Chemoradiotherapy of anal carcinoma: tumour response and acute toxicity

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.

Best time to assess complete clinical response after chemoradiotherapy in squamous cell carcinoma of the anus (ACT II): a post-hoc analysis of randomised controlled phase 3 trial

BACKGROUND

Guidelines for anal cancer recommend assessment of response at 6-12 weeks after starting treatment. Using data from the ACT II trial, we determined the optimum timepoint to assess clinical tumour response after chemoradiotherapy.

METHODS

The previously reported ACT II trial was a phase 3 randomised trial of patients of any age with newly diagnosed, histologically confirmed, squamous cell carcinoma of the anus without metastatic disease from 59 centres in the UK. We randomly assigned patients (by minimisation) to receive either intravenous mitomycin (one dose of 12 mg/m2 on day 1) or intravenous cisplatin (one dose of 60 mg/m2 on days 1 and 29), with intravenous fluorouracil (one dose of 1000 mg/m2 per day on days 1-4 and 29-32) and radiotherapy (50·4 Gy in 28 daily fractions); and also did a second randomisation after initial therapy to maintenance chemotherapy (fluorouracil and cisplatin) or no maintenance chemotherapy. The primary outcome was complete clinical response (the absence of primary and nodal tumour by clinical examination), in addition to overall survival and progression-free survival from time of randomisation. In this post-hoc analysis, we analysed complete clinical response at three timepoints: 11 weeks from the start of chemoradiotherapy (assessment 1), 18 weeks from the start of chemoradiotherapy (assessment 2), and 26 weeks from the start of chemoradiotherapy (assessment 3) as well as the overall and progression-free survival estimates of patients with complete clinical response or without complete clinical response at each assessment. We analysed both the overall trial population and a subgroup of patients who had attended each of the three assessments by modified intention-to-treat. This study is registered at controlled-trials.com, ISRCTN 26715889.

FINDINGS

We enrolled 940 patients from June 4, 2001, until Dec 16, 2008. Complete clinical response was achieved in 492 (52%) of 940 patients at assessment 1 (11 weeks), 665 (71%) of patients at assessment 2 (18 weeks), and 730 (78%) of patients at assessment 3 (26 weeks). 691 patients attended all three assessments and in this subgroup, complete clinical response was reported in 441 (64%) patients at assessment 1, 556 (80%) at assessment 2, and 590 (85%) at assessments 3. 151 (72%) of the 209 patients who had not had a complete clinical response at assessment 1 had a complete clinical response by assessment 3. In the overall trial population of 940 patients, 5 year overall survival in patients who had a clinical response at assessments 1, 2, 3 was 83% (95% CI 79-86), 84% (81-87), and 87% (84-89), respectively and was 72% (66-78), 59% (49-67), and 46% (37-55) for patients who did not have a complete clinical response at assessments 1, 2, 3, respectively. In the subgroup of 691 patients, 5 year overall survival in patients who had a clinical response at assessment 1, 2, 3 was 85% (81-88), 86% (82-88), and 87% (84-90), respectively, and was 75% (68-80), 61% (50-70), and 48% (36-58) for patients who did not have a complete clinical response at assessment 1, 2, 3, respectively. Similarly, progression-free survival in both the overall trial population and the subgroup was longer in patients who had a complete clinical response, compared with patients who did not have a complete clinical response, at all three assessments.

INTERPRETATION

Many patients who do not have a complete clinical response when assessed at 11 weeks after commencing chemoradiotherapy do in fact respond by 26 weeks, and the earlier assessment could lead to some patients having unnecessary surgery. Our data suggests that the optimum time for assessment of complete clinical response after chemoradiotherapy for patients with squamous cell carcinoma of the anus is 26 weeks from starting chemoradiotherapy. We suggest that guidelines should be revised to indicate that later assessment is acceptable.

FUNDING

Cancer Research UK.

New approach to anal cancer: Individualized therapy based on sentinel lymph node biopsy

Oncological treatment is currently directed toward a tailored therapy concept. Squamous cell carcinoma of the anal canal could be considered a suitable platform to test new therapeutic strategies to minimize treatment morbidity. Standard of care for patients with anal canal cancer consists of a combination of radiotherapy and chemotherapy. This treatment has led to a high rate of local control and a 60% cure rate with preservation of the anal sphincter, thus replacing surgical abdominoperineal resection. Lymph node metastases represent a critical independent prognostic factor for local recurrence and survival. Mesorectal and iliac lymph nodes are usually included in the radiation field, whereas the inclusion of inguinal regions still remains controversial because of the subsequent adverse side effects. Sentinel lymph node biopsies could clearly identify inguinal node-positive patients eligible for therapeutic groin irradiation. A sentinel lymph node navigation procedure is reported here to be a feasible and effective method for establishing the true inguinal node status in patients suffering from anal canal cancer. Based on the results of sentinel node biopsies, a selective approach could be proposed where node-positive patients could be selected for inguinal node irradiation while node-negative patients could take advantage of inguinal sparing irradiation, thus avoiding toxic side effects.

T1-2 anal carcinoma requires elective inguinal radiation treatment--the results of Trans Tasman Radiation Oncology Group study TROG 99.02

BACKGROUND AND PURPOSE

Elective inguinal irradiation increases morbidity. We describe outcomes of moderate intensity chemoradiation treating anal canal and adjacent pelvic nodes only.

MATERIAL AND METHODS

Forty patients with T1-2, N0 anal carcinoma were enrolled between March 1999 and March 2003. Inguinal nodes were NOT electively irradiated. The anal canal and regional pelvic nodes received 36 Gy/20# over 4 weeks, and 2 weeks later the anal canal was boosted with 14.4 Gy/8#. Chemotherapy was 5 fluorouracil 800 mg/m(2)/day on days 1-4 and 36-39, and Mitomycin C 10mg/m(2) on day 1.

RESULTS

Median follow-up was 44 months. Complete response was 95%. Four year results were; overall survival 71%, local control 82%, and colostomy-free survival (including salvage) 85%. Inguinal failure occurred in 22.5% but was isolated in only 12.5%. Treatment was well tolerated acutely with no toxic deaths. Severe late toxicity occurred in 7.5%.

CONCLUSIONS

This moderate dose 'non inguinal' chemoradiation regimen resulted in modest acute toxicity, minimal long term morbidity and local control in line with other series. However staging failed to identify 12.5% of patients whose isolated inguinal failure might have been prevented by elective irradiation. Without more effective staging, all patients should receive elective inguinal irradiation.

Tumor response and survival predicted by post-therapy FDG-PET/CT in anal cancer

PURPOSE

To evaluate the response to therapy for anal carcinoma using post-therapy imaging with positron emission tomography (PET)/computed tomography and F-18 fluorodeoxyglucose (FDG) and to compare the metabolic response with patient outcome.

PATIENTS AND METHODS

This was a prospective cohort study of 53 consecutive patients with anal cancer. All patients underwent pre- and post-treatment whole-body FDG-PET/computed tomography. Patients had been treated with external beam radiotherapy and concurrent chemotherapy. Whole-body FDG-PET was performed 0.9-5.4 months (mean, 2.1) after therapy completion.

RESULTS

The post-therapy PET scan did not show any abnormal FDG uptake (complete metabolic response) in 44 patients. Persistent abnormal FDG uptake (partial metabolic response) was found in the anal tumor in 9 patients. The 2-year cause-specific survival rate was 94% for patients with a complete vs. 39% for patients with a partial metabolic response in the anal tumor (p = 0.0008). The 2-year progression-free survival rate was 95% for patients with a complete vs. 22% for patients with a partial metabolic response in the anal tumor (p < 0.0001). A Cox proportional hazards model of survival outcome indicated that a complete metabolic response was the most significant predictor of progression-free survival in our patient population (p = 0.0003).

CONCLUSIONS

A partial metabolic response in the anal tumor as determined by post-therapy FDG-PET is predictive of significantly decreased progression-free and cause-specific survival after chemoradiotherapy for anal cancer.

Radiation therapy for gastrointestinal cancer

This article has reviewed the current role of radiation in the treatment of gastrointestinal malignancies and discussed the data supporting its use. Radiation treatment in this setting continues to evolve with the increasing implementation of more conformal delivery techniques. Further scientific investigation is needed to establish the optimal role of radiation and to better define its integration with novel systemic and biologic modalities.

Management of anal canal cancer

PURPOSE

Chemoradiotherapy has replaced radical surgery as the initial treatment of choice for anal canal cancer. The roles of these therapeutic modalities are discussed and recommendations on management of anal canal cancer are made based on currently available evidence. Areas for further studies also are identified.

METHODS

Literature on management of anal canal cancer from January 1970 to July 2003 obtained via MEDLINE was reviewed. Reports on anal margin cancers were excluded.

RESULTS

Randomized, prospective, Phase 3 trials in Europe and the United States showed that chemoradiotherapy with 5-fluorouracil and mitomycin C was superior in local control, colostomy-free rate, progression-free survival, and cancer-specific survival compared with radiation alone. In larger tumors, the addition of mitomycin C to radiotherapy and 5-fluorouracil improves local control, colostomy-free, and disease-free survival but is associated with more acute hematologic toxicity. Chemoradiotherapy, including Cisplatin and 5-fluorouracil, appeared to be equal or superior to surgery as salvage therapy in patients with residual disease six weeks after initial nonsurgical treatment.

CONCLUSIONS

To improve treatment outcomes and reduce treatment-related toxicities, further studies are required to elucidate the optimal drug combination and doses, optimal radiation field, total dose, and fraction sizes. Randomized, multicenter trials are needed to define the treatment protocol that provides the highest rate of sphincter preservation with acceptable toxicity. Few studies addressed the treatment of metastatic disease, which remains a major cause of mortality.

Radiochemotherapy in the conservative treatment of anal canal carcinoma: retrospective analysis of results and radiation dose effectiveness

PURPOSE

This retrospective analysis reports the results on patients with anal canal carcinoma treated by combined radiotherapy and chemotherapy.

METHODS AND MATERIALS

Between March 1993 and December 2001, 43 patients with anal canal carcinoma were treated with radiochemotherapy at the Hospital do Cancer A.C. Camargo. Stage distribution was as follows: I, 3 (7%); II, 23 (53.5%); IIIA, 8 (18.6%); and IIIB, 9 (21%). The median age was 56 years (range, 36-77 years) with most patients being women (4:1). External radiotherapy (RT) was delivered at the whole pelvis followed by a boost at the primary tumor. The median dose of RT at the whole pelvis and at the primary tumor was 45 Gy and 55 Gy, respectively. Chemotherapy was carried out during the first and last 4 days of RT with continuous infusion of 5-fluorouracil (1000 mg/m(2)) and bolus mitomycin C (10 mg/m(2)). Median overall treatment time was 51 days (range, 30-129 days). Thirty-four patients (79%) did not receive elective RT at the inguinal region. Patient's age, tumor stage, overall treatment time, and RT dose at primary tumor were variables analyzed for survival and local control.

RESULTS

Median follow-up time was 42 months (range, 4-116 months). Overall survival and colostomy-free survival at 5 years was 68% and 52%, respectively. Overall survival according to clinical stage was as follows: I, 100%; II, 82%; IIIA, 73%; and IIIB, 18% (p = 0.0049). Complete response was observed in 40 patients (93%). Local recurrence occurred in 9 (21%) patients, and of these, 6 were rescued by surgery. Local control with a preserved sphincter was observed in 34 patients (79%). According to the RT dose, local control was higher among patients who received more than 50 Gy at primary tumor (86.5% vs. 34%, p = 0.012). Inguinal failure was observed in 5 patients (15%) who did not receive inguinal elective RT. Distant metastasis was observed in 11 patients (25.6%). Temporary interruption of the treatment as a result of acute toxicity was necessary in 12 patients (28%). Four patients developed mild chronic complications.

CONCLUSIONS

This analysis suggests that the treatment scheme employed was effective for anal sphincter preservation and local control; however, the incidence of distant metastases was relatively high. The clinical stage was the main prognostic factor for overall survival. Local control was higher in patients treated with doses of more than 50 Gy at primary tumor. The high incidence of inguinal failure implies the need for elective RT in this region.

Tratamento conservador do carcinoma do canal anal

OBJETIVO: Relatar os resultados do tratamento conservador do carcinoma de canal anal com radioterapia e quimioterapia do Centro de Tratamento e Pesquisa Hospital do Câncer A.C. Camargo. MÉTODO: De março de 1993 a dezembro de 2001, 47 pacientes com diagnóstico histológico de carcinoma do canal anal foram tratados de forma conservadora. A dose mediana de radioterapia na pelve e no tumor primário foi respectivamente de 45 e 55 Gy. A quimioterapia foi realizada com 5- Fluorouracil e Mitomicina-C, com doses medianas de 1000 mg/m² por quatro dias e 10 mg/m² por ciclo, respectivamente. Trinta e oito (80,8%) pacientes não receberam radioterapia em região inguinal. O tempo de seguimento mediano foi de 40 meses (oito dias a 116 meses). RESULTADOS: A resposta completa foi alcançada em 40 pacientes (85,1%). O controle local foi obtido em 31 (66%), e a função esfincteriana foi preservada em 38 (80,9%) casos. Metástases à distância foram detectadas em sete (14,9%) pacientes. A sobrevida global e sobrevida livre de doença em cinco anos foram de 61,5% e 50,1%, respectivamente. A sobrevida global e a sobrevida livre de doença em cinco anos para os pacientes que tiveram controle local foram 77,8% (p < 0,001) e 74,4% (p < 0,001). A sobrevida global e livre de doença em cinco anos para os pacientes com linfonodo inguinal clinicamente tumoral foi de 70,7% e 56,7%, respectivamente (p = 0,0085 e p = 0,0207). Doze (25,5%) pacientes necessitaram de interrupção temporária do tratamento. Cinco pacientes tiveram complicações crônicas leves. CONCLUSÃO: O tratamento realizado foi efetivo tanto para preservação do esfíncter anal quanto para controle local de doença. A presença de linfonodo inguinal clinicamente tumoral e a ausência de recidiva foram os principais fatores prognósticos para sobrevida global e sobrevida livre de doença. A taxa relativamente alta de recidiva em região inguinal sugere a necessidade de radioterapia eletiva nessa região.

An unusual late radiotherapy-related complication requiring surgery in anal canal carcinoma

We herein describe an unusual late radiation-related complication requiring surgery in a 60-year-old male affected by anal epidermoid carcinoma. The patient presented with obstructed defecation and ulcerated perianal lesions. The perianal biopsies were positive for anal squamous carcinoma. Transanal diagnostic investigations could not be performed because of anal stenosis. Computed tomography detected left inguinal lymphadenopathy and a nonhomogeneous presacral mass, infiltrating the rectal wall, the coccyx, and the sacrum. The patient underwent a colostomy, infusion of cisplatin and 5-fluorouracil, and irradiation of the pelvis, perianal region, and inguinal lymph nodes. In June 1997 the patient complained of the onset of continuous pain at the genitalia, and for penis necrosis he underwent penis amputation. The histologic examination was conclusive for postradiotherapy thrombosis. This complication could strengthen the hypothesis of vasculoconnective damage as the origin of long-term effects of radiotherapy. Probably the minimal dose in transit volume could not be achieved. Careful evaluation in choosing the treatment scheme is necessary if different options are available.

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

PURPOSE

To determine the efficacy and tolerance of a standardized protocol of chemotherapy and low-dose radiotherapy in the treatment of anal cancer in human immunodeficiency virus (HIV)-infected patients.

METHODS AND MATERIALS

Between 1987 and 1995, eight HIV-positive patients with squamous cell carcinoma of the anal canal, four of whom had acquired immunodeficiency syndrome (AIDS), received therapy at the Kaiser Permanente Medical Center. All patients were treated using a combined modality approach consisting of low-dose radiotherapy (30 Gy in 15 fractions delivered 5 days/week), and chemotherapy [1000 mg/m2 of 5-fluorouracil (5-FU) delivered on days 1-4 and 29-32 as a continuous infusion over 96 h, and 10 mg/m2 of mitomycin C delivered as a bolus injection on day 1]. Patients have been followed from 4 to 81 months (mean 41, median 38).

RESULTS

All eight patients completed the therapy with minor variations to the protocol, and all have attained a clinical complete response. Four patients are alive and free of disease, and four died as a result of complications of AIDS, but remained free of anal carcinoma. There were no mortalities from the protocol and the morbidity was acceptable. Only one patient each was noted to have Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Grade 4 hematologic and gastrointestinal acute toxicity, and no Grade 4 skin toxicity was noted.

CONCLUSION

This combined therapy is effective for HIV-infected patients and appears to be tolerable with acceptable toxicities. It is best applied to patients who are HIV positive, or who have AIDS without concurrent major opportunistic infections. This approach is reasonable and affords patients a reasonably good chance at sphincter preservation by avoiding abdominoperineal resection. The optimal therapy for HIV-positive patients with advanced AIDS remains less well defined.

Anal cancer: multimodal therapy

Anal cancer is a rare clinical entity which represents 1-2% of all gastrointestinal tract cancers. Due to the paucity of this malignancy it has been difficult to establish generally accepted guidelines for treatment, although various therapy modalities have been evaluated. For a long time radical surgery was the primary treatment for anal cancer and still about 30% of the patients undergo abdominoperineal rectotomy. However, recurrence rates of 20-40% have been observed after this mutilating procedure. Therefore, other treatment options, including external or interstitial radiotherapy and chemotherapy, are used increasingly with the intention to preserve sphincter function. In the last years much interest has been addressed to multimodal therapy with radiation (50 Gy) and chemotherapy (5-fluorouracil and mitomycin C). Presently radiochemotherapy appears to be the most efficient therapy in advanced anal cancer. Locoregional tumor control is obtained in 60-80% of the patients and there is evidence that radiochemotherapy can improve disease-free survival. Despite considerable toxicity, radiochemotherapy should be recommended as primary therapy to most patients.

Malignant anal tumours

Anal tumours represent 5 per cent of anorectal cancers and exist as two clinical entities: tumours of the anal canal and those of the anal margin. Smoking and sexual behaviour, particularly homosexual anal intercourse, are important aetiological factors. This association is related to anal warts and human papillomavirus infection, notably type 16, which is found in around 70 per cent of warts. Symptoms are non-specific and are frequently attributed to benign conditions. Rectal examination reveals a characteristically infiltrating lesion and any suspicious anal area should be biopsied. There are two histological types. Squamous carcinoma comprises approximately 95 per cent of anal tumours and includes the 35 per cent of tumours derived from the anal transition zone (cloacogenic tumours), containing a mixture of squamous and mucinous elements. The remaining 5 per cent of anal tumours are adenocarcinoma. Squamous cell tumours of the anal canal are probably best treated using radiotherapy (with chemotherapy) as complete response rates, 5-year survival rates, and incidences of normal sphincter function and significant toxicity are around 80, 70, 75 and 20 per cent respectively. Treatment failures may be salvaged by surgery. The 5-year survival and local recurrence rates for radical surgery are around 60 and 25 per cent respectively; there are few indications for local excision. In contrast, 60 per cent of anal margin tumours are suitable for local excision, the 5-year survival rate being in excess of 80 per cent. Combining radiotherapy with surgery may give additional benefit. Current randomized controlled trials should further clarify the relative merits and demerits of the treatment options.