess outcomes of patients with anal cancer who underwent intensity-modulated radiotherapy (IMRT) and received less than 1.80 Gy/day.

METHODS

We retrospectively reviewed our experience using a low fractional dose (< 1.80 Gy) of IMRT to elective nodal areas for patients receiving chemoradiotherapy for anal cancer. Three-year freedom from any disease relapse and overall survival were estimated using Kaplan-Meier curves. We documented the daily dose that was delivered to clinically uninvolved regions and to areas of gross disease. Incidence of regional failures in high (≥ 1.80 Gy) and low (< 1.80 Gy) daily dose regions was assessed.

RESULTS

Thirty-four consecutive patients (median age, 59 years) received IMRT from June 2005 through January 2009. Median follow-up duration was 22 months. Twenty-eight patients had T1 or T2 disease and 6 had T3 or T4 disease. Fourteen patients had nodal metastases. Median treatment dose was 50.40 Gy (range, 48.60-57.60 Gy) in 25 to 32 fractions. The range of fractional doses to clinically negative volumes was 1.28 to 1.80 Gy. Seventeen patients (50%) received a fractional dose of less than 1.60 Gy, 13 (38%) received less than 1.50 Gy, and 9 (26%) received less than 1.40 Gy to at least a portion of the clinically negative volume. Three-year freedom from relapse was 80%, and 3-year overall survival was 87%. No patient had treatment failure in the clinically negative volume that received a low daily dose.

CONCLUSIONS

Our data support using doses between 1.50 and 1.80 Gy/day to clinically uninvolved regions.

Cause-Specific Colostomy Rates After Radiotherapy for Anal Cancer: A Danish Multicentre Cohort Study

Purpose

In anal cancer, colostomy-free survival is a measure of anal sphincter preservation after treatment with radiotherapy or chemoradiotherapy. Failure to control anal cancer and complications of treatment are alternative indications for colostomy. However, no data exist on cause-specific colostomy rates. We examined this in a cohort study.

Patients and Methods

Through national registries and review of medical records, we identified patients with anal cancer diagnosed from 1995 to 2003 who had curative-intent radiotherapy or chemoradiotherapy in four Danish centers. We computed cumulative incidence of tumor-related colostomy and therapy-related colostomy, treating colostomy and death as competing events. Follow-up started at completion of radiotherapy and continued throughout 2008. We used competing risk regression to compute hazard ratios (HRs) to compare the cumulative incidence of cause-specific colostomies between age, sex, tumor size, chemotherapy, and local excision before radiotherapy.

Results

We included 235 patients with anal cancer. The 5-year cumulative incidences of tumor-related and therapy-related colostomy were 26% (95% CI, 21% to 32%) and 8% (95% CI, 5% to 12%), respectively. Tumor size greater than 6 cm versus less than 4 cm was a risk factor for tumor-related colostomy (adjusted HR, 3.8; 95% CI, 1.7 to 8.1), and local excision before radiotherapy was a risk factor for therapy-related colostomy (adjusted HR, 4.5; 95% CI, 1.5 to 13.5).

Conclusion

After curative-intent radiotherapy or chemoradiotherapy, one third of patients had a colostomy, of which one third were related to therapy. Large tumor size was associated with a higher risk of tumor-related colostomy, whereas history of prior excision was associated with an increased incidence of therapy-related colostomy.

High-dose split-course radiation therapy for anal cancer: outcome analysis regarding the boost strategy (CORS-03 study)

PURPOSE

To retrospectively assess the clinical outcome in anal cancer patients treated with split-course radiation therapy and boosted through external-beam radiation therapy (EBRT) or brachytherapy (BCT).

METHODS AND MATERIALS

From January 2000 to December 2004, a selected group (162 patients) with invasive nonmetastatic anal squamous cell carcinoma was studied. Tumor staging reported was T1 = 31 patients (19%), T2 = 77 patients (48%), T3 = 42 patients (26%), and T4= 12 patients (7%). Lymph node status was N0-1 (86%) and N2-3 (14%). Patients underwent a first course of EBRT: mean dose 45.1 Gy (range, 39.5-50) followed by a boost: mean dose 17.9 Gy (range, 8-25) using EBRT (76 patients, 47%) or BCT (86 patients, 53%). All characteristics of patients and tumors were well balanced between the BCT and EBRT groups.

RESULTS

The mean overall treatment time (OTT) was 82 days (range, 45-143) and 67 days (range, 37-128) for the EBRT and BCT groups, respectively (p < 0.001). The median follow-up was 62 months (range, 2-108). The 5-year cumulative rate of local recurrence (CRLR) was 21%. In the univariate analysis, the prognostic factors for CRLR were as follows: T stage (T1-2 = 15% vs. T3-4 = 36%, p = 0.03), boost technique (BCT = 12% vs. EBRT = 33%, p = 0.002) and OTT (OTT <80 days = 14%, OTT ≥80 days = 34%, p = 0.005). In the multivariate analysis, BCT boost was the unique prognostic factor (hazard ratio = 0.62 (0.41-0.92). In the subgroup of patients with OTT <80 days, the 5-year CRLR was significantly increased with the BCT boost (BC = 9% vs. EBRT = 28%, p = 0.03). In the case of OTT ≥80 days, the 5-year CRLR was not affected by the boost technique (BCT = 29% vs. EBRT = 38%, p = 0.21).

CONCLUSION

In anal cancer, when OTT is <80 days, BCT boost is superior to EBRT boost for CRLR. These results suggest investigating the benefit of BCT boost in prospective trials.

Chemo-radiation with or without mandatory split in anal carcinoma: experiences of two institutions and review of the literature

Background

The split-course schedule of chemo-radiation for anal cancer is controversial.

Methods

Eighty-four patients with invasive anal cancer treated with definitive external beam radiotherapy (RT) with a mandatory split of 12 days (52 patients, Montreal, Canada) or without an intended split (32 patients, Zurich, Switzerland) were reviewed. Total RT doses were 52 Gy (Montreal) or 59.4 Gy (Zurich) given concurrently with 5-FU/MMC.

Results

After a mean follow-up of 40 ± 27 months, overall survival and local tumor control at 5 years were 57% and 78% (Zurich) compared to 67% and 82% (Montreal), respectively. Split duration of patients with or without local relapse was 15 ± 7 d vs. 14 ± 7 d (Montreal, NS) and 11 ± 11 d vs. 5 ± 7 d (Zurich; P < 0.001). Patients from Zurich with prolonged treatment interruption (≥ 7 d) had impaired cancer-specific survival compared with patients with only minor interruption (<7 d) (P = 0.06). Bowel toxicity was associated with prolonged RT (P = 0.03) duration as well as increased relapse probability (P = 0.05). Skin toxicity correlated with institution and was found in 79% (Montreal) and 28% (Zurich) (P < 0.0001).

Conclusions

The study design did not allow demonstrating a clear difference in efficacy between the treatment regimens with or without short mandatory split. Cause-specific outcome appears to be impaired by unplanned prolonged interruption.

Anal cancer treated with radio-chemotherapy: correlation between length of treatment interruption and outcome

AIM

The purpose of this study was the evaluation of the feasibility and outcome of definitive radio-chemotherapy without split-course technique but with individualised short treatment interruption in anal cancer patients.

METHOD

Between 1993 and 2008, 101 patients with anal cancer were treated in our institution with definitive radio-chemotherapy with individualised short treatment interruptions. Treatment was halted independent of dose in case of acute grade 3 toxicities and started again until improvement. Short interruption was defined as completing treatment without exceeding six cumulative treatment days beyond a scheduled plan; otherwise, it was defined as prolonged interruption.

RESULTS

Median overall treatment time was 47 days corresponding to an interruption of six cumulative treatment days. Fifty-one patients (50%) had treatment interruption of <or=6 days. No acute grade 4 toxicities were observed. One fatality occurred during treatment due to ileus-like symptoms according to acute grade 5 toxicity. After a median follow-up of 56 months, the 5-year actuarial rates for local control comparing patients with short vs. prolonged treatment interruption were 78% vs. 81% (p = 0.904) and, for colostomy-free survival, 83% vs. 85% (p = 0.784), respectively.

CONCLUSIONS

Definitive radio-chemotherapy with short individualised treatment interruption shows high local control and colostomy-free survival rates.